Determination of irrigation regimes based on geospatial technologies in water scarcity areas

Abstract

In the case of increasing water scarcity, determining the water demand of irrigated land is an important process. The water demand for irrigated lands and crops in the Republic of Uzbekistan is realized through nine hydromodular zones, which were developed regarding Bespolov’s methodology in the 1980s. However, in order to determine the water regime in each crop field, it is necessary to create electronic hydromodular zoning maps based on GIS technologies. This study uses GIS technology to create electronic hydromodular zoning maps of the irrigated fields in the Bukhara region of Uzbekistan while considering the mechanical properties of the soils and groundwater levels. Soil mechanical composition of the agricultural land’s geodatabase was created and mapped with three categories of soils: light, medium and heavy. Annually obtained data from observation wells was analysed to determine the distribution of groundwater level by Inverse Distance Weighting (IDW) interpolation method referenced detected coordinate values. The raster calculator function of ArcGIS is used to identify the distribution of hydro module zones by definite criteria of soil and groundwater level. As a result, hydromodular zoning maps of irrigated agricultural lands of the Bukhara region were created for the first time in electronic form.