Three-Dimensional Model of the Geologic Framework for the Columbia Plateau Regional Aquifer System, Idaho, Oregon, and Washington

摘要

The Columbia Plateau regional aquifer system (CPRAS) covers approximately 44,000 mi of Idaho, Oregon, and Washington. The area supports a 6 billion dollar per year agricultural industry, leading the Nation in production of apples and nine other commodities (State of Washington, 2009; U.S. Department of Agriculture, 2009). Groundwater availability in the aquifers of the area is a critical water-resource management issue because the water demand for agriculture, economic development, and ecological needs is high. The primary aquifers of the CPRAS are basaltic lava flows of the Columbia River Basalt Group (CRBG) and overlying basin-fill sediments. Water-resources issues that have implications for current and future groundwater availability in the region include (1) widespread water-level declines associated with development of groundwater resources for irrigation and other uses, (2) reduction in base flow to rivers and associated effects on temperature and water quality, and (3) current and anticipated effects of global climate change on recharge, base flow, and, ultimately, groundwater availability.