Ali Khenamani; Hasan Fathizad; Mohamad Ali Hakimzadeh
Volume 25, Issue 4 , February 2019, , Pages 723-734
Abstract
Over the past decades, due to increased population and consequent increase in the need for food, we have seen extensive changes in land use, and in particular, the increase of agricultural lands. The aim of this study was to evaluate the changes in land use in the Bartash plain ...
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Over the past decades, due to increased population and consequent increase in the need for food, we have seen extensive changes in land use, and in particular, the increase of agricultural lands. The aim of this study was to evaluate the changes in land use in the Bartash plain in Dehloran city of Ilam province during 26 years from 1988 to 2014 using the object-oriented approach. To accomplish this research, the necessary corrections were made after the acquisition of Landsat TM (1988), ETM + (2001) and Landsat 8 (2014) satellite images, and then, using the object-oriented method, the land use map was prepared for the three time periods. The results of the evaluation of the accuracy of the produced maps show that the highest accuracy and Kappa coefficient with the values of 90 and 95% correspond to the image of 2001, and the lowest them with the value of 80 and 90% was related to the image of 1988. Total accuracy and Kappa coefficient in the image of 2014 with 90% and 92%, respectively show a good accuracy. The results of land use change trend showed that the land use of the fair rangeland had the most changes with a decrease of more than 21 thousand hectares. Agricultural lands are in the next place, showing an increase of over 15,000 hectares (twofold) that could be due to the increase in population and the availability of adequate water resources in this area. The land use of poor rangelands also shows an increasing trend of 1.5 fold, indicating the degradation of fair rangelands. The saline lands initially show an increasing trend but then show a decreasing trend due to converting to agricultural lands. The overall accuracy (900-90) and kappa coefficient (95-90) indicate the high accuracy of this method in determining the land use.
Hasan Fathi Zad; Rashid Fallah Shamsi; Ali Mahdavi; Saleh Arekhi
Volume 22, Issue 1 , June 2015, , Pages 59-72
Abstract
Rangelands are one of the most important renewable resources and because of their extent and economic, social and distinctive environmental impacts are of very special importance. Unfortunately, in our country, like most developing countries, rangelands have been exposed to degradation for various reasons ...
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Rangelands are one of the most important renewable resources and because of their extent and economic, social and distinctive environmental impacts are of very special importance. Unfortunately, in our country, like most developing countries, rangelands have been exposed to degradation for various reasons including the non-systematic management of these resources. Remote sensing technology and satellite data are useful tools in the studies of rangeland and vegetation sciences. One of the applications of satellite data is mapping range land use. The aim of this study was to compare two methods of maximum probability and fuzzy for rangeland zonation. For this purpose, Landsat ETM+ was used; then, after final geometric and radiometric corrections, the final classification map was prepared. According to the results of accuracy of these two methods using the kappa coefficient, the artificial neural network algorithm of fuzzy Artmap with a coefficient of 0.9614 was more accurate than the maximum probability algorithm with a coefficient of 0.8058. Results of this study also indicated that the traditional algorithms of classification such as statistical methods due to their low flexibility, and parametric types such as maximum probability method because of the dependence on the Gaussian statistics model, could not provide optimal results, when the samples were not normal. In this study, ENVI 4.5, Idrisi Andes 15 and Arc GIS9.3 software were used
Saleh Arekhi; Hasan Fathizad
Volume 21, Issue 3 , December 2014, , Pages 466-481
Abstract
Rapid land-use/land cover changes have taken place in many arid and semi-arid regions of Iran such as west of Iran over the last decades due to demographic pressure, agricultural pressure, government polices and environmental factors such as drought. This study was aimed to investigate the trends of ...
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Rapid land-use/land cover changes have taken place in many arid and semi-arid regions of Iran such as west of Iran over the last decades due to demographic pressure, agricultural pressure, government polices and environmental factors such as drought. This study was aimed to investigate the trends of changes in the landscape, in Doiraj Watershed. In order to provide land cover maps, the satellite images of TM 1985, ETM+2000, ETM+2007 were applied and landscape metrics of class area, largest patch index, number and mean patch size, patch density and edge density were used to quantify landscape patterns. Various class-level landscape pattern metrics were calculated using FRAGTATS, in order to analyze landscape fragmentation. The results of landscape ecology change revealed that in this area during the first period (1985 - 2000), the area of forest lands decreased to 3,415 hectares, while the agricultural lands with 3514 hectares showed an increasing trend. On the other hand, the area of fair rangelands (20,440 hectares) showed a decreasing trend (in both periods) contrary to the area of poor rangelands, indicating the degradation process in the study area. Our results clearly showed that increased number of patches and decreased mean patch area were two important fragmentation indicators and the trend of landscape degradation and fragmentation was increasing. Therefore, the results necessitated paying attention to the quality of land use and cover in the region for decreasing the degradation of natural resources.