A Spatiotemporal Analysis of Water Quality and Land Use in Tambayakbayan River, Yogyakarta

Abstract The Special Region of Yogyakarta is one of the areas that experienced a fairly high population growth rate and is directly proportional to the rate of development which has an impact on land use, especially in Tambakbayan watershed. This study aims to identify the types of land use that affected water quality of the Tambakbayan River using spatiotemporal analysis and Pearson correlation methods. Land use in Tambakbayan watershed is divided into three segments which are vegetation (VA), agriculture (AG), and building (BU). This study used water quality data from the Environmental Agency of Yogyakarta Province which consists of 14 parameters, i.e., pH, TDS, TSS, DO, BOD, COD, nitrate, nitrite, total phosphate, Zn, Cu, Pb, E. coli, and total coli. Landsat 8 image data from 2013 to 2020 is used from USGS. The result of this study found that vegetation has no correlation on Tambakbayan River water quality. However, agriculture and building areas significantly affected the decreasing water quality of the Tambakbayan River.