Changes in Runoff Coefficient Index as a Result of Land Use Change (Case Study: Malang City)

Abstract

The result of this research is to present observations about changes in the value of the conveyance coefficient in an area or region caused by changes in land use as a basis for decision making for water resources management in urban areas, by considering field data and satellite image classification to observe changes. As well as the consequences of the development of an area as seen from population growth, economy and housing needs. Malang City continues to experience land use change as evidenced by the decrease in agricultural land area. The method used is supervised classification with the help of geographic information systems and analyzing land use change over the past 20 years through map overlay. The data used are Landsat and Terrasar-X satellite images with the land use classes used are open land, settlements, agriculture, and shrubs. Satellite images were classified to analyze the extent of land use change and to see the rate of change in the conveyance coefficient of each class over the past 20 years. The results show that the study area has a change in the value of the conveyance coefficient caused by a fairly high land use change from agricultural land to built-up land such as settlements or housing. Malang City has a tendency to increase the population significantly because it is an educational city that continues to need a place to live and allows the rotation of various economic needs. The results of the analysis showed that there were changes in the value of the conveyance coefficient from 2002 to 2022, with an upward trend. In 2002 the C value was 0.2468; in 2007 it was 0.2899; in 2012 it was 0.3457; in 2017 it was 0.3895; in 2022 it was 0.4119. With an average value of change every year is about 13.78%.