Using Geographic Information Systems and the Analytical Hierarchy Process for Delineating Erosion-Induced Land Degradation in the Middle Citarum Sub-Watershed, Indonesia

Abstract

Land degradation (LD) is an important issue worldwide because it affects food production and people’s welfare. Many factors cause land degradation, but in humid tropical areas, erosion is the main factor. More than 100 countries including Indonesia are affected by LD. Watershed management should be prioritized owing to budget constraints, while on the other side, the area affected by LD is very large compared to the size of the existing land area. The middle Citarum sub-watershed (MCSW) is one of the most degraded drylands in Indonesia, where the environment can be considered a typical humid tropical watershed. The objective of this study was to map degraded lands and prioritize restoration using a combined approach of the universal soil loss equation (USLE), the analytical hierarchy process (AHP) and geographic information systems (GIS) in a multiple-criteria decision analysis (MCDA) environment. The severity of LD was estimated quantitatively by analyzing the parameters of land use and land cover, slope, soil erosion, productivity, and management. The results indicated that the MCSW is dominated by the potentially degraded land classes (38%), followed by the degraded land classes (21%). The prioritization of LD restoration is suggested in the area of very high and high degraded land. The method developed in this research work could be adopted as a tool to guide decision-makers toward sustainable land resource management in humid tropical watersheds affected by LD.

Estimated sediment exports and erosion in Central Citarum watershed

“…Judging from the level of erosion that occurs between 1.77 -284 tons/ha/year, the erosion conditions in central Citarum are equivalent to Adimihardja's research [15], which ranges from 35 to 220 tons/ha/year, which is the amount of erosion that occurs in the territory of Indonesia. Referring Ambarwulan's research [16] showed that the erosion class was smaller than the findings of Ambarwulan's research in the Middle Citarum watershed, where the erosion ranged from 0.87 to 495.30 tons/ha/years, which has a broader study area, thus enabling higher erosion values, which is derived from differences in land cover and a more diverse class of slopes…”

Mapping The Landslide Risk in Kulon Progo, Indonesia Using GeoTOPSIS

“…• Determine the positive ideal solution matrix and negative ideal solution Positive ideal solution matrix 𝐴 + calculated using Equation (11) with the rule of an attribute using Equation (13). Otherwise, the negative ideal solution is calculated using Equation ( 12) and the rule of Equation (14).…”

“…It is a valuable aspect of disaster risk analysis that indicators can continually develop. The integration of MCDA and the geographic information system (GIS) has widely been used in planning and environmental management [11]. The GeoTOPSIS MCDA module serves the integration of MCDA and GIS.…”

Application of spatial environmental indicators in the assessment of degradation potential of water resources in water basins

“…Many scienti c works employ approaches that make use of geotechnologies, such as geographic information systems and remote sensing, as an integrated tool for different types of geographic studies and methodologies (El Jazouli et al, 2017; Ambarwulan et al, 2021). Among these studies, different authors have used indicators and indexes as a tool for environmental analysis together with GIS, contributing with information on the state of degradation in water basins (Silva et al, 2022;Silva & Lima, 2017), and helping in the decision-making of public and private agencies.…”