Geoinformation landscape and geographical mapping of lake-basin systems within the recreational and tourist direction of nature use

Recreational nature use on and near water bodies has recently become increasingly popular among people who want to receive ecosystem services. This type of recreation includes beach vacations, swimming, recreational fishing, boating, kayaking, scuba diving, and other types of recreation. Lakes are especially attractive in this regard. They occupy a prominent place in the landscape structure and economic complex of the Polissia region of Ukraine. From the point of view of landscape and ecological functioning and spatial development of territorial communities (TC), it is appropriate to consider these reservoirs as lake-basin systems. During the development of strategic plans and spatial development models of TC around lake-basin systems (LBS), natural economic cores with the appropriate direction (or specialization) of nature use can be formed. In view of the above, the urgent problem is the landscape-geographical assessment of LBS within TC as operational units of nature management and GIS-mapping of aquatic complexes and their catchment areas. The purpose of the article is to substantiate the idea of developing a digital landscape-geographic model of a LBS (based on the example of Lake Velyshche) as an object of recreational and touristic nature use. Taking into account the results of the field landscape-geographic research, including echo sounding of the reservoir, analysis of a number of space images of the LBS of Lake Velyshche, and a digital relief model created with the QGIS package, a digital bathymetric map of the lake basin was developed, the main hydrological parameters of the lake were calculated, and a landscape map of the natural-aquatic complex and a digital model of the catchment area structure were built. The catchment area is 1.27 km2, and the lake area is 0.19 km2. The maximum depth of the reservoir is 10.7 m, and the average is 4.9 m. The length of the lake is 0.59 km, the maximum width is 0.37 km, and the average is 0.32 km. The volume of water masses is 790,000 m3. The nature-aquatic complex (NAC) of Lake Velyshche includes littoral-sublittoral (8.78 ha) and deep-water (9.80 ha) aquatic sub-tracts and six types of aquafacies. Forests occupy 39.43% of the catchment area, arable land – 18.04%, lake – 14.6%, meadows and other non-cultivable land – 13.17%, land under agricultural farms – 6.58%, roads – 2.36%, residential land – 1.94%, fallow land – 1.89%, wetlands – 1.19 %, ponds – 0.55%, open sands – 0.25%. The ratio of anthropogenically transformed land (ATL) to ecologically stable land (ESL) is as follows: ATL – 29.46% and ESL – 70.54%. The coefficient of anthropogenic load on the catchment area (average degree of development of the LBS) is 0.42. The research established that 41.23% of the volume of the lake basin is filled with sapropel deposits, primarily of organic-limestone composition, which has the potential for the development of peloid therapy. The hydrological parameters of the lake are favorable for swimming, diving, snorkeling, boating, recreational fishing, etc. For the further development of recreational activities, the local self-government bodies of the TC should take into account the geo-ecological features of land use within the LBS, the landscape-ecological condition of the NAC and the degree of anthropogenic load on the near-terrace water complexes of the catchment area.