Mojtaba Pakparvar; Morteza Abtahi
Volume 8, Issue 4 , September 2019, , Pages 93-122
Zahedeh Heidarizadi; Ali Mohammadian Behbahani
Volume 26, Issue 3 , September 2019, , Pages 660-674
Abstract
Protecting an ecosystem and conserving natural resources requires knowledge of the conditions and land-use changes. The purpose of this study was to monitor land-use changes in the past and evaluate the performance of GEOMOD and LCM models in simulating land-use changes in order ...
Read More
Protecting an ecosystem and conserving natural resources requires knowledge of the conditions and land-use changes. The purpose of this study was to monitor land-use changes in the past and evaluate the performance of GEOMOD and LCM models in simulating land-use changes in order to select a more appropriate model for predicting land-use changes in the future. Landsat satellite images were used during the periods of 1990, 2003, and 2016 and land-use changes were monitored by using these images. The simulation of land use status by the LCM model for 2016 was done using the maps of the years 1990 and 2003. Using MLP and Markov chain, the land use map was simulated for 2016. To run the GEOMOD model, the image of the single-user map of 2003 and 2016 were used and the map of "appropriateness of changes" was made by the use of variables affecting land-use change and they were introduced into the model. The results of the accuracy of the simulation map of 2016 showed that LCM and GEOMOD had Kappa coefficients of 81% and 71%, respectively. Therefore, the LCM model was chosen as the most appropriate model and the map of the year 2029 was predicted and prepared.
ali akbar noroozi; Alijan Abkar; Mah,oud Damizadeh; Behrouz Arastoo
Volume 26, Issue 1 , June 2019, , Pages 117-130
Abstract
This study was implemented to prepare a model for soil salinity mapping using Landsat5 images in several provinces including Bushehr, Semnan, Fars, Kerman and Hormozgan. At the beginning, 50-100 samples from soil surface were taken and sent to the Laboratory. Then in order to evaluate ...
Read More
This study was implemented to prepare a model for soil salinity mapping using Landsat5 images in several provinces including Bushehr, Semnan, Fars, Kerman and Hormozgan. At the beginning, 50-100 samples from soil surface were taken and sent to the Laboratory. Then in order to evaluate and identify soil salinity, TM Landsat satellite images and statistical models combined with satellite`s spectral indices were used. After evaluating the accuracy of statistical models using test points, the best model for the study area was selected and the salinity maps were developed based on the regression model. The results showed a significant relationship between soil salinity and spectral index. In Fars province, NDSI salinity index had the highest correlation with soil electrical conductivity (0.35) with a regression coefficient of 66% and RMSE and MBE statistics of 2.58 and 0.66, respectively. In Kerman province, the tasseled cap three index had the highest correlation with soil electrical conductivity (0.47) with a regression method coefficient of 65%, and RMSE and MBE of 10.3 and 0.51, respectively. In Hormozgan province, the results showed high correlation with soil salinity indicators SI2 level of 72 percent. Stepwise method with R-square of 0.518 was selected for the Hormozgan province whre the RMSE and MBE were reported to be 2.5 and -0.35, respectively. Also in Semnan province, 5 and 7 bands of Landsat showed the highest correlation with soil electrical conductivity (respectively 0.65 and 0.75). By using stepwise regression, the linear relation with R-square of 0.6 was obtained, and RMSE and MBE values were reported to be 2.83 and -0.81, respectively.
Zahra Abolalizadeh; Ataollah Ebrahimi
Volume 22, Issue 1 , June 2015, , Pages 21-30
Abstract
Sabzkouh protected area is located in central Zagros. This area, with a variety of natural ecosystems and landscapes, is very rich from the point of diversity of climate, topography, habitats and wildlife. Its ecosystems, like other semi-arid ecosystems of Iran, have undergone changes in their structure ...
Read More
Sabzkouh protected area is located in central Zagros. This area, with a variety of natural ecosystems and landscapes, is very rich from the point of diversity of climate, topography, habitats and wildlife. Its ecosystems, like other semi-arid ecosystems of Iran, have undergone changes in their structure in recent years. Nowadays, Markov chain models are widely used in ecological studies to predict these changes quantitatively. For this purpose, satellite images and geographic information system were used to predict the future condition of the region using CA-Markov model. Finally, the land cover map of the region for the next fifteen years (2003-2018) was predicted by CA-Markov model. According to the prediction map, an increase in the area of agricultural lands, shrub/brush rangelands and forests of the region was observed, while the area of forbs rangelands and bare lands decreased. The results of these predictions provide a valuable tool to the managers and policy makers of natural resources and environment