Environmental monitoring of North-West Pre-Caspian liman lands using GIS technologies

Abstract

Liman irrigation is an effective irrigation method in arid conditions of the Russian Pre-Caspian, which includes the territory of the Republic of Kalmykia ensuring the rational use of local surface runoff and other types of water resources and serving a reliable source of cheap and quality fodder. Based on the existing experience and experimental data, the paper states methodological bases and regulations of the regional monitoring system of ecological-reclamation state of lands and phytocenoses within limans, which ensure effective control of such indicators as fertility level (content of humus, nitrogen, phosphorus, potassium and heavy metals in soil); degree of salinization and alkalinization (using a zonal scale that takes into account the level of resistance of phytocenoses within limans to these negative processes); water-physical and structural properties (particle-size distribution, density, field moisture capacity, etc.), as well as species composition of vegetation (using the developed zonal classification scale) and productivity level and quality composition of fodder. The system of local environmental monitoring of Small Captain – the key section of liman irrigation system – is considered as an example. Based on the results of satellite image processing, the areas of liman zones with different NDVI levels in the time interval from 1985 to 2019 are calculated. The dynamics of the NDVI change of the Small Captain liman plant cover is shown, reflecting the true degradation picture of liman irrigation land during the considered period of study.