Improving Watershed-Model Accuracy by Using Digital Topography

摘要

An 11 square-mile watershed was modeled using three different resolution-triangulated digital-terrain models. The number of triangular elements varied from 176 to 784. The objective was to test the sensitivity of a distributed unit-hydrograph model to changing element size. Each triangular element and stream segment was modeled as a sequential linear-reservoir/linear-channel element. It was determined that the overland-flow elements were relatively insensitive to lag-time proportioning, while the stream segments were relatively sensitive.