T Mesbahzadeh; H Ahmadi; Gh Zehtabian; F Sarmadian
Volume 63, Issue 3 , December 2010, , Pages 399-415
Abstract
Investigation and preparing of wind erosion intensity maps are the main objectives of this research. In this research, the working unit map was prepared and then nine effective factors in wind erosion according to IRIFR.E.A model are determined at each of seven homogeneous units. According to the results, ...
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Investigation and preparing of wind erosion intensity maps are the main objectives of this research. In this research, the working unit map was prepared and then nine effective factors in wind erosion according to IRIFR.E.A model are determined at each of seven homogeneous units. According to the results, active sand dunes and landuse change showed the highest value with the rate of annual sedimentation more than 6000 ton/km2 while lands surrounding the villages showed the least value with an annual rate of sedimentation of 150-500 ton/km2. Also considering whole area which is about 16161 hectares, around 1978 hectares are classified in low class of desertification; 7430 hectares in medium class while 6753 hectares in high and very high classes.
Azam Tayebi; Mohammad Faraji; Shahram Yousefi khanghah
Abstract
This study with purpose analysis the effect of Maroun՚ dam construction on land use changes using Landsat satellite images taken. For this study two The Landsat satellite image of in 16-year period (1999-2014) and maps Topography was used by applying geometric and atmospheric correction. Then using ...
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This study with purpose analysis the effect of Maroun՚ dam construction on land use changes using Landsat satellite images taken. For this study two The Landsat satellite image of in 16-year period (1999-2014) and maps Topography was used by applying geometric and atmospheric correction. Then using the software ENVI maximum likelihood supervised classification land use map to 7 ClassesRiver, Rangeland , Agriculture, Woodlands and gardens, villages, Palms and Bayer, respectively, with an Kappa coffecient of 75% and 86% were classified . Results classified maps years (1999- 2014) showed that during this period due to dam construction, Agricultural lands, Woodlands and gardens, Village, Palms, Rangeland , increased area and River and Bayer levels was reduced. So by comparing the studing periods of use map, the map changes, represents the maximum land use changes, Agricultural conversion to Rangeland is the equivalent 2875/270 hectares, the lowest changed into Bayer to the village with an area of 0/19 hectares. Overall findings showed that the establishment of Maroon Dam improves the user in the region. Therefore, investigation account the cost of building the dam, construction of the dam has been a lot of positive effects, and in the long run lead to positive economic growth in the region . Changes in cross-river bed also shows that in 1999 the average width bed, 106/10 meters but in 2014 115/89meters and an average of about 7/79 Kilometers been reached. These changes represent a reduction of width and curvature of the river was in 2014.
Meisam Samadi; Abdolreza Bahremand; Ali Salajegheh; Majid Ownegh; Mohsen Hoseializade; Abolhasan Fathabadi
Abstract
In order to develop management plans for water and soil conservation, it is necessary to determine the sources of sediment production in watersheds. During the past three decades fingerprinting technique has been used extensively in determining the contribution of different sources of sediment. In this ...
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In order to develop management plans for water and soil conservation, it is necessary to determine the sources of sediment production in watersheds. During the past three decades fingerprinting technique has been used extensively in determining the contribution of different sources of sediment. In this study, was carried out sediments fingerprinting and determine the contribution of each source to sediment production of the Toulbane watershed in Golestan province. To this end, 44 source samples were collected from forest, pasture, agriculture and bank erosion. Also 8 sediment samples were collected using Philips time-integrated sediment sampler. Afterward, the concentration of 34 geochemical properties was examined in the laboratory using the ICP device. Next, the optimal composite tracers were determined to discriminate sediment sources by using statistical tests including mass conservation test and Kruskal-Wallis. The contribution of different sources to sediment production was determined using the multivariate mixing model. Finally, the uncertainty in the case of a low number of data, was examined using the Monte Carlo method. As a result, after statistical tests, 12 tracers were selected as the optimal composite fingerprints. The bank erosion was main source to sediment production with 52.18% and the forest had the lowest contribution to sediment production with 4.39%. The contribution of agriculture and pasture was 33.23% and 10.21%, respectively. According to the uncertainty analysis, bank erosion is the most significant source to sediment production. Also, the high difference between the upper and the lower boundaries in different sources indicates high uncertainty.
Mohhamad Fayaz; Saeedeh Nateghi; Hassan Yeganeh; Taghi Mirhaji; Seyed Ahmad Mousavi
Abstract
In this study the effect of month, place and different years on the preferencevalue of Bromus tomentellus in semi-steppe region was studied. The preferencevalue of the Bromus tomentellus was studied in two years and four months in three sites as cheshme anjir (Fars), Badamstan (Zanjan) Firuzkuh (Tehran). ...
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In this study the effect of month, place and different years on the preferencevalue of Bromus tomentellus in semi-steppe region was studied. The preferencevalue of the Bromus tomentellus was studied in two years and four months in three sites as cheshme anjir (Fars), Badamstan (Zanjan) Firuzkuh (Tehran). To determine the preferencevalue of species the two methods of as preference index and timing method was used. To compare preferencevalue in different sites times the factorial completely randomized design was used. Mean comparison was performed using Duncan's Multiple Range Test at 5% level. And to compare two methods whit each other the T test was used. The results of preference index showed that sites were significant at 1% level. But the other factors were insignificant differences according to the results of timing method all the factors were insignificant. Comparison of two methods by T test showed that the two methods were different.
Haji Karimi; Fathollah Naderi; Behrooz Naseri; Ali Salajeqeh
Abstract
Distinguishing the susceptible areas to landslide using different landslide susceptibility mapping (LSM) models is one of the primitive and basic works to reduce probable damages and reduce risk. The main purpose of this research is the efficiency evaluation of four methods including Information value ...
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Distinguishing the susceptible areas to landslide using different landslide susceptibility mapping (LSM) models is one of the primitive and basic works to reduce probable damages and reduce risk. The main purpose of this research is the efficiency evaluation of four methods including Information value (WINF), Valuing area accumulation (Wa), Analytical Hierarchy Process (AHP), Kopta-Joshi proposed method (LNRF) for LSM in Zangvan watershed, Ilam province. At first, all the effective factors in landslide occurrence were inspected. By analyzing the parameters, nine factors including slope, aspect, elevation, precipitation, distance from road, distance from fault, distance from drainage, land use and lithology were distinguished as the effective factors in landslides occurrence in the studied area. After preparing the information of these nine factors in GIS environment, the location of landslides were determined using areal photographs and satellite images and LSM performed by the above four methods. Finally, the landslide index was used for evaluation the ability of appropriate LSM model. Based on this Index, the information value method classified more 52 percent of occurred landslides in very high danger class. Therefore, this method is more efficient and proposed as the best LSM method in the Zangvan watershed because of compatibility of landslides with high danger classes and ability of differentiation of danger classes.
M. Fayaz
Abstract
More than half of the area of the country are rangelands. Implementing the principles of proper rangeland management and optimal use of rangeland requires proper stock grazing management. Considering the quality and quantity of forage plants, palatability and preference value of species and rates of ...
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More than half of the area of the country are rangelands. Implementing the principles of proper rangeland management and optimal use of rangeland requires proper stock grazing management. Considering the quality and quantity of forage plants, palatability and preference value of species and rates of species utilization are information needed for proper management of livestock grazing in rangelands. In this study, preference value of three plant species of steppic rangelands including of Iran includingArtemisia sieberi, Stipa arabica and Scariola orientaliswere considere. The studied sites are located in Kerman, Yazd and Isfahan provinces. At first, the vegetation type of each site was determined and and its floristic list was prepared over spring and summer. The selection criteria were used in order to determine the value of preferred species. Random sampling with the plot of one square meter was done in different months and factorial experiment in randomized complete block design was usedto compare preference values and their comparison in different times and places. The results showed that preference value between plant species and studied sites at five percent are significant but there was no significant difference among different months.The interaction of species and stage of grazing was not significant in this research. Moreover, the preference value of Stipa arabica andArtemisia sieberi for sheep grazing were different over different months. The results also reveald that Artemisia sieberi in Nadooshan site has the highest preference value.
Masoud Eshghizadeh; Mohammad-Taghi Dastorani; Ali Talebi
Abstract
The management of sedimentation problems in rivers and reservoirs depend greatly on the sediment yield from the catchment land surface. In this research the effects of biological measures and ranges enclose on suspended load in two sub-catchments of Kakhk experimentalWatershed in Gonabad has been studied. ...
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The management of sedimentation problems in rivers and reservoirs depend greatly on the sediment yield from the catchment land surface. In this research the effects of biological measures and ranges enclose on suspended load in two sub-catchments of Kakhk experimentalWatershed in Gonabad has been studied. This catchment contains both control and experimental sub-catchments. These sub-catchments are similar in all aspects and differ only based on watershed management operations. Experimental sub-catchment has been under rangeland enclosures and operation of biological, biomechanical and mechanical measurements since 1998 whereas control sub-catchment is under normal operation. To determine the biological impact of management and biological measurements on sediment production, the yield suspended load on hillslopes in 18 experimental erosion plots during 4 rainfall events occurred in 2011-2012 has been analyzed in both control and experimental sub-catchments. Analysis was performed in SPSS software using independent-sample T test and ANOVAwith repeated measure test. Based on these comparisons, difference between the amount of suspended load in two sub-catchments was significant at 1 percent level, while runoff depth was significant at 5 percent level. Also results showed that correlation between the runoff depth and suspended load has been 94 percent in Control sub-catchment and 62 percent in Sample sub-catchment. Slope of the line changes between the runoff depth and suspended load in Control sub-catchment has been 5.3 times of the Sample sub-catchment. The research clearly showed the effect of the biological measures and ranges enclose on reduction of suspended load and runoff depth in experimental sub-catchment.
Ali Akbar Noroozi; Mahdi Homaee; Abbas Farshad
Abstract
Soil salinity is a limiting factor for plant growth and a serious cause of land degradation. Field sampling and statistical analysis for estimating soil salinity is expensive and time consuming. Estimating soil salinity by spatial statistical models and Geographic Information System (GIS) is recommended, ...
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Soil salinity is a limiting factor for plant growth and a serious cause of land degradation. Field sampling and statistical analysis for estimating soil salinity is expensive and time consuming. Estimating soil salinity by spatial statistical models and Geographic Information System (GIS) is recommended, because it saves labor and time. This study was conducted to evaluate the performance of spatial statistics with ordinary least square (OLS) incorporation with LANDSAT data to predict soil salinity. The electrical conductivity (EC) of 236 soil samples were collected from Garmsar plain at south east Tehran, Iran and were measured and correlated to 27 variables derived from LANDSAT images, including vegetation indices, salinity indices, bands 1 to 7, principal component analysis and tasseled cap indices. Using factor analysis and similarity index, these variables were divided into three components. Furthermore, two models for soil salinity estimation were derived, using the best correlation correlation coefficient (0.58 and 0.60) method. Simultaneously, soil salinity map was produced in ArcGIS by spatial statistics model ordinary least square (OLS) followed by derivation of the error map, calculated using Moran's index. The error map indicated that the spatial statistics models are superior to classic statistics methods, due to high accuracy in estimation and the fact that it doesn't require exchange information between different software programs
Hamid Reza Moradi
Abstract
ABSTRACT Aim Of this research is landslide hazard zoning in Syahdare watershed using logistic regression. Therefore, outset landslide points recognized using air photography and extensive field studies. Then distribution of landslide map was makes. Then each effective element on landslide occurred for ...
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ABSTRACT Aim Of this research is landslide hazard zoning in Syahdare watershed using logistic regression. Therefore, outset landslide points recognized using air photography and extensive field studies. Then distribution of landslide map was makes. Then each effective element on landslide occurred for example slope, aspect, elevation, litho logy, land use, distance of road, distance of drainage, distance of fault and precipitation map makes in GIS environment. These data were saved in raster and vector format in GIS soft ware and they used for analysis with logistic regression. Logistic analysis obtained by Arc GIS 9.2 soft ware and SPSS. Results showed the most important elements in Land slide occurred in this area are slope, elevation, precipitation, distance of drainage and distance of fault respectively. Most of the land slides have occurred in the classes of 10 to 15 degree slope, elevation of 2350-2500 meters, precipitation (473-523 mm) are located. 50% Landslide is located at a distance of 30 meters of the stream. In this region the most landslides are occurrence in the 300 meter to fault distance. While the from 500 meter distance to the fault reduced number and susceptibility to landslides. The evaluation of accuracy model and the results obtained with three methods for the presence of all variables, 98.2 percent, 0.692 and 0.519 respectively. So showed that logistic regression had high accuracy in making landslide susceptibility map in study area.
Ali Fazlollahi; Ali Salajegheh; Sadat Feiznia; Hassan Ahmadi
Abstract
Sediment fingerprinting is a method for identifying sediment sources and determining the rate of contribution of each source. In this method, the natural tracer technology is used, that combined from samples collection, laboratory analyzing and statistical modeling. The natural tracers are measured in ...
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Sediment fingerprinting is a method for identifying sediment sources and determining the rate of contribution of each source. In this method, the natural tracer technology is used, that combined from samples collection, laboratory analyzing and statistical modeling. The natural tracers are measured in both the sources and suspended sediment to determine the rate of contribution each sources. The suspended sediment traps were constructed and used for the first time in country. In this research sediment fingerprinting was used in the loess area. 27 tracers were measured in all samples. Data were evaluated about outlier. The capability of each tracer in separating the sources was evaluated with kruskal-wallis test. All tracers were accepted. Then the best combination of tracers was determined with discriminate analysis. This combination is total carbon, Na, organic carbon, Pb, Co, Sr, Al, C/N and Rb. Then, the rate of contribution of each source was determined with normal method and optimized method. Among all the sediment sources, Gully and forest have the highest and lowest rates, respectively. The field observations were confirmed the results. The use of genetic algorithm increased the accuracy of determination of contribution of each source in comparison to normal method
shahrebanoo rahmani; Ataollah Ebrahimi; alireza davoudian
Abstract
In this study, three methods were evaluated for vegetation mapping. For remote sensing method, in addition to IRS data of LISSIII, Ddigital Elevation Model (DEM) and Normalized Difference Vegetation Index (NDVI) were used for classification of 14 classes of land covers mostly vegetation types using a ...
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In this study, three methods were evaluated for vegetation mapping. For remote sensing method, in addition to IRS data of LISSIII, Ddigital Elevation Model (DEM) and Normalized Difference Vegetation Index (NDVI) were used for classification of 14 classes of land covers mostly vegetation types using a maximum likelihood algorithm. After comparing of produced vegetation maps, overall accuracy and Kappa index were 82% and 79.43% respectively when only the IRS were used. Whereas, the overall accuracy and Kappa index were increased to 93% and 90.63% respectively, when ancillary data of DEM and NDVI were added. Slope, slope direction, elevation above sea level, annual precipitation, temperature, and sun radiation were selected as the main physiographic after a broad literature review. Then the relationship between of these six factors with vegetation types was evaluated. so a multivariate logistic regression was used to draw vegetation map of the study area based on the sixth independent variables. The result showed a predicted vegetation map of 47.08% accuracy.Finally, in the morphological method, relationship between three maps of lithology, undulating form of geomorphology and faces with vegetation/land cover were determined using a neural network synthetic approach and predict vegetation map was drawn as the output. The accuracy of resulted map was 39.1%. Comparison of accuracy of vegetation mapping by three methods of RS, physiographic and geomorphological methods revealed that RS method of vegetation/land cover mapping is significantly promising due to a meaningfully higher accuracy even without using ancillary data such as DEM and NDVI in this method.
elahe zafarian; Ataollah Ebrahimi; Reza Omidipour
Abstract
Land cover mapping is essential for natural resource management. Satellite imagery can be used for mapping land cover. Several methods are available for land cover mapping whilst choosing the best method is one of the most important issue in this context. To compare pros and cons of three methods of ...
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Land cover mapping is essential for natural resource management. Satellite imagery can be used for mapping land cover. Several methods are available for land cover mapping whilst choosing the best method is one of the most important issue in this context. To compare pros and cons of three methods of classification including maximum likelihood, object-based segmentation and artificial neural network, first, the efficiency of these three methods were evaluated. Then the trend of land cover changes in Shahrekord basin was investigated for 1999, 2009 and 2015 using Landsat images of TM, ETM+ and OLI sensors, respectively. After geometric and radiometric corrections, the land cover map of 2015 was prepared based on the three methods. The results of the validation mapping methods revealed that object-based method was more promising than the others with 93 and 90% for total accuracy and Kappa coefficients of agreement, respectively. So, the object-based segmentation method is recommended for monitoring of land cover changes. The results of the land cover change indicated that residential areas increased from 1.727% in 1999 to 2.98% in 2015 and agricultural lands increased from 5.73% to 12.60% but rangelands were decreased by 9.05 in total. Moreover, bare-lands were increased from 1999 to 2009 by 6.19% but decreased from 2009 to 2015 by 5.27%. The result of this study showed that the object-based method is superior to pixel based method of Maximum-liklihood and neural network. So, object-based segmentation is recommended for estimating land cover changes.
Roholah Zeynivand; Majid Ajorlo; Ali Ariapour
Abstract
This study aimed to investigate the effects of livestock grazing intensities (lenient, moderate, heavy and no-grazing) on herbaceous plant species composition and diversity (grasses and forbs) in understory of Quercus spp. and Pistacia spp. forest in Kebirkouh Mountain, Darehshahr city, Ilam Province, ...
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This study aimed to investigate the effects of livestock grazing intensities (lenient, moderate, heavy and no-grazing) on herbaceous plant species composition and diversity (grasses and forbs) in understory of Quercus spp. and Pistacia spp. forest in Kebirkouh Mountain, Darehshahr city, Ilam Province, Iran. Vegetation sampling was carried out with randomized-systematic method at flowering time of the dominant plant species in April 2017. Within each quadrat, number of species, name of plants, density, life form and palatability class were recorded for herbaceous plants. Species diversity with the Simpson’s and Shannon-Weiner indices, species richness with Margalef and Menhinick indexes, and evenness with Peet and Sheldon indices were calculated in Ecological Methodology software version 6.1.4. The highest value of Simpson index for grasses and forbs was 0.972 (moderate grazing) and 96.95 (exclosure). Also, the highest value of Shannon index for grasses and forbs was 4.51 (heavy grazing) and 4.56 (heavy grazing), respectively. The highest richness of grasses and forbs was observed in grazed area with moderate intensity and no-grazing area, respectively. In the area without grazing, the richness of forbs was 4.4 and 2.75 according to Margalef and Menhinick indexes. The values of the Margalef and Menhinick richness indexes for grasses in grazed area with a moderate intensity were18 and 15 percent higher than the grazed area with heavy intensity. Peet and Sheldon evenness indexes were the highest for grasses and forbs in heavily grazed area and the lowest for grasses in the moderate grazing intensity and for forbs in the exclosure.
Arash Malekian; Mahsa Mirdashtvan
Abstract
Nowadays, with the increasing exploitation of groundwater resources, optimal use of these resources is more and more necessary. geostatistical methods can be used to assess and monitor the quality of groundwater resources. Hashtgerd Plain is the case study of this investigation. In this study firstly, ...
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Nowadays, with the increasing exploitation of groundwater resources, optimal use of these resources is more and more necessary. geostatistical methods can be used to assess and monitor the quality of groundwater resources. Hashtgerd Plain is the case study of this investigation. In this study firstly, by using data from qualitative data which were harvested from 41 Piezometric wells, different qualitative parameters were evaluated, then by using the geostatistical methods such as: Kriging, Co-kriging and IDW the best model for mapping for aquifer quality classification was selected. Results showed that most of the indicators are better simulated by Co-kriging method, based on mutual evaluation and RMSE. The parameters of SAR and EC were selected in order to determine the irrigation water quality parameters according to Wilcox diagram. Based on these two parameters by using ArcGIS v.10 software zoning maps were prepared. Results showed that 99% of the aquifer is classified in the category of good quality irrigation water (C2S1) and 1% level in the aquifer is classified as middle class (C3S1) based on Wilcox diagrams. The results of the study can be used in aquifer management and irrigation management in the agricultural purposes.
Farshad Soleimani; Naser Brumand; ali azareh
Abstract
In recent decades, increasing population growth and development of agriculture have increased groundwater consumption and decreased the quality of groundwater resources of most parts of the country. Given the importance of this issue, present study investigates the spatial and temporal changes in parameters ...
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In recent decades, increasing population growth and development of agriculture have increased groundwater consumption and decreased the quality of groundwater resources of most parts of the country. Given the importance of this issue, present study investigates the spatial and temporal changes in parameters of calcium, magnesium, pH, chloride, sodium sulfate and water in Jiroft plain. The data was obtained from 40 wells in the region of Kerman province over which in 2002-2012 water harvesting and qualitative analysis had been done. In this regard, after normalizing the data, the accuracy of different geo-statistical methods including the Kriging and inverse distance weighted were evaluated and then the map of the spatial zoning was prepared in the software quality parameters ArcGIS9.3 using the best method of interpolation. The results showed that the amount of pH, Sodium, Chlorine, and Sulfate increased but the amount of calcium and magnesium declined. But in general, in 2012the quality of groundwater resources of Jiroft plain decreased compared to 2002 and the trend of changes showed water quality reduces toward the South and West.
sadat feiznia; Meisam Samadi; Teimur Teimurian
Abstract
The age determination of sediments is usually performed by different methods, all of them need a lot of cost, effort and research facilities. The goal of this research is to compare the results of sediment granulometery with precipitation data to perform chronology of sediments. In this study four check ...
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The age determination of sediments is usually performed by different methods, all of them need a lot of cost, effort and research facilities. The goal of this research is to compare the results of sediment granulometery with precipitation data to perform chronology of sediments. In this study four check dams were selected and profiles were drilled in their sediments. Then sediment sampling was performed in different horizons based on texture and color of the sediments. Granolumetric analyses were performned on samples and the results were analyzed by Gradistat Software. Long-term (45 years) rainfall statistics of Zanjan Station was obtained from Zanjan Meteorological Office for determination of low-water and high-water periods using PNPI (Percent of Normal Precipitation Index). The results of granolumeteric analyses were compared with the results of rainfall analyses which showed that sandy texture relates to high-water and silty texture to low-water periods. The results showed that in thirteen samples from seventeen samples, there is complete conformity between granolumetric and climatic results and that accurate recognition of high-water and low-water periods can be reached using granolumetric characteristics.The age of sediments in four small dams is as follow: Sediments of profile one were deposited between 2005 to 2011, profile 2 between 2006 to 2011, profile 3 between 2008 to 2011 and profile 4 between 2008 to 2011 years. Using sediment chronology of each horizon in sediment profiles, sediment yield potential of upland drainage basin of each small dam in different temporal phases can be estimated.
tayebeh sohrabi; Abbas Ali Vali; Abolfazl Ranjbar Fordoei; sayed Hojat Mousavi
Abstract
Dust event is one of the secondary complications of ecosystem in arid and semi-arid areas. This phenomenon results from system feedback against multiple factors of pressure and destruction. One of the most important foundations of ecosystems is vegetation. Because the vegetation factor reflects many ...
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Dust event is one of the secondary complications of ecosystem in arid and semi-arid areas. This phenomenon results from system feedback against multiple factors of pressure and destruction. One of the most important foundations of ecosystems is vegetation. Because the vegetation factor reflects many factors in the ecosystem, therefore, the interaction of factors can be understood by studying the relationship between its changes and other factors such as dust phenomena. The aim of this study was to investigate the effect of vegetation and relationship with dust events in Esfahan province during 2000-2016 using Geographic information system and Normalized difference vegetation index. The data of dusty days in the region synoptic stations were provided from Meteorological Organization and the frequency of dusty days in different years were determined. Using the method of Normal Kriging in GIS; dusty days were zoned. Vegetation map was prepared based on NDVI in July for each year using MODIS image. The regression analysis of annual dust and vegetation index were also performed to quantitatively analyze the effect of vegetation cover on the occurrence of dust.The results showed. Vegetation cover has been the lowest during the study period in the east and center of the province. The NDVI was also the lowest in 2011-2012 and 2015, with a change from 0.69 to -0.19. The results showed significant correlation between the number of dust event and vegetation distribution
Mohsen Maleki; reza ghane moghaddam
Abstract
This article investigate the effects of watershed interventions Ghareh-shiran watershed, Ardebil province. In this paper, five socio-human, economic and environmental-physical capital were investigated. Thestatistical population of this research was informed users of six villages covered by the project ...
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This article investigate the effects of watershed interventions Ghareh-shiran watershed, Ardebil province. In this paper, five socio-human, economic and environmental-physical capital were investigated. Thestatistical population of this research was informed users of six villages covered by the project execution and five villages outside the project execution area in the same watershed. Using the Morgan table, 200 households were surveyed using targeted sampling. The research tool was a questionnaire. Its reliability was estimated using Cronbach's alpha coefficient (0.7 to 0.8). The results showed that between socio-human capital and environmental-physical capital at the place of execution, there was a difference between project and its non-implementation. There is no difference in financial capital at the place of execution and non-execution. There was no significant difference in social capital between the two regions in terms of group membership, tendency to migrate and social trust. In human capital, there was no difference between the two regions in the level of awareness. In natural and physical capital, indices of garden-dry land and irrigated land, flood damage and number of livestock were considered, which were significant at 98% level. In financial capital, the basin income index was considered to be no different between the executed and non-executed areas. The results show that although beneficiaries' livelihood are directly dependent on natural resources, watershed management projects have been effective on natural and physical and to some extent social capital of the area and in particular it has not been able to increase income and job opportunities in the region.
Arash Malekian; Mahrou Dehbozorgi; Amir Houshang Ehsani; Amir Reza Keshtkar
Abstract
Consecutive droughts in Sistan and Baloochestan province cause water resources restriction and this isa very significant problem for this region. In this study, in order to forecast the drought cycle in 9climatological stations in the province, we used Artificial Neural Networks. The input data wereaverage ...
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Consecutive droughts in Sistan and Baloochestan province cause water resources restriction and this isa very significant problem for this region. In this study, in order to forecast the drought cycle in 9climatological stations in the province, we used Artificial Neural Networks. The input data wereaverage of annual rainfall data in all stations and also deciles precipitation index, which the first 30years from 1971 to 2000 used for training the network and the last 8 years from 2001 to 2008 forsimulating it. The network consists of Multilayer Perceptron (MLP) and Back Propagation Algorithm(BP) and also sigmoid transfer function. Number of Neurons in hidden layer was 10 with 1-10-1structure and was calculated based on the lowest RMSE. Then drought prediction was done in neuralnetwork with the trained algorithm and without using actual and observed data in 2009 to 2012.Results showed that, the network was able to simulate and forecast DPI index with 97% regressionand average RMSE error less than 5%. According to drought indices, results showed that the droughtwill have an increasing trend in all stations in this region in 2009 to 2011. Therefore, by using thismethod, drought can be predicted in later years without any need to have actual meteorological dataand also can be used in water resources management, drought management and climate changes.
afshin sadeghirad; Hossein azarnivand; mohamad jafari; mohamadali zarechahoki
Abstract
Nowadays climate change, is the most significant threat in terms of sustainable development, particularly in developing countries. So regarding to rangeland ecosystems and their ability is a Particular attention to sequester carbon. This study aimed to assessing the carbon sequestration potential of ...
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Nowadays climate change, is the most significant threat in terms of sustainable development, particularly in developing countries. So regarding to rangeland ecosystems and their ability is a Particular attention to sequester carbon. This study aimed to assessing the carbon sequestration potential of natural and planted ranges through selected three species S. barbata, S.rigida and A.canescens. sampling from vegetation and soil have done along three 200 meters parallel transects by Systematic - random method. So that were taken 30 vegetable and 36 soil samples which were measured the organic carbon plants samples and some physical and chemical properties of soil In the laboratory. Then, by multiplying the amount of organic carbon in soil bulk density, was calculated total weight of carbon sequestration in soil depth. The results showed that among the three sites, the depth first of the soil, the amount of silt, sand, organic carbon, PH and EC (electrical conductivity) and In the second depth of the soil, the amount of silt, organic carbon, nitrogen, PH and EC there was a significant difference at 5% level. The comparison of carbon sequestration to the total habitat by Duncan's test showed that all three species were significantly different from each other at 5% level, So that the greatest amount of carbon stored is in the A.canescens planting of rangeland (39/84 ton/ ha) and the lowest Natural rangeland S.rigida (36/24 ton/ha), However the Natural range S.barbata was intermediate between both other species (31/34 ton/hac).
razie shahbandari; Hossein Arzani; naser baghestani meybodi; Mohammad Ali Zare Chahouki
Abstract
The most important factor affecting forage quality is phenological stage that if it is recognized correctly, the appropriate grazing time will be determined. In this study, four species including Artemisia sieberi, Salsolakerneri, AelieniasubaphyllaandEurotiaceratoides in different phenological stages ...
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The most important factor affecting forage quality is phenological stage that if it is recognized correctly, the appropriate grazing time will be determined. In this study, four species including Artemisia sieberi, Salsolakerneri, AelieniasubaphyllaandEurotiaceratoides in different phenological stages (vegetative, flowering and seedling) were sampled. Samples were taken from the rangelands of Nodooshan-Yazd in 1389 and 1390. At each stage, five replicates for each plant species were selected and at least five vegetable bases from different locations of vegetation type in the region were selected. Samples were grinded after drying and separating different parts (flower, leaf and stem) and then they were analyzed using infrared spectroscopy in the laboratory. Important indicators of quality such as crude protein (CP), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolic energy (ME) were determined. Results showed that the highest percentage of crude protein is found in leaves of A. subaphyllaand in vegetative stage (9.19%), highest percentage of ADF is in shoot and in seedling stage (53.42%) and the highest percentage of DMD (48.13%) and the highest amount of metabolic energy (6.18 MJ/KgDM) is in leaves of A. sieberi and in vegetative stage, respectively. The end of the vegetative period can be considered the best time for grazing.
Leila Fazel Dehkordi; Hossein Azarnivand; Mohammad Ali Zare Chahouki; Farhad Mahmoudi Kohan; Shahram Khalighi Sigaroudi
Abstract
To identify an appropriate index for monitoring and evaluation of drought, rainfall data obtainedfrom meteorological stations of Ilam Province from 2000 to 2011 and MODIS satellite images with16-day intervals were collected and processed. The Standardized Precipitation Index (SPI) wascalculated based ...
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To identify an appropriate index for monitoring and evaluation of drought, rainfall data obtainedfrom meteorological stations of Ilam Province from 2000 to 2011 and MODIS satellite images with16-day intervals were collected and processed. The Standardized Precipitation Index (SPI) wascalculated based on rainfall data; therefore, the rainfall data were used for measuring SPI andsatellite images were used for calculating NDVI. Also, the percentages of canopy cover in rangetypes were selected from the information of the National Evaluation of rangelands in differentclimatic zones. The correlation between SPI and NDVI and also canopy cover and NDVI wasexamined. The relationship between vegetation index (NDVI) and SPI was determined byregression. The results of SPI showed that in 2000 a severe drought and in 2006 a medium wetoccurred in rangelands of Ilam Province. NDVI value variations have as well confirmed it. Theresults showed that NDVI and life form (annual forb and annual grass) has the highest percentage ofcorrelation. Also examining of result showed that most correlation of SPI and NDVI was in 3 and 6-months intervals. Evaluation of regression models performance in range types described thatmodels in 3 and 6- months intervals was suitable for monitoring drought. The result of regressionconfirmed that NDVI was an appropriate index for monitoring and assessment of drought.
Alibeman Mirjalili; Mohammad Musaei Sanjeraei; Shahabodin Zarezadeh Mehrizi
Abstract
A better understanding of rangeland vegetation cover and its variation in different years basedon wetness and droughtiness fluctuations is a great importance. Economical priority setting ofrangelands is based on variations in rainfall and drought patterns, because it yields to bettercharacterization ...
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A better understanding of rangeland vegetation cover and its variation in different years basedon wetness and droughtiness fluctuations is a great importance. Economical priority setting ofrangelands is based on variations in rainfall and drought patterns, because it yields to bettercharacterization of vegetative cover. Yet a comprehensive and continuous monitoring ofvegetative cover of rangelands has not been established. To study the influence of droughtinessand wetness on vegetation cover and production forage, 11 sampling areas and 3 referenceareas were selected in Herat. Three 100-m transects were located 25-m apart within eachsampling area. Production and cover were estimated within 10 located 2- plots along eachtransect. Data were analyzed using Duncan›s test Design a completely random with a factorialGLM procedure at 99% and 95% confidence levels. Results showed that the vegetation coverand production in wetness were significantly different from those in droughtiness (P<0.01).The vegetation production and cover increased by 36.3% and 34% respectively in the wetnesscompared to the droughtiness. The influence on production and cover was positive and efficientin the wetness with the average rainfall higher than the 30-yr average. Finally, the results offlood spreading increased vegetation cover and production forage in dams.
Javad Motamedi; Arezu Alizadeh; Azadeh Alemzadeh Gorji
Abstract
Plants change their environment characteristics and especially soil properties while their growth and adaptation, to develop plant communities. In this study effect of halophyte patches from Urmia lack in a vegetation type of Salsola nitraria and Aeluropus littoralis on chemical and physical properties ...
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Plants change their environment characteristics and especially soil properties while their growth and adaptation, to develop plant communities. In this study effect of halophyte patches from Urmia lack in a vegetation type of Salsola nitraria and Aeluropus littoralis on chemical and physical properties of soil was investigated. So 4 vegitation patches along 2 transect with the length of 150 meter that was established in parallel position with the slop was selected and the distances between these patches considered as bare soil. Then soil samples were collected with four replication from the patches and inter patches areas from two different depths of 0-15 cm and 15-30cm, then soil samples were air dried and some of their properties were measured. Independent T-test was performed to compare soil properties of patches and inter-patches. Results showed that vegetation patches had significant effect on decrease of electrical conductivity and soluble salts of sodium, potassium and total phosphorus in soil samples of surface profile (0-15cm) but soil acidity, nitrogen content, organic matter, sand, silt and clay percent showed no significant differences in soil samples of patches and inter patches areas.
Then comparing these properties in soil samples of second depth (15-30cm) showed that there wasn’t any significant differences between patches and inter-patches, and these results shows effect of vegetation patches and specially their roots on changing properties of surface soil in this study’s experimental field.
sahar ghafari; Ardavan Ghorbani; mehdi moameri; Raoof Mostafazadeh; Mahmood Bidar lord; Azad Kakemami
Abstract
The aim of this study was to investigate the effects of topographic, edaphic, climatic and landscape metrices on the distribution of plant communities in the altitude gradient of Moghan-Sabalan rangelands in Ardebil province. To determine and study the ecological species groups, 28 sites and 840 one ...
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The aim of this study was to investigate the effects of topographic, edaphic, climatic and landscape metrices on the distribution of plant communities in the altitude gradient of Moghan-Sabalan rangelands in Ardebil province. To determine and study the ecological species groups, 28 sites and 840 one square meter sampling plots were samples by the random systematic method. To determine soil factors, soil samples were collected from each site from 0–15 and 15-30 cm depth and physicochemical parameters were measured at the lab. Using TWINSPAN, vegetation of the study area was classified and then PCA and CCA were used to investigate the relationship between species and environmental factors. According to TWINSPAN results, four ecological groups were identified. The first ecological group is located in the opposite direction of elevation, slope, rainfall and patch area gradients, and the same direction with pH, clay and dispersible clay (the first depth), bulk density, edge density and patch area (coefficient of variation). The second and third ecological groups are located in the interfaces of the first and fourth ecological groups in terms of plant composition and environmental conditions. These two groups prefer the middle elevations. The fourth ecological group at the end of the elevation, rainfall, slope, patch area and inverse direction of clay and dispersible clay (the first depth) and typically prefer high altitudes and light texture soils.
