Evaluating the Efficacy of Channel Lining in Ameliorating Soil Salinization in Hetao Irrigation District Using Satellite Imageries

【Objective】 Most channels in Hetao irrigation district have been linned in attempts to reduce seepage and ameliorate soil salinization, but there is lack of understanding of its efficacy at district scales. This paper is to fill this knowledge gap using remote sensing technologies. 【Method】 The analysis was based on Landsat8 multispectral satellite imageries, and saline-alkali soils in the irrigation district were automatically extracted using the ISODATA clustering method. A buffer zone wide d on both sides of each channel was identified using a spatial analysis method, saline-alkali area and the salinization index (φ) in which were statistically analyzed. 【Result】 Saline-alkali soil area decreased significantly on both sides of the channel after the lining, and spatial distribution of the saline-alkali soils is in a trapezoid-shape. From 2013-2016, the salt-alkali soils within the 500m proximal to the channels had reduced from 49.63% to 86.81%, depending on locations, while within the 1 000 m and 1 500 m ad