Evaluation of Multiresolution Digital Elevation Model (DEM) from Real-Time Kinematic GPS and Ancillary Data for Reservoir Storage Capacity Estimation

Yashon Ouma

doi:10.3390/hydrology3020016

Abstract

This study presents the estimation of reservoir storage capacity using multiresolution Real-Time Kinematic Global Positioning System (RTK-GPS) DEM, in comparison with ASTER and contour-derived DEM. Through RMSE comparisons of the elevation point uncertainty and error analysis, the results shows that the RTK-GPS DEM gave the best results for the reservoir capacity-area power curve estimation, defined by a convex slope with an exponential deterministic relationship given by V = 0.09 × A 1.435 . The results further show the existence an empirical relationship between the reservoir volume certainty and the GPS point density d i as V e = c × d i ρ . This relationship is dependent on the reservoir terrain, slope and surface area. Validation of the results with in situ data showed the differences between the simulated and observed storage volumes was less than +10%, and using the Nash-Sutcliffe coefficient of efficiency on the storage volumes, an average efficiency of +0.7 on the monthly observed and simulated reservoir storage volume was observed.

Highlights

With the variations of spatial-temporal distributions of runoff due in part to climate change, small reservoirs for water detention will continue to serve multipurpose uses including water supply, flood control, hydropower generation, navigation and recreation [1,2,3]
(a) Reservoir topography and dam site selection: The slope results show that the proposed reservoir site has a uniform steep‐slope, which is suitable in supporting the reservoir embankments
Reservoir topography and dam site selection: The slope results show that the proposed reservoir site has a uniform steep-slope, which is suitable in supporting the reservoir embankments

Summary

Introduction

With the variations of spatial-temporal distributions of runoff due in part to climate change, small reservoirs for water detention will continue to serve multipurpose uses including water supply, flood control, hydropower generation, navigation and recreation [1,2,3]. In the planning and maintenance of such structures, relationships between a reservoir’s surface area A, storage capacity or volume V, and the depth D of water, are significant in the evaluation of water and dissolved-mass balances of the reservoir system. The correlations amongst these reservoir parameters are significant in real-time and long-term monitoring of such water detention systems. V-D are often determined from fine-resolution topographical maps that are derived from detailed engineering surveys [4] Such conventional methods are time-consuming, field laborious and subject to observational errors

Objectives

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Results

Conclusion