Headwater and downstream attributes for select HUC12 units across the Conterminous United States (CONUS)

This dataset contains topographic, climatic and land cover attributes for headwaters (stream orders 1 and 2 ) as defined by the National Hydrography Dataset High Resolution (NHDHR) and downstream areas (stream orders 3 and up) for a subset of Conterminous United States (CONUS) HUC12s. Specifically, this dataset contains 2021 National Land Cover Database (NLCD) land cover for the following categories: water, developed, forest, shrubland/grassland, crops/hay; topographic metrics including: area, slope, elevation, stream density, stream length, stream slope and depth to bedrock; climatic metrics including aridity and snow persistence; and soil metrics including clay, silt and sand.

本数据集包含由美国国家高分辨率水文数据集（National Hydrography Dataset High Resolution, NHDHR）定义的河源区（水系分级1级与2级），以及美国本土（Conterminous United States, CONUS）部分12位水文单元（Hydrologic Unit Code 12-digit, HUC12）的下游区域（3级及以上水系）的地形、气候与土地覆盖属性。具体而言，本数据集涵盖2021年美国国家土地覆盖数据库（National Land Cover Database, NLCD）的以下土地覆盖类别：水体、建设用地、林地、灌丛/草地、农作物/干草；地形指标包括：面积、坡度、海拔、水系密度、水系长度、河道坡度与基岩埋深；气候指标包括干旱度与积雪持久性；土壤指标包括黏粒、粉粒与砂粒含量。