Fateme Hadian; reza jafari; hosein bashari
Volume 22, Issue 4 , March 2015, , Pages 730-744
Abstract
Urbanization has been a major factor of natural resource degradation in the Semirom region of Isfahan province. This study aimed to evaluate the impact of urban development through land cover/ land use changes over a 37-year period using Landsat 1976 MSS and 2013 TM images and population data. First, ...
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Urbanization has been a major factor of natural resource degradation in the Semirom region of Isfahan province. This study aimed to evaluate the impact of urban development through land cover/ land use changes over a 37-year period using Landsat 1976 MSS and 2013 TM images and population data. First, necessary processing (geometric, radiometric, and topographic) was applied on images. Then, by using field assessment and GoogleEarth software, sample points were selected. The land use/ cover maps of the region and their changes were extracted by maximum likelihood classifier and post classification methods and their accuracy were assessed through overall accuracy and Kappa statistics. The accuracy assessment showed that the accuracy of maps in 1976 and 2013 was about (overall accuracy) 80% and 92%, respectively. The population was increased during three decades from 41973 to 65047 persons, which has led to an increase of 0.90 and 0.26 in the urban, and agriculture area and a 3 percent decrease of rangeland area. The 2.5 fold increase in bare land area in 2013 in comparison with 1976 indicated the severity of land degradation in the study area. Overall, drought and urban area attractions have facilitated the migration of people from villages to the city and had considerable negative effects in natural resources. Therefore, the region requires a holistic approach in all economic, social, and environmental developments.
Zeinab Jafarian; Hossein Arzani; Mohammad Jafari; Ghavamedin Zahedi; Hossein Azarnivand
Volume 19, Issue 3 , December 2012, , Pages 371-381
Abstract
This research was aimed to investigate the relationships between dominant rangeland species and environmental factors in the Rineh rangelands located on the southern slope of Damavand Mountain. Stratified random sampling method was applied and the study area was classified to 37 sample units based upon ...
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This research was aimed to investigate the relationships between dominant rangeland species and environmental factors in the Rineh rangelands located on the southern slope of Damavand Mountain. Stratified random sampling method was applied and the study area was classified to 37 sample units based upon elevation, slop and aspect.
In the study area, 750 plots 1m2 and 75 plots 25m2 were established. One hundred and fifty soil samples were dug at the depth of 0-30 cm and 16 soil properties including pH, CaCo3, bulk density, particle density, total phosphorus, total nitrogen, absorbed potassium, organic matter, saturation moisture, soil texture, field capacity, permanent wilting point, available water capacity and water holding capacity were measured in laboratory. After collecting the climate data, 16 climate factors including average relative humidity, average rainfall, average temperature, average minimum temperature, average maximum temperature in spring, summer and annual as well as annual frost days were selected to reconstruct the missing data. IRS images including red and near-infrared bands and PAN band as well as combined bands derived from RVI, NDVI, and PCA were selected. Regression equation was developed for each species using logistic regression. Results indicated that most of the factors including slop, aspect, average minimum temperature in spring, number of frost days, average daily temperature in summer, and most of the soil factors were entered in regression models. Also, satellite data were used as effective tools in showing the presence of plant species.
Hosein Arzani; Khosro Mirakhorlou; Zeinalabedin Hosseini
Volume 16, Issue 2 , December 2009, , Pages 150-160
Abstract
Range management needs to accessing data by fast and suitable methods for planning. Satellite data and geographic information systems (GIS) can be used for planning and integrating field and remotely sensed data. Landuse map is one of the most important information in range management plans. This requires ...
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Range management needs to accessing data by fast and suitable methods for planning. Satellite data and geographic information systems (GIS) can be used for planning and integrating field and remotely sensed data. Landuse map is one of the most important information in range management plans. This requires overlaying, retrieve and analysis detailed information about the rangelands in GIS. Land use map provided using Landsat7 ETM data (15 Apr. 2004) for the study area (middle catchment’s of Taleghan) in the Tehran province. Based on histogram of bands and statistical analysis, bands 4, 3, 2 were selected for color composite in unsupervised classification method. We identified 4 classes land use type of study area in the fieldwork. Ground data was collected using systematic with random start point, from 86 plots (250*250m), using unsupervised map as a primary map. Overall, with combining the ETM data and the field data using supervised classification method, boundary of the landuse types were put in four classes (Rangeland, Farm land, Dry farming and Bare soil). The classification accuracy assessment showed that the overall accuracy 70.64 percent and accuracy rates of the rangeland, farm land, rain fed carping and bare soil were 81, 54, 61, and 81 percent, respectively. So it is possible to use Landsat 7 ETM+ data for landuse mapping which is essential in range management and range suitability classification.