Examining the variability of small-reservoir water levels in semi-arid environments for integrated water management purposes, using remote sensing

摘要

Accurate, reliable and continuous monitoring of water reservoirs is critical for sustainable water harvesting as well as planning by different water resources management authorities, especially in semi-arid environments. This study thus assessed the utility of remote sensing technologies for extracting critical information on dam water levels for uMzingwane dam, in the south western part of Zimbabwe, for the years 2007, 2009, 2011 and 2013. The Normalised Difference Wetness Index (NDWI), computed from multi-Landsat ETM+ and Landsat 8 images, was applied to extract the dam water levels. Our results indicate that the dam water levels varied significantly (α = 0.05) from 2007 to 2013. It was further observed that dam water levels increased with the increase in rainfall patterns, within uMzingwane catchment between the year 2007 and 2013. The findings of this research therefore demonstrate the importance of remote sensing techniques in assessing water resources in data scarce areas.