Remote Sensing Monitoring of Changes in Soil Salinity: A Case Study in Inner Mongolia, China.

Jingwei Wu,Alain Vidal,Sami Bouarfa,Jinzhong Yang,Bernard Vincent

doi:10.3390/s8117035

Abstract

This study used archived remote sensing images to depict the history of changes in soil salinity in the Hetao Irrigation District in Inner Mongolia, China, with the purpose of linking these changes with land and water management practices and to draw lessons for salinity control. Most data came from LANDSAT satellite images taken in 1973, 1977, 1988, 1991, 1996, 2001, and 2006. In these years salt-affected areas were detected using a normal supervised classification method. Corresponding cropped areas were detected from NVDI (Normalized Difference Vegetation Index) values using an unsupervised method. Field samples and agricultural statistics were used to estimate the accuracy of the classification. Historical data concerning irrigation/drainage and the groundwater table were used to analyze the relation between changes in soil salinity and land and water management practices. Results showed that: (1) the overall accuracy of remote sensing in detecting soil salinity was 90.2%, and in detecting cropped area, 98%; (2) the installation/innovation of the drainage system did help to control salinity; and (3) a low ratio of cropped land helped control salinity in the Hetao Irrigation District. These findings suggest that remote sensing is a useful tool to detect soil salinity and has potential in evaluating and improving land and water management practices.

Highlights

Soil salinization is the process of enrichment of a soil in soluble salts that results in the formation of a salt-affected soil [1]
Results showed that: (1) the overall accuracy of remote sensing in detecting soil salinity was 90.2%, and in detecting cropped area, 98%; (2) the installation/innovation of the drainage system did help to control salinity; and (3) a low ratio of cropped land helped control salinity in the Hetao Irrigation District. These findings suggest that remote sensing is a useful tool to detect soil salinity and has potential in evaluating and improving land and water management practices
Soil salinity seriously threatens the productivity of irrigated land and the livelihoods of the farmers who depend on the affected land [2]

Summary

Introduction

Soil salinization is the process of enrichment of a soil in soluble salts that results in the formation of a salt-affected soil [1]. It may occur naturally or as the result of poor management practices. Soil salinity seriously threatens the productivity of irrigated land and the livelihoods of the farmers who depend on the affected land [2]. It is estimated by IPTRID that 10% to 15% of irrigated areas suffer from varying degrees of salinization, that 0.5% to 1% of irrigated areas are lost each year, and that nearly half of all irrigated areas are threatened in the long-term [1]. The global cost of irrigation-induced salinity is estimated at US$11 billion per year [3]

Objectives

Methods

Results