Distribution of Water Pollution SubBengawan Solo Upstream Watershed on Central Java in 2020

Abstract The Bengawan Solo watershed is included in the 15 priority watersheds that must be restored because it one of 108 critical Indonesia. It indicated Hulu sub-watershed experiencing pollution and water quality degradation due to population growth rate various community activities around area. This research was conducted study using a spatial approach Upper Central Java region. Pollution Index method Geographically Weighted Regression (GWR) modeling BOD, COD, TSS, TDS, DO Phosphate parameters. results carried out show 5 sample points are category light 8 moderately polluted. lowest index value 2. 87 at point 3 Samin River area, Karanganyar Regency. highest 7.5 9 Lower Premulung Surakarta City. GWR on dependent variable BOD has most significant effect. In TDS variables have effect each shows compared other variables.