Geo 314 Study Guide #1

There are two distinctly different orbits for satellites that observe the Earth's atmosphere, hydrosphere and land cover. What are these orbits? In what key ways do they differ, and why? And what are the implications of these differences on the nature and usefulness of the imagery collected?

A satellites ability to detect hazards depends on its orbit and sensors. This involves two orbits. POES (Polar-orbiting Operational Environmental Satellites) By the National Oceanic and Atmospheric Administration is a low-altitude near-polar orbit which provides comparatively detailed, moderately frequent worldwide coverage. An orbital plane inclined slightly to earth's axis moves westward as the satellite circles the globe fourteen times a day in an elliptical orbit. A sensor scanning aground provides a twice a day coverage for mid-latitude locations, and a pair reduces revisit time to six hours. NOAA's Geostationary Environmental Observation Satellites (GOES) in contrast is higher up from the earth's surface above a fixed point on the equator, stares down at a little less than half the globe but reports new imagery every fifteen minutes. This higher orbit limit GOES imagery resolution/quality. The lower POES orbit has less frequent coverage but better quality imagery. POES: uses thermal-infrared imagery from AVHRR scanner (a multispectral scanner which capture separate images for carefully selected portions of the electromagnetic spectrum.) Can sense a range of temperature. With two POES, more info is covered GOEs also used in conjunction with AVHRR, doppler radar, and PODMSP satellites. GOES thermal infrared imagery is similar to AVHRR band 3 sensitivity. GOES satellites are a good platform for detecting and monitoring wildfire, and while a GIS can enhance the reliability by integrating imagery from complementary sources, frequent snapshots are important, and its spatial resolution can be sharpened.

Discuss the similarities and differences in strategies for protecting communities from tornadoes and groundwater contamination. In what ways are these hazards fundamentally different? In what ways are the emergency preparedness strategies similar?

Both are similar in that they require consistent monitoring with continuous data. Both are hard to predict, contamination being an unseen hazard and tornados being abrupt and destructive. Contamination: uses monitoring wells to get info. Tornados: use around the clock doppler radar (NEXRAD). Tornados: Radar-based nowcasting - a severe thunderstorm and tornado watch - on all the time. both general location specific NOAA weather radio: broadcast station/transmitter send signal out/geocoded signal on all the time Tornados call for more early and timely detection, and a warning system and accessible shelter as well as informed citizens. (faster onset) Both rely more on active mitigation and communication warning. Contamination: needs records of pumping rates and water table measurements and a dense network of monitoring wells (as tornados need a dense network of NEXRAD stations). Uses tests. Differences Combo of computer models to simulate local migration of aquifer and a network of monitoring wells with routine sample and testing

The Galveston hurricane of 1900 is estimated to have killed over 8,000 people. Why is an atmospheric disaster of this magnitude in that locality (on the Gulf of Mexico) unlikely today?

Improved technology and warning improved hazard assessment and communication NEXARR dopplar radio 24-7 surveillence satelite imagery NOAA hazard forcasting nowcasting

List and describe briefly three different (and serious) consequences of sea level rise for the localities affected?

Inundation. Submergence of coasts. acceleration of sea level rise a distinct threat to low lying areas (Florida, Mississippi, N. Carolina outer banks/barrier islands). Sea moving inward/inland. Outerbanks moving slowly toward the land. Barrier islands vulnerable because elevated seas intensify the impact of storm surge and wave action (causing erosion and sediment shift and deposit). hypothetical shoreline predictions linear interpolation problematic for scientists concerned with smaller rise predicted by IPCC. erosion - wave erosion and riverine delivery of sediments with which sculpt landforms. sandy beaches erode easily to storm surge. A transfer of sand from the beach to the offshore bottom occurs, which rises in response to sea level rise. This displacement of sand moves the shoreline farther inland. Try to save beach through nourishment and coastal engineering inlets - opening and closing of them Wetlands at risk Storm Surge - carried farther inland, exposes new land to wave action and disturbs a beach slope. Wave onset

What is the difference between magnitude and the intensity of an earthquake? How and why are each of these entities mapped?

Magnitude scales, like the moment magnitude, measure the size of the earthquake at its source. An earthquake has one magnitude. The magnitude do not depend on where the measurement is made. Often, several slightly different magnitudes are reported for an earthquake. This happens because the relation between the seismic measurements and the magnitude is complex and different procedures will often give slightly different magnitudes for the same earthquake. Intensity scales, like the Modified Mercalli Scale , measure the amount of shaking at a particular location. An earthquake causes many different intensities of shaking in the area of the epicenter where it occurs. So the intensity of an earthquake will vary depending on where you are. Sometimes earthquakes are referred to by the maximum intensity they produce. In the United States, we use the Modified Mercalli (MMI) Scale.The Mercalli Scale is based on observable earthquake damage. From a scientific standpoint, the magnitude scale is based on seismic records while the Mercalli is based on observable data which can be subjective. Thus, the magnitude scale is considered scientifically more objective and therefore more accurate. Magnitude: Earthquake size is a quantitative measure of the size of the earthquake at its source. The Richter Magnitude Scale measures the amount of seismic energy released by an earthquake. When an earthquake occurs, its magnitude can be given a single numerical value on the Richter Magnitude Scale. However the intensity is variable over the area affected by the earthquake, with high intensities near the epicentre and lower values further away. These are allocated a value depending on the effects of the shaking according to the Modified Mercalli Intensity Scale.

Discuss the argument that the nature of maps of environmental hazards reflects the extent to which said hazards are understood

Only estimations and probabilities. Cannot be completely accurate. They are human constructions, and the environment is ever-changing and complex, making inaccuracy inevitable. Effect of map scale: determines detail, size, cost, and reliability of a map and restricts range of appropriate use. A numerical concept, large and small. More or less detail? Needed and not needed. Symbols are important as well as info to determine the needed info and clearity. A Generalization. Not definite. A prediction. Cannot fully rely on a generalized and exaggerated map for serious decisions such as building locations, areas of specific risk factors Risk and hazard mapping. differing zones. Need a lot of data throughout history, and even then, data tendency can change. regional and time differences Averages unreliability due to estimations and generalizations Cannot associate low risk with no risk.

A prospective home owner is told by her bank that she is in the "100 year flood zone". aside from the bank's insisting that she buy flood insurance, what does this mean?

This means that, on average, there is a 1% chance of a flood occuring in a given year. This is measured by T = (n + I)/m (reordering the peak discharges Q from lowest to highest and computing the recurrence interval T, a measure of how often, on average, a flood this large appears in the data. So, the larger peak discharge of a given body of water will be equaled or exceeded only once in a 100 year period. This does not forecast what will occur every year, making it easier to use the exceedance probability. Annual peak discharge adn recurrence interval relationship use a precise numerical technique to fit a straight line or other model to the data in a normal-probability plot. A 100 year flood zone means that a storm has a 1 in 100 change of occurence in any calendar year. Properties that are prone to flooding during a 1% annual chance storm event are at high flood risk. This is equivalent toa 1 percent chance of flooding any year and a 26% chance of flooding over the life of a 30 year mortgage. The estimated base flood elevation is the estimated elevation of flood water during the 1% annual chance storm event. Structures below the estimated water surface elevation may experience flooding.

Why and in what ways are historic data and maps of tornadoes likely to be less representative of the hazard than more recent maps? For what kinds of areas are maps of tornadoes likely to underrepresent the hazards? Why?

Tornado incidents have in general fluctuated and increased throughout the years. Annual averages of incidents ignore seasonal variations and seasonal location impact, calling for a need to map by the month for emergency management. It is also a combination of tornado incidents and population density that determines hazard threat. The problem is that Tornado counts are low in low - populated areas, allowing some to go un-accounted for (due to a reliance on observed destruction and detection). There is also a general variation in the amount of tornados, the destructiveness, and geographic pattern, in need of a lot of data throughout a long timespan. Tornadoes also vary in intensity (Fujita scale).

What hazardous locations are attractive to relatively wealthy people? What hazardous locations are often inhabited by relatively low-income people? Explain

Wealthy people: like to live near bodies of water such as coastal regions and rivers. People also like to live at high altitudes / on top of elevated areas. Other attractions include volcanos and the general area of the west coast which is favorable but vulnerable to earthquakes. People of low income are susceptible to hazards such as tornados. This is because low-income housing such as trailer parks in the central U.S are easily damaged. In general, lower-income citizens have structures that are older and not built as well to sustain hazards.

Lidar

(Light detection and ranging) a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light used by satellites.

Urban-wildland interface

A Wildland-Urban Interface (WUI) is a zone of transition between wildland (unoccupied land) and human development. Communities in the WUI are at risk of catastrophic wildfire and their presence disrupts the ecology. Better understanding wildfire behavior and ecology behavior within and around the WUI highlights needs for policy and emergency response planning.

Counterclockwise circulation

A hurricane is a type of tropical cyclone, which is a generic term for a low pressure system that generally forms in the tropics. The cyclone is accompanied by thunderstorms and, in the Northern Hemisphere, a counterclockwise circulation of winds near the earth's surface. Part of this is due to the center of low pressure — the "eye" — at the center of the storm. But it also has to do with physics. In fact, tropical cyclones — the general name for the storms called typhoons, hurricanes or cyclones in different parts of the world — always spin counterclockwise in the Northern Hemisphere, and spin in the opposite direction in the Southern Hemisphere. The reason is something called the Coriolis effect

Septic system

A relatively small and simple sewage treatment system, made up of a septic tank and a leach field, often used for homes in rural areas

Diversion well

A remediation technique to get rid of the contaminant by diverting the contaminated water/plume from drinking-water wells. This relies on a model to simulate the plume movement and to find a good location The interceptor well. These wells "suck" out the bad contaminants like a leach.

Injection well

A well constructed for the purpose of injecting treated water, often wastewater, directly into the ground. Water is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. They are generally drilled into aquifers that are not used as a drinking water source, unused aquifers, or below freshwater levels.

Artesian well

A well in which water rises because of pressure within the aquifer Water rises naturally to surface as aquifer discharges water through the well drilled down to the saturation zone of a confined aquifer (The phreatic zone, or zone of saturation, is the area in an aquifer, below the water table, in which relatively all pores and fractures are saturated with water.)

Evacuation planning

A wide variety of emergencies may cause an evacuation. In some instances you may have a day or two to prepare, while other situations might call for an immediate evacuation. Planning ahead is vital to ensuring that you can evacuate quickly and safely, no matter what the circumstances. Learn the types of disasters that are likely in your community and the local emergency, evacuation, and shelter plans for each specific disaster. To be prepared for a natural disaster and take precautions to prevent casualties and harm/danger, plans are made to escape the area of hazard. This can be communicated differently (fast, slow, through local or governmental officials, locally or nationally), and done differently - vertical evacuation, retreat, finding safe places / shelter Phasing: evacuation of most vulnerable areas first. Mapping determines vulnerable areas and zones of risk in need of prompt evacuation.

Low-earth orbit

Abbreviated as LEO. Orbits which are relatively close to the Earth. POES

active, dormant, extinct

Active: Short-term eruption periodicities (100-200 years) / erupted in the passed 200-300 years Dormant: 1,000 year periodicities or more / erupted 1,000 years ago Extinct: non-active. last eruption within 10,000 years or more with large magma bodies underneath (destructive)

Repetitive loss structure

An NFIP-insured structure that has had at least two paid flood losses of more than $1,000 each in any 10-year period since 1978. has encountered multiple flood damages.

Lahar

An avalanche of volcanic water and mud down the slopes of a volcano

Geostationary orbit

An orbit in which a satellite orbits Earth at the same rate as Earth rotates and thus stays over the same place all the time.

Aquifer; aquiclude

Aquifer: a body of permeable rock which can contain or transmit groundwater. Confined: carries water from recharge area on far side of a hill to deeper interface with the ocean aquiclude (or aquifuge), which is a solid, Aquiclude: impermeable rock (clay/ shale) area underlying or overlying an aquifer that slows water movement. If the impermeable area overlies the aquifer, pressure could cause it to become a confined aquifer.

Shoreline protection

Breakwaters are barriers built offshore to protect part of the shoreline. ( Protect from erosion, storm damage and flooding.) Seawalls, groins, jetties and other shoreline stabilization structures have had tremendous impacts on our nation's beaches. Shoreline structures are built to alter the effects of ocean waves, currents and sand movement. They are usually built to "protect" buildings that were built on a beach that is losing sand.

NOAA all hazards radio

Broadcast station and transmitter. Sends out a geocoded signal that plays all the time. Radio turns on when the hazard is in your location NOAA Weather Radio All Hazards (NWR) is a nationwide network of radio stations broadcasting continuous weather information directly from the nearest National Weather Service office. NWR broadcasts official Weather Service warnings, watches, forecasts and other hazard information 24 hours a day, 7 days a week.

LOMA

By FEMA for adjustments to flood insurance studies. A "Letter of Map Amendment" removes a specific property from the 100-year flood zone, Property owners can appeal a flood boundary by submitting scientific or technical data, and if a charge is warrented, FEMA issues LOMA. this not only confers a lower insurance rate but might allow a new owner to obtain a mortgage without buying flood insurance. The second type is LOMR (A letter of map revision) which orders an official revision of flood boundaries, elevations, or other map features. These reflect local public improvements, new development, annexation, or technical corrections to flood elevations and zone boundaries.

Sea-level rise

Causes erosion of shorelines and rainforests, flooding of wetlands that house freshwater ecosystems. Caused by global climate changes that is melting sea ice

Of what value is a more highly precise elevation in dealing with: coastal flooding, riverine flooding, tsunamis, landslides, wildland fire, sea level rise? In what different ways are these data used in assessments risk?

Coastal flooding: an elevation important factor in predicting risk and determening waters pathway onto land. This is because a gentle continental shelf / slope will bring the storm further onto land. When evacuating a storm surge or flooded coastal area, it is important to move to higher elevation. In addition, elevation and/or topographic mapping is used to determine the storm-surge line (plausible inland penetration of a storm surge). Coastal-inundation maps have to demonstrate the third coastline (after the visible high water shorelines and low water shoreline used as a sounding datum) for the national flood insurance program and evacuation planning. In addition, computer simulation of individual storms composite hazard zone maps and depend on reliable elevation data through LIDAR. In general, relief is an onshore factor to determine relative hazardousness and is calculated as a composite to other factors. EX: Storm evacuation maps: effort by NOAA: National Weather Service and NOS to monitor the atmosphere and storm warnings and survey coasts to make hydrographic charts to estimate mean sea level in conjunction with USGS topographic maps Tsunamis: Rely on elevation for evacuation maps and areas of risk (hazard zones) of being flooded. measured in runup height ( the elevation above sea level reached by water running up the beachfront). Elevation not as much of a problem because tsunamis rarely wet areas more than a half mile inland and damage is confined to a narrow belt along the shore Sea level rise: sea level rise will affect areas of lower elevation prone to flooding (barrier islands and it's inlets which move sediment from the ocean to the sound) (look at packets) Riverine flooding: Occurs when downstream channels receive more water than they can accommodate due to precipitation and blockage. Mapping these hazards requires hydrologic and hydraulic studies to determine ground elevations, the depth of flood waters, the width of floodplains, the number of water that will be carried by watercourses during flood events, and obstructions to water flow. Cross sections based on topographic data from USGS topographic quadrangle maps are taken to define the floodplain and the locations of these cross sections are chosen to capture variations in topography and flow obstructions. (look at packet) landslides: Surface material slides downward caused by rainfall, loss of vegetation, fires. Impacted by the slope (if its steep or shallow). The top of the slope loads and is aggravated due to the increased load on top, causing it to move downward. populations at low elevations / below the slop are prone to its hazards Wildfire: Elevation and topographic maps are needed to assess where the fire will travel Fire-spread models need to consider wind and slope. On a flat, uniform plane a fire expands outward in a circular pattern with hot gases and material igniting areas beyond the flame. Steep slope = upslope fires (windriven) and advances most rapidly. Can explode at the top, making ridges the most dangerous. Narrow canyons hazardous (radiation/embers from one side of corridor will expedite fires advance along the other side. A gully aligned with a strong upslope wind is akin to a flame thrower. Given a fuel model, a wind velocity, and a uniform slope, a fire-spread model can calculate the likely perimeter of a small fire several hours after ignition. Fire perimeter becomes less regular as the fire grows and conditions change, later estimates are based on projection points representing the forward advance of the forefront. Models suggest worst-case scenarios and planning prescribed fires to reduce fuel hazard. Use the expected rate of advance and transfer it to a topographic map Real time: track fire front, monitor positions of fire crews, and Geographic information systems integrate information from diverse sources (weather maps, satellite imagery of vegetation, maps of fire trails, roads, digital terrain models. use satellite images, digital elevation models (DEMS) in fire-spread modeling, fire-ground intelligence based on GPS readings, thermal infrared imagery from Forest Service aircraft, and CDS with topographic data for the state. Terrain maps form the basis for an incident Action plan

Prescribed fire

Controlled burning that is conducted during the cooler months to reduce fuel buildup and decrease the likelihood of serious hotter fires.

plume forecasting model

Determines the potential for contamination of an aquifer system. Determine contamination location, flow and geographies of the aquifer. Also need to know the areal extent of zone of contribution and the time required for leaks to contaminate water wells. Use mathematical models based on fluid dynamic theory. Use info on geology/hydrology, and pumping rate data, water tabel elevation, computer models to simulate water movement, sediment and rock. Numerical models of aquifer systems promote preparedness (assess vulnerability).

What are the three major, distinctly hazard zones that surround an active volcano? How and why do these zones differ in footprint (size and shape) and in likely type of danger or disruption?

Differing hazard zones involved in active volcanos are lava flows, pyroclastic flows, mudflows, and floods. Ash Falls (tephra falls) Hot Ash Flows (pyroclastic flows) Mudflows (lahars) Volcanic Landslides (debris flows and debris avalanches) Lava Flows. Ash hazard differs in distance from the volcano, in which the closest (zone A) has the greatest potential thickness of tephra (ash particles). Lopsided zones reflect east to west air flow, and rounded dashed line boundaries imply uncertainty about distance and wind direction. zone sectors are divided based on data for strong, high-altitude winds (vertical line vs horizontal line pattern). This reflects winds impact on ash travel. Hazard zone maps have to accommodate large, medium, and small eruptions. For instance, the largest eruption from a volcano can be determined by measuring ash thickness in zone C. Can be arc-shaped or linear and elongated/linear pattern (if winds are strong and uniform, the same volume of material would form thicker deposits along a narrow band leading away from the volcano. the distance of material depends on the thickness of ash and wind. Problem: only a small part of ash hazard zone is likely to affect anyone eruption, visual mismatch of hazard zones and ash deposition). Flowage hazard map no more accurate. Slopes of the volcano are susceptible to lava flows, pyroclastic flows, debris flows, and floods and nearby areas are as vulnerable to ash clouds associated with pyroclastic flows. Rivers draining provide corridors for debris flows and floods. Mapping inaccuracy: symmetrical hazard area with some hazard zones going west vs asymmetric damage area with northern devastation (caldera opening) with little southern impact. Couldn't account for debris avalanche or lateral blasts. but could accurately forecast debris flows mudflows: use geographic references (highways, settlements, volcanic landmarks, lakes and streams, and marks areas of intensity). Zones designated in letters show a likelihood of being affected by future mudflows (zone A being most likely), in which no hazard exists in high areas or beyond the zones, and hazard decreases within the zones with more height above stream channels and greater distance from mountains.

Why can't (or shouldn't) nodes in a network of Doppler radar stations be too far apart?

Doppler radar can see not only the precipitation in a thunderstorm (through its ability to reflect microwave energy, or reflectivity), but motion of the precipitation along the radar beam. In other words, it can measure how fast rain or hail is moving toward or away from the radar. From a volume scan (a series of 360-degree sweeps, each tilting a little higher than the last), forecasters can get a detailed look at structures and movements in storms close to the radar. The farther away from the radar a storm is, the more coarse the view, because: 1) The radar beam spreads out with distance, like a flashlight beam, causing small features to be missed at a distance; and 2) The beam shoots straight as the earth curves away from beneath -- a horizon that forces the radar to miss more and more of the low and middle levels of a storm with distance.

How have advances in electronic computing improved the reliability of flood zone mapping? HINT: there are at least two different and important ways.

Elevation and Height Data Purpose of a flood study is to predict the height of water and the extent to which it will inundate the landscape in a modeled flood event = need for accurate standards for land surface elevations Datum: a reference surface against which position measurements are made; it defines the location of zero on the measurement scale. Types of vertical datums: Ellipsoidal, orthometric and tidal. Ellipsoidal datum: The Global positioning system (GPS) establishes reference marks (monuments) on the surface, forming the basis for land (handheld / tripod mounted equipment) and aerial surveys (airborne photogrammetric or remote sensing surveys use GPS and inertial measurment system to track the position of the sensor and project the data into accurate ground coordinates). Heights computed with respect to surface is the ellipsoid heights Orthometric Height Datum: Models flow of water across the Earth's surface defined by a constant gravitational potential on a reference surface (geoid). Height in respect to an equipotential gravity surface = orthometric heights. Geoid models convert ellipsoid heights to orthometric heights. Uses the North American Certical Datum of 1988 (NAVD 88) as the orthometric height datum to survey and map for floods and engineering flood studies ***Orthometric height datum Accuracy requires the use of geodetic survey leveling observations or GPS measurements and a high accuracy geoid model (improved orthometric height datum and geoid model) Tidal Datums: many tidal datums defined by a certain phase of the tide and targeted to a particular application. Measured at tide gauge stations, and measure local water levels, making them location specific. water surface elevations referenced to tidal datums converted to orthometric height datum to reference topographic surface. LIDAR: remote sensing technology (light detection and ranging), superseding DEMS (digital elevation models derived from contours or photogrammetric data compiled from aerial photographic sources). IFSAR (interferometric synthetic aperture radar) which can produce highly accurate surface models over large areas. Helpful to determine elevation changes through continuous monitoring and updating (natural and human activities cause this) The National Elevation Dataset (NED) - USGS digital elevation models and high-resolution datasets Stream gages: measure stream stage or height of the water relative to the gage. Discharge calculated from stage height using a rating curve based on historical measurements of flow and stage at the gage. a large network of them provides real-time data and provide info on water surface elevations used to calibrate flood models and flood frequencies. *** Lidar monitors water surface elevations. Can make inundation maps using it's data. Uses real-time, high accuracy measurements of water surface elevation used to evaluate the relative accuracies of different types of flood studies. Tide gauges: measure water height relative to gage - part of the NWLON. provide a reference for tide prediction, controls for short term water level stations, and used for warning systems (storm surge/ tsunamis). Data is continuity, vertical stability, and careful referencing used to estimate sea level trends

Ensemble forecasting

Ensemble forecasting is a method used in numerical weather prediction. Instead of making a single forecast of the most likely weather, a set (or ensemble) of forecasts is produced. This set of forecasts aims to give an indication of the range of possible future states of the atmosphere. An ensemble weather forecast is a set of forecasts that present the range of future weather possibilities. Multiple simulations are run, each with a slight variation of its initial conditions and with slightly perturbed weather models. These variations represent the inevitable uncertainty in the initial conditions and approximations in the models. They produce a range of possible weather conditions. The uncertainty associated with every forecast means that different scenarios are possible, and the forecast should reflect that. Single 'deterministic' forecasts can be misleading as they fail to provide this information. By generating a range of possible outcomes, the method can show how likely different scenarios are in the days ahead, and how long into the future the forecasts are useful. Ex. SLOSH

Compare and contrast the usefulness in seismic risk evaluation of a map of surface faults and a map of estimated peak horizontal ground acceleration. Explain your reasoning.

Evaluation of a map of surface faults: A half truth that earthquakes occur along fault lines. Ruptures in the earth's crust produce linear fractures geologists call faults, and movement along faults often recurs, and buildings and bridges on surface faults are vulnerable. But earthquakes can still occur far beyond the fault line, and risk depends on the stability of slopes and the susceptibility of poorly consolidated soil to shaking. Also more than a west coast problem which occurs on the Pacific ring of fire, demonstrating major tectonic plates of the circum-pacific region, visibly vibrant map that can be misleading. Maps demonstrating areas of plate subduction and collision such as the Juan de Fuca plate beneath the North American Plate cause friction and small earthquakes and large ones due to sudden ruptures. And the San Andreas, a strike-slip fault, causes not only displacement but stress energy which accumulates and is released abruptly, but large slippage is uncommon. But, while it is a large fault, it cannot be treated as a single well-marked fault because ruptures in the crust occur not along a single fault line but within an elongated zone in which offshoots occur and numerous shorter faults are also accompanied, making hazard planning along one single fault line (Special studies fault zones) inaccurate. Ex: California Earthquake fault zone maps combining land surface with symbols of locations, with labels marking active faults and zone boundaries, with heavy lines showing surface rupture from faults and recurrence possibility, w/ solid line = accurately located fault vs dashed line = uncertain fault. positions turning points on locatable features to determine if a parcel is within a fault zone. DMG set zone boundaries 500 ft away from major active faults, vs 300 feet away from minor ones, used as belts which geologists/engineers should look for active branches of fault and other hazards. In general, contain zone boundaries and faults, and used (in different ways to restrict land use and building / real estate on fault lines. People don't realize until after that a house is on a fault line. Problems: knowledge on faults is vague, do not have accurate knowledge of distance of nearest faults and have a tendency to ignore small faults. Peak ground acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a particular earthquake. Earthquake shaking generally occurs in all three directions. Therefore, PGA is often split into the horizontal and vertical components. Horizontal PGAs are generally larger than those in the vertical direction but this is not always true, especially close to large earthquakes. PGA is an important parameter (also known as an intensity measure) for earthquake engineering, The design basis earthquake ground motion (DBEGM)[2] is often defined in terms of PGA. Unlike the Richter and moment magnitude scales, it is not a measure of the total energy (magnitude, or size) of an earthquake, but rather of how hard the earth shakes at a given geographic point. The Mercalli intensity scale uses personal reports and observations to measure earthquake intensity but PGA is measured by instruments, such as accelerographs. It can be correlated to macroseismic intensities on the Mercalli scale[3] but these correlations are associated with large uncertainty.[4] See also seismic scale. The peak horizontal acceleration (PHA) is the most commonly used type of ground acceleration in engineering applications. It is often used within earthquake engineering (including seismic building codes) and it is commonly plotted on seismic hazard maps.[5] In an earthquake, damage to buildings and infrastructure is related more closely to ground motion, of which PGA is a measure, rather than the magnitude of the earthquake itself. For moderate earthquakes, PGA is a reasonably good determinant of damage; in severe earthquakes, damage is more often correlated with peak ground velocity.[3] (from book) seizmic risk maps showing peak ground acceleration: the maximum horizontal stress on a bridge, foundation or other structure, as a percentage of gravity. Maximum acceleration tells structural engineers how flexible to make a bridge or high-rise building Ground acceleration maps tell highway designers how stiff to make a freeway so its sections do not shake apart. Max acceleration convenient measure for architects, who compute horizontal force on who structure as well as its individual components. Maps on ground acceleration must represent range of possible earthquakes centered in different places and vary in magnitude and likelihood. Research entails systematic collection, evaluation, and integration of massive amounts of seismic and geologic information, and combine contributions by establishing a level of certainty and an appropriate time span. shows how buildings and bridges vary in design life. Determine building codes

Spontaneous evacuation

Ex. Tornado warnings Timely warning/time sensitive warning calling for prompt evacuation - little time to spare.

Fuel map

Factors that influence ignition and spread. Fuel: anything living or dead that will burn, release heat, and feed the fire. Fuel inventory must account for the mass, moisture, and flammability of fuels Reflect wildfire-specific vegetation categories based on carefully controlled laboratory burns. Experimenting with kinds of plant matter and their measurements in temperatures and heat releasted to make numerical "fuel models". This encompases flammability factors such as oils, resins, and volatile compounds, as well as moisture levels. It also considers the amount of time over which surface fuels have accumulated as well as the spacing of burnable material. These are used to assess current fire danger and predict the behavior of actual fires.

Unstructured-grid flood modeling

Finite-difference model simulation groundwater flow by solving flow-line equations and accounting for exchanges of groundwater amoung adjoining cells in a rectangular network etailed geospatial information including the location and shape of each building was extracted from the LiDAR data and used for the grid generation. The developed approach can distinguish buildings from vegetation and treat them differently in the flow model. With this method, a fine unstructured grid can be generated representing the complicated urban land features precisely without exhausting labor for data preparation. The accuracy of the generated grid with different grid spacing and grid type is discussed and the optimal range of grid spacing for direct representation of urban topography is investigated. The developed method is applied to the estimation of inundation flows

Exceedance Probability

For any threshold, x, the probability that during the year the random variable in question, X, will exceed some threshold x. Annual exceedance probability is the probability associated with a return period. Thus an event of return period 50 years has an AEP of 1/T or 0.02. Or, the probability that a specified level of ground motion or social or economic impact in an area will be exceeded in a specified time The chance that PGA can be worse than labeled a 1% (or 0.01) annual flood exceedance probability means there is 1% change in any given year that the flood elevation will be at that level or higher. So in a given year, the given total water level will exceed in a given year

Fire-spread model

Forest managers as well as those engaged in research involving fires in forests, brush fields, and grasslands need a consistent method for predicting fire spread and intensity in these fuels. The availability of the mathematical model of fire spread presented in this paper offers for the first time a method for making quantitative evaluations of both rates of spread and fire intensity in fuels that qualify for the assumptions made on the model. Fuel and weather parameters measurable in the field are featured as inputs to the model. Given a fuel model, a wind velocity, and a uniform slope, a fire-spread model can calculate the likely perimeter of a small fire several hours after ignition. Fire perimeter becomes less regular as the fire grows and conditions change, later estimates are based on projection points representing the forward advance of the forefront. Models suggest worst-case scenarios and planning prescribed fires to reduce fuel hazard. Use the expected rate of advance and transfer it to a topographic map Real-time: track fire front, monitor positions of fire crews, and Geographic information systems integrate information from diverse sources (weather maps, satellite imagery of vegetation, maps of fire trails, roads, digital terrain models. use satellite images, digital elevation models (DEMS) in fire-spread modeling, fire-ground intelligence based on GPS readings, thermal infrared imagery from Forest Service aircraft, and CDS with topographic data for the state. Terrain maps form the basis for an incident Action plan Fuel models are used to predict the behavior of wildfire, which provide coefficients for mathematic equations describing a wildland fire's intensity, flame height, and rate of spread. Used in conjunction with weather data in the National Fire Danger Rating System to calculate the potential for surface fires over large areas. Each model is named for a type of vegetation, and depending on the values of the burning index, the spread component, and the energy release component, officials make an educated guess about whether there will be a fire. Fuel models predict fire behavior by providing coefficients for mathematic equations describing a wildland fire's intensity, flame height, and rate of spread. Also considers wind and slope (flat = circular pattern vs steep = fire moves upward) (steady wind =ellipse fire, higher wind speeds = elongations). Fire advances more steadily in the direction of a steady wind. Pushes head and firebrands. can create fire swirls. Terrain distorts fire (moves rapidly upslope)

GIS

Geographic Information System, A computer system that stores, organizes, analyzes, and displays geographic data. Integrates information about geologic hazards. Differing coverages are overlayed each representing a risk factor, making maps on a combination of factors. used to simulate earthquakes

GOES

Geostationary Operational Environmental Satellite GOES' geostationary status (in which the satellite is always in the same position with respect to the rotating Earth) allows it to hover over one position on the Earth's surface and provide constant vigil for the atmospheric "triggers" for severe weather conditions such as tornadoes, flash floods, hail storms and hurricanes.

Suppression (policy)

Get the fire out right away - suppress then and there

Peak ground acceleration

Horizontal acceleration in meters per second Peak ground acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a particular earthquake. While magnitude can be a predictor of seismic loss, scientists have found that damage to buildings and infrastructure during earthquakes relates more to ground motion than to magnitude itself, and there is no certain magnitude at which more damage will occur. Hence, other metrics have developed to more specifically determine building damageability - PGA. PGA has been more commonly used in earthquake engineering and seismic hazard maps used for building codes

Manufactured hazard

Humans making hazards that heighten and worsen the situation. Where people put themselves at risk Man-Made Hazards are events that are caused by humans and occur in or close to human settlements. The events leading up to a man-made hazard may be the result of deliberate or negligent human actions, but their impact can be equally as devastating.

Ice damming (on rivers)

Ice collection and blockage of a river, causing flooding

Monitoring network

In geosciences, it means to watch carefully at a hazardous situation and to observe its evolution and changes over a period of time. It is also used to define the activity of a device that measures periodically or continuously sensitive states and specific parameters. Remote Sensing and GIS Satelights

Contra-flow

In transport engineering nomenclature, a counterflow lane or contraflow lane is a lane in which traffic flows in the opposite direction of the surrounding lanes (to move away from hazards).

Mainstream floodplain /flooding

Inundation of normally dry land occurring when water overflows the natural or artificial banks of a stream, river, estuary, lake or dam.

What ethical considerations arise in making and publishing hazard maps based on numerical simulation models, probability-based predictions, and extrapolation? reflect critically on hazard-zone mapping as discussed thus far in this course.

Map author's fears, experiences, and group values No where is 100% safe unwillingness and ignorance denial and distaste for long-range planning = little preparedness misinterpreting information / misconceptions Media's take on situations: exaggerated, inaccurate and easily mis-interpreted. Used for shock and awe/disaster cliche cost and funding of mapping and research Acting upon a hazard: hesitance political critique upon mapping and their inaccuracies - can never be completely accurate Generalized or too detailed and complex? Can the public understand it? hazards arising more due to increasing populations - climate change, denser cities, waste and contamination, storm and flooding hazards. Problems in communication and it's effectiveness. Many factors involved in hazard mapping - human and non-human Difficulty in forcasting - need for a lot of data Determening the map and data and how it will be portrayed and used by the viewer. Need to allow the audience to understand imprecisions.

Richter scale

Measures the magnitude of earthquakes: refers to the energy released by a rupture

Address each of the following pairs of items, and describe briefly how they differ in their geographic footprints and in their impact (in human misery and damage) Pair A: East Coast earthquakes, West Coast earthquakes Snowstorms, ice storms

More Earthquakes in the West East coast: less frequent, originate deeper in the crust, so deep that intense shocks from a single rupture can reach cities distant from each other. large damage zones, poor earthquake preparedness, causing E quakes to be very destructive. Snowstorms: In the United States, the National Weather Service defines a blizzard as a severe snow storm characterized by strong winds causing blowing snow that results in low visibilities. The difference between a blizzard and a snowstorm is the strength of the wind, not the amount of snow. Blizzards are dangerous winter storms that are a combination of blowing snow and wind resulting in very low visibilities. While heavy snowfalls and severe cold often accompany blizzards, they are not required. Sometimes strong winds pick up snow that has already fallen, creating a ground blizzard. Ice storms: An ice storm is a storm which results in the accumulation of at least .25" of ice on exposed surfaces. They create hazardous driving and walking conditions. Tree branches and powerlines can easily snap under the weight of the ice.

Wind field

Move with the center of the storm (wind vector). Windfield stronger the closer you are to the center, being to the right of the storm's center also worse (where water is being pushed counterclockwise)

Numerical prediction

Numerical Weather Prediction (NWP) data are the form of weather model data we are most familiar with on a day-to-day basis. NWP focuses on taking current observations of weather and processing these data with computer models to forecast the future state of weather. Knowing the current state of the weather is just as important as the numerical computer models processing the data. Current weather observations serve as input to the numerical computer models through a process known as data assimilation to produce outputs of temperature, precipitation, and hundreds of other meteorological elements from the oceans to the top of the atmosphere.

Finite-difference model

Numerical models to represent differential equations in a computationally Our goal in building numerical models is to represent differential equations in a computationally manageable way. A large class of numerical schemes, do so using finite difference representations of the derivative terms. The model domain is divided into a set of discrete, typically uniform, intervals of the independent variable (or variables). Arithmetic differences of function evaluations at the nodes between those intervals are used to approximate the derivatives of the function over those intervals. Finite difference method includes models in which the spacing of grid lines varies to provide greater detail in selected parts of the study area. (groundwater modeling) For reliable simulation and careful calibration. Type and range of simulation for different models. Need to collect a lot of data at wells and tests For mapping sotmrs: each cell like a bank account, put water into the cell being driven into it by wind force from other cells and moving out of it, simulating water exchange and movement from various cells keeps track of height of water in cell. Simplistic grid with cells

Nor'easter

Occur along the northern New England coast, More destructive than hurricanes. Large, slow-moving storms with high winds and heavy prolonged rain. Occur between November and March. Also called extratropical cyclones because it starts out as a low-pressure cell over the south-central states and moves east and then north along the coast. Cyclonic (counterclockwise) circulation around the storm's low-pressure core produces intense onshore winds ahead and to the right of the storm. These storms pick up a lot of moisture over the ocean and aggravate flooding around tidal estuaries, and winds can create a storm surge and cause beach erosion.

List in a logical order and describe briefly the key operations behind the systematic construction of FIRMs for riverine flooding.

Passing the law simpler and reliable rather than estimating and mapping the risk of flooding Provides federal disaster relief and subsidized flood insurence, all American taxpayers absorb a substantial share of their citizens flood losses. subsidies encourage participation, reduce flood losses, and serve the national interest. Also, lessen shocks on the national economy because flooding is widespread and disruptive. Eligibility is also a factor to determine floodplain vulnerability and construction restrictions. stakeholders need to determine which structures and building sites are in a flood-hazard zone, and relate it to streets, political boundaries, and other reference features. FEMA attempts to update records shows special flood hazard areas (1 percent change of being inundated in any year) Zone AE: E - determination of base flood elevation to estimate potential flood damage and calculate insurance premiums for structures Parallel diagonal lines = floodway - buildings and other obstructions would interfere with the rivers ability to carry away water from flood - ban structures on floodway. Other zones used as well to determine threats of differing floods and the varying insurance rates. Also determines base flood level in relation to buildings uses flood frequency analysis - uses gages and their height to determine the discharge, reflecting water velocity. Continuous recording Use the recurrence interval and exceedance probability by recording peak discharges from lowest to highest and computing recurrence interval to measure how often on average a flood this large appears.

Cold War and nuclear hazard

Place-rating genre. In Risks and Hazards: A state by state Guide. Nuclear and attack and nuclear power plants are involved in the rating of hazards and provide preparations and responses as well as treatments to radioactive fallout. Each state has a nuclear attack map (a threat less troubling now than during the cold war). Features detailed depiction of likely targets. Mutually assured destruction. Shows differing cities, and industrial sites. Also shows stoplight colors to signal survivor rate/casualties. Maps dramatized, arguing civil defense, fallout protection as well as or peace negotiations and nuclear disarmament.

Epicenter

Point on Earth's surface directly above an earthquake's focus

Point-source/non-point-source

Point-source: Specific individual sites of groundwater pollution such as storage ponds build with a plastic liner or floor of clay to prevent leakage, as well as underground tanks for storing toxic chemicals. Landfills and lagoons. Non-point source: Occurs across broad areas are less easily traced or controlled than point sources. Examples are old leaky sewer pipes as well as streams carrying sewage that can leak into aquifers at various places.

Proximal hazard zone (volcano)

Proximal volcanic hazard zones (P) are areas subject to the volcanic hazards within 30 minutes, including but not limited to slow-moving lava flows, pyroclastic flows and lahars. Areas at risk of volcanic eruption hazards due to proximity described by varying hazard zones that correlate with their degree of risk (closter to the mountain, higher danger).

Onset

Rapid predicting the pace and start of which a hazard will occur. Wave onset

stop-light colors

Red, green, and yellow color coding on hazard and geographical maps to indicate the level of danger.

Well and landfill permits

Regulations to permit the use of a well or landfill in a designated area (if the location is suitable and the construction will not harm the surrounding area).

Return interval

Return period: the average time until the next occurrence of a defined event. When the time to the next occurrence has a geometric distribution, the return period is equal to the inverse of probability of the event occurring in the next time period, that is, T = 1/P, where T is the return period, in number of time intervals, and P is the probability of the next event's occurrence in a given time interval. The return period of a flood, T, is a measure of its rarity, defined as the average interval in years between an occurrence of floods that exceed it.

What political and ethnical questions surround insurance programs for natural hazards?

Risk communicatons: problems between gov and state unwillingness to pay and take action Responsibility to warn appropriate distribution of information and access Uncertainty encourages landowners and community officials to c'hallenge cartograp'hers delineations, flood insurence maps are far from static. Average flood elevation error 23% Flood insurence offers a middle ground between ignoring misery and bailing out willfully negligent victims. Passing the law proved simpler than setting up a reliable system for estimating and mapping the risk of flooding

SLOSH

SEA, Lake, and Overland Surges from Hurricanes. Set of mathematical equations for estimating floodwater elevations over both land and sea. Equations represent the effects of wind stress and the sharp drop in atmospheric pressure near the center of the storm. Two kinds of information are needed: the position, pressure, and size of the hurricane and the elevations of land and seafloor at a fan-shaped radial network of grid points. Valuable for simulating a broad range of plausible storms based on meteorological records. The National Hurricane Center has developed models for twenty-two SLOSH basins Model with new topographic information. Includes sea, lake and overland surges and hurricanes. estimates floodater elevations overland and sea, including effect of wind and atmospheric pressure of center. Need info on hurricane and topographic and elevation information to simulate plausible storms

karst sinkholes

Sinkholes, collapsed taverns, disappearing streams, little surface drainage = viral and bacterial contamination. Water percolating through limestone and dissolving bedrock has carved out caves for groundwater movement. When water infiltrates fast and there is no percolation, sinkholes form. topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions.

Building codes

Standards for construction and safety of buildings

NEXRAD radar

The National Weather Service has installed a new type of Doppler Radar called NEXRAD Radar. NEXRAD stands for Next Generation Radar. This radar produces many different views of storms and rain that allows meteorologists to determine if a storm could be severe. Here, there are fewer radar systems with even spacing due to around the clock surveillance and better technology to predict storms. Doppler effect: sound waves from an approaching object bunch up, increasing in frequency and pitch, whereas waves from a receding object spread apart. This radar generates and analyzes its own constructed waves. WSR-88D station (weather surveillance radar) - transmitter-receiver image processor that estimates wind velocity and direction by measuring the Doppler shift of electromagnetic waves reflected backward (backscatter) from moisture and debris. Two modes: Precipitation mode and severe storm mode (doppler radar mode). Timely detection and recognition of tornadoes and storms (severe thunderstorm watch)

Floodplain

The area subject to flooding during a given number of years according to historical trends. an area of low-lying ground adjacent to a river, formed mainly of river sediments and subject to flooding. Another definition A floodplain, or flood plain, is flat or nearly flat land adjacent to a stream or river that experiences occasional flooding. It includes the floodway, which consists of the stream channel and adjacent areas that carry flood flows, and the flood fringe, which are areas covered by the flood, but which do not experience a strong current. Floodplains are formed in two ways: by erosion; and by aggradation. An erosional floodplain is created as a stream cuts deeper into its channel and laterally into its banks. A stream with a steep gradient will tend to downcut faster than it causes lateral erosion, resulting in a deep, narrow channel with little or no floodplain at all.

Ring of Fire

The association of earthquakes and volcanoes in a sweeping band extending up the west coast of South America and Mexico, northward past British Columbia, west-Philippines into the East Indies, and then eastward around Australia and south toward New Zealand. The circumpacific seismic belt not only contains most of the world's active volcanoes but is evident on world maps of major earthquakes. Tsunamis also occur along this ring.

Base flood elevation

The computed elevation to which floodwater is anticipated to rise during the base flood. They are shown on Flood Insurance Rate Maps (FIRMs) and on the flood profiles. It is a the regulatory requirement for the elevation or floodproofing of structures. Estimated using a gage at any point on a stream or river Suffix W means that hydrological engineers have established the base flood elevations, used to estimate potential flood damage and calculate insurance premiums for individual structures

vertical evacuation

The movement of hurricane evacuees to resistant high-rise structures inside the impact area.

Shaking

The movement of rock beneath the Earths surface Due to seizmic activity - horizontal shaking and damage due to unconsoliodation of land and buildings

Vulnerability mapping

The overall goal of performing vulnerability mapping is to determine the most likely locations within the system in development where an attacker will strike. This is done on the design phase of the SDLC A vulnerability map gives the precise location of sites where people, the natural environment or property are at risk due to a potentially catastrophic event that could result in death, injury, pollution or other destruction. Such maps are made in conjunction with information about different types of risks.

Liquefaction

The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud

Subduction

The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.

EF scale

The scale of a tornado's destruction based on observed damage The EF Scale is the standard way to measure tornadoes based on wind damage. The original Fujita Scale (or F Scale) was developed by Dr. Theodore Fujita. All tornadoes, and other severe local windstorms, were assigned a number according to the most intense damage caused by the storm. The enhanced F Scale (EF Scale) was implemented in the United States on February 1, 2007. The EF scale uses three-second wind gust estimates based on a more detailed system for assessing damage, taking into account different building materials.

Water table

The upper level of the saturated zone of groundwater The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. The water table is the surface where the water pressure head is equal to the atmospheric pressure.

List in a logical order and describe briefly the key operations in the systematic mapping of flood elevation for coastal storm surge.

To map coastal flood hazards accurately, many factors must be taken into account, such as the amount of development in the area, the types and strength of storms that historically have affected the area, and onshore and offshore elevations. This page explains the steps involved to identify and map the coastal flood hazards shown on FEMA Flood Insurance Rate Maps (FIRMs). The FIRM is used to determine flood insurance requirements for residents and where floodplain development regulations apply in a community. Each FIRM shows Special Flood Hazard Areas (SFHAs) which are the areas of the flood that has a one percent chance of being equaled or exceeded in any given year. The SFHA includes all 'A' and 'V' FIRM zones, the most common being: A, AO, AH, AE, VE, and V. Insurance rates and building requirements are tied to SFHA boundaries and the Base Flood Elevations (BFEs) that are established for these areas and shown on the FIRM. A BFE is the water level expected in the SFHA for a 1%-annual-chance flood event. V - velocity hazard - likelihood of waves of 3 feet or more, whipped up by high velocity storm winds, and VE identifies a V zone with a base flood elevation to determine insurance premiums. Coastal flooding is usually caused by coastal storms, including tropical storms, hurricanes, and nor'easters. Storm surge is the amount of water, combined with the effect of normal tides that is pushed towards the shore during a storm. The height of the storm surge is driven by many variables, such as the strength and size of the storm, and the speed and direction in which the storm moves. Using information about historical storms that have affected the area, a representative set of storm events are identified and then modeled. The rush of water that extends inland when waves come ashore is called 'wave runup.' The overland wave analysis will determine the elevations to which wave runup extends during a storm. Tide gauges Atlas map - probability of hurricanes / annual percentage Composite map: show varied forces at work: on shore Ishoreline charge, overwash distances, storm surge, storm/wave damage, earth movement, stabilization) and coastal factors (population density and relief. Composite into four risk categories (very high to moderate risk). Rising sea maps and inundation resulting. Predicted shorelines and mean surge penetration distance.

Teabag effect

Water encounters a body of waste and contaminents. Filters in through it and then the water filters out with it being contaminated

Modified Mercalli Scale

a 12 point scale developed to evaluate earthquake intensity based on the amount of damage to various structures. (MM) scale, which uses Roman numerals to describe twelve typical levels of damage. Very Violent - A, Weak - E, XII - massive destruction, VI - felt by all people Measures earthquake intensity (measurement of the local impact of that energy released by a rupture (magnitude)

leach field

a component of a septic system, made up of underground pipes laid out below the surface of the ground

Natural levee

a deposit of sand or mud built up along, and sloping away from, either side of the flood plain of a river or stream

Backswamp

a poorly drained area on a floodplain that results when natural levees are present (a deposit of sand or mud built up along, and sloping away from, either side of the flood plain of a river or stream.)

Perched water table

a quantity of groundwater that lies above the regional water table because an underlying lens of impermeable rock or sediment prevents the water from sinking down to the regional water table

Doppler radar

a radar tracking system using the Doppler effect to determine the location and velocity of a storm, clouds, precipitation, etc. Sends out radar pulses of energy, and when this beam encounters an object it bounces off and returns to the receiver. Shows reflectivity vs velocity formation (but cannot forecast what occurs under the beam's range).

storm surge

a rising of the sea as a result of atmospheric pressure changes and wind associated with a storm. A dome of water that sweeps across the coast where a hurricane lands. Characterized by a low-pressure cell and high-speed winds (counterclockwise) driving across the water to create friction and water uplift/movement Wind flood/hurricanes costal impact and water level]intense low pressure which sucks water and wind-driven water which forces water up

Fujita scale

a scale of tornado severity with numbers from 0 to 6, based on the degree of observed damage and intensity. Divided wind speeds between 73 mph and the speed of sound into twelve equal intervals, each identified by the letter f followed by the integer representing the intensity level (f0-f6). These are divided into three groups (weak, strong, violent), and light to incredible damage. Uses structural damage in relation to storm intensity judged by eyewitness accounts

Derecho (line storm)

a widespread, long-lived, straight-line wind storm that is associated with a land-based, fast-moving group of severe thunderstorms. Derechos can cause hurricane-force winds, tornadoes, heavy rains, and flash floods.

Bathtub effect

accumulation of infiltrated leachate above the impermeable liner Radioactive waste, when put in a lined landfill, can leak out due to horizontal water flow when precipitation occurs above the landfill, resulting in contaminated, radioactive water leaching into other areas.

Unstable air

air that does not resist verticle displacement; if it is lifted, its temperature will not cool as rapidly as the surrounding environment, and so it will continue to rise on its own To be "unstable", the lowest layers of an air mass must be so warm and/or humid that, if some of the air rises, then that air parcel is warmer than its environment, and so it continues to rise. This is called moist convection. Normally in the atmosphere, if an air parcel rises, it will be colder than its environment (due to expansion), and it will then sink back down again. This is called a stable airmass. If the rising air parcel contains enough water vapor, however, then condensation of the water vapor in it occurs, and a cloud is formed. This condensation releases heat, which warms the air parcel, which can cause the parcel to rise higher still. This is the basis for thunderstorm formation. The more unstable the air mass, the more energy there is for thunderstorms to feed off of.

Cone of depression

an area lacking groundwater due to rapid withdrawal by a well. Causing a deep depression and drying up of wells around it due to vigorous pumping, diverting water from it's a normal path.

Safe room

an area within a larger structure that is designed to withstand the wind and debris forces of a major tornado

Social construction (FIRMs)

an entity that exists because people behave as if it exists and whose existence is perpetuated as people and social institutions act in accordance with the widely agreed-upon formal rules or informal norms of behavior associated with that entity FIRMs - example: a construction policy based around human construction and incentives in relation to natural hazards

Beach nourishment

dumping new sand (artificial placement of sand) onto eroding beaches to restore them

Saltwater incursion

excessing pumping of fresh water in coastal areas, causes salt water to contaminate wells

Crustal plates

pieces of the Earth's crust that float on the asthenosphere and move in relation to one another.

Storm track

relatively narrow zones in seas and oceans where storms travel driven by the prevailing winds. The path a storm takes is predicted through the speed and strength of it (pressure at center and windfield direction and strength). As a hurricane moves forward, direction and strength changes.

Recurrence Interval

the average length of time between floods of a given size along a particular stream. Done through a statistical analysis of flood data by reordering the peak discharges (Q) from lowest to highest and computing the recurrence interval T, a measure of how often, on average, a flood this large appears in the data. The calculation is described by the formula T = (n plus I)/m (n =number of years of record and m is the rank order.

Subsidence

the sinking of regions of the Earth's crust to lower elevations

Thermal expansion

the tendency of matter to change its shape, area, and volume in response to a change in temperature. Temperature is a monotonic function of the average molecular kinetic energy of a substance. When a substance is heated, the kinetic energy of its molecules increases. Water expanding - sea level rise

Hundred-year flood

there is a 1% chance that a flood of that size will occur this year or the stage/discharge with only 1 change in a 100 of being equaled or exceeded in a single year. Used in FIRMS to asses base flood elevation places/shelter homes and buildings and if they will need insurence. (on average, the larger peak discharge will be equaled or exceeded once in a hundred year period). Recurrence interval of 100 years on average. Also called the exceedance probability. Difficult to have 100 year data, old data may not reflect current runoff and discharge, and cannot be predicted as a typical record period of current and future weather. This is why analyst works with peak discharges recorded over 30 to 50 years and treats them as a sample drawn at random from a langer set of peak discharges. This is why a probability theory is used (T=(n plus I)/m.

Retreat

to move away from a hazard (coastal hazard, move inland)

Nowcasting

used for quick, short-lived events such as thunderstorms, or tornadoes. Radar-based nowcasting is especially useful when Weather Service posts a "Severe Thunderstorm/Tornado Watch" for the next six to eight hours. Within 20,000 square mile supercells that often form most tornadoes. Radar operators look for vertical structures with rapidly rotating winds.

Test (monitoring) wells

used in modeling and simulations. dense networks of monitoring wells assess pumping rates as well as water-table measurements taken periodically over a representative period of time. These can be used to simulate models when exploring effects of pumping on flow direction and the water table, as well as modeling for tracking a toxic plume and for cleanup measures (finding efficient locations for an interceptor well and additional monitoring wells, and steering plume toward the well by reducing or increasing pumping at other supply wells).

Ash

very small solid particles ejected from a volcano during an eruption which have intermediate axes measuring 2 mm or less (US Geological Survey) and "fine ash" is further defined by the same source as particles smaller than 1/16 (0.0625) mm across. Ash Hazard / Ash Hazard maps: simulates the range of ash emission and its possible threat. Wind affects its pattern and direction, along with the distance from the volcano and geographic blockades. Ash falls from low-volume eruptions. deposition can be long, linear, and extend out Volcanic ash consists of fragments of pulverized rock, minerals and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter.[1] The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as tephra), including particles larger than 2 mm.