SPATIAL AND TEMPORAL PATTERN OF SOIL CONSERVATION IN MOUNTAIN ECOSYSTEM: CASE STUDY OF PATUHA MOUNTAIN, WEST JAVA - INDONESIA

Abstract

The Patuha Mountain area located 50 km south of Bandung City and the upstream of the longest river in West Java, The Citarum River. 12% of the Patuha Mountain area categorized as the steep slope area (>25o). Agriculture and plantations on steep slope locations require appropriate soil conservation methods to reduce erosion rates and avoid the threat of landslides. Land use in The Patuha Mountain area dominated by tea plantations, paddy fields, and various agricultural commodities such as coffee, corn, scallion, and beans. The objective of this study is to identify the spatial and temporal patterns of soil conservation applied by farmers from 1990 to 2018 and project it to 2036 to understand the possible impact in the future. The scenario used in the analysis is the Business as Usual (BAU) scenario. The method used to model the changes in agricultural land use is Cellular Automata - Markov Chain by various driving factors, such as distance from the road, river, settlements, forests, and percent slope. The slope and other driving factors are then correlated with agriculture land to identify soil conservation methods and later validated by field survey. The results indicate that the spatial pattern of soil conservation methods carried out by the community is closely related to slope conditions and the changes in agricultural land caused by development pressure and type of commodities planted by farmers. Agricultural land on <15% slope adopt chemical and vegetative conservation methods, while agricultural land on >40% slopes adopts mechanical, vegetative, and chemical conservation method.