U.S. Geological Survey Stream Gages located in the Central Valley, California

This digital dataset contains the locations of, and links to USGS gages on the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate 50,000 square-kilometer region of California. The complex hydrologic system of the Central Valley is simulated using the USGS numerical modeling code MODFLOW-FMP (Schmidt and others, 2006b). This simulation is referred to here as the CVHM (Faunt, 2009). Utilizing MODFLOW-FMP, the CVHM simulates groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis from 1961-2003. The total active modeled area is 20,334 square-miles. The CVHM includes complex surface-water management processes. The hydrology of the present-day Central Valley and the CVHM model are driven by surface-water deliveries and associated groundwater pumpage. The Streamflow Routing Package (SFR1) is linked to MODFLOW-FMP to facilitate the simulated conveyance of surface-water deliveries. If surface-water deliveries do not meet the farm-delivery requirement, the FMP invokes simulated groundwater pumping to meet the demand. The surface-water network represents a subset of the entire stream network in the valley. Even so, it covers about 3,000 kilometers of surface-water and is simulated using 208 stream segments that represent 2244 stream reaches, with 43 inflows and 66 diversion locations providing 64 routed and 41 non-routed deliveries. Most of these inflows are regulated by dams and most of the deliveries are conveyed through an extensive canal network. The routed deliveries are conveyed through the simulated surface-water network, while the non-routed delivery conveyance typically occurs through small canals or diversion ditches and are not directly simulated. Much of the surface-water diversion and delivery information was compiled by the California Department of Water Resources (DWR) for 21 water-balance subregions (WBSs) covering the valley floor (C. Brush, California Department of Water Resources, written commun., February 21, 2007). The CVHM is the most recent regional-scale model of the Central Valley developed by the U.S. Geological Survey (USGS). The CVHM was developed as part of the USGS Groundwater Resources Program (see "Foreword", Chapter A, page iii, for details).本数字数据集收录了中央谷水文模型（Central Valley Hydrologic Model, CVHM）所依托的地表水网络上的美国地质调查局（U.S. Geological Survey, USGS）水文测站的位置信息及相关链接。中央谷覆盖加利福尼亚州约50000平方千米的区域。中央谷复杂的水文系统采用美国地质调查局的数值模拟代码MODFLOW-FMP进行模拟（Schmidt等，2006b）。本模拟即为本文所称的CVHM（Faunt，2009）。借助MODFLOW-FMP，CVHM于1961年至2003年间以月为时间步长，模拟了中央谷内的地下水与地表水径流、灌溉农业、地面沉降及其他关键水文过程。模型的有效模拟总面积为20334平方英里。CVHM涵盖了复杂的地表水管理过程。当前中央谷的水文状况及CVHM模型均以地表水配水量及相应的地下水抽取量为驱动条件。径流演进包（Streamflow Routing Package, SFR1）与MODFLOW-FMP相连，以实现地表水配水输送过程的模拟。若地表水配水量无法满足农田配水需求，FMP将启动模拟地下水抽取流程以满足用水需求。本数据集覆盖的地表水网络为中央谷全域河网的子集。尽管如此，该网络仍覆盖约3000千米的地表水河道，采用208个河段单元开展模拟，对应2244个河槽段；其中包含43个入流点与66个分水点，可提供64处演进式配水与41处非演进式配水。其中多数入流点由水库大坝调控，多数配水通过大规模渠网输送。演进式配水通过模拟的地表水网络完成输送，而非演进式配水通常依托小型渠道或分水沟进行输送，未进行直接模拟。本数据集的大部分地表水分水与配水信息由加利福尼亚州水资源部（California Department of Water Resources, DWR）针对覆盖中央谷谷底的21个水量平衡子区域（Water-balance Subregions, WBSs）整理汇编（C. Brush，加利福尼亚州水资源部，2007年2月21日书面通信）。CVHM是美国地质调查局（USGS）研发的最新一代中央谷区域尺度水文模型。CVHM作为美国地质调查局地下水资源项目的一部分开发完成，详细信息参见"Foreword"、A章节第iii页。