Masoud Barzali; Mojgansadat Azimi; Mohammad Abdolhosseini; Abdolrahim Lotfi
Volume 29, Issue 1 , February 2022, , Pages 133-144
Abstract
The various services that we obtain directly and indirectly from the natural environment are referred to as ecosystem services. The purpose of these services is to communicate with human welfare in four categories of services: provision, support, regulation and culture. The purpose of this study was ...
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The various services that we obtain directly and indirectly from the natural environment are referred to as ecosystem services. The purpose of these services is to communicate with human welfare in four categories of services: provision, support, regulation and culture. The purpose of this study was to investigate the supply of soil conservation services at different land uses and also to compare their amount. InVEST model was used for this research. To calculate soil retention, this model estimates soil erosion potential using the Modified Soil Erosion Equation (RUSLE) and sediment retention rate based on sediment delivery ratio. Therefore, the required input information of the model including biophysical table and maps of digital elevation model, rain erosion, soil erodibility, vegetation and land use were prepared with the help of ArcGIS 10.4 software and entered into the model in the form of raster maps. The results of this study showed that among different land uses, forests and rangeland with good and average condition had the highest soil conservation and the lowest amount was related to barren lands, residential areas and poor pastures. The results also showed that the highest rate of soil conservation occurs in the east and southeast and upstream of the basin and factors such as reduced vegetation and soil type have contributed to the intensification of erosion in this area. The results of this research can be useful in land management programs and appropriate decision making for rangeland management.
Asghar Farajollahi; Hamidreza Asgari; Majid Ownagh; Mohammadreza Mahboubi; Abolrasoul Salman Mahini
Volume 27, Issue 4 , December 2020, , Pages 682-691
Abstract
In the management of natural resource, recognizing socioeconomic factors affecting land use change is essential for achieving sustainable development and land use planning. In this research, we investigate and determine the socio-economic factors affecting land use changes in the Maraveh Tappeh region ...
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In the management of natural resource, recognizing socioeconomic factors affecting land use change is essential for achieving sustainable development and land use planning. In this research, we investigate and determine the socio-economic factors affecting land use changes in the Maraveh Tappeh region of Golestan province. This area has been affected by land use change in recent years. The rangelands and forests have decreased during the study period (1984-2014), and agricultural use with an annual increase of 132 hectares has reached to 10332.97 ha in 2014. This descriptive-analytic research was carried out in 16 villages in the study area with survey sampling method. Data collection was performed by questionnaire and the numbers of questionnaires were determined 310 people. Sampling was done through a Cochran formula and cluster sampling and multi-stage sampling. Cronbach's alpha coefficient was used to determine the reliability of the study and it was found 0.75. In this study, exploratory factor analysis method was used. For the factor analysis, the principal components method was used using rotation varimax. The results of factor analysis showed that socio-economic factors affect on land-use changes in Maraveh Tappeh region and these factors are including: non-economic efficiency of animal husbandry, Low land per capita for each farmer, rural unemployment, low income and high cost of living, increasing input price, the need for housing and the lack of awareness, social reputation and land ownership. These eight factors explained 63.80% of the total variance. Considering researching findings, attention to economic and financial problems and employment condition of village’s resident of Maraveh Tappeh region is essential. Also, husbandry and livestock production management and supply of livestock inputs have been proposed to reduce the land use changes of forests and rangelands and to protect the natural resources.
Mahdi Boroughani
Volume 27, Issue 3 , October 2020, , Pages 617-631
Abstract
Sistan watershed has caused severe dust storms in the region in recent years due to the drying up of Lake Hamoon and consecutive droughts. This study aimed to identify and determine the characteristics of dust source areas (land use, lithology, slope, and geomorphology) in the ...
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Sistan watershed has caused severe dust storms in the region in recent years due to the drying up of Lake Hamoon and consecutive droughts. This study aimed to identify and determine the characteristics of dust source areas (land use, lithology, slope, and geomorphology) in the Sistan watershed. To identify the dust source area, MODIS satellite images of dust days for the period 2015 to 2019 were used using dust detection indicators including BTD3132, BTD2931, NDDI, and D. The results of identifying dust source area indicate that a total of 211 dust source areas were identified in the whole region. Of these identified dust source area, 61 are in Iran and 150 in Afghanistan. The results of the distribution of dust collection centers in different uses indicate that dryland agricultural lands with 172 centers, dried lake surfaces, and irrigated agricultural lands with 16 and 12 sources have the highest dust collection sources. From the overlap of the lithology map and dust source, it was obtained that the most dust source area with 111 and 98 sources, respectively, are located in continuous and discontinuous sedimentary formations. The results of the distribution of dust source area in geomorphological units indicate that the erosion plain unit with an area of 35.69 percent, 48 dust source area has the highest collection source. Also, the results of the distribution of dust source area in different slopes show that the highest dust source area is in the slopes of 0 to 2% with 107 sources and the lowest located in more slopes of 32%% with 6 sources.
Fatemeh Karami; Masoud Bazgir
Volume 26, Issue 4 , December 2019, , Pages 953-970
Abstract
Climate and land use are two important factors which are greatly influence on soil physical and chemical properties. This research was conducted to study the effects of climate and land use on physical and chemical properties of soil in Ilam province in 2016. After initial studies, Ivan area with semi-humid ...
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Climate and land use are two important factors which are greatly influence on soil physical and chemical properties. This research was conducted to study the effects of climate and land use on physical and chemical properties of soil in Ilam province in 2016. After initial studies, Ivan area with semi-humid climate and Ganjavan with semi-arid climate in Ilam province were selected. In each region, three land uses including forest, rangeland and agricultural were considered. After field studies in each land use, five soil samples were taken from 0-10cm and 10-30cm depths and collected randomly. The results showed that the highest amount of soil lime (47.85%) and soil silt (31.75%) were obtained in semi-arid climate of Ganjvan. The soils of Ayvan as a semi-humid climate had the highest amount of clay and K available. The highest bulk density (1.87 g.cm-3) was obtained in semi-arid climate of Ganjavan under the effect of agricultural use at lower soil depth. The lowest amount of bulk density (1.08 g.cm-3) was observed in semi-humid climate of Ayvan in the soil surface depth under forest land use. The highest amount of organic matter was obtained in forest land use in semi-humid climate in Ayvan, (42.85 %) which was more than semi-arid climate of Ganjvan. Agricultural land use had the lowest amount of organic matter (4.37%). The highest amount of N (0.514%) and P (35.04 mg kg-1) concentrations were obtained in forest land use in the semi-humid climate of Ayvan. The amount of Ca and Mg concentration in subsoil solution (10-30cm) layer was higher than topsoil solution (0-10cm) layer in Ayvan. In general, by changing land use from forest to farm, the percentage of clay, organic matter, nitrogen, phosphorus, and potassium available decreased in semi-arid climates of Ganjvan. Therefore, proper land use management in semiarid climates is essential for optimal preservation of soil properties.
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 ...
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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.
Bakhtiar Fatahi; Soheila Aghabeigiamin; Alireza Ildoromi; Maedeh ghorbanpour Dalivand
Volume 26, Issue 2 , July 2019, , Pages 302-312
Abstract
Land use change, land abandonment, overgrazing, expansion and spread of exotic species are of the most important challenges in the rangelands of the country. For this reason, in this research, it has been attempted to address the challenges by presenting a single improvement solution. Therefore, the ...
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Land use change, land abandonment, overgrazing, expansion and spread of exotic species are of the most important challenges in the rangelands of the country. For this reason, in this research, it has been attempted to address the challenges by presenting a single improvement solution. Therefore, the perennial rainfedd alfalfa was used for cultivation in degraded rangelands or abandoned lands for both goals of rangeland reclamation and carbon sequestration. Three rangelands were studied in the protected area of Lashgardar-Malayer reclaimed rangeland via alfalfa, medium grazing, and degraded rangelands. In each of these rangelands, sites were selected for sampling. The size and number of plots were determined by the minimal area and statistical method. In each plot, the aboveground and underground biomass and litter were collected. Soil sampling was performed in the plots and the measurement of carbon sequestration was conducted in the laboratory. Soil samples were collected from two layers of 0-15 and 15-30 cm and their carbon was measured. The three study rangelands were compared using a One-Way ANOVA analysis, and the results showed that the amount of carbon sequestration in the rangeland reclaimed with perennial rainfed alfalfa (36.8 ton / ha) after 4 years was around 1.25 fold higher than the medium grazing rangeland (29.27 ton / ha) and 1.71 fold as compared with the degraded rangeland (21.54 ton / ha). These results indicate that reclamation of degraded rangelands causes to achieve land conservation goals and increase the ability of the ecosystem for carbon sequestration.
Mahsa Abdolshahnejad; Ali Akbar Nazari Samanni; Mehdi Ghorbani; Aziz Orsham; feridoon Taheri
Volume 26, Issue 2 , July 2019, , Pages 325-339
Abstract
The effects of human activities on the land use and landscape and its subsequent effects on the natural environment have always been considered. Therefore, to have a sustainable landscape planning, knowing about such changes would be essential. Satellite images of TM sensor in ...
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The effects of human activities on the land use and landscape and its subsequent effects on the natural environment have always been considered. Therefore, to have a sustainable landscape planning, knowing about such changes would be essential. Satellite images of TM sensor in 1990, ETM+ Sensor in 2002 as well as OLI Landsat 8 in 2013 were used to investigate the trend of changes and preparation of cover maps. The executive phase of the study included the analysis of the gradient of land use structure in eight geographical directions for class area (CA), number of patch (NP), and mean patch size (MPS) in seven classes such as woodland) low-density forest and garden), water zone, agriculture, bare land, rangeland, urban and sand dunes. The results showed that the land use of woodland, urban, and sand dunes had an increasing trend, while the bare land showed a decreasing trend. The results of gradient analysis of land use structure in eight geographical directions indicated that the most changes were in the west and center of the region. Based on the analysis of changes rate of metrics, the most changes were recorded for rangeland, bare land, and urban during 1990 to 2002; the woodland, agriculture, and urban during 2002 to 2013; and rangeland, woodland and urban during 1990 to 2013. Therefore, given that some aspects of land use change depend on human aspects, the relationship between these quantitative indicators can be used to determine the sustainability level as well as the future trend of land use change to identify the critical affected areas. Metrics of area, number of patches and mean patch size were recognized as the important indices in discussions of monitoring land use and mosaic changes.
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.
Saeed Barkhori; Rasoul Mahdavi; Gholamreza Zehtabian; Hamid Gholami
Volume 25, Issue 2 , August 2018, , Pages 355-365
Abstract
The aim of this study was to investigate the temporal and spatial changes trend of groundwater quality for drinking purposes in Jiroft plain. The role of land use and geological formations in the groundwater quality was also investigated. In this study, the parameters of electrical ...
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The aim of this study was to investigate the temporal and spatial changes trend of groundwater quality for drinking purposes in Jiroft plain. The role of land use and geological formations in the groundwater quality was also investigated. In this study, the parameters of electrical conductivity, sodium adsorption ratio, pH, calcium, chlorine, magnesium, sodium, and sulfate were used and the zoning of qualitative data was done by the geostatistical method of Kriging in ArcGIS9.3 software; then, the classification of the region was done using Schoeller diagram. Results showed that in 2001, southern parts of the study area had a lower quality of groundwater but in 2014, northern parts had a lower quality. According to the results, the groundwater quality decreased overtime and the decreasing trend spread from the south to the center and the north of the region. Also, the land use map showed a low quality of groundwater in agricultural lands. The geology map showed a low quality of groundwater in central and southern parts. In general, it can be concluded that the water quality of the study area for drinking is decreased over time and influenced by land use and geological formations; thus, to improve the quality of groundwater resources the role of human factors (land use and agricultural activities) need be taken into account.
parisa heydari; Saeid Hojati; naieme enayati; amir raiat pishe
Volume 24, Issue 1 , May 2017, , Pages 181-192
Abstract
Soil is a major reservoir of terrestrial carbon, but human activities around the world including land use change lead to a significant emission of carbon from the soil. It seems that soil organic carbon has been significantly decreased due to the land use changes over the last century in Iran. Therefore, ...
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Soil is a major reservoir of terrestrial carbon, but human activities around the world including land use change lead to a significant emission of carbon from the soil. It seems that soil organic carbon has been significantly decreased due to the land use changes over the last century in Iran. Therefore, the objective of this study was to investigate the effect of land use change (rangeland to agriculture) on organic carbon stock and some biological indices of soil quality (soil organic carbon (SOC), basal soil respiration (BSR), microbial biomass carbon (MBC), microbial quotient (MQ), and metabolic coefficient (qCO2) in east of Khuzestan province. Soil samples were collected in eight replicates and two depths (0-15 and 15-30 cm) in both land uses. Results showed that except qCO2, the amount of TOC, MBC, and MQ in agricultural use decreased significantly as compared to rangeland. According to the results, C stock of agricultural lands in 0-15 and 15-30 cm layers was 19.5 and 8.3 Mgha-1, showing 34 and 47 percent decrease when compared to natural rangeland with 29.7 and15.9 Mgha-1 C stock. The SOC content in 0-10 cm soil layers of agricultural use and natural rangeland was (8.47 and 5.28 gKg-1) and (13.29, 6.55 gKg-1), respectively, demonstrating 60 and 71 percent reduction in agricultural lands. In addition, in 0-15 and 15-30 cm layers of agricultural lands, MBC (60 and 71 percent), MQ (37 and 65 percent) showed reduction and qCO2 increased 3-4 times when compared to natural rangeland. Results show that agricultural activities lead to considerable loss in total organic carbon and half of organic carbon stock in the soil. Limitation of organic carbon in agricultural land use makes noticeable reduction in MBC than other properties. Thus, it can be used as a suitable indicator for monitoring changes of organic carbon in the soil.
Hassan Fathizad; Ata Safari; masoud Bazgir; Gholamreza Khosravi
Volume 23, Issue 4 , March 2017, , Pages 729-743
Abstract
Image classification is always one of the most important issues in remote sensing, and the obtained information from image classification is widely used in this field and other applications like urban planning, natural resource management, agriculture, etc. Since the main purpose of processing satellite ...
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Image classification is always one of the most important issues in remote sensing, and the obtained information from image classification is widely used in this field and other applications like urban planning, natural resource management, agriculture, etc. Since the main purpose of processing satellite images is preparing subjective and practical maps, choosing a suitable classification algorithm has an essential role. This paper studies the efficacy of Support Vector Machines (SVM) algorithm regarding satellite image classifications and compares it to artificial neural network algorithm. SVM is a group of classified and observed mechanical learning algorithms, used in remote sensing. In this study, SVM algorithms were employed for land use classification of Meymeh area using ETM+ landsat data. The classification via SVM was automatically performed by three types of linear Kernel, polynomial, and radial basis. Besides, the performance of this method was compared to that of artificial neural network classification method. Results showed that the average overall accuracy and Kappa coefficient of SVM algorithms, including linear Kernel, polynomial and radial basis, were respectively 9 percent and 12 percent more efficient than artificial neural network classification. Consequently, this study substantiates the efficiency and sufficiency of SVM algorithms in classification of remote sensing images.
reza bagheri; sedighe mohammadi; mehrdad saljooghi
Volume 23, Issue 2 , September 2016, , Pages 243-231
Abstract
This research was aimed to investigate the effects of land use change on some soil physical properties. Six sites with similar ecological conditions including ungrazed site (UG), heavily grazed site (HG), moderately grazed site (MG), plowed Glycyrrhiza glabra site (Gl T), dry farming site (D), ...
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This research was aimed to investigate the effects of land use change on some soil physical properties. Six sites with similar ecological conditions including ungrazed site (UG), heavily grazed site (HG), moderately grazed site (MG), plowed Glycyrrhiza glabra site (Gl T), dry farming site (D), and fallow site (F) were selected in Jamalabad region of Baft city. The study was conducted in a randomized complete block design with six replications in 2013. Soil sampling was performed in the study sites and soil physical properties were measured. The results showed that a continuous plowing in Gl T site (plowed every 3-4 years) had no negative impact on soil erodibility; however, if plowing is repeated every year consecutively (the dry farming site), the harmful effects of plowing on soil erodibility will appear and remain on soil along time. The rangelands under grazing management (moderate grazing) significantly reduced the soil erodibility, compared to heavily grazed site; however, there was no significant difference between ungrazed and moderately grazed sites. The bulk density increased in the heavily grazed site (0.35 gr/cm3) compared to moderately grazed and ungrazed sites and there was no significant difference between ungrazed and moderately grazed sites. According to the obtained results, rangeland conservation and moderate grazing strategy are recommended to be applied by the natural resources agencies.
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.
Ali Shahbazi; Farhad Aghajanlou; Fatemeh Einlou; Mamak Ahmadian
Volume 21, Issue 4 , March 2015, , Pages 718-730
Abstract
Determining land capability based on land suitability, climatic characteristics, and soil physical and chemical properties is considered as a method of achieving sustainable management. In this study, FAO model was used to determine land capability. To describe the spatial results, Geographical Information ...
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Determining land capability based on land suitability, climatic characteristics, and soil physical and chemical properties is considered as a method of achieving sustainable management. In this study, FAO model was used to determine land capability. To describe the spatial results, Geographical Information System (GIS) was used. Spatial data, as maps, and descriptive data, as database table, were entered into the GIS environment. The results of current land suitability model for irrigated agriculture and garden land use showed that 64.5% was in N2 class, 17.86% in N1 class, 17% in S3 class and 0.64% in NR class. For dry farming land use, 64.5% was in N2 class, 18.86% in S3 class, 17% in S2 class, and 0.64% in NR class. For rangeland use, 32% was in S3 class, 32.5% in N1 class, and 35.5% in NR class. For forest land use, 64.5% was in N1 class and 35.5% in NR class. From overlaying the current land use map with the current land suitability map, it was found that only 25.5 % of irrigated agriculture land use, 82 % of dry farming land use and 30.3% of rangeland use were consistent with their land suitability map, being exploited properly
Ali Mohammad Asaadi; Ghorban Ali Asadi; Asghar Khoshnoud Yazdi
Volume 21, Issue 2 , August 2014, , Pages 208-220
Abstract
This research was aimed to investigate the ecological capability of Hesare Hosseini Watershed to determine optimum land uses and improve the current environmental management. Ecological and socio-economic characteristics were first studied and mapped. These maps were digitized in Arc/Info software and ...
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This research was aimed to investigate the ecological capability of Hesare Hosseini Watershed to determine optimum land uses and improve the current environmental management. Ecological and socio-economic characteristics were first studied and mapped. These maps were digitized in Arc/Info software and then were entered to the Arcview software with other data for creating database. Digital Elevation Model (DEM) was produced in Arcview using topographic map. Based on that, the maps of slope, aspect and elevation were produced. Then, the environmental units map was prepared by overlying the maps of elevation, slope, aspect, soil types and vegetation cover in Arcview. The land capability for different land uses was determined by Iranian ecological model using Structured Query Language (SQL) in Arcview. According to the obtained results, this region has no first and second-class capability for irrigation farming. Overall, 54.51% of the watershed area is suitable for range management, 12.76% for dry farming, 31.1% for conservation and 1.63% for irrigated farming.
Mehdi Jafari; Gholam Reza Zehtabian; Amir Houshang Ehsani
Volume 20, Issue 1 , June 2013, , Pages 72-87
Abstract
Today, remote sensing data can provide the latest information for the study of land cover and land uses These images are of utmost importance due to the providing updated information, variety of forms and the possibility of processing for making land use maps. Determining the location of each land use ...
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Today, remote sensing data can provide the latest information for the study of land cover and land uses These images are of utmost importance due to the providing updated information, variety of forms and the possibility of processing for making land use maps. Determining the location of each land use together with land cover helps managers in making decisions. Also, the current status of the land cover can be studied by using land use maps at different levels. In order to evaluate the ability of multitemporal satellite data of TM and ETM + in land use classification and the effect of the thermal band on increasing the accuracy of the land use maps, Landsat TM digital data relating to the September 27, 1990 and Landsat ETM + digital data of 10 July 2002 from Kashan were analyzed. Initial studies were performed on images in terms of the presence of geometric errors. In order to prepare the images for digital processing, improved operation and image enhancement were applied on the images. Ground truth map was prepared in the same stage. Then, the supervised classification of satellite images with algorithms and different approaches including a variety of bands were tested and the accuracy of each of the methods and approaches were investigated. The results showed that the highest Kappa accuracy in both Landsat TM and ETM + with all the bands were 86.34 and 83.21, respectively. While the elimination of the thermal band decreases the accuracy to 82.46 and 79.93 % The results of this study showed that using thermal bonding caused an increase of 4 percent in Kappa accuracy, and the highest accuracy was occurred in the classes of clay plains, flood plains, mountains and puffy salt lands. Therefore, despite the lower spectral resolution, the use of thermal bonding is recommended in such studies.
Saleh Arekhi; Mostafa Adibnejad
Volume 18, Issue 3 , September 2011, , Pages 420-440
Abstract
Land use classification using remotely sensed images is one of the most common applications in remote sensing, and many algorithms have been developed and applied for this purpose in the literature. This study investigates the efficiency of Support Vector Machines algorithms in image classification. ...
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Land use classification using remotely sensed images is one of the most common applications in remote sensing, and many algorithms have been developed and applied for this purpose in the literature. This study investigates the efficiency of Support Vector Machines algorithms in image classification. Support Vector Machines (SVMs) are a group of supervised classification algorithms of machine learning that have been used in the remote sensing filed. The classification accuracy produced by SVMs may show variation depending on the choice of the kernel function. In this study, SVMs were used for land use classification of Ilam dam catchment using Land sat ETM+ data. The classification using SVM method was implemented automatically by using four kernel types, linear, polynomial, radial basis, sigmoid and the results were analyzed thoroughly. Results showed that SVMs, especially with use of radial, polynomial and linear function kernels, outperform the maximum likelihood classifier in terms of overall (about 10%) and kappa coefficient(about 15%) accuracies. So, this study verifies the efficiency and capability of SVMs in classification of remote sensed images.
Kazem Dashtakian; Mojtaba Pak parvar; Mohammad hadi Rad
Volume 18, Issue 2 , September 2011, , Pages 292-306
Abstract
Due to the land use changes like increased acreage for agriculture, digging deep and semi-deep wells has increased rapidly in recent decades in Marvast area as these wells are the main source of water supply at the present time unlike the past which rivers and aqueducts had this role. The main purpose ...
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Due to the land use changes like increased acreage for agriculture, digging deep and semi-deep wells has increased rapidly in recent decades in Marvast area as these wells are the main source of water supply at the present time unlike the past which rivers and aqueducts had this role. The main purpose of this study was to monitor land use changes on soil salinity using satellite images and GIS. Our other purpose was to investigate soil salinity changes in each land unit. With using satellite information from 1984 and 2002 years and proposed method for mapping soil salinity, land use and soil salinity maps were produced and then land use and soil salinity changes were studied. The study area had a total land area of 88980 hectares in Marvast, Yazd province. Results showed that land area of playas, deserts and rangelands respectively decreased to 7.8, 2.9 and 1.5 percent versus increase of agriculture and urban land area to 77.8 and 153 percent respectively. Also during this period, sever increase, increase and decrease of soil salinity was respectively recorded for playa, agricultural and rangelands, and deserts while no changes was detected for other regions. According to results, under ground water resources and saline waters of playas have undergone serious changes as with increase in average soil surface salinity, the ecosystem has shown negative changes.
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.
Mohammad mahdi Fatahi
Volume 16, Issue 2 , December 2009, , Pages 234-253
Abstract
The major part of Qom province areas have involved arid and desert conditions. Immethodical expansion of human acts with no attention to environmental affairs, caused intensifying desertification phenomena. In this paper, trend of desertification was studied with emphasis on land use changes and ...
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The major part of Qom province areas have involved arid and desert conditions. Immethodical expansion of human acts with no attention to environmental affairs, caused intensifying desertification phenomena. In this paper, trend of desertification was studied with emphasis on land use changes and as well as water quality and quantity resources. For assessment land use changes, satellite data (TM, 1985 and ETM+, 2002 ) and for evaluation of water quality and quantity resources changes, the hydrometric and climatic data were used. Comparison between land use maps of TM and ETM+, by using visual interpretation method, showed that areas of agriculture lands, rangelands, forest lands, sand dunes and salt lakes, have been decreased in 6.5, 4.14, 70.4, 24.2 and 15.8 percent respectively, whereas, another classes such as saline lands, urban and rural lands have been increased 26.6, 12.78 and 35.6 percent respectively. The output water of 2 main rivers of Qom province (Qomroud and Qarehchay) before establishment of Panzdah-e- Khordad and Saveh dams were 261 million m3, whereas it decreased to 66 million m3 after obstacle foundation. Before construction of Panzdah-e- Khordad dams, The fall of underground water level was 0.5 meter per year in Qom plain, which increased in averages to 1.4 meter per year after establishment of the dam. In addition, balance sheet of underground water, reduced remarkable. Totally, it seems that the human activities and retouching environment by him (especially construction of 2 dams on Qom rivers) are two main factors which have changed (with decreasing plant covering, salinization of major areas et cetera) and reduction of quality and quantity of water resources which could lead to aggravation of desertification in Qom province.
Hamid reza Moradi; Mohammad reza Fazel puor; Hamid reza Sadeghi; Zeinalabedein Hoseini
Volume 15, Issue 1 , January 2008, , Pages 1-12
Abstract
More than one-third of land in the world is located in the areas with arid and semiarid climate and desertification has increased in these areas during recent decades. Around 80% of Iran is located in arid and semiarid areas. Sand dunes as an indicator of desert land cover an area about 32 million hectare. ...
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More than one-third of land in the world is located in the areas with arid and semiarid climate and desertification has increased in these areas during recent decades. Around 80% of Iran is located in arid and semiarid areas. Sand dunes as an indicator of desert land cover an area about 32 million hectare. Among which 12-mil hectare has not been stabilized yet. Advancing moving sand dunes has resulted in much damage to agricultural products and urban areas. In this survey satellite images and aerial photos are used to evaluate the role of land use changes on desertification in 1955, 1997 and 2002. To do so, IRS image of 2002 and available aerials photos of 1955 and 1997 are used. Following making the aerial photos mosaic processing was done using ILWIS software and needed data completed by field surveying and the land use map was produced for two years. To produce the land use map using digital processing methods 10 sample set (training points) were selected uniformly in the area. After preprocessing including geometric corrections, image enhancement and band composition, image classification was done by maximum likelihood method and the land use map was produced. In this phase, obtained land use map was corresponded to the ground truth map which was achieved by field surveying and recording coordinate of points with GPS pixel to pixel and accuracy obtained from numerical classification estimated to be 45.3%. Then due to obtained low accuracy, the visual method used to produce the land use map so the accuracy of 78.5% achieved. Finally, the area of each land use and the rate of changes were calculated. The results indicate a decrease of 2000 ha in the area of the desert land from 1955 to 1997 and of 160 ha from 1997 to 2002 and an increase in the area of the other land uses. Results show no desertification in the study area, even though land degradation can obviously be identified in the area, which is resulted from the changes of gardens, and agricultural land uses to industrial and urban areas.
Mahmood Goudarzi; Mahdi Farahpour; Alireza Mosav
Volume 13, Issue 3 , February 2006, , Pages 265-277
Abstract
In Iran, like many other developing countries, high population growth rate causes unfairly uses of natural resources and consequently land cover change. Therefore, detection of land cover (rangelands, irrigated and rainfed agricultural lands, urban areas…) changes can influence local planning ...
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In Iran, like many other developing countries, high population growth rate causes unfairly uses of natural resources and consequently land cover change. Therefore, detection of land cover (rangelands, irrigated and rainfed agricultural lands, urban areas…) changes can influence local planning and natural resource management. Present study efforts to find a rapid and exact method of recognition different land covers using Landsat satellite data. Methods used in this research were image enhancement, false color composite (FCC), principal components analysis (PCA) and Image classification, i.e. normalized different vegetation index (NDVI) and supervised classification. A GIS environment, ILWIS software, was used. Results showed that irrigated agriculture, rainfed agriculture, rock out crop, rangeland classes (fair, moderate, poor condition) could be separated with overall accuracy of 89%.