Using Landsat to track land use and land cover (LULC) change from 1970 to 2020 in Mayang watershed, East Jawa

Abstract

Land use and land cover (LULC) and climate change (CC) will determine the dominant effect of the hydrological processes on the watershed. The two phenomena may alter hydrological processes on the watershed. The impact may be observed as erosion, sedimentation, landslide, flood, or drought that more frequently occurs on significant magnitudes. The assessment of LULC change is a crucial step to managing our environment. In this context, the Landsat image is a well-suited satellite to analyse the LULC change already proved by many researchers worldwide. In this study, the Landsat images (dated from 1970 to 2020) were exploited as the primary input to calculate the LULC change in Mayang Watershed. The Mayang watershed (1,110.14 km2) covers about 33% of the Jember regency. This watershed subject to regular floods and drought during the last decades. This study use landsat 1 MSS, Landsat 5 TM, Landsat 7 ETM+, Landsat 8 OLI/TIRS captured from 1972 to 2020 as main input. The images data are processed using the procedure of image treatment using open-source image processing software. In this case, the well-known pixel-based classification algorithm (i.e., Gaussian maximum likelihood classification) applies to produce LULC maps of 1972, 1997, 2002, 2017, and 2020. The LULC change is analysed by comparing the area extent of eight LULC classes (i.e., built-up (pavement) areas; paddy field; heterogeneous agricultural land; Dense vegetation; sparse vegetation; barre land/sand/rock; shrubland; and water body. The results show that the pavement area change slightly increased from 1972 to 1997, and then exponentially increased from 1997 to 2020 by 7,5% per year. The rapid change in pavement areas shows how human activities have influenced the watershed during the last 30 years. This rapid change also affects significantly the area occupied for paddy fields and decreases proportionally the area occupied for heterogeneous agricultural land.