Hamid Reza Matinfar; Fereydoun Sarmadian; Seyed Kazem Alavipanah
Volume 2, Issue 4 , January 2011, , Pages 211-220
Abstract
Soil salinity is one of the main increasing problems of the world. In the recent years application of remote sensing and GIS techniques in order to assess saline soils is used because they bring about vast uniform coverage of ground phenomena in a short time. The images of LISS III sensor of the Indian ...
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Soil salinity is one of the main increasing problems of the world. In the recent years application of remote sensing and GIS techniques in order to assess saline soils is used because they bring about vast uniform coverage of ground phenomena in a short time. The images of LISS III sensor of the Indian satellite (IRS) were used in this research. The Brightness index (BI) could discriminate highly saline soils from non –saline and the salinity index (SI) show high potential to separate very high, high and non- saline soils. Results of supervised classification without combination DEM and remote sensing data have overall accuracy of 76%, producer accuracy of 78% and user's accuracy of 82%. While in supervised classification combination of remotely sensed data and DEM have overall accuracy of 98.1% , producer accuracy of 98.28% and user's accuracy of 98.4% .The reason for low accuracy of the classification , before combination of remote sensing and topographic data , can be explained by highly moist saline soils spectral interference with non-saline soils (soil with 25 to 65% gravels) , but these two soils had different topographic condition with 200 meters elevation difference , thus , with combination of the DEM , this kind of area and other areas with similar conditions have been separated from each other.
Ali Mohammadi Torkashvand; Davood Nikkami; Mehrdad Esfandiari; Seyed Kazem Alavipanah
Volume 2, Issue 3 , October 2010, , Pages 150-160
Abstract
Rill erosion map is one of the basic maps in erosion and sediment studies and also watershed management programs. Some methodologies for preparing rill erosion map (1:250000) by using RS and GIS were compared in a research carried out in Kan-Sologhan and Jajrood sub-basins in North-west and North-east ...
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Rill erosion map is one of the basic maps in erosion and sediment studies and also watershed management programs. Some methodologies for preparing rill erosion map (1:250000) by using RS and GIS were compared in a research carried out in Kan-Sologhan and Jajrood sub-basins in North-west and North-east Tehran, Iran. At the first phase, four working units' maps were prepared by integration of a) plant cover, geology and slope b) land use, geology and slope c) land use, rocks sensitivity to erosion and slope and d) land use, rocks sensitivity to erosion and land units’ layers in Kan-Sologhan basin. For comparing the efficiency of four working units’ maps, 53 ground control points were investigated. Results showed that map "d" was better than "a", "b" and "c" in providing rill erosion regarding economic and executive considerations. At the second stage, map "d" was compared with three maps of e) land units f) rocks sensitivity to erosion and g) satellite image photomorphic units (ETM+ images) in a broader basin of Jajroud. Rill erosion intensities in 314 ground control points were controlled and ground truth rill erosion map was prepared. Rill erosion map was crossed with different working unit maps where results showed that the highest accuracy is related to the images interpretation (81.0% accuracy). Accuracy was 78.4, 66.8 and 59.9 percent for methods of "d", "e" and "f", respectively. Root Mean Squared Error was the highest for map "f" and the least for integrated layers method (map "d"). The greatest precision is related to image interpretation and the images interpretation method is better than other methods in preparation of rill erosion map.
