Assessment of the Space-Time Dynamics of Soil Salinity in Irrigated Areas Under Climate Change: a Case Study in Sirdarya Province, Uzbekistan

摘要

Saline areas are progressively increasing in irrigated lands of the Aral Sea Basin and this obstructs intensive agricultural development and food security in this region. Such circumstances, leading to the expansion of salt-affected areas, are assumed to become climate change, rising of groundwater levels and its mineralizations, poor functioning of the collector-drainage system, and insufficient compliance with agro-technical requirements. These drivers, in turn, lead to the withdrawal of arable land for agricultural purposes and a significant drop in crop yields. Regarding Uzbekistan, this research on soil salinity assessment was conducted in the irrigated areas of the Sirdarya province by analyzing raw data derived from traditional methods from 2000 to 2015, as well as from 2016 to 2019, using the integrated traditional and geographic information systems (GIS)-based methods. Soil salinity maps of the Sirdarya province were created to investigate spatial and temporal changes in soil salinity using the inverse distance weighting (IDW) interpolation method based on the results of field survey and laboratory studies. The results of this research revealed that the IDW interpolation method had a great potential and accuracy to map longitudinal changes in salt-affected irrigated areas. Moreover, it was determined that soil salinity highly depends on local terrain conditions and there is a weak dependence on climatic factors. The main findings of this research advocate agricultural specialists and local farmers to get distinctly encouraged to take the following measures to address the actual soil salinity state in the irrigated areas of the province: targeted and economic use of irrigation water; existing drainage networks are in perfect working condition and monitoring their full effective operation; and, lastly, accelerating the integration of innovative GIS technologies into traditional methods.