Predicting the impact of land-use changes on soil erosion rates in three small sub-catchments of Larona Catchment
Mahmud Achmad (a), Samsuar (a), Mahatma Lanuru (b), Husnul Mubarak (a)

(a)Department of Agricultural Engineering Faculty of Agriculture, UNHAS, Jl. Perintis Kemerdekaan KM 10 Makassar 90245, Indonesia
(b) Department of Marine Science Faculty of Marine Sciences and Fisheries, UNHAS, Jl. Perintis Kemerdekaan KM 10 Makassar 90245, Indonesia

Abstract

This study aims to predict the amount of soil erosion in the three sub-catchments of Larona Catchment which are Larona, Balambano, and Karebbe sub-catchments. The USLE method is used to predict soil erosion rates in the year of 2009 and 2015 by using rainfall data of 13 rainfall stations, soil maps, DEM data for generating LS factors, Landsat 8 Images, and land use maps to create CP factors. Four thematic maps (R, K, LS, and CP) were overlaid and clustered using ArcGIS 10.4. The results show that soil erosion rates in the period of 6 years have change in the three sub-catchments. Erosion rate in Larona sub-catchment slightly increased from 43.092 tons in 2009 to 50.982 tons in 2015. In Balambano and Karebbe sub-catchments, the value of erosion rate increased dramatically during the period. Total erosion for both sub-catchments in 2015 become 5 to 7 times of the total erosion in the year of 2009. The increased sediment yields in the three cascade-reservoirs in Larona Catchment were caused by the change of land-use and land cover which are mostly the result of increasing agricultural activities and not only as a result of mining development.

Keywords: land-use change, Larona Catchment, soil erosion, USLE

Topic: Geospatial Agriculture