Hossein Arzani; Zeinolabedin Hosseini; Khosro Mirakhorlou
Volume 21, Issue 1 , June 2014, , Pages 24-31
Abstract
This study was aimed to assess the applicability of LANDSAT ETM+ satellite images for estimating vegetation production and cover. The images were digitized using topographic maps and geometrized in 1:25000 scales. Required processes such as spectral ratio measurement and vegetation indices were applied ...
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This study was aimed to assess the applicability of LANDSAT ETM+ satellite images for estimating vegetation production and cover. The images were digitized using topographic maps and geometrized in 1:25000 scales. Required processes such as spectral ratio measurement and vegetation indices were applied on the images. Collection was carried out for vegetation cover and production in various vegetation types in homogeneous units. Sampling points' locations were recorded with GPS. Sampling method was random-systematic in such a way that in each unit, a circle with 20 meters radius was considered. One and 9 sampling plots were placed on the centre and on the perimeter, respectively. The plot size was 1m * 1m. In each plot, vegetation percentage was estimated and the production was calculated using double sampling method. Then, DN values for each sampling unit (9 pixels for one unit) were elicited in respect to primary bands' images, vegetation indices and spectral ratios. Correlation and regression analyses between geo-information and satellite information (Digital numbers) were carried out. Results revealed that 7th and 5th Bands and IR1, MIRV2 and VNIR2 indices had a significant correlation with production and given parameter could be estimated through regression models. Likewise, RA, IR1 and TVI indices had a significant correlation with vegetation percentage and this parameter could be estimated through regression models.
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.
Saeid Choopani; Mohammad khosroshahi; Mohammad Gholampoor; khosro Mirakhorlo
Volume 13, Issue 1 , February 2006, , Pages 17-26
Abstract
The country of Iran is situated in an arid and semi-arid zone, with an average precipitation of about 250 mm per year. Hormozgan province in southern Iran, is one of the most arid parts of Iran with an average annual rainfall of only 170mm. The study area is located ...
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The country of Iran is situated in an arid and semi-arid zone, with an average precipitation of about 250 mm per year. Hormozgan province in southern Iran, is one of the most arid parts of Iran with an average annual rainfall of only 170mm. The study area is located in the Zagros and Makran geological zones.. In the study area the oldest formations are of Palaeozoic age. Another characteristic of the Zagros zone are diapirs. Diapirs rise up from the deepest part of sedimentary rocks, and after cutting through the upper layers, they may appear at the surface, which seriously affect groundwater quality and land use. Desertification; in Iran has occurred from Neosene and Quaternary. Geological formation have important effect on salinisation and desertification. Thus, the geographical investigation of desert area is very important. This investigation is based on GIS method Applications, geological map (1:250000) and supported by, fieldwork. At the first, prepared and digitizing of geological maps by Ilwis program and was carefully checked and corrected where possible. The next step prepared evaporation formation and Quaternary maps and its overlying. Prepared cross map of Quaternary and Hydrographic network and determination of primary and secondary deserts area. The final step was prepared a cross map of primary and secondary desert area map and checked by fieldwork. To comparison between units of desert area map, can be result, more than 78 percent of study area is situated in the deserts area.
Khosro Mirakhorlo; Zein ... Hosseini
Volume 13, Issue 2 , February 2006, , Pages 127-138
Abstract
Estimating rangelandsۥ production is one of the range management tools. This requires detailed information about the present available forage of the rangelands. The assessment of the parameters is difficult and cost-intensive using clipping method. Therefore, new estimating methods are required. We ...
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Estimating rangelandsۥ production is one of the range management tools. This requires detailed information about the present available forage of the rangelands. The assessment of the parameters is difficult and cost-intensive using clipping method. Therefore, new estimating methods are required. We estimated available forage using remote sensing data in the production model that it extracted from ecological parameters and remote sensing data. For quantifying evaluation of vegetation cover stratified random sampling and transect sampling methods were selected. Plot size calculated from “minimal area and species curve” method. Overall, 28 transects (50m) one transect in each site that contain 280(1m2) sample plots were measured. Modeling performed using NDVI index, animal density and effective ecological factors (altitude, slope, aspect, precipitation, temperature and evaporation) on rangelandsۥ yield. After analyzing of ecological factors of Damavand region, some ineffective factors omitted. Finally three factors namely slope, precipitation and NDVI index were entered in the model for calculating the available forage in the study area. The calculated amount of average standard predict value of forage model is 38% and its standard deviation value is 97%. They show that the validation of model for predicting of forage is fairly acceptable.