Mapping and Analysis of Peatland Subsidence Using GIS: A Case Study of Karya Tani Village, Indonesia

Abstract

This study was conducted in Karya Tani Village, Kempas District, Indragiri Hilir Regency, an area where signs of peatland subsidence have become increasingly evident. Surface subsidence of peat is notably observable through the exposure of root systems in perennial vegetation, particularly on community-managed lands. Subsidence represents a serious environmental threat, serving as a key indicator of peatland degradation. Though gradual, this process can result in extensive ecological damage and, in extreme cases, the irreversible loss of land. Accordingly, mapping and analyzing subsidence rates using Geographic Information Systems (GIS) is crucial for assessing the spatial extent and severity of this phenomenon. Field observations were conducted to document subsidence indicators, which were primarily identified through mature coconut trees exhibiting exposed root systems above the soil surface. Data collection was carried out over a 30-day period, from October 27 to November 27, 2022, in Karya Tani Village. Subsidence rate mapping was performed using ArcGIS software, employing the Topo to Raster interpolation method for spatial analysis. The results indicate that subsidence rates in the study area range from 2.75 to 6.50 cm/year, with an average rate of 4.45 cm/year.