Iowa Stream Order Download

This coverage contains selected arcs from the Iowa Stream Centerline coverage which was developed by the DNR and U of I IIHR. The selected arcs represent the centerlines of wide streams, impoundments, reservoirs, and wetlands as well as the segments of single line streams. The pseudonodes were removed so that each segment was from confluence to confluence. The headwater reaches were selected and given the Stralhler stream order of 1. Those arcs were removed and then the next set of arcs at the headwaters were selected and given the next Strahler stream order until all the arcs had been given a stream order.

本数据集涵盖由美国自然资源部（DNR）与爱荷华大学IIHR联合开发的爱荷华州溪流中心线数据集（Iowa Stream Centerline coverage）中的精选弧段。所选中的弧段代表宽幅溪流、蓄水区、水库及湿地的中心线，同时包含单线溪流的分段。所有伪节点（pseudonodes）已被移除，使每个弧段均以汇流点为起止节点，即从一个汇流点延伸至下一个汇流点。研究人员首先选取源头河段，并为其赋予斯特拉勒河道分级（Strahler stream order）1级；随后移除这些1级弧段，再选取新的源头河段并赋予下一级斯特拉勒河道分级，重复该流程直至所有弧段均被赋予对应的河道分级。