Mohammad Golshan; Abazar Esmaili; ali afzali; Afshin Jahanshahi
Abstract
Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed ...
Read More
Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed with area 67.8 square kilometers in Mazandaran province. To prepare the Requirements maps for running HEC-HMS model was used HEC-GeoHMS extension. Hyetograph data with 15 minutes time step and its related hydrograph was entered to two models based on 1 hour time step. Then simulation of the flood hydrograph was done based on 15 minutes time step. CP and RE% statistical coefficients was used for evaluation of models performance. Values of this coefficients using the HEC-HMS model for flood 26 November 1994 was calculated 0.72 and 118.26 respectively and for flood 6 October 1996, 0.89 and -24.63 respectively and using the implementation of IHACRES model these coefficients in the first flood was calculated 0.63 and 152.4 respectively and in the second flood 0.79 and -35.6 respectively. The results showed that both use models have acceptable performance for simulation of flood hydrograph in this area and HEC-HMS model has better performance in compared with IHACRES model.
Morteza Saberi; vahid karimian
Abstract
The studies of functional features of patches of rangelands will help effectively in the detection the healthiness of arid and semi-arid rangelands, the improvement of soil conditions as well as the recognition of the effects of managerial and natural changes of rangelands. In order to investigate the ...
Read More
The studies of functional features of patches of rangelands will help effectively in the detection the healthiness of arid and semi-arid rangelands, the improvement of soil conditions as well as the recognition of the effects of managerial and natural changes of rangelands. In order to investigate the function of landscape, sampling from Niatak region of Sistan was conducted in the same condition that had some native plant species such as Alhagi camelorum and Salsola rigida and two planted species namely Tamarix ramosissima and Haloxylon persicum. Effect of these plant pots was investigated on characteristics of ecosystem function. 4 transect with 150 meters long was established and 11 soil surface indices was determined by using of three characteristics of stability, infiltration and cycling of nutrient from LFA method. The results indicated that two planted plant species had higher function rather than native plant species and differences were significant. Tamarix ramosissima had the highest function among the native and established plant species. In general, high function in planted patches ecological could be suggested to select suitable species in restorations of similar rangeland.
Mohamad reza Akhundi; Hedaiatollah Mirshamsi; Seyed Hoseyn Moussavi nia
Abstract
Collaborative governance strengthens the relationship between different beneficiaries in line with up-bottom approach to natural resources management. Social capital is one of the major components contributing to the collaborative governance of natural resources. Accordingly, the level of social capital ...
Read More
Collaborative governance strengthens the relationship between different beneficiaries in line with up-bottom approach to natural resources management. Social capital is one of the major components contributing to the collaborative governance of natural resources. Accordingly, the level of social capital of local beneficiaries was investigated both prior and post collaborative project implementation through the measurement of trust and collaboration ties as well as the measurement of whole network quantitative and mathematical indexes (density, reciprocity, transitivity, and Geodesic distance). Present study was carried out in AsadAbad Sofla village in Abarkuh district of Yazd province as a part of carbon sequestration project. It was revealed that all above-mentioned indexes increased following project implementation during two years (from 2014 until 2016. Density of trust and collaboration ties increased hugely. In other words, bonding social capital enhanced. Consistency and the balance of network was average pre-project implementation but these indicators increased to higher levels. The unity of beneficiaries increased significantly and considerable improvement in trust ties was observed. Therefore, following the implementation of carbon sequestration project, trust building and reinforcement of cooperation occurred and bonding social capital strengthened which left positive effects upon the collaborative governance of natural resources.
Mahdi Ghorbani; Mahrou Dehbozorgi
Abstract
Nowadays, a lot of natural resource co-management plans due to lack of attention to stakeholders’characteristics and position in network of social relationships have failed. Actors or key personnel’srecognition has been one of administrative requirement of natural resources co-management ...
Read More
Nowadays, a lot of natural resource co-management plans due to lack of attention to stakeholders’characteristics and position in network of social relationships have failed. Actors or key personnel’srecognition has been one of administrative requirement of natural resources co-management plans.The most influential actors in environmental decisions making can be identified based on stakeholdersand network analysis. This study is aimed to determine the social powers based on network analysisapproach and stakeholders analysis at the local users level of common rangeland of Nariyan village inTaleghan region. In this study, first, Rangeland users were identified based on survey methods thentrust and cooperation matrixes are produced and then degree centralities index and betweennesscentrality were computed by questionnaire finally each actor’s topology has shown in the network.The result of this research is effective in identifying actors with central position that perform a keyrole in Nariyan rangeland co-management plan. Also, the result of this study can assist naturalresource managers and planers in identifying social powers in order to organize and implement thesustainable landscape management plans.
hosain kaffash; mostafa taleshi; hosain rahimi
Abstract
Government policies and investments that have been made in the past few decades with the aim of sustaining rural settlements have not reached desirable results, but today, most villages have adapted and adapted to environmental crises such as water crisis, adaptability and less agitation. In this research, ...
Read More
Government policies and investments that have been made in the past few decades with the aim of sustaining rural settlements have not reached desirable results, but today, most villages have adapted and adapted to environmental crises such as water crisis, adaptability and less agitation. In this research, policy and government investments in arid areas have been investigated and by means of quantitative and quantitative analysis, the effect of the above measures on reducing the water crisis is explained. The research is a descriptive and inferential goal from a strategic point of view, from surveying strategy, from the point of view of the causal nature and from the point of view of the method of collecting field data and documentation. The statistical population is 4626 rural households. The sample size with the Cochran formula is 354 people. In data analysis, the structural equation modeling model with partial least squares method and Smart PLS2 software were used to examine the conceptual model. The internal structure of the questionnaire and the convergent validity were determined using the results of the verifiable factor analysis and the mean of variance explained by AVE. For this purpose, standardized load factors were calculated and the AVE index was calculated for all items and variables. The test of assumptions proves that limited government actions in the past 10 years have had no effect on the reduction of the water crisis in the research area and the process of instability of rural settlements has not stopped.
ALIREZA Arabameri; kourosh shirani; Mahdi Tazeh
Abstract
Present study seeks to identify effective factors in landslide occurrence and landslide sensitivity zonation using logistic regression and multivariate linear regression. Accordingly, through the interpretation of arial photos with scale of 1:40000, geological, topographic maps, and field survey using ...
Read More
Present study seeks to identify effective factors in landslide occurrence and landslide sensitivity zonation using logistic regression and multivariate linear regression. Accordingly, through the interpretation of arial photos with scale of 1:40000, geological, topographic maps, and field survey using GPS, landslide hazard map was prepared as dependent variables. For determination of effective factors in landslide occurrence, using Support Vector Machines in Rapid Miner Software, the numerical values of the parameters were analyzed and from 21 selective data layers, 15 data layers were selected and were prepared and digitized for zonation map as the independent variable in ArcGIS 10.1. After weighing the layers, zonation map was prepared using selective method in five classes: very low, low, moderate, high and very high. Result of weighting layers showed that in both methods, land use and aspect have the greatest impact on landslides. The ROC (Receiver operating characteristic) curves and area under the curves (AUC) for landslide susceptibility maps were constructed and the areas under curves was assessed for validation purpose and its values showed that multivariate linear regression model (0.890) has a higher efficiency than the logistic model (0.829) for landslide hazard zonation. According to result of superior model (multivariate linear regression), 16046.1 hectare (20.13%) of the region was found to be located in high risk class and 15671.2 hectare (19.66%) was in very high risk class.
Mehdi Ghorbani; Vahid Jafarian; Mohammad Reza Yazdani; Mahsa Abdolshahnejad
Abstract
Achieving integrated natural resource management fundamentally needs effective and coordinatedrelationship, collaboration, and synergy among various actors who have common but differentresponsibilities. In this sense, the foundation of comprehensive and integrated management is notcompatible with centralization ...
Read More
Achieving integrated natural resource management fundamentally needs effective and coordinatedrelationship, collaboration, and synergy among various actors who have common but differentresponsibilities. In this sense, the foundation of comprehensive and integrated management is notcompatible with centralization and top-down strategies. The aim of this paper is analysis of networkand organizational cohesion of natural resources stakeholders in Semnan province. In this study,relations of existing organizations within the network have been investigated based on interorganizationalinformation transfer and collaboration through social network analysis method andapplying macro-level and middle indexes of institutional network including; the network size,density, ties reciprocity, and centralization at macro-level and core-periphery index at middle level.Policy monitoring emphasized in present paper’s title refers to this question that how successfullynatural resource integrated management policies have been realized at least within the fourth andfifth development programs. Therefore, present study is an attempt to address this questionquantitatively and relying on the results of indexes of structural analysis of natural resourcestakeholders’ network in the pilot area. The results of this study indicate that institutional cohesionis 40 percent (poor) and sustainability of institutional network based on reciprocity is about 47percent (medium). Additionally the core-periphery index showed that the density of institutionalnetwork of Semnan province in core actors’ subgroup is 77 percent and in periphery actors’subgroup is 25 percent. Research findings identify existing capacities for applyin integrated naturalresources management and reveal the necessity of reducing network centralization andstrengthening the relationship among various stakeholders of this section.
Aliakbar Nazari Samani; Hesam Heravi; Mehdi Panahi; Masoud Jafari Shalamzari
Abstract
Natural landscape alternation is a problem that has been under debate for a long time. Landutilization techniques like agriculture, forest and rangelands, residential and urban are amonginfluential criteria affecting erosion severity and sediment yield in a given region. In this respect,land management ...
Read More
Natural landscape alternation is a problem that has been under debate for a long time. Landutilization techniques like agriculture, forest and rangelands, residential and urban are amonginfluential criteria affecting erosion severity and sediment yield in a given region. In this respect,land management is a promising option to mitigate it. Thus, acquaintance with quantitative soilerosion owing to land-use changes is of great importance for estimating disadvantages andlatent and intangible symptoms of erosion. Strategic planning for sustainable developmentcould be benefited from such knowledge. The current research considered a statistical periodfrom 1970 to 2004. This period was sub-divided into two separate periods from 1970 to 1987and from 1987 to 2004. During these periods, statistics relating to sedimentation, climatology(precipitation) and hydrology were analyzed. Results revealed that the sediment reduction inthese two periods under similar rainfall would be as a result of an increase in abandoned areas.
mohammad mirzavand; Hoda ghasemieh; mahmud akbari; seyed javad sadatinejad
Abstract
Kashan aquifer is adjacent to Salt Lake. Because of this adjacency, the saline water of the lake has moved to the aquifer. In this study groundwater quality of the aquifer was simulated using Artificial Neural Network (ANN) model. For this purpose, the dominant ion of water was first determined by Piper ...
Read More
Kashan aquifer is adjacent to Salt Lake. Because of this adjacency, the saline water of the lake has moved to the aquifer. In this study groundwater quality of the aquifer was simulated using Artificial Neural Network (ANN) model. For this purpose, the dominant ion of water was first determined by Piper diagram. Results showed that the sodium chloride is the dominant ion of water and so it was selected as the target variable to be simulated So the output variable of the ANN model was the concentration of sodium chloride in current year while the input variables were the water table of groundwater, yearly rainfall and the concentration of sodium chloride in previous year. Result showed that Multilayer Perceptron ANN model has better result in predict of chlorine concentration compared to Radial Basis ANN model. The sensitivity analysis showed that concentration of chloride in previous year and water table of groundwater are the most important variables in the ANN model respectively.
zahra Abdolalizadeh; Ardavan Ghorbani; Raoof Mostafazadeh; Mehdi Moameri
Abstract
The purpose of this research is to facilitate the quantitative evaluation of various ecological factors in determining the rangeland condition by four-factors method and six-factors method using mainly structural variables of vegetation. In this study, the condition of 28 sites located in the northern ...
Read More
The purpose of this research is to facilitate the quantitative evaluation of various ecological factors in determining the rangeland condition by four-factors method and six-factors method using mainly structural variables of vegetation. In this study, the condition of 28 sites located in the northern part of Ardebil province was determined by 4 and 6 factors methods, separately for grassland and shrubland habitats, and some parameters of vegetation were quantitatively measured. The results of condition determination were compared in the two mentioned methods. Finally, using Pearson correlation test, the relationship between variables of vegetation and the scores of rangeland condition were compared and regression relations were extracted. The results indicated that the average score of the rangeland condition in the modified four-factors in both grasslands and shrublands (69 and 60 scores, respectively) was higher than the six-factors method (64 and 54 respectively), and paired t-test comparison showed a significant difference (P≤ 0.05) between the two methods. Also, the results showed that variables such as canopy cover of decreasing specious canopy cover, forbs canopy cover, annual forbs canopy cover and production had the most significant positive relationship (P≤ 0.05), and the variables of invaders and pebble-gravel cover had the highest negative correlation (P≤ 0.05) with rangeland condition. The results of extraction of multivariate linear regression models by step-by-step method showed strong relationship (R2=68.46-88.41) between evaluated variables with condition score. Also, validation analysis of the models indicated the ability of both methods to predict the rangeland condition score.
Mohsen Farzin; Aliakbar Nazari Samani; saeideh menbari; sadat feiznia; gholamabbas kazemi
Abstract
This research tries to show the role and importance of karst formations in the infiltration of surface flows and recharge of groundwater resources in the region by determining the lineaments of geological formations in watersheds leading to the Persian Gulf and explaining the relative contribution of ...
Read More
This research tries to show the role and importance of karst formations in the infiltration of surface flows and recharge of groundwater resources in the region by determining the lineaments of geological formations in watersheds leading to the Persian Gulf and explaining the relative contribution of each formation. For this purpose, The closest sub-basins to the Persian Gulf from the four basins of the rivers including Mond, Helleh, Kol-Mehran and Zohreh, to extract the lineaments, draw rose diagram and analyze them using ENVI® 5.3 software, PCI Geomatica, GIS10.3.1 and Rock works 2016 was selected. Initially, the frequency, density, intersection, direction, size and intensity of the lineaments in the formations of the region were determined. Then, by explaining and defining the lineament index, the importance and impact of each formation in the potential recharge of groundwater resources were determined. The results show that the highest percentage of frequency, intersection percentage and length of lineament are attributed to Asmari-Jahrom Formation and the highest percentage of Lineament intensity to Ilam-Sarvak Formation; the numerical value of the lineament intensity in the karst formations is three times as non-karstic formations. In general, the investigation of the condition of the lineament shows that the lineaments are basically created in the karst formations, so that the numerical value of the lineament index in the karst formations is 72.7, while the value in the non-karstic formations is 2.3. Furthermore, orientation of lineaments according to their frequency and length, in the whole range of study,
saeedeh Nateghi; Rostam Khalifehzadeh; Mahshid Souri; Morteza Khodagholi
Abstract
Soil organic carbon is one of the most important indicators of soil quality. The purpose of this study is to study the spectral and non-spectral behaviors of soil in order to estimate the organic carbon of topsoil using factor analysis and multiple regression methods in the semi-steppe rangelands of ...
Read More
Soil organic carbon is one of the most important indicators of soil quality. The purpose of this study is to study the spectral and non-spectral behaviors of soil in order to estimate the organic carbon of topsoil using factor analysis and multiple regression methods in the semi-steppe rangelands of Asuran, Semnan province. Soil sampling was performed using stratified random sampling method. After creating a map of homogeneous units in the area, in each homogeneous unit according to its area, several sampling points were selected completely randomly. A total of 145 sampling points were collected. At each sampling point, a composite soil sample (a mixture of 9 observations) was taken. Soil organic carbon was measured using Valkyli-Block titration method. Data of 114 samples were used to calibrate the model and data of 31 samples were used to validate it. The results showed that the correlation of spectral variables obtained from Landsat OLI sensor with surface soil organic carbon is higher than non-spectral variables obtained from 1: 25000 topographic maps. Also, the results of factor analysis by principal component analysis with eigenvalues greater than one showed that the total cumulative variance explained by 14 variables was equal to 90.2%, which was explained by three factors. The regression equation generated by the three extracted factors had suitable potential for predicting surface soil organic carbon (R2 = 0.59). The root mean square error (RMSE) of the proposed model was calculated to be 0.3.
Ali Akbar Mehrabi; Mohammad Mohammadi; Mohsen Mohseni Saravi; Mohammad Jafari; Mehdi Ghorbani
Abstract
Providing of landing use maps and detecting of land capacity are required to manage of natural resources and environment and planning of land use. On the other hand, it is necessary to detect of the human deriving forces affecting land use change. In this research, we selected Seyed mohaleh and Drasara ...
Read More
Providing of landing use maps and detecting of land capacity are required to manage of natural resources and environment and planning of land use. On the other hand, it is necessary to detect of the human deriving forces affecting land use change. In this research, we selected Seyed mohaleh and Drasara villages in Tonekabon city. First, were provided the land use maps in 1987 and 2008 by using TM and IRS Satellite images. Second, were investigated the human deriving forces affecting land use change through survey methods. According to results of this research can state that had been destroyed much percents of forests and added residential and agricultural lands in two villages. The most important of land use changes in two villages related to the economic problems (low income) and the economic loss of agricultural activities. Recently, the most important deterrent forces of land use changes are the property market downturn and land price that can prevent of severe changes in land use through the implementation of efficient land use law and supporting of farmers and gardeners in this region. Moreover, the most important indicators in the intensification of land use changes are being a tourist area, increasing of land price and unemployment.
Seyed Alireza Mousavi; Hossein Arzani; Gholamali Sharzei; Hossein Azarnivand; Mahdi Farahpour; Stephani Engel; Esmail Alizadeh; Aliakbar Nazari-Samani
Abstract
Soil conservation is one of the most important regulative functions of natural ecosystems. This function is of high importance in Taleghan Watershed due to high erosion quantity and sediment accumulation in Taleghan Dam reservoir. Soil loss reduction, sedimentation control and fertility conservation ...
Read More
Soil conservation is one of the most important regulative functions of natural ecosystems. This function is of high importance in Taleghan Watershed due to high erosion quantity and sediment accumulation in Taleghan Dam reservoir. Soil loss reduction, sedimentation control and fertility conservation were considered as different aspects of soil conservation. Effect of land use and vegetation cover on soil conservation was studied by overlaying soil erosion map with other environmental data layers. Abandoned rainfed lands with low cover were considered as benchmark to evaluate the role of rangeland vegetation cover in soil conservation. Economic value of soil loss reduction function was estimated using opportunity cost approach and the benefits of rainfed agriculture. Economic value of sedimentation control also was calculated considering SDR ratio and avoided cost approach. Soil fertility conservation was quantified regarding the volume of soil conserved and nutrient content of soils of the study area. Economic value of this function was estimated using replacement cost approach. Results show that Mid-Taleghan rangelands conserve 60545 cubic meters of soil per annum. Annual economic value of soil loss reduction, sedimentation control and fertility conservation functions were estimated about 6262, 25287 and 8626 US dollars, respectively. These functions are just some limited aspects of rangeland functions and economic valuation of these functions could effectively be utilized for conservation of rangeland ecosystems.
.
kazem Nosrati; Mohsen Mohseni Saravi; Hasan Ahmadi; Hosein Aghighi
Abstract
Estimation of evapo-transpiration is necessary in cases such as irrigation planning, determining of evaporation of the water bodies, water balance assessment, estimation of runoff and watershed management and ecological and meteorological studies. Evapo-transpiration can be determined precisely using ...
Read More
Estimation of evapo-transpiration is necessary in cases such as irrigation planning, determining of evaporation of the water bodies, water balance assessment, estimation of runoff and watershed management and ecological and meteorological studies. Evapo-transpiration can be determined precisely using field measurements. However, these methods provide evapo-transpiration just for limited areas from spatial point of view. This limitation has motivated the development of using remote sensing data to evaluate evapo-transpiration over vast area. Surface Energy Balance Algorithm for Land (SEBAL) is a new model that has been used at different areas all over the world for estimating of evapotranspiration. Due to the fact that no written report in evapo-transpiration estimation using this algorithm in the country has been published yet, the objective of this study is to investigate the validation of revised SEBAL model in mountainous region. In this project, actual evapo-transpiration values were estimated using MODIS image data and revised SEBAL model for mountainous region in 22 different dates in 2006 in Taleghan Drainage Basin. The result showed that the correlation between estimated and measured values is significant (R2=0.88, p<0.001). Thus, MODIS image data and revised SEBAL model were able to estimate actual daily evapo-transpiration values in Taleghan Drainage Basin. Therefore this revised algorithm could recommend as suitable method for further studies in different area with variation topography.
afshin sadeghirad; Negar Eini; Atefeh Fatahi; Harir Sohrabi
Abstract
Any plant according to its needs selects an optimal location of the environment as habitat. The aim of this study was to evaluate the relationship between plant species composition and edaphotopopographic factors in the steppe rangelands of Marvdasht in Fars province. Soil and vegetation sampling was ...
Read More
Any plant according to its needs selects an optimal location of the environment as habitat. The aim of this study was to evaluate the relationship between plant species composition and edaphotopopographic factors in the steppe rangelands of Marvdasht in Fars province. Soil and vegetation sampling was carried out by random sampling and transect method, respectively. In this study, transects with a length of 30m were used. After sampling the soil samples were transported to the laboratory. In the laboratory content of OM, EC, pH, sand, silt and clay, Na, K and P were measured. The relationship between environmental factors and species composition was determined using DCA and CCA multivariate analyzes. The most important factors in the distribution of vegetation, were soil EC and Na. Altitude and slope were identified as effective topographic factors the composition of plant species.
zohreh asar; masoud masoudi
Abstract
Desertification refers to land degradation in arid, semi-arid, and dry sub-humid region. It is a global environmental problem with political and socio-economic consequences. Land degradation occurs as a result of impoverished vegetation cover that may lead to a progressive and irreversible reduction ...
Read More
Desertification refers to land degradation in arid, semi-arid, and dry sub-humid region. It is a global environmental problem with political and socio-economic consequences. Land degradation occurs as a result of impoverished vegetation cover that may lead to a progressive and irreversible reduction of the biological or economic productivity. Overgrazing may cause degradation of soil and vegetation. Degradation of vegetation and soil in dry lands, sometimes called desertification, is thought to be a serious threat to the sustainability of human habitation. Therefore, the intensity of grazing can serve as an index of environmental pressure. The Miandehi region, located in the Northeast Iran, has been selected as a test area to assess livestock pressure. Present paper assessed the pressure of livestock within the studied area using GIS. FAO-UNEP model (1984) proposes the use of a ratio of potential carrying capacity to present livestock density as an estimate of pressure of livestock. This method has been adopted with some modifications for the present study. Therefore, maps of the hazard of pressure of livestock were prepared after overlying and calculating different parameters in GIS. According to the final map of pressure of livestock in Miandehi region, areas of no hazard, slight hazard, severe hazard and very severe hazard comprised respectively 21.3, 5.6, 9.8 and 63.3 % of the study area. Results showed that areas under very severe hazard dominate Miandehi (63.3 % of total land).
Hamzeh Nour; Seyyed Khallagh Mirnia; Maliheh Sadat Zarif Moazzam
Abstract
Some contaminants associate with soil particles and, thus, their transport and fate in the environment is determined by the soil erosion processes. Eutrophication, low oxygen levels and high nutrient (nitrogen and phosphorus) concentrations in reservoirs, canals and other water courses, is a common water ...
Read More
Some contaminants associate with soil particles and, thus, their transport and fate in the environment is determined by the soil erosion processes. Eutrophication, low oxygen levels and high nutrient (nitrogen and phosphorus) concentrations in reservoirs, canals and other water courses, is a common water pollution feature. Phosphorus (P) is one of the major plant nutrients and also the major nutrients controlling eutrophication of surface water. P load pulsed by heavy rainfall may damage the ecological quality of downstream. The present study was conducted in Kojour Watershed located in Mazandaran province.The results showed that P loss varied from 0.26 gr lit-1 to 1860.64 gr lit-1. It also proved that P concentration could not estimated by flow discharge, while sediment concentration can estimate loss of P with determination coefficient and estimation error of 94% and 23%, respectively. The results could facilitate the application of given methods obtained in the present study to other ungauged watersheds with similar conditions and leading to the suitable soil and water management and planning.
Mohammad Jafari; Hossein Azarnivand; Ahmad Sadeghipour; Nadia Kamali; Ahmad Heidari; Hassan Maddah arefi
Abstract
Global warming and climate change have drawn special attention to soil and its potential for stable carbon sequestration. Soils are the largest stores of carbon in terrestrial carbon cycle and contain about three times more carbon than vegetation cover and two times more than that of atmosphere. Studying ...
Read More
Global warming and climate change have drawn special attention to soil and its potential for stable carbon sequestration. Soils are the largest stores of carbon in terrestrial carbon cycle and contain about three times more carbon than vegetation cover and two times more than that of atmosphere. Studying the effects of grazing on soil carbon storage is important because of the major role soil organic carbon has in production. Grazing is potent for changing the carbon storage of rangeland ecosystems. In this research, the effect of different grazing intensities on carbon sequestration and nitrogen stabilization in pastures cultivated with Atriplex canescens in Shahriar was studied. Soil and plant samplings were done in low, moderate and high grazing intensity areas as well as exclosure, using randomized – systematic method. Soil samples were taken from 0-10, 10-30 and 30-100 Cm depths of 20 soil profiles. In each soil sample, stone percent, bulk density, organic carbon and nitrogen were calculated. Data analysis was done using one – way ANOVA and Duncan test in SPSS 17 software. Results showed that all three grazing intensities have caused significant reduction in carbon and nitrogen of soil.
Mohsen Farzin; saeideh menbari
Abstract
Karstic water resources are one of the most important sources of water for the world's population, which accounts for 25-20% of the world's population; these resources are subject to increasing pressure and require special management due to the nature of the point recharges. In this research, after mapping ...
Read More
Karstic water resources are one of the most important sources of water for the world's population, which accounts for 25-20% of the world's population; these resources are subject to increasing pressure and require special management due to the nature of the point recharges. In this research, after mapping vulnerability and zoning protection on karstic aquifer of Tange-Konara Yasuj using COP method, proposed restrictions was presented. At first, the geological and topographic maps of the area to transfer to GIS software were digitized. In order to provide data, maps, and information about the situation of karstification, soil, and vegetation field surveys was conducted multiple times. Then, the operations and mathematical calculations to mapping of factors and sub-factors considered in COP method, was conducted in GIS media. The results show that karstic aquifer vulnerability rate changes 0.6 to 4.2 which showing high to very low vulnerability for the study area; So that, high, moderate, and low vulnerability classes are on Quaternary, Asmari, and Pabdeh-Gurpi-Razak formations, with 1.6, 77.1, and 21.2 percent of the area, respectively. The importance of each of the factors in determining the sensitivity of the aquifer in the study area can be considered as P> C> O. Finally, three protection zone was considered including I for areas with high vulnerability, II for areas with medium vulnerability, and III for areas with low and very low vulnerability that was presented in the form of a protective map.
Tayyebeh Mresbahzadeh; Hasan Ahmadi; GHolamreza Zehtabian; Fereydun Sarmadian; Firoozeh Moghiminejad
Abstract
Desertification is specific phenomenon of arid, semi-arid, dry sub humid regions. This phenomenon has a high rate in developing countries such as Iran. The main objective of this research was calibration of IMDPA model in Abuzeidabad (Kashan) region with emphasis on land criteria. IMDPA model, introduced ...
Read More
Desertification is specific phenomenon of arid, semi-arid, dry sub humid regions. This phenomenon has a high rate in developing countries such as Iran. The main objective of this research was calibration of IMDPA model in Abuzeidabad (Kashan) region with emphasis on land criteria. IMDPA model, introduced by Iranian researchers to assess desertification intensity in Iran. Before application, the criteria and indices applied in model were re-defined For this study. Regarding to region conditions three criteria were defined as key criteria for desertification which were: Geology-geomorphology, soil and wind erosion criteria. Then each criterion was assessed based on selected criteria, which resulted in qualitative mapping of each criterion based on selected criteria. Finally, by mean of all the indices and criteria desertification mapping was provided and these results obtained. Regarding the studied criteria, Geology– Geomorphology benchmark has the highest effect on desertification. Among the total studying are (16161 hectars), the medium class is about (4792 hectars), and the high class is about (11369 hectars). Among indicators, slop index with 3.9 and lithology sensitivity to erosion and wind erosion with the value of 3.5 and 3.4 are the main indexes of increase in desertification intensity in the study area. According to map of desertification statue 70.3% of study area have a high intensity and 29.7% have a medium intensity.
Mahadi Vatakhah; Hamzeh Saidian
Abstract
Erosion and sediment movement phenomena are one of the most complex issues in management of rivers drainage areas that in water projects are very important. That its measurement wants high time and cost. Issue of surface runoff in river basin is a complex issue that human knowledge and understanding ...
Read More
Erosion and sediment movement phenomena are one of the most complex issues in management of rivers drainage areas that in water projects are very important. That its measurement wants high time and cost. Issue of surface runoff in river basin is a complex issue that human knowledge and understanding about its physical laws a viewpoint of some mathematical formulas is limited. In this study to investigate modeling runoff and sediment production in different land uses of Aaghajari formation deposits, part of Margha watershed in Izeh city with area 1609 hectares was selected. In this study, some soil physical and chemical characteristics such as percentage of sand very fine, sand, clay, silt, pH, electrical conductivity, moisture, calcium carbonate and soil salinity in different land uses of Aghajari formation were used. Then the rain simulator in 7 point and with three replicated in different intensities 0.75, 1 and 1.25 mm in minute in three land use range, residential areas and agricultural lands, were used the amount of runoff and sediment. And the same of number were sampled in 0-20 cm in soil layer. In totally, 126 times sampling runoff and sediment were done. And 189 soil experiments were done. In order to perform all statistical analysis were used 11.5 SPSS and EXCEL and MATLAB 2008 software. The results showed that multi regression analysis in conditions with high input and little output data shows more favorable results than neural network. And in high intensities owing to data homogeny, neural network operation than to low precipitation intensities is better. But in multi regression in high and low precipitation intensities showed acceptable operation. The average of relative error in three land uses in sediment production in precipitation intensity 0.75 mm in minute were in multi regression 7.2 percent and root mean square error 0.06. And in neural network in same precipitation intensity the average of relative error 146/9 percent and root mean square error 0.41 were. The average of relative error in three land uses in sediment production in precipitation intensity 1 mm in minute were in multi regression 8.5 percent and root mean square error 0.19. And in neural network in same precipitation intensity the average of relative error 96.36 percent and root mean square error 0.85 were. The average of relative error in three land uses in sediment production in precipitation intensity 1.25 mm in minute were in multi regression 1.8 percent and root mean square error 0.38. And in neural network in same precipitation intensity were the average of relative error 37/6 percent and root mean square error 0.73.
elham fakhimi; Hossein Naderi
Abstract
Floristic studies are fundamental for the applied sciences such as rangeland management and conservation. Rangelands of Sadrabad with an area of 40000 hectares is jocated in South West of Yazd province that it remarkable habitat for the floristic studies. In this study the floristic list of the region ...
Read More
Floristic studies are fundamental for the applied sciences such as rangeland management and conservation. Rangelands of Sadrabad with an area of 40000 hectares is jocated in South West of Yazd province that it remarkable habitat for the floristic studies. In this study the floristic list of the region is presented and their life forms and endangered species are distingushed Plants were sampled following the common method in the regional taxonomic studies and their families, genera, and species were determined using indispensable references. The life form of plant species was determined using Raunkier’s method. The results showed that 235 plant species belonging to 39 families and 169 genera exist in this area. Hemicryptophytes, Therophytes, Chamaephytes, Geophytes and Phanerophytes included 36.45, 25.65, 23.47 , 7.82 and 6.55% of the total species, respectively. Furthermore, the endangered species of the region were identified on the basis of IUCN criteria and Red Data Book of Iran. Accordingly, 43endangered species were identified, of which 34 were in lower risk (LR) class, , 7 species were in vulnerable (VU) class, and 2 were put in data deficient (DD) class.
M. Nabizadeh; A. Mosaedi; A. A. Dehghani
Abstract
River flow forecasting for a region has a special and important role for optimal allocation of water resources. In this research, for forecasting river flow process, Fuzzy Inference System (FIS) is used. Three parameters including precipitation, temperature and daily discharge are used for forecasting ...
Read More
River flow forecasting for a region has a special and important role for optimal allocation of water resources. In this research, for forecasting river flow process, Fuzzy Inference System (FIS) is used. Three parameters including precipitation, temperature and daily discharge are used for forecasting of daily river flow of Lighvan River located in Lighvanchai watershed. For the initial preprocessing, the randomness of data was examined by return points test. Then, for determination of the optimum lags for input parameters, correlogram of data was considered. Finally to investigate the effects of temperature on river flow forecasting, the process were done for any months separately. Assessments of prediction by using various criteria such as Nash-Sutcliff coefficient showed that FIS model had high precision (CNS=0.9976) and low error (RMSE=0.0113) in prediction which shows that the FIS model can be employed successfully in river flow forecasting. Final assessment of the results was also revealed the effects of temperature on prediction in some months (April and December).
golaleh ghaffari; Hassan Ahmadi; Omid Bahmani; Ali akbar Nazari samani
Abstract
In Iran due to the lack of long experience in the implementation of Soil Conservation and Watershed Management Plans, these measures have not been evaluated quantitatively and specific methods for this purpose have not been provided. In this research effort is to investigate the effect of watershed management ...
Read More
In Iran due to the lack of long experience in the implementation of Soil Conservation and Watershed Management Plans, these measures have not been evaluated quantitatively and specific methods for this purpose have not been provided. In this research effort is to investigate the effect of watershed management operations performed in Can Basin in 1379, on the amount of erosion and sedimentation and rate of project success or failure and its causes. So after providing the required information and statistics and being sure about the authenticity and accuracy of statistics and statistical reconstruction of defects with conventional methods, to investigate the effect of implemented projects on erosion and sedimentation rates, average of suspended sediments in the period before project implementation (1986-2000) and in the period after project implementation (2001-2008) was calculated using sediment rating curves through intermediate technique class, and using daily water discharge, watershed erosion and deposition were also calculated using MPSIAC model. Specific erosion and deposition map was provided in the period after project implementation using Arc GIS software and finally the amount of efficiency and effect of this operation on the amount of erosion and deposition rates was judged. The results of studies showed that due to operating this plan, the average amount of suspended sediment has changed from 47892 tons per year during the statistical period before the plan to 22365 tons per year during the eight-year statistical period after it. The amount of erosion and sedimentation has shifted from 66758 tons to 50549 tons, which shows the positive effect of plan on reducing the amount of suspended sediment and the lack of effective role in reducing the rate of erosion. The main reasons for the low efficiency of Watershed Management Plan implemented in relation to decreasing the amount of erosion are: lack of suitable biological operations in the basin (less than 25 percent of the volume of the proposed action), focusing on mechanical operations, weaknesses in project monitoring and evaluation During all stages of its implementation, failure to observe the standards and technical points such as non-conforming structures built between locations and proposed locations, lack of standards in building the necessary structures and inappropriate dimensions of structures, destruction of floor section in mortar stone structures and etc.
