Soil salinization monitoring method evolution at various spatial and temporal scales in arid context: a review

Abstract

All across the world, and particularly in arid and semi-arid zones, the negative effects of agricultural productivity and unsustainable development have led to soil salinization, which is one of the critical environmental issues. Since the problem of salinization evolves at the scale of space and time, it is necessary to develop a comprehensive strategy for the sustainable development of irrigated areas. First, it is required to adopt a good evaluation of the spatiotemporal distribution. Several approaches and techniques have been developed to study this distribution under the effect of several natural and anthropogenic factors. The result gives emphasis to the techniques used for predicting and monitoring soil salinity throughout different regions in the world. There are two categories of laboratory methods: destructive methods and non-destructive methods. The field methods are non-destructive unless we keep the need to dig holes for instrumentation or sampling for the calibration of measurements and the validation of results. However, we can distinguish between fixed instruments (point method) and mobile instruments (spatial method) which were used for different purposes. Toward the late 1980s, several works have been undertaken in order to understand the spatial and temporal variabilities of soil salinity. There are methods of geophysical prospection and geostatistical analysis. The combination of these two methods remains effective until today. The latest results show that spatial methods were better than punctual methods. Also, there was a complementarity between digital mapping approaches and geophysical techniques for monitoring the spatiotemporal variation of soil salinity.