This site describes how and when 100-year floods occur. It states that flood designations are based on statistical averages, not on the number of years between big floods. It also suggests that it would make more sense to refer to 100-year floods as 1-in-100 chance floods. This resource is a United States Geological Survey (USGS) Fact Sheet. It can be used in teaching quantitative skills.

This site from the Hydrologic Information Center of the National Weather Service discusses the flood risk in the United States. Maps and satellite images support the text. The site also provides information about snow levels, stream flow, soil conditions, forecasts and outlooks.

The Aral Sea is actually not a sea at all, but an immense fresh water lake. In the last thirty years, more than sixty percent of the lake has disappeared because much of the river flow feeding the lake was diverted to irrigate cotton fields and rice paddies. Concentrations of salts and minerals began to rise in the shrinking body of water, leading to staggering alterations in the lakes ecology and precipitous drops in the Arals fish population. Powerful winds that blow across this part of Asia routinely pick up and deposit the now exposed lake bed soil. This has contributed to a significant reduction in breathable air quality, and crop yields have been appreciably affected due to heavily salt laden particles falling on arable land. This series of Landsat images taken in 1973, 1987 and 2000 show the profound reduction in overall area at the north end of the Aral, and a commensurate increase in land area as the floor of the sea now lies exposed.

This BBC News clearinghouse website provides a wide variety of information regarding Hurricane Katrina. Information includes news stories, scientific analysis and background, eyewitness accounts, photo galleries, pressing questions, hurricane animations and more. Information has been updated frequently.

This USGS site contains information on the geology units, topography, and precipitation rates of the Black Hills as it relates to the hydrology. Included is a map defining the study area, precipitation graphs, a stratigraphic column, a map denoting the distribution of hydrogeologic units, a geologic cross section, and a photo of the hydrogeologic setting. Links to an introduction to this study, objectives, products, references, and digital map services are also available through this site.

" This course covers examination of the state of knowledge of planetary formation, beginning with planetary nebulas and continuing through accretion (from gas, to dust, to planetesimals, to planetary embryos, to planets). It also includes processes of planetary differentiation, crust formation, atmospheric degassing, and surface water condensation. This course has integrated discussions of compositional and physical processes, based upon observations from our solar system and from exoplanets. Focus on terrestrial (rocky and metallic) planets, though more volatile-rich bodies are also examined."

Students calculate recurrence intervals for various degrees of flooding on a portion of the Des Moines River in Iowa, based on historical data. Then they plot these calculations on a flood frequency curve. Combining flood frequency data with a topographic map of the region, students do a risk assessment for the surrounding community. This webpage includes teaching notes and tips and downloadable teaching materials.

GEOLogic questions are puzzles that were developed to support students understanding of geoscience concepts while challenging them to develop better logic and problem solving skills. In this exercise, students are asked to match up students with their home state, and their states with the area and percentage of area of surface water that they contain, as well as where each of the states rank nationally in terms of water area. Students are given clues from various perspectives to help them deduce the answers to the problem. This activity is appropriate for a high school science class or an introductory level undergraduate geoscience course, and can be given as an in-class assignment or homework assignment. Learning goals, context for use, teaching tips, materials, assessment tips and related resources are provided.

This webpage from SERC features GEOLogic questions, which are puzzles that were developed to support students understanding of geoscience concepts while challenging them to develop better logic and problem solving skills. In this example, students are asked to convert measurements in cubic feet per hour (cfh) to cubic feet per second (cfs) and then match up the names of the researchers measuring the flows at the river station with the correct flow rate. There is also a second part in which students graph the different flow rates with time and answer questions by interpreting the information in the graph.

This website is a cooperative research project between the U.S. Geological Survey (USGS), NASA, the U.S. Army Corps of Engineers, and the University of New Orleans. The goal of the project is to investigate coastal change that occurred as a result of Hurricane Katrina. The site includes aerial video, still photography, and laser altimetry surveys of post-storm beach conditions that were collected August 31 and September 1, 2005 for comparison with earlier data. The comparison data can be used to refine predictive models of coastal impacts from severe storms and aid in disaster recovery and erosion mitigation.

This transcribed article from American Radio Works discusses the hurricane risk in New Orleans. The 2002 article talks about how deep flood waters would be in a Category Five hurricane and the likelihood that such a storm would hit. Users may also listen to the article using Real Player audio program.

This is a field investigation where students will gather data about the South Crow River using techniques of their own design and develop a group (multimedia) presentation for class presentation.

This EPA document provides detailed information about the gold mining industry in terms of the wastes associated with gold mining and processing. The report briefly characterizes the geology of gold ores and the economics of the industry. Following this discussion is a review of gold extraction and beneficiation methods; this section provides the context for descriptions of wastes and materials managed by the industry, as well as a discussion of the potential environmental effects that may result from gold mining. The report concludes with a description of the current regulatory programs that apply to the gold mining industry as implemented by EPA, Federal land management agencies, and selected states. Specific information from EPA site visits is included for the Brewer Mine, Colosseum Mine, Nerco Minerals Cripple Creek, and the Newmont Gold Company in Nevada.

In this class activity, students determine the discharge of a 100-year flood for two human-impacted streams. This activity supports the quantitative concepts of recurrence intervals, floods and flooding, and probability. It is appropriate for a class of under 40 students. This assignment uses real data, asks students to graph and interpret data, examines the errors associated with that data and its analysis, and requires the students to look at societal impacts. Learning goals, context for use, teaching tips, materials, assessment tips and related resources are provided.

This activity is an inquiry based field investigation where students measure and map a small stream and then develop an understanding of the formation of a variety of small stream features.

This 15-page PDF was prepared by the USGS and provides information about sources of water and groundwater quality on St. George Island. Maps, tables, chemical analysis, cross sections and well logs are included in the report.