RNR 1001 Lecture : RNR Notes 102
Document Summary
One the most important renewable resources on the planet is water, a substance critical to al life that is subject to problems with quantity (e. g. , relative resource scarcity) and quality (e. g. , agricultural runoff) 97. 5% of water on earth is saltwater, 2. 5% is freshwater, and 70% of that is soil moisture of is in deep aquifers and groundwater that are not accessible. About 0. 007% of all water on the planet is available for human use. Water availability is directly related to the hydrologic cycle. Water exists primarily as ice, water vapor in the atmosphere, and a liquid. We discussed some problems with agricultural runoff as a surface water quality problem, and groundwater pollution from nitrate. And additional problem is the over-use of aquifers in many parts of the world. Groundwater in aquifers is typically recharged from precipitation, although groundwater flow from nearby streams is also possible. Recharge rates depend on permeability (meters per week to centimeters per century)
