Кількісна оцінка ерозійної небезпеки сільськогосподарських угідь

Abstract

The largest and practically non-renewable losses of erosion in all sectors of the economy undergoes agrarian sphere. The area of land damaged by water erosion in Ukraine reaches 33.3% or 13.3 million hectares, of which 4.5 million hectares are medium and strongly ground, of which 68 thousand hectares completely lost the humus horizon. The reasons for the acceleration of erosion processes in Ukraine are the mass ignoring of the simplest agrotechnical anti-erosion measures, the imperfection of the land management organization of the territory to provide elementary anti-erosion protection, underestimation of the role of wild forest belts, ineffective use of funds aimed at preventing erosion, resulting in degradation processes lately unprecedented. High degree of cultivation of agricultural land and excessive saturation of crop rotation with crop rotation against the background of non-compliance with the basic provisions of a set of measures to increase and maintain soil fertility is a direct way to the destruction of soil cover as a basis for the existence of life on our planet. The quantitative estimation of water erosion involves two systems of evaluation criteria: the actual soil erosion and the potential danger of erosion at a certain level of probability of the effects of erosion factors (the world experience in the organization of anti-erosion protection indicates that it is sufficient to calculate 10% security). To update the outdated data on soil erosion in Ukraine, it is necessary to conduct a repeated continuous survey of soil cover on a modern methodological basis, which requires significant financial costs. However, it is possible to assess the erosion hazard using mathematical models of erosion, in particular the Water Erosion Prediction Project (WEPP) model, which provides information on the intensity and tension of erosion processes and the determination of the magnitude of possible erosion losses in the soil. WEPP is a physically grounded model that allows the modeling of erosion processes of agricultural lands located on small water catchments (up to 250 hectares). The model is based on mathematical equations describing physical processes of soil erosion and hydrology of erosion runoff. In this case, the catchment area, according to its relief, is divided into elementary units - slopes and watercourses. The model allows you to trace the routes of drainage and flushing along the elements of the relief up to the exit of the catchment. Simulation can be carried out in two modes: in the mode of long-term modeling and in mode of modeling of a single shower. The input data for the model are data on the terrain, the characteristics of the catchment soil, types of cultivating soil and agricultural vegetation on its fields, parameters characterizing the climatic conditions of the terrain. Two series of forecast calculations were conducted: the first one was for the conditions of the existing land placement, the second one for the case of implementation of the project of soil protection of the territory. For this purpose, in both cases, the preferred lines of the drain lines were determined, for each runoff line, soil erosion loss calculation using the WEPP model was performed, after which regularization and interpolation of the obtained data were performed and erosion hazard maps for each case were constructed. Quantitative estimation of two series of forecast calculations for the conditions of existing land placement and in the case of implementation of the project of soil protection of the territory using WEPP erosion model and specialized software showed that in the event of a 10% rainstorming of equipment, the territory of forest bands and drainage facilities significantly reduces erosion danger, even in the black pair.