Assessment of Ethiopian Lakes Level Change and Identification of Endangered Lakes for the Last four Decades Using Landsat Satellite Image
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Date
2016-05
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Addis Ababa Universty
Abstract
Lake level change is fluctuation of water level within the lakes that resulted from the shifting
of water balance from its static state. At national scale, the Ethiopian lakes level change was
not studied yet using remote sensing method and there was no well-organized geodatabase that
shows their spatial variation with specified time interval. Therefore, this was the biggest
challenge in order to identify whether the lakes are in dynamic or in steady state. This study
aims to solve the above mentioned problem through assessing the Ethiopian lakes level change
by developing well-organized geodatabase and identifying the endangered lakes for the last
four decades using Landsat satellite images (Landsat MSS, TM, ETM+ and OLI sensors). The
result shows that there are 108 natural and man-lakes and from these lakes endangered lakes
were identified with ranking their spatial extent fluctuation. Accordingly, Lake Abiyata,
Chamo, Chelelek and Haromaya, ranked top three declining lakes, and Lake Beseka, top one
rising lake, was identified as endangered lakes. Furthermore, Lake Abiyata and Chamo were
shrunk by 33.59% (66.64 km2) and 8.98% (29.43 km2) respectively and Lake Beseke was
drastically raised by above 900% compared to their 1970’s spatial extent. However, Lake
Chelelek and Haromya were desiccated before 2010’s due to anthropogenic factors. The main
factors considered in this study was the Land use land cover of the lakes surrounding and over
consumption of the lakes water. Moreover, the verification for identified endangered lakes were
done using the field collected coordinates of the lakes edge and the trend of water level of the
lakes measured by Ministry of Water, Irrigation and Energy. Due to the drastic decline, Lake
Abiyata needs special rehabilitation practice and Lake Beseka also needs proper treatment.
Furthermore, the final result of this study used as a benchmark for the coming researches.
Key words: Landsat image, lakes level change, endangered lakes, Ethiopia, geodatabase
Description
Keywords
Landsat image, Lakes level change, Endangered lakes, Ethiopia, Geodatabase