Unit 8: Water Resources // Visuals

Animation(s)

Karst geology: Because of the karst geology of the Suwannee River Basin, water and dissolved nutrients move quickly to the aquifer with little chance for remediation View animation
Nutrient remediation: Because of the karst geology of the Suwannee River Basin, water and dissolved nutrients move quickly to the aquifer with little chance for remediation. View animation
Pumping water near streams: The pumping of groundwater directly affects the quantity of water in nearby rivers or streams. View animation
Surface water, groundwater, and aquifers: Almost all of the natural surface water in Arizona has been developed, leaving only ground water available for human consumption. View animation
Three critical levels for the water table: There are three critical points related to plant survival in the height of the water table. View animation
Understanding transpiration rates: Gathering data about the transpiration process is important in creating accurate models of groundwater flow. View animation

Photograph(s)

Fields in central California suffering from severe salinization: High salinity stresses plants and reduces crop yields. Excess salt affects about 30 percent of U.S. irrigated lands. View image
Sedimentation in Chattahoochee River, Atlanta, Georgia: Excess sediments can clog river channels and damage wildlife habitat. If sediments are contaminated with pesticides or industrial chemicals, they can also reduce water quality and introduce hazardous substances into the food chain. View image
Sodium hypochlorite solution for disinfecting water: Sodium hypochlorite, also known as chlorine bleach, has been used for more than a century to kill water-borne bacteria. View image
Types of wetlands: Specific functions vary with each site's vegetation, geology, and hydrologic patterns, but wetlands typically perform a number of purifying functions. View image

Graphic(s)

Average annual precipitation, Washington, 1971-2000: Water supplies can vary widely within a state or country depending on geography, rainfall patterns, and regional uses. View image
Components of a typical flood hydrograph: Perennial streams that flow year-round have a high baseflow component, but quickflow (runoff over land after storms) can substantially increase their flow patterns. View image
Confined and unconfined aquifer: Unconfined aquifers receive recharge directly from rainfall and surface water infiltrating downward. Confined aquifers are connected to unconfined areas where water can flow in. View image
Contaminant flow in groundwater: Mapping how a contaminant plume will migrate once it reaches groundwater requires understanding of the pollutant's chemical properties, local soil characteristics, and how permeable the aquifer is. View image
Current and projected freshwater stress areas: Areas with good freshwater endowments are still vulnerable to freshwater stress if they withdraw water from reserves more quickly than it is replenished. View image
Dams and diversions along the Rio Grande: The Rio Grande River is heavily managed for irrigation, flood control, power generation, and recreation. Low water levels have concentrated pollutants in river water, and the lower Rio Grande has become increasingly saline. View image
Eastern U.S. aquifers contaminated with salt water: Withdrawing freshwater from coastal aquifers can cause saltwater to intrude into the aquifers. This problem is likely to increase in areas where coastal development is expanding. View image
Effects of groundwater pumping: Excessive groundwater pumping can lower the water table, deplete nearby rivers and streams, and cause land to subside as water is pulled from soil and the soil collapses and compacts. View image
Groundwater flow under the Housatonic River, Pittsfield, Massachusetts: Groundwater moves from areas of high hydraulic head to areas of low hydraulic head, so sometimes it can move upward. View image
Gulf of Mexico dead zone, July 2006: The Gulf of Mexico hypoxic zone, which occurs in an important commercial fishing region, forces fishermen to travel farther to find live fish and shellfish. View image
Impaired U.S. waters, 2000: U.S. waters are considered impaired if they cannot fully support their aquatic biological communities or other designated uses or conform to guidelines set by states, territories, or tribal governments defining fishable and swimmable water quality. View image
The water cycle: The water cycle is essentially a closed loop, but water can be diverted from one sink to another or contaminated as it cycles. View image
Water in the ground: Groundwater is water flowing through the saturated zone underground where all pores, cracks, and spaces between rocks and soil particles are filled with water. View image
World freshwater supplies: Some countries receive enormous amounts of rainfall, while others receive virtually none or get most of it during a brief rainy season. These imbalances contribute to the unequal distribution of world water supplies. View image

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