Assessment of Soil Erosion Rates Using Revised Universal Soil Loss Equation (RUSLE) and GIS in Bačka (Serbia)

Pol. J. Environ. Stud. Vol. 30, No. 6 (2021), 5175-5184 DOI: 10.15244/pjoes/135617 ONLINE PUBLICATION DATE: 2021-09-01 Original Research Assessment of Soil Erosion Rates Using Revised Universal Soil Loss Equation (RUSLE) and GIS in Bačka (Serbia) Nikola Milentijević1, Miloš Ostojić2, Renata Fekete2, Kristina Kalkan2, Dušan Ristić1*, Nikola R. Bačević1, Vladica Stevanović1, Milana Pantelić2 1University of Priština in Kosovska Mitrovica, Faculty of Sciences and Mathematics, Department of Geography, Lole Ribara 29, 38220 Kosovska Mitrovica, Serbia 2University of Novi Sad, Faculty of Sciences, Department of Geography, Tourism and Hotel Management, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia Received: 20 January 2021 Accepted: 4 April 2021 Abstract Soil erosion assessment enables the identification of manifested soil erosion categories, their spatial distribution and the relationship between soil erosion and land use patterns. The integrated approach of the RUSLE method and GIS tools was used in estimating soil erosion rates in Bačka (Serbia). Previous research of soil erosion intensity in the study area was last performed 50 years ago. The spatial distribution of the calculated erosive factors shows the diversity of erosive conditions. The results indicate that the average annual soil loss is from 0 to 28.6 t ha–¹ yr–¹. The soil erosion is particularly pronounced in the area of the Titel loess plateau (up to 28.6 t ha–¹ yr–¹). The results indicate the diversity of the erosion rates depending on the land use. Multiple correlation indicates that the LS factor has the largest effect on erosion (correlation coefficient 1). The results in this paper can be used in planning future conservation measures, especially if the recent field measurements of soil erosion are added. This research is also important since the RUSLE method represents a new approach in determining the soil erosion intensity. Keywords: soil erosion, RUSLE and GIS, land use, conservation measures, Bačka Introduction problem that was recognized in the 1930s [1]. This process is in most cases caused by natural factors Soil erosion is a natural process that refers to the [2], although it can be accelerated by anthropogenic removal of the upper layers of the soil by the action of activities such as intensive agriculture, inadequate various erosive agents such as water, wind and gravity. land use, deforestation and tillage on steep slopes [3]. This phenomenon represents a serious environmental Agricultural land is particularly endangered, which records the loss of the fertile layer, more pronounced surface water runoff and reduction of water reserves used by vegetation [4]. It was estimated that 33% of land *e-mail: duš[email protected] 5176 Milentijević N., et al. worldwide is affected by land degradation (more than in environmental modeling [21]. Based on the DEM 4,900 million ha) [5]. The average global erosion rate model, the absolute heights of the terrain vary from is 2.4 t ha–¹ yr–¹, while this rate is lower at the national 61 m to 141 m (Fig. 1). The relief uniformity of the area level (~1.4 t ha–¹ yr–¹) [6]. The potential increase in is mostly disturbed by the Subotica-Horgoš sandstone global soil erosion rate is caused by the expansion of (north of Subotica, Palić and Horgoš, extending deep arable land. The largest increases in erosion intensity into Hungary towards the north). On the territory are predicted for sub-Saharan Africa, South America, of Bačka, its absolute height ranges from 100 m to and Southeast Asia [7]. 141 m. The area of Bačka is 8,956 km2 [22], while The first systematic observations of erosive the area obtained by vectorization using GIS tools is processes in Bačka were performed by R. Lazarević a research area of 8,786.23 km2 with 990,364 inhabitants from 1966 to 1971. Although in AP Vojvodina erodible [23]. Bačka represents a significant agricultural region terrains occupy 72.29% of the territory, the erosive of Autonomous Province of Vojvodina and the Republic process mainly belongs to the category of very slight of Serbia, with 591,332 ha (37.6%) of used agricultural erosion [8]. Based on the dominant geomorphological land and only 23,579 ha (1.5%) of unused agricultural agent, aeolian erosion is expressed in the north of land [24]. Bačka (Subotica-Horgoš sandstone) [9]; possible pluvial erosion can occur in the Pannonian Basin (including parts of Bačka) [10]; fluvial erosion is expressed on the Materials and Methods large border rivers of Bačka (Danube and Tisza), as well as larger rivers and their tributaries in Bačka [11]. RUSLE Method In recent years, the intensity of erosion of the Titel loess as a small part of Bačka has been investigated. It was A widely used model for estimating soil erosion determined that soil erosion is the dominant process, intensity is the RUSLE method, developed by the while the estimated values of soil loss ranged from Department of Agriculture (USA) for the purpose of −1.58 t ha−1 yr−1 to −10.60 t ha−1 yr−1, which classifies the soil conservation and land-use planning. This method erosive process as moderate [12]. is a modification of the USLE method most commonly Numerous widespread and popular empirical models used to predict the average rate of agricultural land have been developed that serve to assess the intensity loss. The RUSLE method is often used to assess of erosion: Erosion Potential Method – EPM [13], The the average soil erosion, which demands the set of Universal Soil Loss Equation – USLE [14], Modified proposed measures in order to control the erosion Universal Soil Loss Equation – MUSLE [15] and intensity in different land uses [25]. The disadvantages Revised Universal Soil Loss Equation – RUSLE [16]. of the RUSLE empirical model are presented through The RUSLE method is suitable for determining the several problems: a) poor availability of reliable long- rate of erosion in agricultural regions of lowland type term modeling data; b) inability to take into account such as Bačka with a slope ranging from 3 to 18% [17]. soil erosion originating from gullies and transported The subject of this paper is an integrated approach of eroded material; d) prediction of potential sediment RUSLE method and GIS techniques in estimating the deposition [26]. Despite its disadvantages, the RUSLE rates of soil erosion in Bačka (Serbia). The intensity method [27] remains a popular tool for determining the of soil erosion in Bačka was estimated by the EPM intensity of soil erosion due to the simple data entry and method [18] but not yet by applying the RUSLE method. the simple model structure. The ArcGIS 10.7 software With this approach, it is possible in future research to was used to generate maps using the RUSLE method. compare the results obtained using the RUSLE method The integration of the RUSLE method with the GIS with the EPM method [19]. This fact has importance tool aims to more efficiently predict the intensity of soil since the field research of soil erosion in the study area erosion and its spatial distribution. The RUSLE method dates back to 1970’s [8]. is represented by the Eq. 1 [28]; (Fig. 2): Bačka is located in the southern part of the Pannonian Plain and the northwestern part of the A = R * K * L * S * C * P (1) Autonomous Province of Vojvodina and the Republic of Serbia. The natural border of Bačka consists of ...where A – average annual soil loss per area unit (t ha−1 the rivers: the Tisza towards Banat (eastern border of yr−1), R – rainfall erosivity factor (MJ mm ha−1 h−1 yr−1), Bačka), the Danube towards Srem (southern border K – soil erodibility factor (t ha h MJ−1 mm−1), L – slope of Bačka) and the Danube towards the neighboring length factor, S – slope steepness factor, C – land use state of Croatia (partly in the south and west). The and P – support and conservation practices factor. border with Hungary belongs to artificial borders. This border intersects and connects the largest rivers of the Rainfall Erosivity Factor (R) Pannonian Plain - the Danube and the Tisza [20]. Digital elevation models (DEM) are mainly used in The recorded monthly precipitation values were geomorphological research, relief shape classification, used in order to determine the mean annual value of geomorphometry and represent a significant factor the R factor [29]. Data from available meteorological Assessment of Soil Erosion Rates Using Revised... 5177 Fig. 1. Location map of Bačka in the Republic of Serbia a), in Europe b) and Digital Elevation Model (DEM) of study area. Fig. 2. Flowchart of applied methodology. 5178 Milentijević N., et al. stations (Novi Sad, Sombor, Bečej and Palić) were used Table 1. Value of K based on soil texture with the assumption in order to determine the average values of the R factor that the organic matter content is <4%. and analyzed for a thirty-year period (1981-2010). The R Soil texture K value factor was determined based on the modified Fournier index (F). This index takes into account data on sand 0.02 monthly and annual precipitation as well as empirical loamy sand 0.04 formulas that indicate the relation between F and R sandy loam 0.13 (Eq. 2): loam 0.3 muddy loam 0.38 (2) mud 0.6 ...where, pi represents the monthly amount of sandy clay-loam 0.2 precipitation for the month i (mm), and P represents the annual precipitation (mm). An equation was proposed clay-loam 0.3 for determining the value of R [29] (Eq. 3): muddy clay-loam 0.32 sandy clay 0.14 R = 0.739 * F1.847 (3) muddy clay 0.26 The map of rainfall erosivity factor was obtained clay and compacted clay 0.22 using IDW (Inverse Distance Weighting) interpolation technique where unknown values were calculated based on the values of known points [30].

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