Examining Different Digital Elevation Models (DEMs) on the Hydrological Model Performance Under Extreme Climate Storms

Abstract

During the recent years, frequent and more intense extreme weather events, especially severe storms, have been increasing globally due to ever-changing climate. Severe storm events continue being a formidable challenge to sustainable environment, infrastructural development and disaster preparation and readiness. In the region of Algeria rainfall patterns and hydrological regimes have shown changes due to climatic variabilities. Therefore, accurate prediction and modeling of hydrological changes in response to severe storms remain critical in disaster preparedness and risks reduction. Digital Elevation Model is one of the key tools used in hydrological modeling due to its provision of topographical information that aid in developing water runoff simulations and evaluations of credible influence of extreme storm events. High resolution commercial DEMs obtained from LiDAR data offer more precise and detailed representations but they are expensive, thus not suitable especially in resource-constrained regions. On the other hand, freely obtainable DEMs are inexpensive but differ in resolution and accuracy, which might affects the precision of modeling.The current research, therefore, aims to compare the performance of freely available digital elevation models in hydrological modeling as influenced by extreme storm conditions in Algeria. The study further examines how DEM resolution affects the performance of HEC-HMS hydrological model that is widely used in hydrological forecasting. It focuses on the spatial resolution influence of NASA (30m), ASTER GDM2 (30m), SRTM V4 (30m), MERIT (90m), TANDEM-X (90m), SRTM V4 (90m) and ALOS PALSAR (12.5m). The research objectives are to understand how differences in spatial resolutions of these DEMs affect modeling and to provide recommendations for suitability and applicability in robust hydrological modeling. Generally, the current research is expected to help in the determination of appropriate DEM models for disaster planning and management strategies and water resource planning for enhancing infrastructure resilience to impacts of extreme climate conditions. It is expected that the findings of the current research will benefit the study region in Algeria as well as assist other parts of the world with almost similar environmental and climate conditions. The findings will help in the understanding of DEM characteristics influencing hydrological model accuracy and overall disaster readiness.