parisa farzi; maryam azarakhshi; ali rasoulzadeh; mehdi bashiri
Abstract
Characteristics of stones forming the earth's surface contribute significantly to environmental changes such as soil erosion and movements of soil particles. This study seeks to investigate the main and reciprocal effects of geological units and slope gradient on runoff and sediment production in Senobar ...
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Characteristics of stones forming the earth's surface contribute significantly to environmental changes such as soil erosion and movements of soil particles. This study seeks to investigate the main and reciprocal effects of geological units and slope gradient on runoff and sediment production in Senobar watershed using rainfall simulator. To this aim, the geological map was created in Arc GIS 10 software and three dominant units i.e. green tuff, sandstone, marl (Et), Orbitolina Limestone (Kl) and Conglomerate, Sand stone (Ngcs) were identified. Besides, to study the effect of slope gradient, the slope map was provided in three classes: 0-10, 10-30 and more than 30%. Then, the rainfall intensity equal to 0.9 mm min-1 (10- years return period) was created by rainfall simulator. Analysis of variance showed significant differences between geological units for runoff, sediment yield and sediment concentration at 5% significant level. It was found out that there is significant difference between different slope gradients in runoff and sediment production; however, there was no significant difference regarding sediment concentration. The results of interaction between geological units and slope gradient for runoff volume was significant at the 95% level of confidence but regarding sediment yield and sediment concentration interaction effects were not significant. Generally, it was found that the type of geological units and slope of the study area impacted on soil erosion process. Also, the impressibility of runoff variable was more than that of the sediment.
abbas ali ghezelsofloo; Mahboobeh Hajibigloo
Abstract
Estimation of suspended sediment basins of data and information is readily available but for basins without statistics, other methods require. The experimental method known as sediment rating curves or relationship "discharge sediment load" is provided. This study seeks to provide better separation of ...
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Estimation of suspended sediment basins of data and information is readily available but for basins without statistics, other methods require. The experimental method known as sediment rating curves or relationship "discharge sediment load" is provided. This study seeks to provide better separation of data and the preparation and suspended sediment curve refine hydrometric stations Maraveh Tape, Houtan, Qazanqayeh on the Atrak River in the Atrak watershed is located in Golestan province. To increase the accuracy of the classification scale monthly, quarterly, all samples, wet and dry periods and classifieds sediment discharge with frequency curve fitting techniques to fit a linear, linear fit by adjusting FAO, fitting combination (multi-line ), graphical approach (maximum concentration) and is fitted intermediate categories. For this purpose, statistical indicators were used to select the top. The results showed that sediment rating curve model by fitting a line to the correct application of FAO data Maraveh Tape station, method fitting a line dividing adjusted by applying FAO data on dry and wet period in the station Qazanqayeh and method Fitting a line segmentation classification data on discharges in Houtan Station Among the models tested with the least amount of mean square error and the predictability of the study is to estimate precipitation stations. Selected on the basis of the average amount of sediment suspended for watershed Atrak to Maraveh Tape station, Qazanqayeh and Houtan respectively 705, 683 and 781 Ton/Km2.day was estimated.
hamed farzi; reza tamartash; zeinab jafarian; Mohammad reza Tatian
Abstract
Restoring vegetation can change the structure and dynamics of vegetation, as well as the change in other parts of the ecosystem such as soil. The success of recovery efforts will be achieved when assessing the characteristics of ecosystems over time and comparing with the control areas. Therefore, the ...
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Restoring vegetation can change the structure and dynamics of vegetation, as well as the change in other parts of the ecosystem such as soil. The success of recovery efforts will be achieved when assessing the characteristics of ecosystems over time and comparing with the control areas. Therefore, the aim of this study was to investigate the effects of reducing plant cover and soil carbonation in rangelands of the southern slopes of central Alborz. Sampling from vegetation during the growing season of May and May was done in a systematic-random manner in 400 plots of 2 m2, along 40 transects of 100 meters. In each plot, crown cover percentage, species presence, functional characteristics of species including vegetative form, distribution type, pollination type and biological form were recorded. During each transect, two soil samples were harvested at different depths of 0-15 and 30-30 cm in different treatment and control areas. A total of 160 soil samples were collected from four different regenerative operations including clamping, seeding, grazing management, grazing and a natural rangeland as a control site. . showed that biological measures significantly changed the canopy cover percentage of three herbs. In the meanwhile, the Graminea strain in the regeneration zone and the legumes of Leguminosae and Cruciferae in the area had a significantly higher mean canopy percentage. The percentage of organic matter and the amount of organic carbon sequstration in the two depths of the soil and bottom of the soil in different biological operations at level have a significant difference.
Mehdi Ghorbani; Leila Avazpour; Mohsen Yoosefi
Abstract
Social capital is one of the most important criteria related to social network resilience. In trust networks as the most important factor of social capital in adaptive governance, sensitivity to disorders and irregularities is considerable and resiliency improvement and compatibility capacity depends ...
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Social capital is one of the most important criteria related to social network resilience. In trust networks as the most important factor of social capital in adaptive governance, sensitivity to disorders and irregularities is considerable and resiliency improvement and compatibility capacity depends on trust level in network. This research is applied in Zangooi village, South Khorasan province where international project ROLL is operated. In this research social capital in local beneficiaries is studied to enhance resilience in pilot village. Trust and cooperation ties are studied based on survey method and network analysis questionnaires and direct interviews with actors (members of rural development small groups). Results show that trust, cooperation, cohesion and social capital is at average level before RFLDL project and after operating this project these indices increase and reach optimum level. The speed of trust and cooperation exchange through people increases after operating the project and this develops unification and alliance between members. At last it can be concluded that conveying this project increases trust and cooperation and social capital, so resilient social systems have undoubtedly much more trust level.
Mansureh Kargar; Zeinab Jafarian; Mohadeseh Ehsani
Abstract
For the scientific and accurate management of rangeland ecosystems, having information about ecosystem as indicators of ecosystem health and function is needed. The aim of this research is to study the effects of grazing on soil surface indicators and rangeland functional properties by using Landscape ...
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For the scientific and accurate management of rangeland ecosystems, having information about ecosystem as indicators of ecosystem health and function is needed. The aim of this research is to study the effects of grazing on soil surface indicators and rangeland functional properties by using Landscape Functional Analysis (LFA) method. For this purpose, the present study was conducted in two regions, including the enclosure and outside the enclosure, Donna rangelands of Siah Bisheh watershed. Systematic sampling was carried out by three 100 m transects with 100 m interval. Along each transect, ten 1m2 plots with 10 m interval were placed. In order to compare triple indices including infiltration, stability and nutrient cycling in two regions of the enclosure and outside the enclosure, the independent T test was employed in this study. The results showed that there are significant differences among soil surface indicators except soil surface cover, perennial plants, trees and shrubs canopy, surface roughness and erosion type and severity (P < 0.05). Therefore, there are significant differences among three functional attributes of rangeland in these study regions.
mahdieh salehi; Hossein Arzani; ِAli Tavili; Mahdi Ghorbani
Abstract
Rrecently, rangeland multiple use has been found to be one of the primary solutions to alleviate livestock grazing pressure while improving stakeholder's welfare and per capita income and sustainable management and development. Beekeeping in rangeland as a profitable approach and one of multiple use ...
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Rrecently, rangeland multiple use has been found to be one of the primary solutions to alleviate livestock grazing pressure while improving stakeholder's welfare and per capita income and sustainable management and development. Beekeeping in rangeland as a profitable approach and one of multiple use components in upper Taleghan basin and Saman Orfi of Narian, Dizan and Mehran were studied. The present study was aimed to determine beekeeping suitability as well as ecological and social issues. According to permanent standards and resource sites priority for comprising of these Samans Orfi reserves 4 criteria to be considered such as vegetation,environmental, physical and social issues.These criteria are included overall 14 sub criteria. So Multi-Criteria Decision Making Methods (MCDM) has used because of problem complexity. The hierarchical formed in the 4 levels that is purpose, criteria, sub criteria and options. One of the criteria were qualitative. For accessing logical results, we benefit specialist cooperation. The results showed that social problem are more important than the other criteria in priority. Also, final results of Analytical Hierarchy Process (AHP) indicated that Saman Orfi Narian, and Mehran and Dizin were fall into first to third priorities respectively.
nasibe ghanbari; hossein azarnivand; hamed joneidi jafari; mohammad jafari
Abstract
This study aimed to effect of converting rangeland to afforestation on carbon and nitrogen storage was done in forested areas of Hassan Abad in Sanandaj. Masses of studied was include Cupressus arizonica, Pinus eldarica, Fraxinus rotundifolia, Robinia psedoacacia and Thuja orientalis whit an average ...
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This study aimed to effect of converting rangeland to afforestation on carbon and nitrogen storage was done in forested areas of Hassan Abad in Sanandaj. Masses of studied was include Cupressus arizonica, Pinus eldarica, Fraxinus rotundifolia, Robinia psedoacacia and Thuja orientalis whit an average age of 20 years and adjacent rangeland that converting was not created was selected as control. Sampling of soil was done in afforestation mass and control and characteristics of organic carbon, nitrogen, phosphorus, potassium, bulk density, pH, electrical conductivity, percent clay, silt and sand was measured. To compare the effect of forestry corrective operations on carbon sequestration was used independent t-test analysis and to compare the effects of different types of afforestation on soil carbon and nitrogen sequestration rates was used one-way ANOVA. Results shows that Robinia psedoacacia have a significant effect on increase of carbon and nitrogen sequestered and amount of phosphorus and potassium in soil and in total in Robinia psedoacacia mass amount of cabon sequestered and nitrogen stored in soil was calculated 80.62 and 5.42 ton/ha and in control 47.05 and 3.08 ton/ha and Robinia psedoacacia mass cause to increase of soil carbon and nitrogen amount of 71 and 75 percent and lowest amount of carbon and nitrogen was obtained in soil of Cupressus arizonica mass. Stepwise regression results showed that nitrogen, phosphorus and potassium, respectively are most important components affecting in soil of investigated mass.
Morteza Saberi; vahid karimian; Hamid Niknahad Gharemakhar
Abstract
Many regular visits were done to investigate the phenological stages of the plant in Zabol and Saravan habitats. Plant cover of the species was investigated by plot with 4 square meter along to 4 transect with 200 meters. To investigate their physicochemical properties of soil, soil sample were taken ...
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Many regular visits were done to investigate the phenological stages of the plant in Zabol and Saravan habitats. Plant cover of the species was investigated by plot with 4 square meter along to 4 transect with 200 meters. To investigate their physicochemical properties of soil, soil sample were taken from 0-30 cm depth under the species and area without species. Forage quality index was analyzed by 4 replication on three phenological stages (vegetative, flowering and maturity stages). Results indicated that the first leaves of the species were initiated in March and August is the end of growing period. The average of canopy cover and density of Citrullus colocynthis had significant difference in the two regions (P<0.01). The rooting depth of this species was 207 and 123 centimeters in Zabol and Saravan habitats, respectively. The results showed that the electrical conductivity, carbon and organic matter under the studied species were significantly higher than the control area. The results of soil analysis under the species of two habitats also showed that sand, silt, acidity, lime and organic carbon content were significant at 5% level (p <0.05) and organic matter was significant at 1% level (p <0.01). Also, the average of sand, acidity, organic creatinine and organic matter of Zabol habitat was higher than Saravan, but the amount of silt and lime in the plant cover was higher in Saravan than that of Zabol.
khaled Hajimaleki; rouhollah mousavi; Manochehr Gorji; Fereidon Sarmadian
Abstract
Nowadays, the importance of soil conservation in agriculture and natural resources, with the goal of preventing its deterioration and degradation are necessary. Soil and land degradation as a direct cause of the threat to the global environment and human welfare is evident. In this study soil degradation ...
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Nowadays, the importance of soil conservation in agriculture and natural resources, with the goal of preventing its deterioration and degradation are necessary. Soil and land degradation as a direct cause of the threat to the global environment and human welfare is evident. In this study soil degradation mapping was carried out in East Qazvin. Soil map using geopedological method by integration of information layer of lithology, geomorphic and pedogenic was prepared in ArcGIS9.3 software. Data from soil maps with field studies was used as input in GLASOD model and the soil degradation map was prepared. In this study soil map units was used as basis of soil degradation status investigating in the region. Results showed that less than 25% of the study area has a low degree of degradation and in the present circumstances do not require specific management actions, but in other parts of the region, with various degrees of soil degradation was observed. Soil chemical properties degradation include decrease of soil organic matter, loss of soil nutrients and soil salinity are the most important aspects affecting on soil degradation of region. At total of 16,630 hectares of land, about 4028 ,5987, 5128 and 866 respectively low, middle, high and very high soil degradation class are located. Thus according to the results to prevent the spread of this process in this area, management actions is recommended.
Seyde maryam Alibakhshi; Alireza Faridhosseini; kamran davari; amin alizadeh; Henry Munyka Gathecha
Abstract
Satellite precipitation products have been used in scientific studies in global and regional scales from several decades ago. The purpose of this research is quantitative comparison between TRMM and GPM precipitation products in Kashafrud basin. The important point about these products is their accuracy ...
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Satellite precipitation products have been used in scientific studies in global and regional scales from several decades ago. The purpose of this research is quantitative comparison between TRMM and GPM precipitation products in Kashafrud basin. The important point about these products is their accuracy and pixel size. GPM satellite launched on 28th February 2014 and there is no research in Iran and few in the world. This research aims to assess GPM and its predecessor i.e. TRMM products in comparison with 34 ground rain gauge stations in the basin. Comparisons are done in basin and gauge spatial scales and each in daily and monthly time scales. For validation, the statistical metrics including RMSE, MAE, CC, BIAS, FAR, POD and CSI are used. The results indicated that generally the 3B42V7 product from TRMM has higher accuracy than IMERG product from GPM in our study region. IMERG product only in monthly and basin scale has better accuracy in comparison to 3B42V7 product. Regarding time scale comparison, monthly analysis showed higher accuracy. RMSE value for TMPA product in daily time scale for rain gauge and basin scale is 1.88 and 1.55 and in monthly scales is 2.87 and 2.77, respectively. Also, RMSE for IMERG product in rain gauge and basin in daily time scale is 2.43 and 2.3 and for monthly time scale 3.64 and 2.56, respectively.
mahdie mahmoodi; Ataollah Ebrahimi; Mohammad Hasan Jouri; pejman tahmasebi
Abstract
The evaluation of utilization of key species is cornerstone of decision-making in rangeland management. Measuring utilization is essential for regulating grazing intensity, grazing pressure and distribution of animals. utilization of two key grass species of Dactylis glomerata and Bromus tomentosus, ...
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The evaluation of utilization of key species is cornerstone of decision-making in rangeland management. Measuring utilization is essential for regulating grazing intensity, grazing pressure and distribution of animals. utilization of two key grass species of Dactylis glomerata and Bromus tomentosus, as two important rangeland species is determined using height-weight relationship. The research is done in two vegetative periods of prior to flowering and flowering stages in two region of grazing land and exclosure by 32 transects of 100-meter length. To do so, the height of species was measured and cut at 1-cm above soil surface and weighted freshly. The samples are clumped and moved to the laboratory and oven dried at 65°c after separating litter divisions Then, the whole individual plants were weighted and cut in 5-cm intervals and each part was re-weighted and recorded separately for each species. Height-weight relationships were analyzed by different regression models in SPSS v.18 software. Result shows that sigmoid model significantly illustrate the height-weight relationship of both species of Dactylis glomerata and Bromus tomentosus with R2=0.994 and 0.997 at prior to flowering stage in the exclouser respectively. Similarly, sigmoid model also elucidate the height-weight relationship of both species of Dactylis glomerata and Bromus tomentosus with R2=0.975 and 0.998 at the flowering stage in the exclouser, respectively. The sigmoid model also best fitted for depicting height-weight relationship of both species at prior to flowering stage in grazing land for both species with R2=0.996, too.
Amir Alambeigi; Mohsen Malekli
Abstract
The phenomenon of climate change, especially the drought in Iran during the past decades are increasingly on the rise. In this respect the role of institutions and institutional entrepreneurship in areas that suffer from drought are can be used as the perfect solution for the management of drought. The ...
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The phenomenon of climate change, especially the drought in Iran during the past decades are increasingly on the rise. In this respect the role of institutions and institutional entrepreneurship in areas that suffer from drought are can be used as the perfect solution for the management of drought. The aim of this study was to analyze the institutional management of drought with approach of social network analysis. The statistical research community is smallholder farmers of Saveh town. The dominant statistical method in this study is to measure and extract the total network indexes through the network analysis technique. Based on information obtained from the institutional rankings were determined that the most current information on educational information network two-sided with ministry of agriculture and veterinary. In the context of the flow of information, banks and credit institutions support the centrality of the ranking. In terms of information flow as well as the largest specialized veterinary related role information to current technical and specialized in order to catch up with climate change. The research results show that the different dimensions of social networks effect on the mobilization of resources and on the other hand, the lack of institutional entrepreneurship can damage caused by climate change will intensify. At the end, suggestions are made to improve the management of droughts.
maryam mombeni; hamid reza asgari; ali Mohammadian Behbahani; Salman Zare; hossein yousefi
Abstract
One of the main challenges of land degradation management in arid and desert areas of Iran is the stabilization of sand as well as the control of dust; therefore the use of mulches, particularly eco-friendly mulch, is one of the ways to stabilize sand used. The purpose of this study was to investigate ...
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One of the main challenges of land degradation management in arid and desert areas of Iran is the stabilization of sand as well as the control of dust; therefore the use of mulches, particularly eco-friendly mulch, is one of the ways to stabilize sand used. The purpose of this study was to investigate the possibility of using residues such as black liqueur and malass as mulch to stabilize the sand. To prepare the substrate for treatments in the laboratory environment, Rig Boland sandy of Kashan was used. Metal trays with dimensions of 100 × 30 × 2 cm were used for the experiments. For spraying of malass, black liquor and control treatments in a single layer and double layer of 2.5-liter sprinkler were applied and a completely randomized design with three replications was performed. To evaluate the performance of these materials, the shear strength, saturation, and dry strength and water permeability were measured and the data were analyzed by appropriate statistical software. In vitro results showed that the penetration resistance of molasses and black liqueur mulches were 9.8 and 7.8 kN/m2, respectively. These two types of mulch have significant differences with each other and with control (water) treatment. The highest penetration and shear strength were related to Malass treatment, which increased the penetration resistance by 9.8 times and the shear resistance by 14 times. The infiltration rate in one-layer liqueur mulch was significantly different compared to Malass and control (water) mulches, while the infiltration rate decreased with increasing thickness.
Mehdi Vatakhah; Mohsen Mohsenisaravi; Hasan Ahmadi
Abstract
Land use optimization is one of the suitable methods for soil conservation. The present research with objective of land use optimization for soil erosion minimization and pure income maximization was conducted in the part of Taleghan Watershed which comprises 80427.23 ha in area. To achieve this propose, ...
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Land use optimization is one of the suitable methods for soil conservation. The present research with objective of land use optimization for soil erosion minimization and pure income maximization was conducted in the part of Taleghan Watershed which comprises 80427.23 ha in area. To achieve this propose, area, erosion rate and net income value of each land uses according to requiring standards of each land uses area was extracted. Then, limitations and two objective functions were determined and optimization problem was solved by using ADBASE software. The results revealed that the optimization decrease 6.99 percent of erosion rate(6.28 ton/ha/year to 5.84 ton/ha/year) and 4.65 percent of pure income(118174.38 to 112681.02 million Rials). Also, the results proposed that drylands farming are changed to garden and orchard and rangelands.
Abbas Gholami; Kaka Shahedi; Mahmud Habibneghad; Mahdi Vafakhah; Karim Solymani
Abstract
Present study is aimed at forecasting and comparison of future climate change by using GCM model (General circulation model) under different climate scenarios in Talar watershed of Mazandaran province. Regarding the data of existing stations, to study the climate change phenomenon in Talar watershed, ...
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Present study is aimed at forecasting and comparison of future climate change by using GCM model (General circulation model) under different climate scenarios in Talar watershed of Mazandaran province. Regarding the data of existing stations, to study the climate change phenomenon in Talar watershed, the LARS-WG5 model and 3 climate scenarios i.e. A1B, A2, B1, each in three emission series i.e. 2011-2026, 2046-2061, and 2080-2095, that were extracted from Gharakhayl regional synoptic stations in Quaemshahr, were used and the base year was considered 1992-2007( for a 15- year duration). Since this model is one of the most authentic statistical downscaling methods and its data is produced in three phases of calibration, evaluation and development of meteorological data, it was applied for research in present study. According to the findings, the most precipitaion changes occurred in May and October and the most severe reductive changes occurred in 2080-2095, the result of which warns about seasonal floods in rainy months and drought or water shortage in dry months in the relevant watershed study area. Besides, in future in June, July, August, and September temperature increase will be experienced but in January and February, the minimum simulated tempreture mean will be observed.
Sana Mohebbi; Ghasem Ali Dianati Tilaki; Mehdi Abedi
Abstract
Assessment of rangeland ecological characteristics have been proposed as an important factor inreviewing and monitoring the effects of various management measures and it demands differenttools for quantifying and offering a reasonable criterion for comparison of different managements.For this purpose, ...
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Assessment of rangeland ecological characteristics have been proposed as an important factor inreviewing and monitoring the effects of various management measures and it demands differenttools for quantifying and offering a reasonable criterion for comparison of different managements.For this purpose, the Landscape Function Analysis (LFA) method is capable of displaying thestructural and functional status of pastureland with considering the basic and simple indicators andit can be resorted to as a basis for selecting optimal and sustainable management. In this study, itwas found out that among different types of pasture management in Kojour Noshahr including;exclosure, grazing, plowing and planting management - in almost identical conditions regardingplant types, animal types, soil, geology, and climate the exclosure management was significantly(P<0/05) more favorable than other kinds of managements in terms of structural and functionalfeatures and it was followed by planting and grazing. Meanwhile, the plowed pastures weresignificantly unfavorable (P<0/05) both in terms of structural features and functional characteristics.Therefore; exclosure can be a perfect option to protect rangeland resources in this region.
1 1; 1 1
Abstract
Stochastic climate generators are used in many studies such as application of hydrologic, environmental management and assessment of agriculture risk. These studies require for assessment of risk to long term series from meteorological data. Considering of climate data limitation at large area in Iran ...
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Stochastic climate generators are used in many studies such as application of hydrologic, environmental management and assessment of agriculture risk. These studies require for assessment of risk to long term series from meteorological data. Considering of climate data limitation at large area in Iran and short term of data, it is necessary using of climate generator and evaluation of precision and accuracy. Therefore in this study have been evaluated the efficiency of three generators namely CLIGEN, ClimGem and LARS-WG in sangeneh and Zidasht station with different climate condition. Statistical test of t (t paired) have been used to compare the differences between observed and production weather data such as yearly and monthly precipitation amount, yearly number of wet day, yearly average of max. and min. temperature. The obtained results show that CLIGEN generator have the better efficiency than two others generator in two stations and five considered variables. ClimGen haven't had the good efficiency in two stations. Also, LARS-WG generator have had the good efficiency in Zidasht station, but it's efficiency have had the less efficiency for product of temperature variables in Snganeh station. Generally, the obtained results show that the efficiency of these generators is better in mild climate than arid and semi-arid climate.
Seid Saeid Ghiasi; Sadat Feiznia; Alireza moghadam nia; Ali Najafinejad; Somayye Najirad
Abstract
Landslide susceptibility assessment is a primary tool for understanding the basic characteristics of slopes that are prone to landslides. In this study, a landslide susceptibility assessment was accomplished, by adopting the Statistical Index Method (SIM) and the Analytic Hierarchy Process (AHP). Ten ...
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Landslide susceptibility assessment is a primary tool for understanding the basic characteristics of slopes that are prone to landslides. In this study, a landslide susceptibility assessment was accomplished, by adopting the Statistical Index Method (SIM) and the Analytic Hierarchy Process (AHP). Ten landslide causing factors were considered including: elevation, slope, aspect, lithology, land use, drainage density, plan curvature, precipitation, geomorphologic faces, and rock unit’s sensitivity to erosion. The SIM was used to determine the weighted value (Si) for classes of every landslide causing factor, the AHP was utilized to determine the weighted value (Wi) for every factor. The summation of the product of Si by Wi represent the landslide Susceptibility Index (LSI) value for every pixels. Based on the derived LSI, landslide susceptibility map (LSM) was produced then the study area was grouped into five susceptibility classes. The densities of landslide for five susceptibility classes implying there is a satisfactory agreement between the susceptibility map and the actual landslide data. In the following, the results of the LSM were quantitatively validated using observed landslide dataset and the receiver operating characteristic (ROC) method. The validation results showed that the AUC for prediction rate of model was 95.2%. The landslide susceptibility showed the areas with lithology of old terraces, young terraces, lahar, and porphyritic trachyandesite-trachyte with different degrees of sensitivity to erosion which distribute between 10–40% slope and more than 60% are very prone to slope failure. Therefore, SIM and AHP were found to be effective models for landslide susceptibility mapping.
javad Motamedi(torkan); Hossein Arzani; Mehdi Ghorbani
Abstract
More than 20 sheep breeds having different body size utilize various rangelands in different climate regions which the conversion coefficient of each breed compared to animal unit must be recognized. For this purpose, two herds were selected from each breed sheep grazing at the central region during ...
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More than 20 sheep breeds having different body size utilize various rangelands in different climate regions which the conversion coefficient of each breed compared to animal unit must be recognized. For this purpose, two herds were selected from each breed sheep grazing at the central region during 2001-2007. Among selected herds, 30 animals randomly weighted at various age and sex groups and at various grazing seasons. Mean weight of three and four years old sheep was considered as mature weight of each breed. Conversion coefficient of each breed to animal unit (animal unit equivalent) calculated from the ratio of metabolic weight ((live weight)0.75 to animal unit metabolic weight. According to the results, Naeeini breed classified as light body breeds, Zandi, Kermani and Varamini as medium body and Shaal as heavy body breeds. Equivalent animal unit for each breed to animal unit were 0.7, 0.86, 0.9, 0.97, 1.06 and 1.20. based on proposed conversion coefficient and using MAFF proposed equation, daily requirement of each breed at maintenance condition and at grazing condition were as 4.76, 5.85, 6.12, 6.60, 7.21 and 8.16 MJ per day. Results represent that considering to same forage amount as daily requirement of grazing sheep breed in rangelands in order to calculating grazing capacity, without considering their body size is not valid.
Mojtaba Nassaji Zavareh; Bagher Ghermezcheshmeh; Moslem Mohammadpour
Abstract
Land use and climate change can alter the seasonal and annual discharge of rivers. Annual and seasonal river discharge changes should be considered in the management and planning of water resources in basins. For this propose, Karkheh basin was selected for study. For trend analysis of this basin daily ...
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Land use and climate change can alter the seasonal and annual discharge of rivers. Annual and seasonal river discharge changes should be considered in the management and planning of water resources in basins. For this propose, Karkheh basin was selected for study. For trend analysis of this basin daily discharge time series in 15 sub-basins during the 1969-2012 period. After reconstruction of time series of selected sub-basin, five discharge indicators including seasonal and annual Q5, Q10, Q50, Q90 and Q95 were prepared for future analyses. The seasonal an annual discharge trends were calculated using Thiel-Sen method, then discharge percent changes in the 1969-2012 for selected sub-basins were determined and seasonal and annual discharge map for each indicator was prepared. The result showed that seasonal and annual discharge in most selected sub-basin had decreasing and negative trend. The selected sub-basin in the southeast had less decreasing trend relative to other ones. Low flow (Q5, Q10) relative to high flow (Q90, Q95) had steeper decreasing trend. The spring high flow indicator related to Kakareza and Afrineh sub-basins had increasing trend. These two sub-basins were independent and are not influence by any other runoff. The increase in high flow in these two sub-basins can be caused by increase in temperature due to climate change and early snow melting in recent years
mohsen yosefi; Fatemeh Barzegari
Abstract
Suspended sediment estimation is an important factor from different aspects including, farming, soil conservation, dams, aquatic life, as well as various aspects of the research. There are different methods for suspended sediment estimation. This study aims to estimate suspended sediment using feed forward ...
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Suspended sediment estimation is an important factor from different aspects including, farming, soil conservation, dams, aquatic life, as well as various aspects of the research. There are different methods for suspended sediment estimation. This study aims to estimate suspended sediment using feed forward neural network with error back propagation with Levenberg-Marquardt back propagation algorithm and compare the results with best sediment rating curves among commonly used sediment rating curves, including: linear, seasonal, monthly and Mean load within discharge classes. To attain this, the sediment discharge and the corresponding water discharge data for ten hydrometric stations of Lorestan province of Iran were used. In next step different methods of sediment rating curves along with different correction factors, a total of 20 methods were applied to data. Results showed among examined methods; monthly rating curve with MUVE correction factor has been selected as best, based on Nash and Sutcliffe index and accuracy index. Then results of estimating sediment load by using selected sediment rating curve were compared with the results of the neural network. Mean-square error and Nash and Sutcliffe index were applied to select more appropriate method. The results showed the suitability of the feed forward neural network error propagation in compare with sediment rating curves.
leila avazpour; mahdi ghorbani; reza erfanzadeh
Abstract
Social capital is the prerequisite of co_management. Evaluation of social capital for achieving community-based management is therefore of capital importance. Detection of key actors in local communities for co_management of natural eco_systems is as well quite important. These people are generally regarded ...
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Social capital is the prerequisite of co_management. Evaluation of social capital for achieving community-based management is therefore of capital importance. Detection of key actors in local communities for co_management of natural eco_systems is as well quite important. These people are generally regarded as local leaders and they have the potential to play a key role in co_management. Social Network Analysis method was applied and macro level and micro level indexes of rangeland users’ network in traditional boundary of Hagh-ol-Khaje in Mayamey District were analyzed as a way for measuring the social capital and recognizing influencial local leaders. It was found out that the level of social capital of beneficiaries based on trust tie was moderate and based on collaboration tie it was low. Sustainability of ties and network balance were as well weak and trust and collaboration ties were not optimally established. Low speed of exchange in trust and collaboration ties and lack of unity among beneficiaries are other important challenges in rangeland co_management. Gh_Gh and Es_Sa were recognized as the corest actors among Hagholkhaje rangeland users. These people can play important role in co_managements because of their authority and social influence and they can act as gatekeepers connecting governmental institutions and other users for sustainable rural development.
Ali Reza Mahmoodi; Ali Tavili; Hamid Reza Boostani; Mohammad Jafari; Salman Zare
Abstract
An appropriate amount of soil was picked up from the surface horizon (0-30 cm) from the rangeland of Darab city. After air drying and passing through a 2 mm sieve, some physical and chemical properties of the soil were measured. A factorial pot experiment was conducted in a completely randomized design ...
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An appropriate amount of soil was picked up from the surface horizon (0-30 cm) from the rangeland of Darab city. After air drying and passing through a 2 mm sieve, some physical and chemical properties of the soil were measured. A factorial pot experiment was conducted in a completely randomized design with four replications. The first factor includes biochars in 7 levels (no application of biochar (C), wheat biochar (1.5 % w/w) (GB1), wheat biochar (3 % w/w) (GB2), corn biochar (1.5 % w/w) (ZB1), corn biochar (3 % w/w) (ZB2), cotton biochars (1.5 % and 3% w/w) and the second factor includes the use of lead (Pb) at 3 levels (0 (Pb0), 150 (Pb150) and 300 (Pb300) mg kg-1 soil) under forage panicum cultivation. After copmpleting vegetative growth, the plants were cutted and harvested from 0.5 cm of the soil surface. This study indicated that with increasing the biochar levels from 0 to 3 % (w/w), the electrical conductivity (0.31, 0.15 and 0.02 dS/m), soil organic carbon (53, 59 and 63%) and soil pH (0.13, 0.05 and 0.15 units) were increased and the Pb availabity (16.12, 12.83 and 10.25%) was decreased, respectively. With enhancing the Pb levels from 0 to 300 mg kg-1 soil, the concentration of soil manganese (17.27%) and potassium (4.54%) availability were significantly reduced.
Ahmad Ghanbari; Rafat Zare Bidaki; Afshin Honarbakhsh; Vafa Mahmoodinejad
Abstract
Check dam is the most costly watershed management practice. This research was an attempt to evaluate the effectiveness of individual check dams in different watersheds of Chaharmahal-va-Bakhtiari. 11 criteria impacting upon check dams’ individual efficiency were considered: check dam location, ...
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Check dam is the most costly watershed management practice. This research was an attempt to evaluate the effectiveness of individual check dams in different watersheds of Chaharmahal-va-Bakhtiari. 11 criteria impacting upon check dams’ individual efficiency were considered: check dam location, check dam stability, longitudinal profile fixing, check dam's coefficient of sediment storage, check dam's crest to be perpendicular to channel's axis, spillway dimensions, check dam strength, anchorage, check dams built according to channels' cross section, consistency of spillway center with stream alignment and apron length. The importance of each criterion for each check dam’s efficiency was measured using analytical hierarchy processes. 41 cement- masonry and gabion check dams constructed previously in different parts of the province were selected and were scored based on these criteria. Then by multiplying the weight of each criterion by the score each check dam received on that criterion, the distance of performance of each check dam from expected efficiency was computed. Results show that check dam's crest perpendicular to stream axis and consistency of spillway center with stream alignment averagely gained the highest score but longitudinal stream fixing and correct spillway dimensions gained the lowest score. And the location of check dams with the weight of 0.214 and apron length with the weight of 0.035 gained the highest and lowest weights, respectively. Economic assessment of check dams were done by comparing their final score in efficiency and the size of material used for that. It was revealed that small check dams constructed by consideration of designing principles showed more efficient and cost effective than huge check dams.
Elham Kianisalmi; Ataollah Ebrahimi
Abstract
Wetland meadows as a natural ecosystems plays an important role on sustainability of nature, although are enormously under drainage and changing in the recent years. Shahrekord meadow, which is located adjacent to the city, considered as a natural heritage due to its contribution to tourist visiting, ...
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Wetland meadows as a natural ecosystems plays an important role on sustainability of nature, although are enormously under drainage and changing in the recent years. Shahrekord meadow, which is located adjacent to the city, considered as a natural heritage due to its contribution to tourist visiting, balancing weather in addition to supplying forage for animals. However, this meadow is declining due to anthropogenic effects that this article aims at studying and evaluation of its change and prediction of future condition using Landsat TM5, ETM+7 and OLI/TIRS. To do so, first of all the images of 1987, 1994, 2001, 2010 and 2016 were gathered, then radiometric and geometrically were evaluated. After that, landuse/landcover of the study area was depicted using a maximum likelihood method in TerrSet (Ver. 18.31). Afterward, change detection of the study area was done using a cross-tabulation method and the future condition was predicted using a CA-Markov model. Results indicated that a significant change was occurred in this study area whereas in 1987 whole of the study area was covered by meadowland but land cover changes altered this valuable ecosystem to constructed area (3.33%), arable land (25.02%) and airport (19.65%) in 2016. Results of change prediction also depicted that 5.08% of the study area will be converted to other land cover in 2026. Therefore, we recommend that land use and land cover of this valuable ecosystem should be conserved due to the function and services that this meadowland offered.
