Leila Biabani; Hassan Khosravi; Gholamreza Zehtabian; Esmaeil Heydari Alamdarloo; Behzad Raygani
Abstract
Soil erosion modeling is becoming more significant in the development and implementation of soil management and conservation policies. For a better understanding of the geographical distribution of soil erosion, spatial-based models of soil erosion are required. Wind erosion is a significant cause of ...
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Soil erosion modeling is becoming more significant in the development and implementation of soil management and conservation policies. For a better understanding of the geographical distribution of soil erosion, spatial-based models of soil erosion are required. Wind erosion is a significant cause of land degradation and desertification, negatively impacting the economy, society, and environment, particularly in arid and semi-arid regions. To control and reduce the effects of wind erosion, the first step is to identify sensitive areas. The aim of this research is to identify areas susceptible to wind erosion using the ILSWE model in the watershed regions of the Dar Anjir-Saghand Desert, Namak Lake, and Sefidrud. This model has been calculated by combining five erosion indices, including climate erosivity, soil erodibility, surface crust, vegetation cover, and surface roughness. The model's results indicate that climatic factors, such as precipitation, evaporation, and wind, vary across these regions. These factors play a significant role in determining areas that are susceptible to wind erosion. It is noted that other factors, including differences in vegetation cover, soil characteristics, topographic conditions, and the extent of bare lands, salt marshes, sandy dunes, low-density pastures, and rainfed agricultural lands, have also influenced the results of this. In general, this study presents a new method for identifying wind erosion-sensitive areas in various climates. This method can prioritize regions that require further research and corrective measures.
Hamed Eskandari Damaneh; Gholamreza Zehtabian; Hassan Khosravi; Hossein Azarnivand; Aliakbar Barati
Abstract
The present research aims to assess climate change in the Minab plain and its effect on groundwater level variability in the future period. Climate change was explored by the climatic model CanESM2 using the SDSM4.2 software package, and the effect of climate change on groundwater resources was quantitatively ...
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The present research aims to assess climate change in the Minab plain and its effect on groundwater level variability in the future period. Climate change was explored by the climatic model CanESM2 using the SDSM4.2 software package, and the effect of climate change on groundwater resources was quantitatively modeled in the GMS10.0.5 software package under the emission scenarios of RCP2.6, RCP4.5, and RCP8.5. The results for the effect of climate change in the future period in the context of these scenarios showed that temperature will increase by 1.88ºC, 2.60ºC, and 4.28ºC and precipitation will decrease by 34.19%, 42.08%, and 59.43% versus the reference year, respectively. The results for the application of the climatic scenarios using the groundwater model revealed that due to the decline of precipitation in this period, mean groundwater level balance in the future periods leading to 2019, 2024, 2029, and 2035 versus the reference year (2003-2004) will be -13.99, -19.003, -22.70, and -25.61 m/yr in RCP2.6, -13.99, -18.95, -22.75, and -24.73 m/yr in RCP4.5, and -14.23, -19.22, -22.003, and -25.46 m/yr in RCP8.5, respectively. This shows that the drawdown will be being aggravated over time. Finally, this decline of precipitation and rise in temperature due to climate change and the subsequent increase in water abstraction for different uses will result in the growing depletion of the groundwater tables in Minab. So, it is recommended to planners and authorities to adopt strategies for adaptation to new climatic conditions and water scarcity and accommodate themselves with future conditions.
Ahmad Gillvare; Gholamreza Zehtabian; Hassan Khosravi; Hossein Azarnivand; Salman Zare
Abstract
Due to the importance of vegetation cover in these areas, the aim of this study was to investigate the effect of drought, on vegetation of HablehRood watershed.Initially, NDVI index obtained from MODIS sensor was used to study vegetation cover and then SPI index based on rainfall data of two basins in ...
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Due to the importance of vegetation cover in these areas, the aim of this study was to investigate the effect of drought, on vegetation of HablehRood watershed.Initially, NDVI index obtained from MODIS sensor was used to study vegetation cover and then SPI index based on rainfall data of two basins in two arid and semi-humid climates was used for drought assessment (2001-2018) using image processing methods. The results showed that during this 18-year period, 53% of the region had droughts on average. Also during the period 2001-2003, drought was more severe than other periods (2003-2018). In addition, the highest vegetation index occurred in 2005, indicating that vegetation was affected by rainfall fluctuations in the region. The correlation matrix between the three indices indicated that NDVI had the same correlation with SPI and annual rainfall. The results of this correlation in dry and semi-humid climates showed that the correlation was 0.38 and 0.25, respectively. These results indicate that this relationship is positive and robust in different climates of a region؟. On the other hand, drought class is mainly located in dry and semi-humid climates, with 55.55% and 50% in relatively normal drought class, respectively. Based on the above, it can be concluded that using remote sensing data can monitor the response of semi-humid and dry arid ecosystems to climate change. The study also showed that arid and semi-arid regions are highly susceptible to climate change and human anomalies. Therefore, the destruction of these lands will have many environmental and economic consequences.
Sahar Zakeri Anaraki; Gholamreza Zehtabian; Hassan Khosravi; Hossein Azarnivand; Arash Malekian
Abstract
Intergovernmental Panel on Climate Change report shows that the world average temperature has increased to 0.6 ° C ± 0.2 ° C in the twentieth century. Therefore, long-term prediction of climate variables and the consideration of measures to mitigate the adverse effects of climate change ...
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Intergovernmental Panel on Climate Change report shows that the world average temperature has increased to 0.6 ° C ± 0.2 ° C in the twentieth century. Therefore, long-term prediction of climate variables and the consideration of measures to mitigate the adverse effects of climate change is evident. The SDSM model was used to downscale observation data of the minimum and maximum temperatures of the Vazvan Meyme station in Isfahan province. The CanESM2 global model data under new emission scenarios: RCP2.6, RCP4.5, and RCP8.5 are used to predict the near future (2006-2036), mid-term (2037-2078) and far-away future (2079-2100). The studies show the ability of the SDSM model to model maximum and minimum temperatures in the base period. The results of this study necessary indicate that as we get closer to the 21st century, the minimum and the maximum temperatures increase in the area of study. The average maximum temperature changes will have the highest increase under the RCP8.5 scenarios in the (2079-2100), in July, which will reach 7.9 ° C. The average changes in minimum temperature show the highest increase in August under the RCP8.5 scenarios. Therefore, considering that this temperature increase in future periods will affect the status of the study area, water resources, and natural resources. Planners and authorities of the relevant departments will take the necessary measures, such as measures to correct irrigation systems, methods for reducing evaporation and improving the cultivation system, to adjust the damage caused by heating or adapt to the new climatic conditions.
Serveh Darvand; Hassan Khosravi; Hamidreza Keshtkar; Gholamreza Zehtabian; Omid Rahmati
Abstract
The purpose of this study was to compare machine learning models including Support Vector Machine, Classification and Regression Tree, Random Forest, and Multivariate Discriminate Analysis to prioritize susceptible areas to dust production. To determine the dust days, hourly meteorological data of Alborz ...
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The purpose of this study was to compare machine learning models including Support Vector Machine, Classification and Regression Tree, Random Forest, and Multivariate Discriminate Analysis to prioritize susceptible areas to dust production. To determine the dust days, hourly meteorological data of Alborz and Qazvin provinces and satellite images of the same days for the period 2000 to 2019 were used. 420 dust collection points were identified and the map of their distribution was prepared. The maps of factors affecting the occurrence of dust, including landuse map, soil orders map, slope map, slope aspect map, elevation map, vegetation map, topographic surface moisture, topographic surface ratio, and geology mam were prepared. Using the mentioned models, the impact of each of the effective factors of dust was determined and prioritization maps of dust harvesting areas were prepared. Models were evaluated using the ROC curve. According to the results, the elevation factor is more important in all models than the other parameters used in the model. The modeling results also showed that the Random Forest )RF( and Multivariate Discriminate Analysis (MDA) models had the highest values of accuracy (0.96), precision (0.94), Probability of Detection (POD) (0.98), and False Alarm Ratio (FAR) (0.051) compared to the others. The performance of the RF and MDA models is better than the other models, followed by the Support Vector Machine (SVM) and Classification and Regression Tree (CART) models, respectively. Also, in evaluating the models using Receiver Operating Characteristic (ROC), the RF model was selected as the best model.
Sayyed Alireza Hosseini; Hassan Khosravi; Hamid Gholami; Yahya Esmaeilpour; Artemi Cerda
Abstract
In this study, land use change trend in coastal areas of south of Iran, including Sistan Baluchestan, Hormozgan, Bushehr were studied during 31 years (1988-2019). Landsat satellite images including TM, ETM +, OLI were used for this purpose. The maximum likelihood method was also used to classify satellite ...
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In this study, land use change trend in coastal areas of south of Iran, including Sistan Baluchestan, Hormozgan, Bushehr were studied during 31 years (1988-2019). Landsat satellite images including TM, ETM +, OLI were used for this purpose. The maximum likelihood method was also used to classify satellite images. Vegetation indices (SAVI) and salinity index (SI1) were used to influence land use classes on land degradation and desertification. The results of land use change trend showed that Changes in land use classes of man-made areas and saline lands as the most dynamic land use classes followed an increasing trend of 2.72% and 1.14%, respectively. The results of multivariate regression analysis showed that three vegetation, saline and man-made variables, and four vegetation, saline, man-made and sandy areas explain 22.3% and 37.8% of the dependent variables of vegetation and salinity indices, respectively. Therefore, in more than 60% of changes, other environmental variables are affected. Hence, with respect to the results of land use area and regression analysis and the mean trend of SAVI and SI1 changes, where vegetation and SAVI classes show decreasing trend and saline land and SI1 classes have increasing trend, it can be concluded that land use changes is phenomena that changes ecosystem services with almost irreversible impacts. This will have nothing to do with disturbing the ecosystem balance and intensifying land degradation in coastal areas.
Shima Javadi; Gholamreza Zehtabian; Mohammad Jafari; Hassan Khosravi; Azam Abolhasani
Abstract
The reduction of soil quality and health due to the lack of proper management or land use change in arid and semi-arid regions of Iran has become a major challenge, which affects the nutritional properties of the soil. Regarding to the importance of nutrients in plant growth, the aim of this study was ...
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The reduction of soil quality and health due to the lack of proper management or land use change in arid and semi-arid regions of Iran has become a major challenge, which affects the nutritional properties of the soil. Regarding to the importance of nutrients in plant growth, the aim of this study was investigation and comparison of soil nutrients under different agricultural land uses in Eshtehard region. At first, different maps of region including soil map, elevation and land use maps were prepared using ArcGIS 9.3. Five land uses including garden lands, monoculture lands, multiple cropping lands, fallow lands and rangelands were recognized as the treatments. After sampling the soil, nutrients including N, Ca, Mg, K, P were measured in two depths of 0-30 cm and 30-60 cm. In addition, the amount of ESP, as a destructive factor, was assessed in order to determine the corrective or destructive role of different land uses. The results of statistical analysis of data using SPSS software showed that there was a significant difference between nutrients average. In addition, the results showed that rangelands and garden lands had the corrective role in surface and deep layers respectively and monoculture lands had destructive role in the deep layer. Follow lands had the most destructive role in both surface and deep layers. Generally, garden lands, rangeland and multiple cropping lands were determined as the most desirable treatments and follow lands and monoculture lands were determined as the most undesirable treatments.
mohsen kazemi; sadegh naji; Sadat Feiznia; Hassan Khosravi
Abstract
One of the strategies to achieve sustainable management of lakes and wetlands is change detection of lakes, wetlands and their surrounding landuses during the specific time periods. In this research, the satellite images from 1381 to 1394 applying geometric and atmospheric corrections were used in order ...
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One of the strategies to achieve sustainable management of lakes and wetlands is change detection of lakes, wetlands and their surrounding landuses during the specific time periods. In this research, the satellite images from 1381 to 1394 applying geometric and atmospheric corrections were used in order to monitor the changes of the Maharloo Lake level and its surrounding lands Image subtraction techniques, the principle component analysis (PCA) and fuzzy logic were used for providing the maps of landuse changes and drastically changes. The obtained results of Maharloo landuse changes showed that the lake water level has decreased 78 percent during 1381 to 1394. Reducing the lake water level, the landuses of bare and saline lands increased 46 and 58 percent respectively. The obtained results of the drastic changes showed that 82% of the changes have had the intensity between 50-100 percent. The most intensity of the changes with reduction of 22 percent was related to water body of Maharloo. The reduction of Maharlu Lake water level have different consequences therefore management planning is necessary to prevent its ecosystem degradation and Risks of reduced water levels in recent years.
Bahareh Jebalbarezi; Gholamreza Zehtabian; ِAli Tavili; Hassan Khosravi
Abstract
Investigation of the effect of plant community on limited water resources of deserts is an important issue in water resources management. Different species of Haloxylon are compatible with desert condition and can use groundwater resources due to deep roots and proper structural condition. The purpose ...
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Investigation of the effect of plant community on limited water resources of deserts is an important issue in water resources management. Different species of Haloxylon are compatible with desert condition and can use groundwater resources due to deep roots and proper structural condition. The purpose of this study was investigation of the effect of Haloxylon planted forests on groundwater resources in Jafarieh plain. For doing the study, at first the number of Haloxylon plants was determined in these forests using satellite images and JMicroVision software. Then using minimum water requirement of each plant, estimated with lysimeter, the number of surplus plants was determined based on their water requirement and rainfall of the region. Then groundwater level status was determined using GMS 8.3 software and MODFLOW model. The results showed that the number of Haloxylon plants in the study area was equal to 3746291 and the amount of groundwater evacuation by these plants was equal to 56.194 Mm3. The reduction of groundwater table was about 0.46 meter in the first study period (1992-2001) and 0.93 meter in the second study period (2002-2012) so that the reduction of groundwater level in the second study period was about 2 times bigger than the first study. This results showed that severe reduction of groundwater table has happened in recent decade because of planting Haloxylon. However the positive effects of these forests on reducing damages of dust storms should not be ignored.
Farhad Zolfaghari; Hossein Azarnivand; Hassan Khosravi; Gholamreza Zehtabian; Shahram Khalighi Sigaroodi
Abstract
Any Changes in a dry land surface ecosystem will be affected by the climate near the ground or microclimate in the vertical plane. In recent decades' wetland drying cause to reduced vegetation significantly. Assessing Zabol synoptic station statistics shown an increased temperature of this place. It ...
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Any Changes in a dry land surface ecosystem will be affected by the climate near the ground or microclimate in the vertical plane. In recent decades' wetland drying cause to reduced vegetation significantly. Assessing Zabol synoptic station statistics shown an increased temperature of this place. It seems that there has a direct relationship between the changes in land surface vegetation and increases the ambient temperature. The situation ground roll on microclimate has been investigated to illustrate this relationship. In this study we compare and assessment temperatures at depth of 5cm and surface and height about 150 cm and heat fluxes and energy in three microsites with different vegetation cover. The distance between the experiment microsites is about 20 km, and the elevation difference is less than 10 meters. Microsite A with the total vegetation average about 65%, B microsites 20% and microsites C with 100% bare soil. It evaluated the equation ρc_p z_a (dT_air)/dt to investigate the role and effects of vegetation on the ground surface. Data analyzes showed temperatures in the period of study at the C microsites were higher than other microsites. It seems the lack of vegetation in microsites C has a major role in the higher air temperature. In micro site C At 00:30 Am (local time) the air temperature was 3.2ºC higher than microsite A and B. The results showed there is a direct relationship between the vegetation cover percentage and air temperature because of different soil heat fluxes and surface temperature.
Hamed Eskandari Damaneh; Gholamreza Zehtabian; Ali Salajegheh; Mehdi Ghorbani; Hassan Khosravi
Abstract
In this study, the effect of land use changes on groundwater resources as well as monitoring of spatial and temporal changes of groundwater quantitative and qualitative parameters were assessed in west basin of Jazmoryan Wetland. Landsat satellite images of TM 2002 and OLI 2015 sensors by applying of ...
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In this study, the effect of land use changes on groundwater resources as well as monitoring of spatial and temporal changes of groundwater quantitative and qualitative parameters were assessed in west basin of Jazmoryan Wetland. Landsat satellite images of TM 2002 and OLI 2015 sensors by applying of Maximum Likelihood Method were used to investigate land use changes trend. Also, information related to wells in years of 2002 to 2015 was used to assess groundwater quantitative and qualitative parameters. To do this, zoning maps of spatial and temporal changes of groundwater quantitative and qualitative parameters were prepared using the best interpolation method in ArcGIS software. The results related to evaluation of the best interpolation method showed that Kriging method had the least error. According to the results of this study, the area of agricultural and urban land uses has been increased, while the area of ephemeral stream, dam, rangelands, bare and mountain land uses has been decreased in 1394 compared to 1381.These changes indicate the increased degradation as well as unstable conditions of the region that adversely affect groundwater resources. As a result of these changes, groundwater quality in southern parts of the study area has been declined. Among the factor causing this declined groundwater quality are construction of Jiroft dam on Halil-rood permanent river, lack of water right and expanded urban and agricultural lands which have caused decrease in groundwater quality over time.
Pouyan Dehghan; Hossein Azarnivand; Hassan Khosravi; Gholamreza Zehtabian; Alireza Moghaddam Nia
Abstract
The excessive reducing capacity of natural resources is one of the most important challenges that human beings have faced it in the last century. Proper land use and land use management based on its ecological potential play an important role in achieving sustainable development. Hence, in order to achieve ...
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The excessive reducing capacity of natural resources is one of the most important challenges that human beings have faced it in the last century. Proper land use and land use management based on its ecological potential play an important role in achieving sustainable development. Hence, in order to achieve sustainable development and in order to use land appropriately, tendencies should be directed towards the planning and utilization of resources on the basis of their resources. Therefore, since agriculture has a great deal of environmental impact on urban areas, the evaluation of agricultural lands is necessary. The aim of this study is evaluation of ecological potential of land in Eshtehard in terms of agriculture and rangelands. For this purpose, the ecological potential of the lands of Eshtehard was evaluated using ecological criteria and using Fuzzy, Fuzzy AHP methods and Geographic Information System (GIS). The Fuzzy method was used to standardize the layers and also to assign weight to each of the indices used by Fuzzy AHP method. The results of this study showed that class 1 lands with 1.50% is the lowest and the class 4 lands with 25.36% of the total area of the study area has the biggest area. The results of the analysis in this study indicate the high efficiency of Fuzzy AHP method in assessing the ecological potential of the area and can be used with changes necessary for other areas and also other location actives.
Nooshin Shakerian; Gholamreza Zehtabian; Mohammad Ali Zareh Chahooki; Hassan Khosravi
Abstract
Nowadays, land degradation and desertification are serious and complex problems that have turned into a worldwide crisis in the world. Using evaluative systems to study degradation and adopting an appropriate strategy to deal with this phenomenon is necessary and important. The first step in the ...
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Nowadays, land degradation and desertification are serious and complex problems that have turned into a worldwide crisis in the world. Using evaluative systems to study degradation and adopting an appropriate strategy to deal with this phenomenon is necessary and important. The first step in the study of land degradation and desertification is determining criteria and indicators that affect upon this process. Therefore, in this study the importance and priority of a considerable number of criteria and indices that influence upon land degradation and desertification were examined. Accordingly, 8 criteria and 49 indicators were chosen based on questionnaires and expert panel and they were evaluated based on eight metrics. We weighted suitable criteria for evaluation indicators with the help of Shannon entropy method, and then by using the TOPSIS method (one of Multiple Attribute Decision Making Methods) we determined the most effective indicators on land degradation and desertification for management and dealing with this phenomenon. The results show that among the evaluation criteria and indices that should be considered for a benchmark or index, a scale, has the highest weight and importance, and being sensitive to change, has the minimum weight and importance.The results of the prioritization and ranking criteria and indicators based on TOPSIS model indicates that the severity of exploitation of water resources in the factor of water with the 0.79 efficiency, has the most effect and the use of facilities and personal management in the management factor with the 0.11 efficiency has less effect in land degradation and desertification.
Fatemeh Azariyan; Sara Valizadeh; Pouyan Dehghan; Hassan Khosravi
Abstract
Iran is mostly consisted of arid and semi-arid areas. Rudab region, Sabzevar, is indicative of an areaexposed to and affected by the risk of desertification. This study accordingly is aimed at assessingthe risk of desertification using ESAs model, through mapping the risk of desertification. Initially,work ...
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Iran is mostly consisted of arid and semi-arid areas. Rudab region, Sabzevar, is indicative of an areaexposed to and affected by the risk of desertification. This study accordingly is aimed at assessingthe risk of desertification using ESAs model, through mapping the risk of desertification. Initially,work units’ map was prepared based on which relevant indicators were valued. Then, relevantindices were prepared based on ESAs model using GIS. Finally, ESAI index was calculated foreach work unit. After mapping the risk of desertification, desertification damages were evaluated. Itwas found out that the risk of desertification in Rudab can be classified at three classes i.e. class I,II, and III; and subclass III1 covered the biggest surface of the study area i.e. 44.48%. Based ondesertification damage map, Rudab region is divided into five classes so that class III covering35.20 percent of the area is the biggest area. Active sandy dune faces are prone to the highest risk ofdesertification since they entail significant risk factors and need to be paid due attention for desertgreening programs.
Moslem Borji Hassan Gavyar; Hadi Eskandari Dameneh; Hassan Khosravi
Abstract
Nowadays, temperature increase, rainfall decrease and its effect on the time dynamics of carbon fixation cycle still are faced by many uncertainties. Net Primary Production (NPP) is one of the main factors of carbon cycle; precipitation and temperature measurement are known as two useful tools to study ...
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Nowadays, temperature increase, rainfall decrease and its effect on the time dynamics of carbon fixation cycle still are faced by many uncertainties. Net Primary Production (NPP) is one of the main factors of carbon cycle; precipitation and temperature measurement are known as two useful tools to study different ecosystems stability and resilience in terms of climate. Hence, in this study, NPP distribution affected by climate parameters of temperature and precipitation have been investigated in four ecosystems of forests, grassland, irrigated agriculture and rain fed agriculture during the period of 2003-2010. Considering climate conditions of biomes, NPP estimation at regional scale was done based on the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) MOD17 NPP product. The results showed that the regression relation was weak between NPP and rainfall for four studied ecosystems, in the other words, low coefficient between these two variables has caused no justified relationship between them. The regression relation between temperature and NPP in forests, pastures and rain-fed agriculture ecosystems follows quadratic equations with determined coefficient over 0.55. The results of this study show that the forest ecosystem resilience to water and temperature tensions is more than other ecosystems, and irrigated agriculture has the least resilience
Kamran Karimi; Gholamreza Zehtabian; Marzban Faramarzi; Hassan Khosravi
Abstract
Remote sensing is a key technology for assessing expansion and rate of land cover changes that awareness of these changes as the basic information has a special importance for various programs. In this study, land use changes were examined over the past 24 years, and the feasibility of predicting ...
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Remote sensing is a key technology for assessing expansion and rate of land cover changes that awareness of these changes as the basic information has a special importance for various programs. In this study, land use changes were examined over the past 24 years, and the feasibility of predicting it in the future was evaluated by using the Markov chain model of the Abbas Plain. Landsat TM, ETM+, and OLI satellite images for the years 1968, 2003 and 2013, respectively; along with topographic and vegetation maps of the study region were used in this research. The images for three periods were classified into five land-use classes of rangeland, agricultural land (irrigated and rain-fed)), residential land, riverbed and barren and hilly land. According to the results, agricultural land is the most dynamic land-use class in the study area and its area has followed an upward trend during the period 1968 – 2003, so that 4337 ha (7.12%) has been added to this land-use class during this period. The trend of rangeland use change has had a descending trend during the period 1968 – 2003, so that has caused its area to be decreased by 3.19% (6573.6 ha) during this period. The results obtained from Markov chain analysis in the period 1968-2003, for model calibration; the maps for the years 1968 and 2003, and its matrix for predicating land use changes of the year 2023 indicate the Kappa coefficient equal to 80 percent. Based on the obtained results, in the year 2023, 49.1 and 10.1 percent of the study region are comprised of agricultural land and rangeland, respectively.
ali azareh; Gholamreza Zehtabian; Aliakbar Nazari Samani; Hassan Khosravi
Abstract
In management, the monitoring means systematic collection and storage of data from activities and strategies that provide assessment and report about the overall condition of the study area. In this research, among different existing methods, IMDPA model was selected for monitoring desertification in ...
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In management, the monitoring means systematic collection and storage of data from activities and strategies that provide assessment and report about the overall condition of the study area. In this research, among different existing methods, IMDPA model was selected for monitoring desertification in Garmsar plain. Based on the study area two criteria including agriculture and water were selected as the main effective criteria on desertification and desertification intensity was evaluated on the basis of seven indices including: groundwater table fluctuation, electrical conductivity, sodium absorption ratio, agricultural mention cropping pattern, agriculture yield according to land suitability, irrigation method and highly inappropriate utilization of machinery, fertilizer and pesticide chemicals. The results showed that the average weights of agriculture criterion were 2.17 and 2.27 in 2002 and 2011 respectively classified in medium class of desertification. Also, the index of irrigation method classified in very high class of desertification was the most effective factor on land degradation among studied indices in during 2002-2011. Studying the average weight of numerical value, it is distinguished that the intensity of desertification for the total area were 1.93 and 2.10 in 2002 and 2011 respectively.
Afshin Jahanshahi; Alireza Moghaddamnia; Hasan Khosravi
Abstract
To assessment and preparation of desertification mapping, much research has been conducted ever within and outside the country that has led to numerous regional models. To provide a regional model and quantitative assessment of current state of desertification, ShahrBabak plain with an area of 4112 square ...
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To assessment and preparation of desertification mapping, much research has been conducted ever within and outside the country that has led to numerous regional models. To provide a regional model and quantitative assessment of current state of desertification, ShahrBabak plain with an area of 4112 square kilometers (Km2) located in the Northwest of Kerman province were considered. In this study, to assess the severity of desertification using thirteen indices that five of them based on groundwater and include: electrical conductivity (EC), sodium absorption ratio (SAR), chloride (Cl), drop of groundwater and water table depth and three of them based on climate data and included: annual rainfall, Transeau drought index, drought index and also three of them based on vegetation and included: Conditions, exploitation and restoration of vegetation, water erosion and irrigation methods in format of desertification Iranian model IMDPA to investigation and determine the class of desertification intensity were done in each of work units. The final score of each of work units and then total area were determined using Geometric average from any of the mentioned indices. Finally the current status of desertification intensity classes were estimated in low, medium, high and very high classes. The results indicated that in the regional proposed model, the study area with respect to intensity of desertification is placed in about 61351 ha (14.92 %) in low class and about 138575 ha (33.7%) in medium class, about 117685 ha (28.62 %) in high class and about 93589 ha (22.76 %) in very high class. Also the weight average of quantitative value estimated 2.06 in total area that it indicated the medium desertification class in the total area.
Gholamreza Zehtabian; Hassan Khosravi; Ali Azareh
Abstract
Need to Increasing agricultural land in order to improve food resources in the past two centuries recentlead to widespread changes in land use and improper management of these lands. Continue thisprocess can lead to land degradation and desertification, and improve such soils is very costly;Therefore, ...
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Need to Increasing agricultural land in order to improve food resources in the past two centuries recentlead to widespread changes in land use and improper management of these lands. Continue thisprocess can lead to land degradation and desertification, and improve such soils is very costly;Therefore, prevention of land degradation is more desirable. This function requires to research on theutilization of land agricultural and how to use. With this aim, the Khatam city was selected as thestudy region and various maps of the region, including soil, land use and height maps was prepared tohelp ArcGIS9.3 and ENVI software. Four dominant land region mention mono cultivated and multicultivated systems under irrigation, garden lands and range lands as control treatments wereconsidered as the treatments. The soil was sampled and soil factors in two corrective factors, includingcorrection factors N, P, K, CO, Caco3, Mg and damaging factors Hco3, Cl, Na, pH, EC and SAR atdepth 0 to 30 cm of the soil surface horizons were studied. Factors the design of split plots showed thatthere are significant differences between treatments in the region and soil of region is relatively poorfrom CO, N, K and P in soils Rdhy. The comparison of treatment means with Duncan MeanComparison indicated that the garden lands as the most suitable treatments and range lands as the mostunsuitable one.