Temporal monitoring of surface runoff using remote sensing in Pabelan watershed, Central Java.

In general, current spatial planning tends to focus on the need for land and its economic value. The land has a limited capacity while the need for land continues to increase. Numerous watersheds in Indonesia are enduring the impact of land changes due to exploitative land use. Changes in watershed conditions as a result of uncontrolled land expansion without regard to environmental aspects often lead to undesirable conditions, in addition the lack of consideration of environmental aspects can lead to various disasters. So that there is a need for spatial planning so that the fulfillment of land and space needs still pays attention to environmental aspects. This study aims to map the spatial distribution of surface runoff using remote sensing data in the Pabelan watershed and to describe the relationship between land cover changes and surface runoff in the watershed. Remote sensing is used to determine changes in land cover and surface runoff in this watershed. Analysis of land cover changes and mapping of the surface runoff area was carried out to describe the relationship between land cover changes and surface runoff. The method used in the surface runoff mapping was made using the Cook. The results of this study are in the form of land cover maps of the Pabelan watershed in different years, visualization maps of surface runoff, and the relationship between land cover changes and surface runoff. The results show that surface runoff in 2020 is still dominated by the same runoff class as the runoff class in 2009 and 2015, which is dominated by the normal class but has a different area. The normal class in 2020 has an area of 69,92 km2. In 2020, the normal class has the widest area compared to previous years. The low runoff class also has the most extensive area this year. In 2009 the low runoff class had an area of 0,27 km2, in 2015 it was 0,48 km2 while in 2020 it was 1,49 km2. The high runoff class in 2020 is the lowest compared to the previous year. In 2009 this high-class area was 46,12 km2, in 2015 it was 43,42 km2 and in 2020 it was only 40,46 km2. The extreme runoff class has the widest area this year. In 2009 the extreme runoff class was 0,23 km2, in 2015 it decreased to 0,17 km2, and in 2020 it was 0,36 km2. In this study, it can be concluded that land cover change is not a major factor in the formation of surface runoff. There is another factor, which can affect the surface runoff. [ABSTRACT FROM AUTHOR]