Wetland mapping and evaluating the impacts on hydrology, using geospatial techniques: a case of Geba Watershed, Southwest Ethiopia

Abstract

Wetlands are one of the world’s most important ecosystems threatened by man. This investigation explores the use of Landsat TM and OLI imageries with SRTM DEM for mapping them. Mapping and monitoring of wetlands is done with 86.66% accuracy. As a result, a loss of 21,400 ha yr−1 could be noted. Due to this, differences were also found in the water quality and groundwater level between the degraded and un-degraded areas. As most rivers within the watershed punctuated from the wetlands, their existence was determined based on the hydrological function. Wetland degradation occurred mainly due to climate and agricultural changes over time. Thus, geospatial techniques employed in the present study have proved very useful in simplification and visualization of wetland monitoring.

Keywords

• agriculture
• climate
• wetland loss
• water quality
• water level