Effects of Land Cover Change and Deforestation on Rainfall and Surface Temperature in New Capital City of Indonesia

Abstract

Land cover change and deforestation have a significant impact on climate change. This study investigates the effect of land cover change and deforestation on surface temperatures and extreme rainfall in the New Capital City of Indonesia (IKN), particularly in Samboja and Sepaku Subdistricts, East Kalimantan Province. Land cover change and deforestation were analyzed from Landsat 5 TM, 7 ETM+, and 8 OLI satellite data during 2001-2020. Land cover is divided into four classes: built-up land, water bodies, vegetation, and agricultural area. Rainfall data were obtained from the Integrated Multi-satellite Retrievals for GPM (IMERG) version 6 satellite, and extreme temperatures were taken from fifth-generation ECMWF reanalysis (ERA5) data. A significant decrease in vegetated land area is observed every year, followed by an increase in residential land and buildings (built-up area) and agricultural land. The highest rate of increase was observed in the area of ​​agricultural land. Such change is correlated with an increase in surface temperature in the IKN. The strongest correlation is shown by increased built-up area and agricultural land. The relationship between rainfall and land cover is weak, and the body of water shows a relatively strong relationship. The extreme number of very wet days (R95p), ​​consecutive dry days (CDD), and max 1-day precipitation (RX1day) rain index showed a decreasing trend during 2001-2020. However, the consecutive wet days (CWDs) index showed an increase. This needs to be a concern because consecutive precipitation extremes may cause more catastrophability than occasional extreme events.