Protection against the harmful effects of water on the left bank terrace of the Lower Dnipro River

Abstract

Relevance of research. In the area of ​​irrigated agriculture, one of the most difficult as to developing flooding processes is the area of ​​terrace drift within the ancient delta of the Lower Dnieper in Kherson region. The terrace area is located on a flat area within a large drainless bowl about 40 km long and up to 5-10 km wide. On the surface of the bowl there are large drainless depressions (Chornyanske, Novomayatske, Podokalynivske, Tarasivske) and many small ones. The purpose of the work is to establish the patterns of developing flooding processes and substantiate a system of reliable protection of the territory against that in difficult natural and water conditions. Methods and objects of research. The research was conducted at the research and production site located near Tarasivka village, Oleshkiv district, Kherson region. The results of the research were based on the data of reconnaissance surveys, long-term observations on the depths of the groundwater table (GWT), precipitation, space images, etc. In addition, it was assumed that the area is considered to be flooded if the depth of the GWT exceeds the critical limit, which for the study region is defined as 2 m. Research results and main conclusions. In modern conditions, part of the village and adjacent lands are subject to constant groundwater flooding and periodically  surface water flooding. In the central part of the village, groundwater depths exceed the critically acceptable depth, which for the study region is defined as 2 m. The water and ecological situation in the village is significantly exacerbated in wet periods. Current development of flooding within the terrace requires the development and implementation of a more effective protection system. One of the important options for protecting the village territory is the construction of a horizontal drainage system, which is set up in the village and its surroundings. The depth of drainage is 3.0-3.2 m. The runoff is discharged into the North-Crimean Canal by means of a pressure pipeline. The surface drainage system should be represented by a network of trays and ditches arranged in the streets of the village and a collector, which provides self-flowing of excess water into an artificial reservoir - pond. Options for the reconstruction of the NCC, which provide for using the drainage capacity of the canal and the construction of a regional self-flowing reservoir, were addressed. The modernization of irrigation and drainage systems and implementation of the developed proposals will significantly increase the protection level of the ancient terrace of the Dnieper River against the harmful effects of water. The decision on a proposal is made on the basis of feasibility study.