Abazar Esmali; Hasan Ahmadi; Mohammad Tahmoures
Abstract
The aim of this research is to describe the development of a methodology based on present knowledge and available data for evaluation of water erosion behavior and risk as well as modeling and estimation of soil erosion, which is compatible for other similar areas of Iran. Accordingly, the conducted ...
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The aim of this research is to describe the development of a methodology based on present knowledge and available data for evaluation of water erosion behavior and risk as well as modeling and estimation of soil erosion, which is compatible for other similar areas of Iran. Accordingly, the conducted research was based on four major types of water erosions including: sheet, rill, channel and riverbank which have considerable role on sediment yields of Baleghli Chay Watershed, Ardebil Province, were separately and spatially studied. In order to determine the inter-effects of effective factors, the study was conducted using stepwise multivariate statistical tests. For each erosion type, an individual model was then presented. In the next step, after determining of relations between sediment yield and environmental factors (fixed & variable) through statistical analyses and selecting of effective factors on erosion and sediment yields, was created an empirical structure for modeling erosion and sediment yields based on MPSIAC erosion model. In formulation of the new model, were used of eight effective factors on erosion in the area. These factors are susceptibility of geological formation, soil erodibility, rainfall erosivity, runoff erosivity, topography, hydrographic drainage, Normalized Difference of Vegetation Index (NDVI) and field conditions of erosion features. In the presented model, with summation of the scores of mentioned eight factors, obtains the M value, which can estimate the amount of erosion and sediment yields of the area, using exponential formula between sediment yield and M values. In addition, in order to obtain the confidence of presented model, it was used in "Nir" catchment for evaluation the precision. The results showed 11 percent difference. With accepting of this error value, the water erosion hazard map of the area was provided and presented using new model.
S. H. Hosseini; M. Abbasizadeh; M.R. Khaleghi
Abstract
In regions with deficient or no data, it is necessary to apply indirect methods to estimate the peak flow. Regional flood analysis is the most accurate and reliable technique in such cases. One of the regional flood methods for flood analysis in arid and semi arid regions is Hybrid technique, which was ...
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In regions with deficient or no data, it is necessary to apply indirect methods to estimate the peak flow. Regional flood analysis is the most accurate and reliable technique in such cases. One of the regional flood methods for flood analysis in arid and semi arid regions is Hybrid technique, which was applied on data of Khorasan Razavi province watersheds to estimate the peak flow. Hybrid method based on station - year method which considers available statistics from all stations to overcome statistics shortage problem. Hybrid method consists of two sections. At first, the most important parameters including area, annual rainfall and height are determined using factor analysis. Annual peak flow was standardized based on an approximate factor and then approximate standard factor was improved based on combined regression and analysis frequency. The results showed that the lowest relative error for the models was related to 50-year return period while relative error increased in other return period. As the relative errors were 1.03 and 0.79, respectively in the return periods of 2 and 100 years. Therefore, according to results, Hybrid method is suitable for return periods 20 to 50 years in the study area.
Kazem Saedi; Adel Sepehry; Mohammad Pesarakli; hosein gharehdaghy; Adel siosehmardeh
Abstract
This study conducted to investigate the effects of grazing in a short-term stocking system on the water-soluble carbohydrates (WSC) and nitrogen (N) reserves of permanent parts of Bromus tomentellus, Cephalaria kotschyi and Ferula haussknekhtii in Saral rangelands. A key area was selected with a permanent ...
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This study conducted to investigate the effects of grazing in a short-term stocking system on the water-soluble carbohydrates (WSC) and nitrogen (N) reserves of permanent parts of Bromus tomentellus, Cephalaria kotschyi and Ferula haussknekhtii in Saral rangelands. A key area was selected with a permanent exclosure area and two temporary exclosure areas. Root excavation was conducted at six to nine phenological stages. Five samples of typical plants were randomly selected for each species at each stage at each of these two sites for studying. Before excavation of the plants, their heights, canopy cover and basal area were measured. WSC and N concentrations were determined as a percentage of sample dry matter with phenol-sulphuric acid and Kjeldahl methods, respectively. The WSC concentration of B. tomentellus was not affected neither by studied grazing conditions nor by differences of weather conditions of the studied years. This species had lower carbohydrate concentrations than the forbs. In C. kotschyiWSC level was not affected by grazing or the weather condition each year. The low point of WSC reserves in F. haussknekhtii occurred during the rapid spring growth, and the highest levels were attained at the end of its growing seasons. Grazing increased the WSC concentrations in the storage organs of the plants of F. haussknekhtii and N concentrations of all the studied species. This study suggested that the plant response to grazing increased the resource allocation to storage organs to compensate the deprived reserves in the studied grazing system, so that the rest periods works well to improve the plants’ vigor. It seems that livestock grazing in this grazing system does not significantly harm two of the three studied species in their sizes.
Mohammad Fayaz; Hossein Piry Sahragard; Hassan Yeganeh; Anvar Soor; Mirtaher Ghaemi
Abstract
Having a comprehensive and correct understanding of grazing behaviour of livestock helps to maximize livestock products. Moreover, a good understanding of livestock behavior allows us to predict the effects of livestock on rangeland and finally we can do livestock grazing management the best possible. ...
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Having a comprehensive and correct understanding of grazing behaviour of livestock helps to maximize livestock products. Moreover, a good understanding of livestock behavior allows us to predict the effects of livestock on rangeland and finally we can do livestock grazing management the best possible. Recognition of grazing behavior of animals can provide solutions enables the optimal use of rangeland forage and can also help in preventing the reduction of animal products and will prevent of Ranchers income loss. For this purpose cow grazing behaviour investigation was performed in Tezkharab rangelands for 4 years. Long distance path following day in the pasture, and livestock speed (maximum and minimum average) time for rest and time for the motion and applied grazing system were studied. To study for grazing cycle was used from the geographic position locator (Garmin GPS). Use the belt to the back of a cow's day package. At the end of the day, data was extracted in Elvis using in track mode. The results showed all traits in a significant level 1% Effect was significant difference in years and months (May, June, July, August, September and October) except average speed traits. This trait was significant at the 5% level. This study showed that environmental factors such as seasonal variations and therefore its temperature changes is one of the most important factors that influencing grazing behavior of livestock.
Reyhane Azimi; Mohammad Jankju; Hamid Reza Asghari
Abstract
Improved pasture establishment in plants, especially in arid and semi-arid is very important Application of biological fertilizers in pasture can be considered as a useful approach. that is one of the sources of the symbiotic fungus.. The purpose of the present study was to investigate the possibility ...
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Improved pasture establishment in plants, especially in arid and semi-arid is very important Application of biological fertilizers in pasture can be considered as a useful approach. that is one of the sources of the symbiotic fungus.. The purpose of the present study was to investigate the possibility of enhancing seedling establishment and growth rate of Bromus kopetdaghensis under natural habitats by inoculation with mycorrhiza species, Seeds of alfalfa were sown under greenhouse for 20 days and inculcated with two species of Glomus intraradices and Glomus mosseae. After one month growth, the inoculated seedlings were transplanted into the natural as sub plots as split plot based on RCBD (Randomized complete block design) were evaluated with three replication. Inoculation percent with G.mosseae was 62/7 % and with of G. intraradices 81/3%. Symbiosis increased establishment of alfalfa at the early and late growth stages, with stronger effects G,intra than G.mosseae. Furthermore leaf and root dry matter, total dry matter and the ratio of above ground to underground plant parts was increased in association with G. intraradices, where as such effects were not associated with G.mosseae. In conclusions, it Glomus intraradices can be used as a biological fertilizer for establishment of alfalfa in semiarid rangeland of Bahar Kish rangeland, Quchan.
Mohsen Sarshad Ghahfarrokhi; Seyed Alireza Mousavi; Saeed Soltani; Saeed Pourmanafi
Abstract
Natural resources are valuable capitals for all nations. Rangelands as the most extensive natural ecosystems in Iran provide numerous services, including fodder production and red meat supply, soil conservation and water regulation. Although uncontrolled exploitation of these resources has imposed much ...
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Natural resources are valuable capitals for all nations. Rangelands as the most extensive natural ecosystems in Iran provide numerous services, including fodder production and red meat supply, soil conservation and water regulation. Although uncontrolled exploitation of these resources has imposed much pressure and caused many losses within the ecosystems. Impacts of overutilization of nomadic livestock on Semirom rangelands from runoff control perspective has been the core objective of this study. Considering the utilization conditions, vegetation cover was measured within the vegetation types before and after livestock grazing during 2013 grazing season. Curve Number method was selected to evaluate the runoffs originating from rainfalls with different return periods before and after livestock grazing and the difference was considered as the grazing impact. This externality was valuated using replacement cost method. Results showed that utilization pressure is extremely more than grazing capacity which has distorted water regulation function of the rangelands, e.g. it has increased the runoff volume from a rainfall with 2-year return period from 1660884 to 2600487 m3. In other words, it has diminished the potential of rangelands in controlling water runoffs. Economically speaking, the external damage to water regulation function of rangelands was calculated at the rate of 25391 million Rial/year. This information on the externalities of nomadic livestock will provide the useful basis for economic appraisal of the utilization process and adjustment or rectification of economic activities which entail social costs on their way towards private profits.
Mozafar Ansari; Sadat Feiznia; Hassan Ahmadi; MohammadAli Fattahi Ardekani
Abstract
Soil is one of the most vital natural resources in any country. Nowadays, lands are rarely found worldwide without having severe erosion problem. Landslide is one of the soil erosion processes in which a huge volume of soil is washed away. SHETRAN Model was used in this study to assess the landslides ...
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Soil is one of the most vital natural resources in any country. Nowadays, lands are rarely found worldwide without having severe erosion problem. Landslide is one of the soil erosion processes in which a huge volume of soil is washed away. SHETRAN Model was used in this study to assess the landslides being occurred in Zidasht catchment, Taleghan. At the first stage, sediment-water mixed samples were gathered at the outlet of the Catchment for calibration purpose in 2011. To run the model, regions undergoing landslide were identified using GISLIP sub-model. Secondly, after hydrological and sediment production simulations in a sub-model of SHETRAN for the region, calibration was made for spring season. After the calibration process, the model was run again, this time for the regions having landslide (for 418 spots), and in regions where landslide sediments do not pour into water courses, these regions were omitted, the final amount of sediment was calculated using SHETRAN sub-model and the results were compared with the previous studies. The results show that 19.75% of the total sediment belongs to landslides. With regard to the current sediment quantity of about 111248 kg, total sediment in landslides was estimated to be around 120668kg.
mahboobeh sarbazi; Sadat Feiznia; Mohammad Mahdavi
Abstract
Water quality is always one of the major challenges for managers and decision makers in water resource management. However, the problems of water quality are more important than quantity. One of the main ways in thorough review and assessment of water quality using multivariate statistical techniques ...
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Water quality is always one of the major challenges for managers and decision makers in water resource management. However, the problems of water quality are more important than quantity. One of the main ways in thorough review and assessment of water quality using multivariate statistical techniques are, the majority of changes to a system, in order to identify important factors that influence could explain. This study classified zone Groundwater Quality Mashhad plain terms of agricultural potential and its quality review process has been carried out in recent decades. Therefore, the quality of groundwater for agricultural use was studied and maps of quality classification for 2001-2011 years were prepared. Then, using geological map, the effect of geological formations on degradation of groundwater quality was assessed. For water quality analyses, 10 important water quality variables in 39 selected wells were measured and they were analyzed using multivariate statistical techniques. The statistical analyses which were used are: Factor analysis for determining the most important variables, cluster analysis for determination of variables homogenous groups and Pearson Correlation for investigation of relationships between variables. The results have shown the best relationship between geological formation and quality factors. Also, the results of Factor Analysis also showed that EC and TDS 71.02 of the total variance explained by factor loading 0.98 and pH 14.91 of the total variance explained by factor loading 0.93 are the most important variables affecting the quality of groundwater in the study area.
saeedeh joriz; Meghdad Jourgholami; arash malekian; maryam etehadi
Abstract
Land use changes can significantly affect the hydrology of a forest watershed. Ground cover is important to protect the soil against erosion. Timber harvesting has been changed the canopy cover and forest soil was exposed to the wind and water. Soil compaction and removing the forest floor in the skid ...
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Land use changes can significantly affect the hydrology of a forest watershed. Ground cover is important to protect the soil against erosion. Timber harvesting has been changed the canopy cover and forest soil was exposed to the wind and water. Soil compaction and removing the forest floor in the skid trails was reduced the capacity of water absorption in mineral soils and thus reduced water infiltration, increased runoff, which caused to soil erosion. In order to measure the rate of sediments in two slopes and to study the effect of skid trails on the amount of sediments, the plot-level study was carried out in the Gorazbon district in Kheyrud forest in the control area and skid trail after skidding operations in the sample plot. The results showed that the most sediment value was 1.938 g. liter-1 in the skid trail with a 20-40 percent slope in the autumn and the lowest deposition was 0.103 g. liter-1 in the control area with a slope of 20-40 percent in the autumn. Type of Coverage (skid trail and control area), the season and the interactions between the cover and the season statistically have significant effect on the sediment yield, but the slope and the interactions between the slope and cover, as well as the interactions between the slope and season have no statistically significant effect on the sediment yield. Duncan’s test showed that there was a yield statistically significant difference between sediment yeild in different seasons and the autumn had the highest sediment
Kazem Nosrati; Frouzan Ahmadi; Ali Akbar Nazari Samani; Mohammad Reza Servati
Abstract
Soil erosion is one of the most destructive phenomena which cause significant ecological changes in many areas. Soil conservation and erosion control is essential because of the irreparable damage caused by soil erosion. Soil conservation programs will not achieve until to find adequate methods of combating ...
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Soil erosion is one of the most destructive phenomena which cause significant ecological changes in many areas. Soil conservation and erosion control is essential because of the irreparable damage caused by soil erosion. Soil conservation programs will not achieve until to find adequate methods of combating land degradation and ways to reduce the sediment. Therefore, we need to have enough knowledge of the sediment sources and identify places to be at high risk to soil erosion. In this study we used fingerprinting technique in the Taleghani catchment, Khorram Abad city, Lorestan Province to determine the contributions of sediment sources including agricultural, rangeland, and forest in sediment yield. In view of this, 39 soil were collected from different sources: agriculture, rangeland, forest and channel bank and 19 sediment samples including 11 samples from bed sediment and 8 samples from suspended runoff, respectively. 11 tracers including C, N, P, Na, K, Cu, Zn, Mg, Mn, Fe and Ca were selected as the primary tracers. The results showed that discriminant function analysis were selected Mg, C, Zn and Ca as the optimum set of tracers that can discriminate 3 sediment sources. Mixing model results showed that the contribution of each sediment source is 53.37, 30.37, and 16.26 percent for agriculture, rangeland, and forest, respectively. These results were consistent with the evaluation results of nitrogen and organic carbon stocks. The results of this study can be used in selecting most appropriate erosion control method the study area and generalized to similar areas.
khabat Khosravi; Edris Marufinia; Ebrahim Nohani; Kamran Chapy
Abstract
In order to prevent any damages which can be caused by flood at Haraz watershed in the Mazandaran province, it is essential to prepare a flood susceptibility map using logistic regression. About 211 flood locations and 211 non-flood locations were first recognized. Ten flood conditioning factors such ...
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In order to prevent any damages which can be caused by flood at Haraz watershed in the Mazandaran province, it is essential to prepare a flood susceptibility map using logistic regression. About 211 flood locations and 211 non-flood locations were first recognized. Ten flood conditioning factors such as Slope, plan curvature, altitude, distance from river, topographic wetness index (TWI), stream power index (SPI), rainfall, landuse and normalized differences vegetative index (NDVI) were then identified. The maps of all affecting factors were prepared using ArcGIS10.1, ENVI 5.1 and SAGA GIS2 software and they were exported to raster formats. Flood locations were randomly divided into two groups: 70% (151 flood locations) and 30% (60 flood locations) for modeling and validation, respectively. Enter method was selected for weighing the 10 factors in SPSS.18. The factors with their corresponding weights were used in the ArcGIS software for generation of flood susceptibility map. The map was divided into 5 classes. ROC curve and area under curve (AUC) are used for the validation of derived map. The results indicated that for prediction rate, the AUC is 78.3%; thus, the logistic regression has a reasonable accuracy for flood susceptibility mapping. The findings of this research are useful and necessary for scholars, the Mazandaran Regional Water Authority (MRWA), Ministry of Energy, and other agriculture and natural resources-related organizations in order for mitigating losses and damages during flooding events.
Maryam Asadi
Abstract
In this research, was investigated the effect of grazing intensities on carbon and nitrogen allocation in aerial and belowground biomass of Artemisia austriaca in summer rangelands of Darvishchae (including Alvares, Aldeshin and Asbmarz villages) at southern slope of Sabalan. The study areas based on ...
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In this research, was investigated the effect of grazing intensities on carbon and nitrogen allocation in aerial and belowground biomass of Artemisia austriaca in summer rangelands of Darvishchae (including Alvares, Aldeshin and Asbmarz villages) at southern slope of Sabalan. The study areas based on grazing rate, rangeland condition, previous researches and department of Natural Resources and field survey in three grazing intensity low, medium and heavy was selected. Sampled in each grazing intensity, from vegetation and soil with randomized-systematic method on 3 transects parallel with the length of 200 meters and plot 1×1 m2 was carried out at intervals of 50 meters. Biomass was determined using cut and weighting method. After digging profiles at the base of the plant, roots were harvested. Then, allocation in aerial and underground plant was determined. The comparisonof allocation in plant was conducted using analysis of variance (ANOVA) and Tukey's test was performed to examine the differences between means. Results showed the effect of different grazing intensities (mostly sheep of Moghani breed) on biomass of A. austriaca was significant. Results of compare mean showed that the greatest amount of nitrogen allocation in the aerial biomass of A. austriaca (2.2 mg/kg) was observed in the moderate grazing intensity. Moreover, the greatest amount of carbon allocation in the roots of A. austriaca (22 mg/kg) was occurred in the moderate grazing intensity. In general, attention to effects of grazing different intensities on vegetation factors such as carbon and nitrogen allocation, is essential for rangelands correct management and protection.
elham rezaei; somayeh dehdari
Abstract
Current study is investigate the effects of range improvement treatments on vegetation performance in Zaloo-Ab rangeland that is 10 Kilometers far from west south of Abdanan County in Ilam Province. Vegetation sampling was done randomly in every control and corrective operation sites in length of three ...
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Current study is investigate the effects of range improvement treatments on vegetation performance in Zaloo-Ab rangeland that is 10 Kilometers far from west south of Abdanan County in Ilam Province. Vegetation sampling was done randomly in every control and corrective operation sites in length of three transects of 100 meters in 30 plots of one square meter. Vegetation specifications including production, density, percentage of cover crown, bare soil, stone and pebbles, litters and different classes of palatability. Obtained data were analyzed by version 16 of SPSS software using t-independent test and variance analysis to compare each corrective and control sites and three corrective sites together. The obtained results showed that provided corrective operations have caused increase in cover crown, production, density of class I and II plants and decrease in class III plants, bare soil and pebbles respected to control site (in one percent level). Results of one-way variance analysis and comparison of averages of measured vegetation specifications in three treatment sites also showed a significant difference in one percent level.
ali dastranj; ahmad nohegar; Arash Malekian
Abstract
Abstract Feeding areas, and the spatial distribution of recharge in karstic aquifers, depends to factors such as geomorphology karst and its development, climate, slope, vegetation, soil and geological factors. Karstic aquifers in the study area, has the main role in the development of human civilization ...
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Abstract Feeding areas, and the spatial distribution of recharge in karstic aquifers, depends to factors such as geomorphology karst and its development, climate, slope, vegetation, soil and geological factors. Karstic aquifers in the study area, has the main role in the development of human civilization and supply water to communities. The purpose of this research is modeling the aquifer feeding areas Azhvan-Bisotun in Kermanshah province using KARSTLOP model. The results feed zoning show that the annual charge Bisotun karst aquifer obtained for between 36 to 83 percent. The greatest amount of recharge in areas with more than 78% charged, is accordance sinkholes and the recharge rate of 36 to 40% and 40% to 45% occur in alluvial plains. Bisotun geomorphology karst mountains represent a major role in the spatial distribution of values in the aquifer is recharged.
M. Samimi; S. Kochakzadeh; A. Parvaresh-Rizi
Volume 62, Issue 1 , June 2009
Abstract
Muskingum-Cunge is one of the widely employed methods for flood routing. Direct calibration of the model based on previous flood events is not required and the routing parameters in this method are determined according to physical characteristics and hydraulic conditions of the stream. During the last ...
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Muskingum-Cunge is one of the widely employed methods for flood routing. Direct calibration of the model based on previous flood events is not required and the routing parameters in this method are determined according to physical characteristics and hydraulic conditions of the stream. During the last decade, different modifications were proposed for the method to increase its accuracy. In this paper Muskingum-Cunge method and its different modifications have been presented and the applicability and the precision of the proposed schemes were determined. To study the applicability of constant and variable parameter Muskingum-Cunge method in field conditions, some observed flood events of Karoon River have been routed with these methods. Inflow hydrographs were routed by the mentioned method and the results were compared with that of the observed values of the downstream end of the reach. The results were also compared with the outputs obtained by routing the same hydrographs by HEC-RAS hydrodynamic model. The results of this study demonstrated successful performance of the simplified routing methods and showed that in circumstances where the availability of intensive data required by hydrodynamic model are limited, relying on such simplified method would provide satisfactory results. Based on comparison among the results of the employed method with that of the hydrodynamic one, the most suitable method for the studied condition is determined.
Mohammad Rostamtabar; Sadat Feiznia; ziaodin Shoaii
Abstract
More accurate understanding of rock formations and sedimentary units sensitive to erosion willenable us to present appropriate and timely methods in order to prevent accelerated erosion. In thisstudy, through predefined sampling from main and minor channels and granulometric analysisusing index sieves, ...
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More accurate understanding of rock formations and sedimentary units sensitive to erosion willenable us to present appropriate and timely methods in order to prevent accelerated erosion. In thisstudy, through predefined sampling from main and minor channels and granulometric analysisusing index sieves, mineralogical investigation has been performed qualitatively and quantitativelyby binoculars in laboratory. After that, sedimentation potential has been calculated by usingpractical formulas. Then, sedimentation potential of each sedimentary unit has been estimated fromaverage results of sedimentary sample and with this method, sedimentation potential of ShafaroodWatershed has been obtained from average results of five sub basins. An equation has beencalculated for each sub basin and by this, an equation for whole watershed was presented. In thisequation, the Y which refers to the amount of delivered sediments has been placed in one side androck unit coefficients on the other side. The coefficient of each rock unit has a rule in sedimentproduction. These coefficients are dimensionless and demonstrate rock unit sensitivity to erosion.The bigger this value, the more sensitive that rock unit is to erosion. In this way, the map ofsensitivity to erosion for each sub basin has been prepared by using (ARC GIS) software.According to average sedimentation potential of Shafarood Watershed, marl units (Pgf), silty sandyshale (Jsh) and sandy limestone (Kusl), have respectively the highest sensitivity and limestone units(P), andesite - basalt (Pev) and tuffy shale (V) have the least sensitivity to the erosion.
zahra zangane; Kamalaldin Naseri; Fereydoon Mellati; Mansoor Mesdaghi
Abstract
Because plant density is often measured by using plots and also in most cases are done by the method of estimation and counting the individuals, so one of the important cases that we have to decide on is the size and shape of plot. In this research, the density of Astragalus verus that it's one of the ...
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Because plant density is often measured by using plots and also in most cases are done by the method of estimation and counting the individuals, so one of the important cases that we have to decide on is the size and shape of plot. In this research, the density of Astragalus verus that it's one of the dominate species in the area and has separate and recognizable individuals plant from each other,for investigate the effects of different size and shape of plots on sampling precision and accuracy are estimated in Mayan Mashhad area. The shapes of plot are square, wide rectangular, long rectangular, and sizes of plot are 1, 2, 4, and 8 m2 respectively, that we have been investigated in total 3x4 plots (treatments). In this research, the coordinates of individual plants and the boundary of study area are located by using digital camera. Then, with help of R software, the digital map of study area was sketched. The results show that long rectangular 0.5x4 m plot has the highest accuracy and precision, so it is selected as optimum plot. Finally, it can be concluded that for saving time and expenses in sampling, using of locating coordinates method of individual plants and application of R software can be appropriate approach for estimating the density of shrublands, so for similar shrublands, the optimum plot of this research (4x0. 5 m) can be used.
Majid Rahimi; Arash Malekian; Amir Alambeigi
Abstract
Water is a source of life, even when it is abundant. In the last few years, the unreal certainty of water services in Iran has caused institutional structures of water to be unsuitable and incompatible with environmental changes, and when water-related crises such as drought, flood occurrence and in ...
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Water is a source of life, even when it is abundant. In the last few years, the unreal certainty of water services in Iran has caused institutional structures of water to be unsuitable and incompatible with environmental changes, and when water-related crises such as drought, flood occurrence and in the larger scale, climate change, are capable of flexibility and resilient in the face of these changes. In this regard, the recognition of the present governance system in the country is considered essential. Therefore, in this study, mode and regime of water governance were studied in one of the problem areas of water scarcity. In order to determine the mode of governance, questionnaires were used in two levels of the institution and local stakeholders. In order to determine the regime of governance, formal and informal institutional network analysis method was used in the Arsanjan, Neyriz, Kherameh and Estahban counties. The results of the governance mode showed that in ten sub-functions of governance under consideration, the more hierarchical mode has been observed. In addition, the results of the analysis of the institutional network also showed that the current governance regime in all four counties is a centralized (Rent-seeking) regime, which is considered a hierarchical governance mode feature. Finally, the combination of methods of governance and arrival to meta-governance is proposed.
Fariba Alavizadeh; Kamalledin Naseri; Ali Golkarian; Ali Tavili
Abstract
Soil erosion is a main hazard in most area of the country specially in arid and semi-arid regions and itis very important because of sedimentation, pollution, increased flooding and its negative effects onsoil productivity. One of the features of arid and semi-arid areas is the presence of low cover ...
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Soil erosion is a main hazard in most area of the country specially in arid and semi-arid regions and itis very important because of sedimentation, pollution, increased flooding and its negative effects onsoil productivity. One of the features of arid and semi-arid areas is the presence of low cover ofvascular plants. These empty spaces are usually good niches for biological soil crusts or cryptogamslike mosses. These crusts contribute to a variety of ecological functions and have different effects onsoil features and vascular plants. The present study was carried out in the rangelands of Torogh dambasin of Khorasan- Razavi province in order to find the effects of such kind of plants (mosses) onwater erosion. For this purpose, artificial runoff streams in plots with two intensity (low and high) for30 minutes. In order to study the effects of different amount of mosses on sedimentation and specificerosion, four different density of mosses in the same experimental situation were studied: high (60-75% of plot), medium (35-50% of plot), low (10-20% of plot) and control (0%). The results ofanalysis of variance and tukey method by the use of Minitab software showed a significant differencein 95% level between the four considered density of mosses and the two intensity of water. As mossesdensity decrease, sedimentation and specific erosion increased consequently. But there were nosignificant differences in infiltration between the different treatments.
Behzad Rayegani; Susan Barati Ghahfarokhi; Ahmad Khoshnava
Abstract
The aim of this study is to develop a comprehensive approach to identifying dust & sand sources and to investigate their changes over a set period of time using remotely sensed data. For this purpose, data OLI data of Landsat 8 during the years 2013 through 2015 were used to make maps of vegetation ...
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The aim of this study is to develop a comprehensive approach to identifying dust & sand sources and to investigate their changes over a set period of time using remotely sensed data. For this purpose, data OLI data of Landsat 8 during the years 2013 through 2015 were used to make maps of vegetation cover, soil moisture and land cover sensibility to wind erosion. These maps were combined with geology and roughness by multi-criteria evaluation method to obtain a map of sand & dust source potential areas. In the second step, information of synoptic stations, meteorological and air pollution measurements was prepared, and using statistical analysis and with the help of Modis data, the history of local events was obtained. These regions were integrated with the map of sand & dust source potential areas using the MCE method (WLC) and based on a stratified random sampling plan, susceptible sites of sand & dust sources were identified. In order to validate the identified areas and investigate the trend of their changes, the time series of satellite data and weather stations data were used and the trend of vegetation, soil moisture and surface temperature at the location of identified areas during a 15-year period were monitored. Validation results show high accuracy of identified areas and significant reduction trend of vegetation, soil moisture and surface temperature in the locations of identified sites during the study period
somaieh dehdari; nezam armand; mohammad faraji; nasim arman; fatemeh hadian
Abstract
The study aimed to evaluate the effects of Karon 3 and 4 dams on land use and cover changes, for this aim 4 images over 28 years (taken in 1985, 2003, 2009 and 2013) were obtained and geometric, atmospheric and topographic corrections were applied. Maximum likelihood and post-classification techniques ...
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The study aimed to evaluate the effects of Karon 3 and 4 dams on land use and cover changes, for this aim 4 images over 28 years (taken in 1985, 2003, 2009 and 2013) were obtained and geometric, atmospheric and topographic corrections were applied. Maximum likelihood and post-classification techniques were used to detect land use/cover changes and their accuracy then was assessed using topographic maps and field works. The overall classification accuracy and Kappa statistics for all the maps were more than 0.79 and 86.24% respectively. The classification map of year 2009 indicated that about due to Karron3 dam and 6734.88 hectares because of rangeland and forest were destroyed. Classificated map of 2013 indicated about 5127.39 hectares increased because of Karon 4 too. The overall findings of this study indicate that forest and range land degradation in the region, is due to the construction of Karun 3 and 4.
Ja'afar Dastorani; Mohammad Mahdavi; Ali Salajegheh; Ahmad Fakheri Fard
Abstract
Hydrological Simulation FORTRAN Program (HSPF) has long been used in modeling watersheds and many studies have been carried out around the world in this regard. Hablerood watershed is located in Semnan province with an area of 3200 km2 which suppies the required water, especially for farming, in Garmsar ...
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Hydrological Simulation FORTRAN Program (HSPF) has long been used in modeling watersheds and many studies have been carried out around the world in this regard. Hablerood watershed is located in Semnan province with an area of 3200 km2 which suppies the required water, especially for farming, in Garmsar plain. Previous studies on daily step and related to hydrology and water resources in this watershed were limited to computation of statistics summaries of daily stream flows. Therefore, simulation of daily stream flows is very important. In this research, the parameters of HSPF model were estimated and the results of model in current conditions with minimum data availability are discussed. In general, it was found out that since the model performance using WinHSPF has high errors in metric system, English system must be used in stead. Also, due to the model’s need to hourly time series data, more detailed information about Hydrological components, and other terrestrial data as well as due to low accuracy of these data and model’s objection in some cases such as using the mean of infiltration parameter for a given land use segment and the lack of certain criteria in watershed delineation, high errors occurred in daily stream flow simulation with the Nash-Sutcliffe model efficiency coefficient of 0.77 and 0.18 as well as 0.468 and 0.49 for R2 in calibration and validation period, respectively. Also, simulated flows in late spring are higher than observed value, while in late summer through fall are lower than observed value. Finally, at the end of the paper we discuss the solution to obtain better results.
A Kavian; ALI Azmodeh; K Soleimani; GH Vahabzadeh
Volume 63, Issue 1 , June 2010, , Pages 89-114
Abstract
Globally, soil erosion is one of the most important environmental problems which is threaten soil and water resources. Soil properties are main parameters to affect runoff and soil erosion processes. So, this study was conducted to investigate the effects of some soil properties on runoff and soil erosion ...
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Globally, soil erosion is one of the most important environmental problems which is threaten soil and water resources. Soil properties are main parameters to affect runoff and soil erosion processes. So, this study was conducted to investigate the effects of some soil properties on runoff and soil erosion in the forest lands located in vicinity of Sari city. Rainfall simulator was set in 15 random points in 2 sites to create experimental rainfall. Runoff and sediment yield resulted from each experiment was measured based on field and laboratory investigations. Soil samples from 0-20 cm depth close to the simulation points were collected and analyzed. The results showed that soil initial moisture, percentage of soil organic matter (% SOM), bulk density and sand percent are most effective factors in runoff generation, respectively. Also, the results illustrated that percentage of soil organic matter, soil initial moisture and silt percent affect on soil erosion, respectively. The results of multiple linear models showed that runoff and soil erosion can be predicted based on percentage of soil organic matter, soil initial moisture and percentage of clay with coefficient of determination of 0.638 and 0.752, respectively.
Shahrebanoo Rahmani; Ataollah Ebrahimi; Alireza Davoudian
Abstract
The analysis of the relationship between spatial distribution of environmental factors andvegetation types is crucial for understanding mountainous ecosystems. In this research aGIS based approach was used to produce a vegetation map for Sabzkouh protected area inthe Chaharmahal-Va-Bakhtiari province. ...
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The analysis of the relationship between spatial distribution of environmental factors andvegetation types is crucial for understanding mountainous ecosystems. In this research aGIS based approach was used to produce a vegetation map for Sabzkouh protected area inthe Chaharmahal-Va-Bakhtiari province. To identify environmental parameters affecting thevegetation cover, 6 primary and secondary environmental parameters including hypsometric,slope steepness, slope direction, annual precipitation, temperature and sun radiation maps werederived from the study area DEM. To investigate the relationship between these factors andthe spatial distribution of vegetation cover, quantitative analyses using statistical techniqueslike Principal Components Analysis(PCA) were undertaken. Then, the spatial distributionof vegetation types was predicted using a multi-logistic regression. Results showed thattopographic variables derived from the DEM were very useful for indicating habitats ofrange and forest types. Although lack of information on the anthropogenic effects led to someuncertainties in the interpretation of spatial pattern of vegetation types, the topographic andclimatic variables, derived from the DEM, were considerably effective in modelling the spatialdistribution of vegetation types.
Emad Zakeri; Hamidreza karimzadeh; Seyed Alireza Mousavi; mohammad ghorbani
Abstract
Rangelands provide a diverse array of vital services that pertain to human life. But market failure to consider the value of these ecosystem services has disturbed provision of many ecosystem services. In this study the economic value of water conservation functions by Arnaveh basin located in northwestern ...
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Rangelands provide a diverse array of vital services that pertain to human life. But market failure to consider the value of these ecosystem services has disturbed provision of many ecosystem services. In this study the economic value of water conservation functions by Arnaveh basin located in northwestern Iran was estimated. Rainfall-runoff simulation was carried out by using Curve Number (CN) method. Also by means of Replacement Cost method the value of the hydrological services were quantified. The role of vegetation cover in water conservation was estimated by comparing the surface runoff under current condition and uncovered soil conditions. Moreover the role of rangelands on water retention and surface runoff reduction by devising three more hypothetical scenarios and then the effects of land use changes associated with these scenarios on rainfall-runoff rate of the region were compared. Results showed that the role of rangelands vegetation cover in water conservation and surface runoff reduction was 7.19×106 m3, with the economic value of 123×109 IRR. Also, the results of a comparing between 3 hypothetical scenarios and current conditions showed that, under the case of scenario one which assumes that the entire of rangelands area is becoming to rain-fed farming, total outflow would be in the maximum amount and the most negative effects will accrue. Also the scenarios of improvement of vegetation cover to 25-50 percent has the most positive effects (1.95×106 m3 yr-1 decrease) on water retention. The results of this study could help decision-makers in selecting appropriate and economically feasible development strategies.
