The Impact of Satellite Digital Elevation Models in Hydraulic Modelling of Water Distribution Network in Addis Ababa, Ethiopia

Abstract

Digital elevation models (DEMs) generated from different satellite sources are being used for many engineering projects. Among those engineering projects, DEMs are now being used for water distribution network modeling as input data sources in Ethiopia. Due to its free availability with different resolutions, DEMs are considered as a very cost-effective way of gathering input data for the design and modeling purposes, particularly in water sectors. However concrete studies about the accuracy of DEMs that it might possibly produce are not conducted so far in Ethiopia. In this regard, this study was conducted to quantify and evaluate the impacts of available satellite DEM resolutions in hydraulic modeling of the water distribution network (WDN).Hydraulic modeling of WDN was performed for steady state and extended period simulations for the 12.5X12.5m, 30X30m, Google Earth (GE) and 90X90m DEM resolutions by using WaterGEMSv8i software. The modeling outputs of the software were portrayed that the existence of significant variations in water pressure for the evaluated DEMs.

Keywords: RMSE, MAPE, Field Survey, DEM, Modelling, WaterGEMSV8i

DOI: 10.7176/CER/11-12-03

Publication date: December 31^st 2019