Remote Sensing and GIS Applications in Environmental Sciences
Soil degradation mapping using a GIS based multi-criteria decision- analysis in Khoy County
Document Type : Original Article
Authors
1 urmia university
2 Department of Remote Sensing and GIS, Faculty of Planning and Environmental Sciences, University of Tabriz, Tabriz, Iran
Abstract
Nowadays, soil erosion is recognized as one of the greatest contemporary environmental and socio-economic problems because its significant agriculture, natural resources, the environment, and the social economy. The aim of this study is to zone the soil erosion risk in Khoy County. For this purpose, a land use map was first obtained using Landsat images and object-oriented classification techniques. In doing so, they were classified into respective classes including: agricultural lands, gardens and pastures, saline lands, residential lands, mountainous and barren lands, and weak vegetation cover. The next stage carried out, by identifying the factors affecting soil erosion in the region and preparing information of each factor in GIS environment. the standardization of the factors was carried out using the fuzzy membership function, the ranking method, and the weighting of the criteria using the ANP method using Super Decision software. the final modeling was done using the ANP multi-criteria analysis method. In the next step, the sensitivity analysis of the criteria was applied using training data. Then, by applying different stages of the model on the maps based on the GIS aggregation functions, the soil erosion sensitivity map of the area was developed in 4 classes with very high erosion to low erosion. The ANP analysis process method assigned the highest weight to the sixth criterion (distance from the watercourse) and the lowest weight to the second criterion (digital elevation model). According to the results and the erosion modelling map, the criteria of distance from the river, land use, and slope received the highest weight with weight values of 0.271, 0.25, and 0.197, respectively. It is observed that the largest area obtained from soil erosion modelling is related to the medium erosion class, which almost includes the classes of barren and mountains, pastures and some agricultural and garden lands. Considering the results obtained and the area of the very high and high erosion classes, it can be stated that, the Khoy County area has a very high potential in terms of environmental conditions in the region, including the abundance of waterways (the main river is the Qaturchay or Aland), as well as land uses in terms of erosion.
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