Fatemeh Narmashiri; mehdi ghorbani; Gholamreza Zehtabian; Hosein Azarnivand; Amir Alambeigi; Roland W Scholz
Volume 29, Issue 1 , February 2022, , Pages 53-65
Abstract
Desertification has been considered as a serious threat to arid, semi-arid and even semi-humid climate in recent decades and it is a major obstacle to sustainable global development, so monitoring its changes is urgent. Using remote sensing and GIS is one of the cost-effective, often free and accessible ...
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Desertification has been considered as a serious threat to arid, semi-arid and even semi-humid climate in recent decades and it is a major obstacle to sustainable global development, so monitoring its changes is urgent. Using remote sensing and GIS is one of the cost-effective, often free and accessible method to monitor changes in these areas. In this study, change vector analysis method was used for evaluation and analysis of desertification change in a part of Ghalehganj county in south of Kerman province. For this purpose, Landsat 8 image bands in two time periods of 2014 (first period) and 2020 period (second period) for March and April was used in Google Earth Engine. Image pre-processing were applied and averaging was done separately for both periods which was followed by calculation of EVI and BSI indices. For the next step, using these two indicators and the change vector analysis method in the GIS software, the magnitude and direction of desertification change trends were determined. The results of the present research indicated the dominance of the reclamation process in the region during the years studied and the overall results indicate that development of cultivated lands and land use change have the greatest impact on monitoring indicators and desertification trends in the region. Thus, degradation of lands around residential areas are witnessed and on the other hand, there is a significant relationship between agricultural activities and rehabilitation areas in the region.
Golmohammad garivani
Volume 10, Issue 3 , September 2019, , Pages 263-288
Mehdi Farahpour; fatholah Ghayour; Hosein Sharbaf; Ali Yousefizadeh
Volume 12, Issue 2 , September 2019, , Pages 121-134
Mohammad Darvish; Ali Akbar Pir Azizi; Karamatolah Imandel; Masoud Shkouie
Volume 8, Issue 2 , September 2019, , Pages 61-92
Mojtaba Pakparvar; Morteza Abtahi
Volume 8, Issue 4 , September 2019, , Pages 93-122
Mohammad Darvish
Volume 10, Issue 3 , September 2019, , Pages 301-320
Reza Norouz Valashedi; Jaber Rahimi; Abbas Alipour
Volume 26, Issue 3 , September 2019, , Pages 640-649
Abstract
The main purpose of this study was to analyze the effective factors on farmers' participation in combating desertification plans in Iran. Thus, a number of farmers as a sample population were selected using Cochran’s formula and multi-stages sampling for selecting samples was done. A questionnaire ...
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The main purpose of this study was to analyze the effective factors on farmers' participation in combating desertification plans in Iran. Thus, a number of farmers as a sample population were selected using Cochran’s formula and multi-stages sampling for selecting samples was done. A questionnaire was used to collect data whose validity was confirmed by advisor and supervisor professors and some experts of desert organization. The reliability of the questionnaire was confirmed by computing Cronbach's alpha that was more than 0.75. Data were analyzed using SPSS and Expert choice 11 software and results showed that the population of the study had low literacy and income. They also had participated very few in education courses, whereas it was observed a significant positive relationship between variables such as literacy, income, and participation in education courses with the participation variable. Also, the correlation relationship between independent factors such as psychological, cultural, economic, education/extension and institution factors with the dependent variable of participation variable showed that except psychological factor, all of those factors had a significant relationship (sig level of 0.01) with participation variable. The results of the regression analysis also revealed that social/cultural and economic factors were the most important factors on the participation variable and explained 66% of participation changes. The model output indicated that rural communities showed significant interest in the city.
Hosein Golbabaie; Abolfazl Khalilpour; Alimohammad Tahmasebi Beyragani
Volume 11, Issue 3 , August 2019, , Pages 255-274
Mohammad Khosroshahi; Majid Hassani; Seyed Aziz Karami
Volume 10, Issue 1 , August 2019, , Pages 40-56
Hamidreza Abbasi; Mohammad Darvish
Volume 11, Issue 2 , August 2019, , Pages 163-178
Nematollah karimi; Soudabeh Namdari
Volume 26, Issue 2 , July 2019, , Pages 500-515
Abstract
In the present study, the severity and extent of desertification in Iran was evaluated using Landsat satellite images with spatial resolution of 30 m during 1984 and 2015. In this regard, new remote sensing techniques (spectral mixture analysis methods) were used. Spectral Mixture Analysis (SMA) is a ...
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In the present study, the severity and extent of desertification in Iran was evaluated using Landsat satellite images with spatial resolution of 30 m during 1984 and 2015. In this regard, new remote sensing techniques (spectral mixture analysis methods) were used. Spectral Mixture Analysis (SMA) is a technique for estimating the proportion of each pixel that is covered by a series of known cover types in mixed pixels. In this regard, changes in vegetation, soil, water, and salt marshes of the entire country were studied. Results showed that about 227000 km2 of Iran included dsertification with low intensity over the past 32 years. In addition, the areas most affected by the desertification and dried water bodies were about 33000 and 5000 km2, respectively. This indicates the occurrence of desertification with varying intensities in 15.6% of the country. Results showed that the contribution of southwest provinces (Ilam, Kermanshah, Lorestan and Khozestan) and southern provinces (Boushehr, Fars and Hormozgan provinces) were much more than other provinces.However, in the eastern and southeastern provinces of the country, due to the dominance of desert and semi-desert climate, the lowest desertification intensity was observed.
Fatemeh Bahmani; Hosin Pirisahragard; Jamshid Piri
Volume 26, Issue 1 , June 2019, , Pages 201-213
Abstract
Estimation of the soil temperature in arid regions is one of the most important issues in planning the projects of desertification, water resource management, and establishment of vegetation.The present study aimed to compare the accuracy of artificial intelligence methods in order to estimate soil daily ...
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Estimation of the soil temperature in arid regions is one of the most important issues in planning the projects of desertification, water resource management, and establishment of vegetation.The present study aimed to compare the accuracy of artificial intelligence methods in order to estimate soil daily temperatures using meteorological data (daily minimum and maximum of temperatures, sunshine, and evaporation), as well as, identifying the most important factors on soil temperature in Zabol and Shiraz synoptic stations. For this purpose, soil daily temperature was estimated at 5, 10, 20, 30, 50 and 100 cm depths by using the three-year period data (2011-2014) and artificial neural network, neuro-fuzzy adaptive genetic programming, and combined neural network-genetic algorithm approaches. Thae results were evaluated using the root mean square error (RMSE) and mean absolute error (MAE) and determination coefficient. Based on the results, there was more dependence between the air temperature and soil temperature at the topsoil so that, the highest and the lowest correlation between actual and simulated data were observed at 5 cm (mean R2=0.92) and 100 cm depths (mean R2=0.56), respectively. The accuracy of the methods used was different from each other in estimating the soil daily temperature. Based on results, in Zabol and Shiraz stations, combined neural networks - genetic algorithm approach and artificial neural network methods provided the most accurate estimation of soil daily temperature, respectively (the mean RMSE=3.69, 2.86 and mean MAE=3.23, 2.57 respectively). According to the results of the present study, it is suggested that in order to choose appropriate time and depth of seeding in the vegetation reclamation projects in arid regions, through considering of climatic conditions of each region, precise artificial intelligence techniques could be used to estimate the soil daily temperature.
Zeynab Gandomi; Amir Hosein charkhabi; Hasan Mohseni; Manouchehr Amiri
Volume 24, Issue 4 , January 2018, , Pages 897-906
Abstract
The southwest province of Iran has a dry and semi-arid climate, with about 250,000 hectares of sand dunes; therefore a comprehensive review and overview of these features and their correlation with other features is needed. In this study, over 200 sand samples were collected from the ...
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The southwest province of Iran has a dry and semi-arid climate, with about 250,000 hectares of sand dunes; therefore a comprehensive review and overview of these features and their correlation with other features is needed. In this study, over 200 sand samples were collected from the mobile and not mobile sand dunes to study the grain size of sand dunes in Khuzestan. The results showed there was no significant difference in the mean grain size from east to west, along a 200 km transect of the sampled area. The mean grain size in the west was 2.87 to 2.14 φ scale (136 to 226 microns) and in the east 3.05 to 2.16 φ (120 to 223 microns). The standard deviation of particle size of the samples was good and fairly good (0.71 to 0.35 φ). Using tilt condensation particle diameter in the range of sand dunes area, folk scale (0.1 to 1 φ) was positive. These distances represent 20 to 50 km with mean transported distance of 35 km for the west and 50 to 200 km transported distance with mean value of 125 km for the east section of the Khuzestan province for the sand dunes. For the transport distances, average transport distance could be divided into four categories, including 3, 12.5, 35 and 125 km. According to the results, the source of particles of the sand dunes in Khuzestan province is local, mainly from northwest and west.
seyed Jafar seyed Akhlaghi; seyed Javad Miri Soleyman; Amin nemati
Volume 24, Issue 2 , July 2017, , Pages 348-359
Abstract
This study was conducted to evaluate the effects of economic, social and technical factors on the success rate of all executives in implementing combat desertification participatory projects in Sistan and Baluchistan province, 2013. The results of correlation coefficients showed that there was a statistically ...
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This study was conducted to evaluate the effects of economic, social and technical factors on the success rate of all executives in implementing combat desertification participatory projects in Sistan and Baluchistan province, 2013. The results of correlation coefficients showed that there was a statistically significant and positive relationship between the success rate of the executives in the implementation of combat desertification participatory projects in the province and variables including residence status of the executive in the region, executive and managerial skills, communication with expert and state supervisor before implementing the project, and the level of technical, regulatory and managerial support of natural resources experts in the province. Furthermore, the results of linear regression model estimation showed that three variables including the amount of bank facilities, personal investment of the executives in the implementation of the project, and the level of executive and managerial skills had a positive significant effect on the success rate of the executives in the implementation of combat desertification participatory projects. According to the results, it is suggested that the Department of Natural Resources and Watershed Management of the province should provide needed facilities with appropriate lending conditions to increase the willingness of individuals to implement the aforementioned projects. Secondly, in order to enhance the executive and managerial capability, the Department of Natural Resources and Watershed Management of the province should conduct training and practical courses on implementation of combat desertification projects.
Abolghasem Dadrasi Sabzevar; Alimohammad Akhondali; Fereydon Radmanesh; Aliakbar Norouzi
Volume 24, Issue 2 , July 2017, , Pages 370-382
Abstract
The purpose of this paper was to make the preparation of soil surface moisture map applied in arid and semi-arid regions using satellite imagery of OLI and TIRS along with the calculated values for spectral reflectance, principal component analysis and Tasseled Cap transformation.Twenty-four predictor ...
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The purpose of this paper was to make the preparation of soil surface moisture map applied in arid and semi-arid regions using satellite imagery of OLI and TIRS along with the calculated values for spectral reflectance, principal component analysis and Tasseled Cap transformation.Twenty-four predictor variables were used and the most correlated ones were identified at three moisture levels of 4 to 5 percent, more than 5 percent and less than 4 percent by exploratory regression and bivariate correlation method through calculating the inflation factor of variance, Pearson coefficient and coefficient of explanation. The Moran'sI index was used for geo-spatial autocorrelation. Forty-seven soil samples were collected randomly by creating 1800-meter networks in a systematic algorithm and the soil moisture was calculated by W-thermal method. The estimation functions of soil surface moisture were derived in the form of partial least square regression (PLSR), enter regression and stepwise regression. All models had acceptable calibration. Our results clearly showed that the Landsat 8 data could be useful in estimating soil surface moisture and the accuracy of the functions extracted with stepwise regression method was more than that of other methods (RMSE=0.585 to 1.425 %). The models introduced for a moisture level of ≤5%, tend to over estimate (MBE= 0.788) and for other moisture levels tend to underestimate.
seyed hojat Mousavi; Abasali vali; Abolfazl Ranjbar Fordoye
Volume 23, Issue 3 , January 2017, , Pages 499-515
Abstract
Desertification is defined as rapid change in vegetation cover, plant community composition, hydrologic conditions, soil properties, or climate conditions, which results in an overall loss of ecosystem services and poses serious threats to sustainable livelihoods. The process represents one of the most ...
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Desertification is defined as rapid change in vegetation cover, plant community composition, hydrologic conditions, soil properties, or climate conditions, which results in an overall loss of ecosystem services and poses serious threats to sustainable livelihoods. The process represents one of the most threatening environmental hazards due to the large amount of people and land at risk. Therefore, this research was aimed to modeling of desertification and zonation of Haj Ali Gholi Playa according to the climate parameters such as temperature, rainfall amount, evapotranspiration potential, number of sunny hours, climate condition, drought (aridity), and maximum prevailing wind speed, using GIS technique and statistical methods. The modeling was performed using stepwise multiple regression analysis. According to the results, maximum significant relationship was found among desertification classes and dry zone with a determination coefficient of 0.999 and STD error of estimate of 0.033 (α ≥ 0.01). Other results are included the zonation map of desertification in the study area from very high zone to no-desertification zone, so that, the very high desertification zone is included about 679.75 km2 (%92.66) of present land degradation and has the possibility of increasing up to 5668.11 km2. In addition, the high desertification zone, covering about 5.22 km2 (%0.44) of present land degradation, can develop to 933.86 km2. The obtained results from validation test of the model show the descending trend of accuracy assessment index from the very high desertification zone to the no-desertification zone, indicating the necessary accuracy of the model.
Zahra Eslamian; Mehdi Ghorbani; Tayebeh Mesbah zadeh; Hamed Rafiee
Volume 23, Issue 1 , June 2016, , Pages 188-196
Abstract
D Desertification and land degradation have created a defective cycle of environmental problems, and have intensified degradation trend. Economic-social challenges and political crisis are considered parts of the consequences of land degradation, which may increase the vulnerability of the affected societies. ...
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D Desertification and land degradation have created a defective cycle of environmental problems, and have intensified degradation trend. Economic-social challenges and political crisis are considered parts of the consequences of land degradation, which may increase the vulnerability of the affected societies. To strengthen the resilience of local communities to cope with any natural disaster, it is necessary to identify and prioritize the impact of these phenomena to solve them based on prioritization of these effects. The aim of this study was to evaluate and prioritize the social - economic impact with moderate desertification in the Nasrabad region from the perspective of local communities and the participation of the villagers in line with desertification. In this study, numerical taxonomy was used to prioritize socio-economic impacts of desertification. Using the Cochran formula and given the population of the study area (5579 Person), 80 samples were collected. In this study, due to the average wind erosion, the first rank was allocated to the spread of dust and environmental problems from the perspective of local communities. The people of the region, more than anyone else, have experienced and understood the ways of interacting with these fragile ecosystems over time. Therefore, these interaction methods should be considered as the key to solving the challenges of desertification or as the best and perhaps last chance to deal with it comprehensively.
Abolfazl Rahmatizadeh; Mohammad Jafary
Volume 21, Issue 3 , December 2014, , Pages 496-506
Abstract
Due to the population growth and human intervention in nature, desertification has increased drastically. The Masileh watershed is located in the southern highlands of central Alborz. In this study, vegetation condition, the volume of water entering the area, soil chemical characteristics, and ...
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Due to the population growth and human intervention in nature, desertification has increased drastically. The Masileh watershed is located in the southern highlands of central Alborz. In this study, vegetation condition, the volume of water entering the area, soil chemical characteristics, and agricultural production statistics of the region were examined and compared before and after the construction of dams during two periods with an interval of five years. Results showed that since the construction of 15- Khordad dam in 1995, the volume of water entering the Masileh plain has reached zero.The hydrograph study showed that the groundwater level of Masileh plain has dropped on average five meters/year. Due to the lack of flood entering and soil washing, the salt concentration of soil surface layers in most vegetation types has increased. Due to the lack of root access to water, the canopy cover percentage in halophyte vegetation types with shallow roots such as Aeloropus litoralis and Cyperus sp has been reduced up to 100%, and new species such as Halocnemum strobilaceum and Halostachys caspica have been replaced. In terms of agriculture, significant changes have occurred in the composition and type of agricultural crops. Our results clearly showed that the Masileh plain is turning from a productive agricultural area into a real desert.
Saeed Rashvand; Jamal Mosafaee; Mohammad Darvish; Ammar Rafee emam
Volume 20, Issue 1 , June 2013, , Pages 38-49
Abstract
Vegetation and biological production is one of the most important factors in providing human needs and sustainability of ecosystems and living organisms. Otherwise, the natural lands will become desert and non-residential regions. Deterioration of vegetation is one of the major causes of desertification. ...
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Vegetation and biological production is one of the most important factors in providing human needs and sustainability of ecosystems and living organisms. Otherwise, the natural lands will become desert and non-residential regions. Deterioration of vegetation is one of the major causes of desertification. In the current research, the assessment of desertification in terms of deterioration of vegetation was performed using the FAO and UNEP method in Rood shoor, Qazvin. For this purpose, the digital map of potential vulnerability was generated from geometric mean of three indices including moisture regime, temperature regime, soil depth and texture. For digital mapping of perennial to annual plants ratio, the map of vegetation types (31 even vegetation types) was prepared and in each type four plots were established in order to record the production and canopy cover percentage. Finally, the final map of potential desertification was generated and classified by the integration of digital maps of potential vulnerability and perennial to annual plants ratio. From the total area of the sub basin which is equal to 2275000 hectares, agricultural lands and non rangelands (1034745 ha) which covers 46 % of the sub basin were not assessed in the classification. The rest was classified as follows: 31685 ha (low), 1191394 ha (medium) and 17176 ha (high).
Ali Farmahini Farahani; Mohammad Darvish
Volume 19, Issue 4 , March 2013, , Pages 547-556
Abstract
Desertification is a global problem and most of arid and semi-arid countries of the world including Iran face this phenomenon. Desertification causes many limitations in terms of agriculture, food supply, livestock farming, industry development and so forth. This phenomenon is a process that has gradually ...
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Desertification is a global problem and most of arid and semi-arid countries of the world including Iran face this phenomenon. Desertification causes many limitations in terms of agriculture, food supply, livestock farming, industry development and so forth. This phenomenon is a process that has gradually developed and intensified and the costs of modifications increase exponentially. Therefore, identification and assessment of factors effective in desertification, and determining the regions affected by this disaster are necessary for each region. FAO and UNEP method is considered as one of the best methods to evaluate desertification in which several processes are investigated. Vegetation degradation, water erosion, wind erosion, decline in the quality and quantity of water resources and soil salinization as well as livestock and population pressure on the environment are considered as the main processes in this study. This study was carried out in a twenty-year period with considering the oldest data, aerial photographs and satellite images. To evaluate each process, several indicators were considered and selected indicators were evaluated by field and library work. Four classes of low, moderate, severe and very severe were also selected for separation of desertification intensity. Each process was studied from three aspects i.e. current situation, velocity and the potential of desertification. Desertification maps were generated in GIS and then integrated to produce final map of desertification. According to the results, 125853 ha (%23), 251504 ha (%45), and 158819 ha (%29) were classified in classes of low, moderate, severe and very severe, respectively. Severe desertification mainly was observed in mountainous areas with slopes over 60 percent, and in saline and sodic marginal lands of Kavire-e-Meighan basin. Vegetation degradation and water erosion were identified as the main factors of desertification in this basin and livestock grazing was the main cause of worsening desertification. Obtained results provide a basis for better recognition and proper combating desertification in this area.
Saeedeh Nateghi; Gholam reza Zehtabian; Hasan Ahmadi
Volume 19, Issue 4 , March 2013, , Pages 590-600
Abstract
Segzi plain is one of the most critical areas of the province in terms of the extent and severity of desertification process. This area has a special strategic position due to the industrial centers, Shahid Babaee airport, Shahid Beheshti International Airport, railroads, transit road of Bandar Abbas- ...
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Segzi plain is one of the most critical areas of the province in terms of the extent and severity of desertification process. This area has a special strategic position due to the industrial centers, Shahid Babaee airport, Shahid Beheshti International Airport, railroads, transit road of Bandar Abbas- Esfahan, agricultural centers and vicinity to historical city of Esfahan. Consequently, investigation on the main cause of desertification phenomenon is the main objective of this study. Therefore, the IMDPA model was used to study desertification intensity in Segzi plain. In this research, two criteria including geology – geomorphology and soil, consisting of seven indicators (sensitivity of the formation, land use, and slope based upon geology–geomorphology criterion, and soil texture, soil depth, percentage of stone and gravel, and EC based upon soil criterion) were studied. Desertification intensity map was generated by using geometric mean of criteria. With regard to the geometric mean of criteria, soil criterion, with a numerical value of 3.4, and geology – geomorphology criterion, with a numerical value of 3 were classified in severe desertification class. Finally, the severity of desertification (DS) was calculated to be 3.26 indicating that the region was in severe desertification class. Results showed that EC, with an average value of 3.75, was classified as very intense indicator and had the most impact on desertification of the region.
Seyed Jafar Seyed Akhlaghi; Hamid Reza Abbasi; Ammar Rafiee Imam; Mohammad Darvish
Volume 19, Issue 3 , December 2012, , Pages 498-511
Abstract
Desertification is a multifactorial phenomenon and relates to different aspects. Thus, this concept can be studied around multiple axes in natural resources and environment. Nowadays, the rapid growth and huge population in environments and ecological areas are of the most important concerns that have ...
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Desertification is a multifactorial phenomenon and relates to different aspects. Thus, this concept can be studied around multiple axes in natural resources and environment. Nowadays, the rapid growth and huge population in environments and ecological areas are of the most important concerns that have attracted the attention of experts and planners to the concept of desertification or combat desertification .On the one hand, astounding growth of metropolises and unbridled industrial development have led to adverse outcomes for the residents. Moreover, land is a limited resource and the situation will get worse over time in many countries due to the exponential growth of population and extensive use of land and with regard to the fact that only 5 million km2 of the earth has remained for sustainable utilization in future. There are many issues surrounding population supporting capacity based upon the quality of the land in order to maintain the sustainability of resources and environment. The purpose of this article was to estimate population supporting capacity of Tehran and Alborz on the basis of the potential of land units through the method introduced by Central Department of Agriculture of USA. This is the first step to determine the extent of land degradation and detection of man-made desertification. In the current situation, it is obvious that a demographic development of Alborz and Tehran provinces has led to instability in the environment and desertification. Based on the results, classes 1, 4 and 9 of the land quality covered 20.38, 14.93, and 37.44 percent of the surface area, respectively. These three classes could be accounted for 81.9% of population supporting capacity according to the potential of production. Our results showed that lands of the study area were exposed to desertification classified as very high risk (38.55 % of the total area), high risk (25.06 % of the total are), moderate risk (23 % of the total area), and low risk (13% of the total area). Accordingly, it was found that the current population of Tehran province was 5 times higher than the optimal population. This ratio also reaches 4.7 times in high-density areas such as Tehran, Karaj, Shahriar and Robat Karim.
Tayebeh Sohrabi; GHolamreza Zehtabian
Volume 19, Issue 1 , June 2012, , Pages 17-31
Abstract
Iran with its special geographical position mainly has an arid and semi-arid climate. The average annual rainfall in Iran is about 240 mm equivalent to one-fourth of the world average rainfall. In addition, irregular spatial and temporal distribution of rainfall has caused problems in natural resources ...
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Iran with its special geographical position mainly has an arid and semi-arid climate. The average annual rainfall in Iran is about 240 mm equivalent to one-fourth of the world average rainfall. In addition, irregular spatial and temporal distribution of rainfall has caused problems in natural resources and agriculture and annually huge amount of our water and soil resources are degraded. Since the advent of the farming activities until the present, human needs have been based upon farming activities. Considering the growing population and the social and economic developments, most of rangelands have been subject to rainfed cultivation. Therefore, to prevent further degradation of soil in these regions research should be conducted on agricultural lands and the exploitation methods. For this reason, Taleghan was selected as the study area. Map of the area, including soil maps, land types and the current land use were produced by GIS. After determining the main treatments, soil samples were taken in every part of the area and in agricultural area and soil factors were measured within two groups of soil improvement factors including nitrogen, phosphorus, potassium, humus and lime and soil degradation factors including acidity, sodium adsorption ratio (SAR) and salinity in two depths of 0-10 and >10 cm. These factors were studied in a split-plot design. The results showed significant differences among treatments. According to the results of soil improvement and degradation factors, orchards and rangelands are in an ideal condition and monoculture treatment decreases the performance of the products.
Mohammad mahdi Fatahi; Mohammad Darvish; Hamid reza Javid kia; Mahdi Adnani
Volume 17, Issue 4 , November 2011, , Pages 575-588
Abstract
Desertification is defined as the reduction of biomass potential and degradation of environmental resources and ecosystems which affects regional and cross-regional levels of human life.Assessment and mapping of desertification in Daryache Namak watershed with a 1614176 hectares area were considered ...
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Desertification is defined as the reduction of biomass potential and degradation of environmental resources and ecosystems which affects regional and cross-regional levels of human life.Assessment and mapping of desertification in Daryache Namak watershed with a 1614176 hectares area were considered as the aim of the current research. Desertification aspects were determined from vegetation degradation, water and wind erosion, quantitative and qualitative loss of water resources and soil salinization using FAO-UNEP method.Desertification was classified by overlaying and averaging of current status and natural capacity and all maps were made in GIS. According to the results, vegetation degradation (23.25%) and water resources degradation (59.63%) included the most area in current status and natural capacity of the study area respectively. Desertification total risk was also classified and mapped considering current status, natural capacity and human impacts and results indicated that 23.51, 76.47 and 0.02 percent of this watershed located in moderate, severe and very severe desertification classes respectively.
Motahareh Esfandiari; Mohammad ali Hakimzadeh Ardakani
Volume 17, Issue 4 , November 2011, , Pages 624-631
Abstract
Desertification is one of the most important problems in arid and semiarid lands of the world. Rapid growth of human population and increasing of cultivation cause the degradation of soil and water resources. In the other hand, the reclamation of soil is time consuming and very expensive; therefore, ...
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Desertification is one of the most important problems in arid and semiarid lands of the world. Rapid growth of human population and increasing of cultivation cause the degradation of soil and water resources. In the other hand, the reclamation of soil is time consuming and very expensive; therefore, it is necessary to know the destruction factors of soil and its effects on desertification. In order to evaluate soil degradation in agricultural lands of Abade-Tashk, the IMDPA model was used. Four soil indexes: Electrical Conductivity, percent of gravel, depth and texture were applied in this model. For evaluation of soil indexes, randomized network sampling was used and then each index measured according to its effect in the model. The geometrical mean of indexes were calculated using GIS software. Desertification map of each index was prepared and then the current situation of each index obtained. The final map of desertification was prepared by combination of the index maps using mean geometrical method. The results showed that 47% of total area (2212 ha) located in low class of desertification, 43% (2019 ha) in medium class and 10% (467 ha) in high class of desertification.