Remote sensing approaches and mapping methods for monitoring soil salinity under different climate regimes

摘要

Soil salinizationis one of the severe land-degradation problems due to its adverse effects onland productivity. Each year several hectares of lands are degraded due toprimary or secondary soil salinization, and as a result, it is becoming a majoreconomic and environmental concern in different countries.? Spatio-temporal mapping of soil salinity istherefore important to support decision-making procedures for lessening adverseeffects of land degradation due to the salinization. In that sense, satellite-basedtechnologies provide cost effective, fast, qualitative and quantitative spatialinformation on saline soils. ?The mainobjective of this work is to highlight the recent remote sensing (RS) data andmethods to assess soil salinity that is a worldwide problem. In addition, thisstudy indicates potential linkages between salt-affected land and theprevailing climatic conditions of the case study areas being examined. Web of Scienceengine is used for selecting relevant articles. "Soil salinity" isused as the main keyword for finding "articles" that are publishedfrom January 1, 2007 up to April 30, 2018. Then, 3 keywords; "remotesensing", "satellite" and "aerial" were used to filterthe articles. After that, 100 case studies from 27 different countries wereselected. Remote sensing based researches were further overviewed regarding totheir location, spatial extent, climate regime, remotely sensed data type,mapping methods, sensing approaches together with the reason of salinity foreach case study. In addition, soil salinity mapping methods were examined topresent the development of different RS based methods with time. Studies areshown on the K?ppen-Geiger climate classification map. Analysis of the mapillustrates that 63% of the selected case study areas belong to arid andsemi-arid regions. This finding corresponds to soil characteristics of aridregions that are more susceptible to salinization due to extreme temperature,high evaporation rates and low precipitation.