초록
영어
Waterlogging and unintended lake formation become the main problem in some parts of the world. Starting from 1989, the waterlogging problem was observed in the farmland of the Jarso community of Konso Woreda adjacent to the Segen River in Ethiopia. Therefore, the objectives are determining the extent and causes of unintended lake formation using GIS/RS in addition to a preliminary field survey to mitigate the problem. The analysis of satellite images revealed that over the years invasion of the irrigable land by unwanted water had increased, as, in 1989, the size of the wetland area was about 8 Km2; in 2000 the size of the un-intended lake was only 8.23 km2. Alarmingly the size of the lake increased to 19.68 Km2 in 2014. Silting up of Weir and changing the flow of River Segen and Human Intervention and changing the natural flow of River Yanda were the main causes of this unwanted prolonged water-logging. The ecological and social environment has been degrading as the people of the waterlogged area have been experiencing some settlement and losing their land. Another problem encountered was flooding from River Barka and invasion of the farmland. Sediment control best management practices (BMPs) i.e, Removal of sediment, providing sandbags and well-scheduled maintenance; Changing the junction point of Yanda and Segen River were suggested for the long-term and short term possible remedial measures. Gabion retaining wall on the bank of the Segen River to the face of Barka River was suggested to protect the farmland from flooding.
목차
1. INTRODUCTION
2. Materials and Methods
2.1 Study Area
2.2 Climate and Soils
2.3 Data Acquisition (Primary and Secondary Data)
3. Results and Discussion
3.1 Laboratory observation of soil samples
3.2 Identified Causes of Un-intended Lake Formation
3.3 Silting Up of Weir and changing flow of River Segen
4. Conclusions
References