Quantitative Assessment of Desertification Intensity Indices in the Agricultural Lands of Dargaz Plain, Khorasan Razavi Province

Abstract

The purpose of this study was to assess the effects of agricultural development on increasing the intensity of desertification in Dargaz plain in northern Khorasan Razavi province. The intensity of desertification caused by agricultural development, using important criteria that is mainly related to human activities, such as groundwater, irrigation and drainage, agriculture, soil, industrial-urban development, and socio-economic criteria, in 20 years period from 1996 to 2016, were estimated using IMDPA model. Desertification intensity of Dargaz plain was classified into moderate and severe classes with frequency of 22% and 78%, respectively. Therfore, the irrigation and drainage criterion were the most important human factor in increasing of desertification intensity in this region. Then, soil criteria, agricultural development, urban-industrial development, socio-economic factors, and finally, quantitative and qualitative degradation of groundwater, respectively, had the most effective role in increasing the intensity of desertification in the agricultural land of Dargaz plain. Results showed that the increase of salinity in the eastern and northeastern parts of the region due to irrigation with salt water and the conversion of range and forest into agricultural and residential with an area of more than 7000 hectares over the past 10 years were the most important factors of increasing the intensity of desertification in this region. Therefore, to prevent extending of desertification, sustainable land management and preventing of land use change were suggested.

Keywords

• irrigation efficiency
• land degradation
• soil salinity
• land use change
• agricultural development