IMPACT OF LAND USE LAND COVER CHANGE ON VEGETATION DENSITY AND LAND SURFACE TEMPERATURE VARIATIONS: THE CASE OF ABAYA – CHAMO LAKE CATCHMENTS, SOUTHERN ETHIOPIA

Abstract

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The direct effect of land use land cover dynamics on one environmental parameter can cause significantly indirect effect on the other land surface parameters. The central purpose of this study is to analyze the impact of LULC dynamics on the spatial distribution of vegetation density and LST in Baso – Shafe, and Sile – Elgo catchments. Landsat images of TM (1986), ETM+ (2003), OLI/TIRS (2019, and MODIS LST (2019) were used to analyze LULC, NDVI, and LST from 1986 to 2019. To support remote sensing data analysis, field observation, and FGD were undertaken. ERDAS IMAGINE version 2015 and ArcGIS 10.5 platforms were employed. The supervised image classification with maximum likelihood rule was employed to obtain the study theme and finally, accuracy for all classified LULC maps was checked using GCPs. The regression analysis between LST and NDVI was carried out by SPSS version 21. In Baso – Shafe, from 1986 up to 2019 the forest area radically declined from 35.06% to 25.75% and agricultural area rapidly increased from 15.58% to 26.16%. In Sile – Elgo, rangeland was declined from 36.31% to 16.68%, and the agricultural area was increased from 14.35% to 42.7%. The conversion matrix result revealed the agricultural area experienced the highest gain between 1986 and 2019, in Baso – Shafe, and Sile – Elgo and contrary, forest and rangeland areas had shown the highest loss in Baso – Shafe, and Sile – Elgo catchments respectively between 1986 and 2019. NDVI value declined from 0.631 (1986) to 0.518 (2019) in Baso – Shafe and from 0.648 (1986) to 0.508 (2019) in Sile – Elgo catchments. The area covered with the lower dense vegetation was increased by 35.4% in Baso – Shafe and 29% in Sile – Elgo catchment. In Baso – Shafe, maximum LST was declined from 40.3o C in 1986 to 37.98o C in 2019, while in Sile – Elgo declined from 41.09o C in 1986 to 38.26o C in 2019. The statistical regression coefficient between LST and NDVI indicates a negative correlation. The LST result derived from Landsat 8 was verified by MODIS LST data and result shows both sensors value were close to each other. Among other LULC types, the barren area experienced maximum LST while forested and water bodies experienced low LST values. Therefore, to rehabilitate and restore the degraded ecosystem services, implementation of Landscape based sustainable land management strategies should need to halt from further land resources degradation.