Mean Fraction of Summer Runoff from Forest Service Lands (Map Service)

Available water supply varies greatly across the United States depending on topography, climate, elevation and geology. Forested and mountainous locations, such as national forests, tend to receive more precipitation than adjacent non-forested or low-lying areas. However, contributions of national forest lands to regional streamflow volumes is largely unknown. Using outputs from the Variable Infiltration Capacity hydrologic model, we calculated mean annual and mean summer (July and August) streamflow metrics based on total flow and flow from national forest lands for each 1:100,000 scale National Hydrography Dataset stream reach in the contiguous United States. Specifically, this data publication contains twenty-one comma-delimited ASCII text files (for different drainage areas and processing units across the United States) containing 1915-2011 mean annual flow and mean summer flow.Data can be downloaded here: Geodatabase or ShapefileThese files also contain the mean annual and mean summer flows from National Forest System (NFS) lands as well as the portion of total mean annual and summer flow contributed by flow from NFS lands.These data provide insight into 1915-2011 hydrologic regimes and national forest contributions to total water yield. These non-spatial files were then merged and joined to the September 2012 snapshot of the National Hydrography Dataset (NHD), version 2.Note: 'Forest Service lands' are here defined as those lands within the Forest Service administrative boundaries; these include some inholdings and other non-USFS lands enclosed within these boundaries.This record was taken from the USDA Enterprise Data Inventory that feeds into the https://data.gov catalog. Data for this record includes the following resources: ISO-19139 metadata ArcGIS Hub Dataset ArcGIS GeoService For complete information, please visit https://data.gov.

美国可供利用的水资源分布广泛，受地形、气候、海拔和地质条件的影响。森林和山地地区，如国家森林，通常比邻近的非森林或低洼地区接收更多的降水。然而，国家森林土地对区域河流径流量的贡献在很大程度上仍属未知。利用可变入渗能力水文模型，我们根据连续统一美国每个1:100,000比例尺国家水文数据集河流段的总体流量和国家森林土地的流量，计算了平均年径流和平均夏季（七月和八月）径流指标。具体而言，本数据出版物包含包含1915-2011年平均年流量和平均夏季流量的二十一個以逗号分隔的ASCII文本文件（针对美国不同排水区和处理单元）。数据可在此处下载：地理数据库或形状文件。这些文件还包含来自国家森林系统（NFS）土地的平均年径流和平均夏季流量，以及由NFS土地流量贡献的总体平均年径流和夏季流量的部分。这些数据提供了1915-2011年水文状况及国家森林对总水量的贡献洞察。然后，这些非空间文件被合并并与2012年9月的国家水文数据集（NHD）版本2快照连接。注：'森林服务土地'在此定义为森林服务行政边界内的土地；这些包括一些保留地以及其他被这些边界包围的非USFS土地。此记录来自为https://data.gov目录提供数据的美国农业部企业数据目录。此记录的数据包括以下资源：ISO-19139元数据、ArcGIS Hub数据集、ArcGIS地理服务。欲获取完整信息，请访问https://data.gov。