Evaluating LiDAR-based Elevation-derived Hydrography in Low-lying Agricultural Landscapes

Hydrologic connectivity network is crucial to understand hydro-geomorphological process and environmental resources management. Current hydrography products such as National Hydrography Dataset are often insufficient to support field-level management in important basins due to an absence of finer-resolution drainage flow networks. With high spatial resolution and accuracy, LIDAR has been proved to improve the representation of surface water features in fine scales. However, features such as bridges and graded roadbeds over culverts in LIDAR-derived high-resolution Digital Elevation Models (HRDEMs) can cause very large sinks which create false watershed boundaries and even produce non-existent sub-watersheds. The objective of this research is to develop a method for improving the quality of hydrologic connectivity network using HRDEM-derived hydrography information based on identified hydraulic structures, which can extend hydrologic connectivity networks across scales.