Maryam sadat Jaafarzadeh; Ali Haghizadeh; Iraj Vayskarami
Abstract
Agriculture is not only the largest user of groundwater resources throughout the world but also its economy is highly dependent on these sources. Thanks to having more effective parameters and subsequently more accurate results, the classification methods in many fields, such as sustainable agriculture ...
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Agriculture is not only the largest user of groundwater resources throughout the world but also its economy is highly dependent on these sources. Thanks to having more effective parameters and subsequently more accurate results, the classification methods in many fields, such as sustainable agriculture has been taken into consideration. Discriminant analysis models are more complex, more accurate and more efficient in comparison to modern methods. In current study, the areas with infiltration potential located in some parts of Khomein, Shazand, Azna, Aligudarz and Durood areas (Marboreh watershed) were went under investigation using the mixture discriminant analysis (MDA) model. For this purpose, the infiltration samples gathered by double ring test, with the environment-effecting layers on infiltration, were prepared and then introduced to R_studio, employed to run MDA. In order to assess the results, validation indices (ROC curve, CCI, TSS, Recall and Precision indices) were used. According to the results, 6.2, 6.1, 12.7, 13.3 and 15.9% of areas of Shazand, Khomein, Durood, Azna and Aligodarz respectively lie in highly potential infiltration, whereas 1.1 16.5, 14.3, 19.6 and 10.8% of those areas were found to have extremely potential infiltration. Most of these areas have sandy soil texture and Quaternary formations with agricultural and range land uses. The accuracy indices that obtained as 0.89%, 76.66, 0.53, 0.91% and 0.73%, witnessing the acceptance and excellence of model performance. The results of this study can be useful in the decision-making for managers and planners regarding to the groundwater recharge in accordance with urban and agricultural needs, because groundwater resources and ensuring their stability are the main factors for sustainable agriculture.
sahar ghafari; Ardavan Ghorbani; mehdi moameri; Raoof Mostafazadeh; Mahmood Bidar lord; Azad Kakemami
Abstract
The aim of this study was to investigate the effects of topographic, edaphic, climatic and landscape metrices on the distribution of plant communities in the altitude gradient of Moghan-Sabalan rangelands in Ardebil province. To determine and study the ecological species groups, 28 sites and 840 one ...
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The aim of this study was to investigate the effects of topographic, edaphic, climatic and landscape metrices on the distribution of plant communities in the altitude gradient of Moghan-Sabalan rangelands in Ardebil province. To determine and study the ecological species groups, 28 sites and 840 one square meter sampling plots were samples by the random systematic method. To determine soil factors, soil samples were collected from each site from 0–15 and 15-30 cm depth and physicochemical parameters were measured at the lab. Using TWINSPAN, vegetation of the study area was classified and then PCA and CCA were used to investigate the relationship between species and environmental factors. According to TWINSPAN results, four ecological groups were identified. The first ecological group is located in the opposite direction of elevation, slope, rainfall and patch area gradients, and the same direction with pH, clay and dispersible clay (the first depth), bulk density, edge density and patch area (coefficient of variation). The second and third ecological groups are located in the interfaces of the first and fourth ecological groups in terms of plant composition and environmental conditions. These two groups prefer the middle elevations. The fourth ecological group at the end of the elevation, rainfall, slope, patch area and inverse direction of clay and dispersible clay (the first depth) and typically prefer high altitudes and light texture soils.
Shahram Yousefi khanghah; Damoon Razmjuee; Somayyie Dehdari; Nasim Arman
Abstract
To better managing of rangeland the vegetation map is one of major factors, because plant communities is planning units of rangeland management and vegetation map shows the current status of plant communities. This research was conducted to produce vegetation type's map using Landsat 8 image classification ...
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To better managing of rangeland the vegetation map is one of major factors, because plant communities is planning units of rangeland management and vegetation map shows the current status of plant communities. This research was conducted to produce vegetation type's map using Landsat 8 image classification in Behbahan, Khuzestan province. Rangelands of the study region is warm semi steppe and winter grazing. Geometric correction of satellite image was performed by ground control points with an error of less than one pixel. Atmospheric correction of existing data using the dark object subtraction was done. Field visits for vegetation type's border controlling and sampling training area was conducted. Eight supervised classification algorithms included Parallelepiped (PP), Minimum Distance to mean (MD), Mahalanobis distance (MAH), Maximum Likelihood (ML), Neural Net (NN) and Support Vector Machine (SVM) was performed. The results showed that ML algorithm has the highest overall accuracy (87.5 percent) and kappa (0.867) and PP algorithm has the lowest overall accuracy (67.1 percent) and kappa (0.571). It is suggested that, along with digital methods of classification of satellite images, visual interpretation should be used to clarify the boundary of the obtained vegetation types map.
Mohammad Ali Zare Chahouki; Masoud Yousefi; Mohammad Jafari; Hossein Azarnivand; Marjan Shafizadeh Nasrabadi
Abstract
The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the ...
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The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the region were determined. Sampling method was randomized–systematic and within each sampling unit 3-5 parallel transects with 300-500 m length, each containing 30-50 quadrates (according to vegetation variations) were established. Quadrate size was determined for each vegetation type using the minimal area; hence suitable quadrate size for different species was determined 1*2m–10*10m (2-100 m2). Soil samples were taken from 0-30 and 30-80 cm in starting and ending points of each transect. Measured soil properties included gravel, texture, available moisture, saturation moisture, organic matter, lime, gypsum, pH and electrical conductivity. To analyze environmental data, classification (using TWINSPAN) and ordination (using PCA, CCA) were used. The results indicated that soil salinity, texture and available water play the main role in distribution of plant species.
M. Jafari; A. Tavili; M. Rostampour; M. A. Zare Chahouki; J. Farzadmehr
Volume 62, Issue 2 , October 2009, , Pages 197-211
Abstract
This study was carried out to investigate the effective environmental factors in the distribution of vegetation in Zirkouh rangelands of Qaen. After delimitation of the study area, sampling of soil and vegetation were performed using randomized- systematic method. Vegetation cover was recorded by using ...
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This study was carried out to investigate the effective environmental factors in the distribution of vegetation in Zirkouh rangelands of Qaen. After delimitation of the study area, sampling of soil and vegetation were performed using randomized- systematic method. Vegetation cover was recorded by using Braun-Blanquet combined abundance-cover scale in each sample. Within each sample, one profile was dug and soil samples being taken at 0-20 cm and 20-100 cm depths. Physical-chemical characteristics were determined include texture, lime, organic matter, soil moisture content, saturation moisture, EC and pH. Five vegetation groups were identified after the application of TWINSPAN method and were named after the characterizing species as follows: Salsola richteri-Aelorupes littoralis; Zygophyllum eurypterum-Haloxylon ammodendron; Artemisia sieberi-Zygophyllum eurypterum; Ammodendron persicum-Stipagrostis pennata; Artemisia aucheri-Amygdalus scoparia. The results of PCA showed that environmental factors best related with the distribution of this vegetation are texture, lime, organic matter, soil moisture content, saturation moisture, elevation and slope.
