Distance to the nearest stream by stream order for selected watersheds in the United States

​Accurate representation of stream networks at various scales in a hydrogeologic system is integral to modeling groundwater-stream interactions at the continental scale. To assess the accurate representation of stream networks, the distance of a point on the land surface to the nearest stream (DS) has been calculated. DS was calculated from the 30-meter Multi Order Hydrologic Postion (MOHP) raster datasets for 18 watersheds in the United States that have been prioritized for intensive monitoring and assessment by the U.S. Geological Survey. DS was calculated by multiplying the 30-meter MOHP 30-meter MOHP Distance from Stream Divide (DSD) datasets by a fraction of the Lateral Position (LP) datasets for stream orders one through five. DS was calculated for the purposes of considering the spatial scale needed for accurate representation of groundwater-stream interaction at the continental scale for a grid with uniform cell sizes. The data are available at the 30-meter resolution as multi-banded GeoTIFF files, where each band is a stream order, and as Comma Separated Value formatted files where each column is a stream order.

在水文地质系统中，准确表征不同尺度的河网，是开展大陆尺度地下水-河流相互作用模拟的核心前提。为评估河网的准确表征效果，研究人员计算了陆地表层点到最近河流的距离（Distance to Nearest Stream, DS）。该DS基于美国地质调查局（U.S. Geological Survey）划定的18个优先开展密集监测与评估流域的30米多阶水文位置（Multi Order Hydrologic Position, MOHP）栅格数据集计算得到。具体计算方式为：将30米MOHP的河流分界距离（Distance from Stream Divide, DSD）数据集，与1至5级河流的侧向位置（Lateral Position, LP）数据集的分数值相乘。本次DS计算的目标，是为确定大陆尺度下采用均匀格网进行地下水-河流相互作用模拟时，保障河网准确表征所需的空间尺度。数据集以两种格式提供：一是30米分辨率的多波段GeoTIFF文件，每个波段对应一个河流等级；二是逗号分隔值（Comma Separated Value, CSV）格式文件，每一列对应一个河流等级。