Investigate the Capability of Distributed Hydrologic Modeling and Remote Sensing in Capturing the Spatiotemporal Dynamics of Small Intermittent Streams

Abstract:

Drying may be more important than flooding or any other physical process when health of watershed ecosystem is considered. In traditional watershed ecology, hydrologic and ecosystem variables were mostly linked at point scale using historical data. Hence, the spatial variability of their relationship was not fully understood. Distributed hydrologicmodels and remote sensing observations are well-suited to bridge this gap. As the first step towards this goal, we investigate the capability of distributed hydrologic modeling along with LANDSAT products in capturing the spatio-temporal variability of small streams in Blue River basin, OK. Coupled Routing and Excess STorage (CREST), a distributed hydrologic model, is used to simulate spatiotemporally varied streamflow in intermittent streams. Dynamic Surface Water Estimate (DSWE), a LANDSAT product that reveals inundation at sub-pixel level, as an additional validation source to USGS stream gauge. Results show that CREST simulation well captures low-moderate flow conditions while underestimating high flow values due to the daily time step. DSWE products agree with the hydrologic simulation in terms of water occurrence especially in higher-order, larger streams. In general, mapping of long-term stream intermittency proves the value of distributed hydrologic simulation in providing the spatio-temporal continuity for monitoring of the watershed eco-hydrology.