Erosion Assessment Modeling Using the Sateec Gis Model on the Prislop Catchment

The Sediment Assessment Tool for Effective Erosion Control (SATEEC) acts as an extension for ArcView GIS 3, with easy to use commands. The erosion assessment is divided into two modules that consist of Universal Soil Loss Equation (USLE) for sheet/rill erosion and the nLS/USPED modeling for gully head erosion. The SATEEC erosion modules can be successfully implemented for areas where sheet, rill and gully erosion occurs, such as the Prislop Catchment. The enhanced SATEEC system does not require experienced GIS users to operate the system therefore it is suitable for local authorities and/or students not so familiar with erosion modeling. Introduction Accelerated soil erosion is a serious concern worldwide, and it is difficult to assess its economic and environmental impacts accurately because of its extent, magnitude, rate, and complex processes associated with it. Many human-induced activities, such as mining, construction, and agricultural activities, disturb land surfaces, resulting in accelerated erosion. To estimate soil erosion and to develop optimal soil erosion management plans, many erosion models, such as Universal Soil Loss Equation (USLE) (Wischmeier and Smith, 1978), Water Erosion Prediction Project (WEPP) (Flanagan and Nearing, 1995), Soil and Water Assessment Tool (SWAT) (Arnold et al., 1998), and European Soil Erosion Model (EUROSEM) (Morgan et al., 1998), have been developed and used over the years. The Sediment Assessment Tool for Effective Erosion Control (SATEEC) system was developed in 2003 (Lim et al., 2003) and has been upgraded with various enhanced modules incorporated into the system (Lim et al., 2005; Park et 1 PhD Student, West University of Timisoara, Geography Department, nasui@ubm.ro 2 Technical University of Cluj Napoca, North University Center of Baia Mare, gheorghe.damian@ubm.ro Gheorghe Damian, Daniel Năsui, Floarea Damian, Dan Ciurte 218 al., 2010). The system requiring only USLE inputs was developed with the philosophy of “very limited dataset for reasonable soil erosion estimation accuracy with commonly available GIS interface” and “easy-to-use”. 1. Study site The Prislop Valley Catchment is located north of the Somesan Plateau (fig. 1). Over 60% of its surface is characterized by steep slopes covered with forest, while less than 40% is given by gentle slopes covered by arable land, orchards and meadows. Fig. 1 Location of the Prislop Valley Catchment The catchment has an area of 15 square kilometers, with altitudes varying between 240 m and 608 m. The GIS database was made by digitizing the 1:5.000 scale topographic maps, the 1:5.000 aerial photographs, and by collecting and analyzing 14 soil samples. All the resulting maps have a 10 meter resolution, for a high accuracy modeling. 2. USLE input data & maps The USLE equation factors are generated by the digital elevation model – (fig. 2) which gives the LS factor (fig. 3), the soil texture (Table 1) which gives the K factor (fig. 4), the land use map (Table 2) for C factor (fig. 5), the precipitation distribution map (R factor) and the erosion management practices map (P factor). Erosion assessment modeling using SATEEC GIS model on Prislop catchment 219 Because of its constancy, the R factor has a value of 100 MJ.mm/ha.hr.year, while the lack of erosion management practices gives the P factor a value of 1. Fig. 2 The Digital Elevation Model Fig. 3 The LS Factor Table 1 – Soil texture Soil texture USLE K factor Sand 0.02 Sandy loam 0.13 Silty clay 0.26 Silty clay loam 0.3 Loam 0.3