# Soil Erosion Assessment and Prediction in Urban Landscapes: A New G2 Model Approach
## 1 Introduction  
Erosion is one of the most important contemporary problems of soil degradation and a significant factor endangering the environment all around the world [1]. Soil erosion and the consequent production of erosion material are affected by time-static, conditionally invariant parameters, such as relief characteristics, geological and pedological properties, and also time-dynamic (variable) parameters: climate, hydrological environmental conditions, groundwater oscillations, land use, land cover, etc. [2, 3, 4]. With the development of anthropogenic systems, through the processes of urbanization and inadequate use of natural resources, the process of soil erosion has been intensified in various structural and functional entities [5, 6, 7]. It is estimated that about two billion hectares of the total area in the world are affected by soil erosion as a result of human activities [8, 9]. According to some research, about 450,000,000 ha arable land in the world was found to be unproductiveuntil the mid-1990s, and it is estimated that 10 million ha of arable land is lost each year due to soil erosion [10; 11]. Population growth and rapid expansion of urban functions have resulted in changes in land use and land cover structures, leading to the transformation of agricultural, as well natural and semi-natural areas [12], into non-porous areas. In Europe, 2% of agricultural land is lost due to urbanization every ten years [13]. These processes of modification of urban landscapes have resulted in the development of erosion processes of different types, which under the conditions of changed climatic parameters, have become one of the main catalysts for the occurrence of torrential floods [14]. One of the most important environmental problems related to the trifecta of impacts of urbanization--soil erosion--torrential floods, is the negative impact on the quality, quantity and spatial distribution of soil and water resources [15]. Changes related to the infiltration and retention capacity of soil directly affect the amount and intensity of erosion and the generation of surface runoff [16; 17]. In addition to being affected by the frequency and intensity of natural disasters, environmental risks in urban areas escalate due to population growth and the impacts of socio-economic activities on land use and land cover [18]. Modeling methodologies are of great importance for understanding these processes and the impacts of various factors on the occurrence, genesis, and intensity of erosion [19], as well as on the prediction of erosion material production [20; 21; 22]. However, the application of these methods has advantages and disadvantages. First of all, modeling has a certain degree of uncertainty that is related to the quality of the used input data, which is necessary for the application of a certain model. On the other hand, modeling methods have a wide range of applications in the calculation of erosion production under the impact of climate change and/or changes in land use and the resulting changes in land cover [23; 24]. In spatially and temporally dynamic systems, the application of modeling methods allows more expeditious and trustworthy conclusions about the causes of erosion processes [25; 26]. Contemporary cities are areas with the most pronounced dynamics of change in the relationship between urban areas, on the one hand, and the surrounding natural and semi-natural elements, as well as agricultural areas, on the other hand. In the urban context, the application of modeling methods is the only justified set of instruments that allows precise and exact assessment, as well as the prediction of the erosion process, which is of great importance for the sustainable development of contemporary urban areas [11; 15]. In order to investigate different approaches, the modeling of soil erosion, sediment production and identification of erosion areas, as well as hazard zones, will be applied to the territory of the urban landscape of Belgrade City, i.e., the territory of the Master Plan of Belgrade (MPB).