ORIGINAL ARTICLE Estimation of soil erosion using RUSLE in a GIS framework: a case study in the Buyukcekmece Lake watershed, northwest Turkey Ali Demirci • Ahmet Karaburun Received: 12 July 2010 / Accepted: 8 August 2011 / Published online: 23 August 2011 Ó Springer-Verlag 2011 Abstract This study was aimed at predicting soil erosion risk in the Buyukcekmece Lake watershed located in the western part of Istanbul, Turkey, by using Revised Uni- versal Soil Loss Equation (RUSLE) model in a GIS framework. The factors used in RUSLE were computed by using different data obtained or produced from meteoro- logical station, soil surveys, topographic maps, and satellite images. The RUSLE factors were represented by raster layers in a GIS environment and then multiplied together to estimate the soil erosion rate in the study area using spatial analyst tool of ArcGIS 9.3. In the study, soil loss rate below 1 t/ha/year was defined as low erosion, while those [ 10 t/ha/year were defined as severe erosion. The values between low and severe erosion were further classified as slight, moderate, and high erosion areas. The study pro- vided a reliable prediction of soil erosion rates and delin- eation of erosion-prone areas within the watershed. As the study revealed, soil erosion risk is low in more than half of the study area (54%) with soil loss \ 1 t/ha/year. Around one-fifth of the study area (19%) has slight erosion risk with values between 1 and 3 t/ha/year. Only 11% of the study area was found to be under high erosion risk with soil loss between 5 and 10 t/ha/year. The severe erosion risk is seen only in 5% of the study area with soil loss more than 10 t/ha/year. As the study revealed, nearly half of the Buyukcekmece Lake watershed requires implementation of effective soil conservation measures to reduce soil erosion risk. Keywords RUSLE  Soil erosion  GIS  Buyukcekmece Introduction Soil erosion is a complex dynamic process that involves detachment, transportation, and accumulation of produc- tive surface soil across the earth’s surface (Jain et al. 2001). Wind and water are the main agents of erosion causing soil particles to move down a hill. Loose soils can be blown away from flat or hilly terrain by high winds (Kouli et al. 2009), while water wear down earth materials by mainly rill and interrill erosion. Rill erosion is the detachment and transportation of soil particles by concentrated surface water flow, while interrill erosion occurs by raindrops accompanied by shallow overland flow (Beskow et al. 2009). Soil erosion contributes to shaping of landscapes and fertilization of soil in flood plains if it occurs naturally and slowly. However, it becomes a destructive process when it is exacerbated by a number of anthropogenic fac- tors such as deforestation, overgrazing, incorrect methods of tillage and unscientific agricultural practices (Lal 2003; Zhou and Wu 2008). The average amount of soil loss from natural erosion is around 0.1–1 t/ha/year; however, the soil loss becomes 10–1,000 times faster when erosion is exac- erbated by human activities (Plan Bleu 2003). Soil erosion has always been a problem for human beings throughout history. It has caused some civilizations, such as the Lydian kingdom in the Mediterranean region, to collapse in the past (Lal 2001). Unprecedented increases in soil loss and its economic and environmental impacts have made erosion one of the most serious global problems of the day (Bewket and Teferi 2009; Wang et al. 2009; Zhang et al. 2009). Soil erosion, especially by water, constitutes serious problems in watersheds by eroding A. Demirci (&)  A. Karaburun Department of Geography, Fatih University, 34500 Buyukcekmece, Istanbul, Turkey e-mail: ademirci@fatih.edu.tr A. Karaburun e-mail: akaraburun@fatih.edu.tr 123 Environ Earth Sci (2012) 66:903–913 DOI 10.1007/s12665-011-1300-9