The ability to effectively manage water resources to meet present and future human and environmental needs is essential. Such an ability necessitates a comprehensive understanding of hydrologic processes that affect streamflow at a watershed scale. In the United States, water-resources management at scales ranging from local to national can benefit from a nationally consistent, process-based watershed modeling capability to provide the requisite understanding. The National Hydrologic Model (NHM) infrastructure, which was developed by the U.S. Geological Survey to support coordinated, comprehensive, and consistent hydrologic modeling at multiple scales for the conterminous United States, provides this essential capability. NHM-based applications provide information to enable more effective water-resources planning and management, fill knowledge gaps in ungaged areas, and support basic scientific inquiry. In the future, as process algorithms and data sets improve, the NHM infrastructure will continue to evolve to better support the nation's water-resources research and management needs.

有效管理水资源以满足当前和未来人类与环境需求的能力至关重要。这种能力需要对影响分水岭规模的水流的水文过程有一个全面的了解。在美国，从地方到国家的不同规模的水资源管理都可以受益于国家一致的，基于过程的流域建模能力，以提供必要的了解。由美国地质调查局开发的国家水文模型（NHM）基础结构可为美国本土提供多种规模的协调，全面和一致的水文建模支持。基于NHM的应用程序可提供信息，以实现更有效的水资源规划和管理，填补未就业地区的知识空白，并支持基本的科学探究。将来，随着过程算法和数据集的改进，NHM基础设施将继续发展，以更好地支持美国的水资源研究和管理需求。