M. Akbarian; S. H. Kaboli; N. Moradi
Abstract
Determining the relative sensitivity of land to erosion and its factors, could be the basis of soil conservation programs. The aim of this study is to compare water and wind erosion functions in land degradation of Dasht-e-Jeihoon using PSIAC and IRIFR.EA models and the source studying of aeolian sediments ...
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Determining the relative sensitivity of land to erosion and its factors, could be the basis of soil conservation programs. The aim of this study is to compare water and wind erosion functions in land degradation of Dasht-e-Jeihoon using PSIAC and IRIFR.EA models and the source studying of aeolian sediments in geomorphologic facieses as homogeneous units. The results indicate that in Dasht-e-Jeihoon, water erosion has been transferred fine and coarse grained sediments to the center of plain. In fact, in this region wind erosion fulfills the effect of water erosion in center of the plain. Erosion estimation shows that 50.3 percent of the region includes the mountain facieses )erosional or bare pediment (which water erosion is moderate to high, have minute to low wind erosion and 49.7 percent of the region includes the facieses of Epandage and covered pediment which water erosion is low while wind erosion has moderate to high effects. Water erosion not only results 39.7 percent of the Dashte-Jeihoon sedimentation, but also it has a significant role to supply erodible particles in downstream of the region. Observations and the results showed that for estimating the erosion in dry areas such as Dashte-Jeihoon, we need to use water and wind erosion estimator models as supplements.
F. Amiri; H. Arzani; E. Gavili
Abstract
Existence of pollen and nectar plants in vegetation composition of natural environment is essential for apiculture as one of the utilization types in multiple uses of environmental resources. Therefore, development of this strategy based on indigenous knowledge will increase stakeholder income, which ...
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Existence of pollen and nectar plants in vegetation composition of natural environment is essential for apiculture as one of the utilization types in multiple uses of environmental resources. Therefore, development of this strategy based on indigenous knowledge will increase stakeholder income, which can decrease stocking rate based on range grazing capacity. Due to high dependence of bee to plant flowers, recognition of such plants, studying their phonology and distributed regions is an important issue. Such information can help mangers to classify environmental suitability for bee keeping. The present study investigates the potential of plant species in Ghareh Aghach Watershed in beekeeping. Sample collection was carried out from vegetation species, percentage and composition along two hundred meter transects in three replications and within 30 one square meter quadrates of each Vegetation type. The most import vegetation families utilized by bees in the area were Labiatae, Fabaceae, Asteraceae, Umbelifera, Rosaceae and Cruceferae. Among 114 plant species, 78 species are utilized by bees. These species were not palatable for grazing animals but were dominant in degraded rangelands. Therefore, it is important to define species and flowering time which essential for preparing beekeeping calendar and potential of this utilization type in the area.
Kh. Osati; A. Salajegheh; S. Arekhi
Abstract
Spatiality assessment of groundwater pollution is very important to determine water quality condition, pollution sources and management decisions. In this case, GIS and geostatistics methods can be useful tools. Spatiality of groundwater quality parameters, in relation with various land uses, can be ...
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Spatiality assessment of groundwater pollution is very important to determine water quality condition, pollution sources and management decisions. In this case, GIS and geostatistics methods can be useful tools. Spatiality of groundwater quality parameters, in relation with various land uses, can be very extremely. Therefore water samples from 52 wells in the Kurdan area were analyzed in this study. The results show that nitrate concentrations are less than maximum acceptable concentration in drinking water (i.e. 50 mg/L as nitrate recommended by ISIRI and WHO guideline values) except to one sample (2 percent of samples) in the study area. Various geostatistics methods, e.g. IDW (power 1-4), ordinary Kriging and RBF (five Kernel functions) were compared after assessing the variograms and the spatiality of nitrate samples. Then the model parameters were calibrated and through the specific methods, predicted and standard errors maps were prepared. Errors criteria show that Kriging is the best fitting model in the study area. Finally, probability map of NO3 concentrations exceeding the threshold value of 50 mg/L, is generated using the Indictor Kriging method. Spatiality of NO3 show that Nitrate concentration is increased where the rock type is permeable, land use is agriculture and slope is enough low to infiltrate polluted water into the wells. This research also tries to describe how to assess the spatiality of groundwater parameters by GIS.
M. Padyab; S. Feiznia
Abstract
Importance of sediment storage has been expressed as being higher than that of water in floodwater spreading networks. To determine the contribution of each geological formation in sediment input of Gachsaran Floodwater Spreading Station after 12 years of flood spreading, sediment sampling was conducted ...
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Importance of sediment storage has been expressed as being higher than that of water in floodwater spreading networks. To determine the contribution of each geological formation in sediment input of Gachsaran Floodwater Spreading Station after 12 years of flood spreading, sediment sampling was conducted in 16 points and 0-15 cm depth of the field. Using dry sieve analysis, all samples were analyzed for granolumetry. To determine mineralogical composition of sediments, particles on 150 and lower than 62 micron sieves were used. The lithology of formations was identified using geologic maps. The mineralogical composition of samples was also compared with lithological units of upstream watershed. Then percentages of share of each lithological unit in sediment production were determined. By considering the area of each lithological unit, weighted percentage of share of each unit was calculated. The results showed that Pabdeh-Gurpi formations with 55.3 % of the sediment input, has had the most contribution in the production of the largest particle size of 150-300 micrometers, followed by Kazhdomi formation with 14.1% share, Ilam-Sarvak formations with 13.1 % share, Khami formation with 10.8 % and Asmari formation with 6.5% share in the sediment production, respectively. With regard to the particles size less than 62 micrometers, Pabdeh-Gurpi formations with 80% of input sediment, had the largest contribution in the production of these particles. By using erosion control measures and storing sediments of streams on Pabdeh-Gurpi formations, 80% of very fine sediments (less than 62 microns) and 50% of fine sediments (150-300 micrometers) will be decreased.
M. Jankju; F. Noedoost
Abstract
Ecological studies on range plants enhance our knowledge on the rangeland ecosystems which are useful for their planning and management. By doing field and laboratory experiments during 2008-2009, ecological conditions were studied in the main habitats of Z. atriplicoides in the rural and winter ...
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Ecological studies on range plants enhance our knowledge on the rangeland ecosystems which are useful for their planning and management. By doing field and laboratory experiments during 2008-2009, ecological conditions were studied in the main habitats of Z. atriplicoides in the rural and winter rangelands of Northern Khorasan province (NKP). Forage quality was also studied at different phonological stages. According to the results, Z. atriplicoides grows in the habitats with mean annual rainfall ranging from 260-380 mm, temperature 8-16 ºC, and altitude 680-1200 meter a.s.l. Topography was as plains and rolling lands, with geologic formations being conglomerate, marl, shale and sandstone. Soil texture was silty loam, weak alkaline, and poor in phosphorus and nitrogen. Vegetative growth and flowering stages were simultaneously occurred at early April till early June, but seed ripening and shedding happened at late June-mid August. Toward the end of growing season, ADF and NDF increased while crude protein decreased, which led to a gradual decrease in forage quality. Ability for growing in different habitats – from cold dry to warm humid- and having protein content and metabolic energy higher than the critical level for rangeland livestock are the relative advantages, whereas significant leaf reduction in response to drought and heat stresses, inability for growing in saline lands and low palatability and preference values are the major disadvantage for Z. atriplicoides in the rangeland of Iran. The most suitable time for livestock grazing and seed collection of Z. atriplicoides in the NKP are May-June and July, respectively.
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.
J. Sharifi; M. Akbarzadeh
Abstract
A major part of the rangelands of Iran are located in arid and semi-arid regions. In this climate, rainfall fluctuation is an important factor which affects vegetation and forage production. In dry years that rainfall decreases, surface vegetation and forage production is damaged. This study was conducted ...
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A major part of the rangelands of Iran are located in arid and semi-arid regions. In this climate, rainfall fluctuation is an important factor which affects vegetation and forage production. In dry years that rainfall decreases, surface vegetation and forage production is damaged. This study was conducted on semi-steppic rangelands of Ardebil over nine years (1999-2007), to study of vegetation changes with rainfall fluctuation. The results showed that canopy cover of Salsola gemmascens and Noaea mucronata species was decreased but Artemisia fragrans and Kochia prostrata species were increased.Generally density of shrub species was decreased about 40% and showed a positive correlation with seasonal precipitation (fall and winter). Grass species showed different response to precipitation changes over nine years period and in general, no significant changes were observed. Stipa hohenackeriana species was affected by winter precipitation but Poa bulbosa and Cynodon dactylon were correlated with spring precipitation. Density of perennial forbs species was increased considerably (about seven times), but in dry years (2000-2002) forage production reduced. Forage production over nine years increased from 296 kg to 747 kg per hectare, which is approximately 2.5 times higher. Meanwhile, proportion of plants in classes I, II and III, were respectively, 23.1, 51.9 and 25.2 percent of forage production. Also, forage production in wet periods increased from 747 to 1968 kg per hectare which shows an increase of about seven times.
E. S. Shokoohi; Gh. R. Zehtabian; A. Tavili
Abstract
More than 80% of Iran’s area has arid and semi arid climate. Therefore, Iran is exposed to desertification process. Practical activities in controlling desertification must be based on current desertification situation and its severity. Based on this theory, evaluating desertification rate indices ...
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More than 80% of Iran’s area has arid and semi arid climate. Therefore, Iran is exposed to desertification process. Practical activities in controlling desertification must be based on current desertification situation and its severity. Based on this theory, evaluating desertification rate indices in Khezrabad region was done based on IMDPA model. In this research two factors with 10 indices were investigated. Each of the investigated indices was analyzed and scored based on work units. Data layers of each index were made by Arc GIS software. By compiling data layers and calculating geometric mean of indices, desertification rate map of the region was then prepared. According to the selected indices, final desertification map shows the mean rate of desertification. Soil index by 2.21 scoring value was classified in median class while water index by 1.46 scoring value was classified in poor class. Soil depth had the biggest influence while SAR and Cl of water had the least influence on desertification. Based on the assessments, geometrical mean of desertification rate quantity value for the entire region was 1.76, thus the entire region was classified in median class.
D. Askarizadeh; Gh. A. Heshmati
Abstract
Abiotic factors, as topographic and physicochemical properties of soil, are the most important effective factor on vegetation in rangeland ecosystems which have the most important performances to forming and succession of plant vegetation. Ecologic management of rangelands can be desired by better understanding ...
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Abiotic factors, as topographic and physicochemical properties of soil, are the most important effective factor on vegetation in rangeland ecosystems which have the most important performances to forming and succession of plant vegetation. Ecologic management of rangelands can be desired by better understanding of these effective factors. Then, rangeland of Javaherdeh (Ramsar) in the northern Alborz Mountains ranging 2000-3200 m a.s.l. was selected in this study and altitudinal classes of 300 meter were selected to obtain field records on the basis of field monitoring and plants structures. About 15 plots (1 m2) in each altitudinal class were considered in order to obtain the field data, e.g. percentage of life-form covers. It was also chosen five plots to gather soil samples. Statistical analyses, using cluster analysis, DCA and CCA, were done by PC-Ord V.5.1 software. The results showed that life forms of plant under 183 species and 33 families have been divided into five sub-associations so that their segregation is done based upon elevation, aspect, and soil properties. Multivariate analysis (CCA) also can as well divide the life forms of plants based on their ecological requirements into subgroups include annual and perennial grasses with perennial forbs, annual forbs, shrubs, and bushy trees. These life forms are also found different ecologic niches funded upon influence of the topographic factors and physicochemical properties of soils. Hence, ecologic management of terrestrial ecosystems needs to knowing and understanding of vegetation structures under different environmental factors.
M. Fayaz
Abstract
More than half of the area of the country are rangelands. Implementing the principles of proper rangeland management and optimal use of rangeland requires proper stock grazing management. Considering the quality and quantity of forage plants, palatability and preference value of species and rates of ...
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More than half of the area of the country are rangelands. Implementing the principles of proper rangeland management and optimal use of rangeland requires proper stock grazing management. Considering the quality and quantity of forage plants, palatability and preference value of species and rates of species utilization are information needed for proper management of livestock grazing in rangelands. In this study, preference value of three plant species of steppic rangelands including of Iran includingArtemisia sieberi, Stipa arabica and Scariola orientaliswere considere. The studied sites are located in Kerman, Yazd and Isfahan provinces. At first, the vegetation type of each site was determined and and its floristic list was prepared over spring and summer. The selection criteria were used in order to determine the value of preferred species. Random sampling with the plot of one square meter was done in different months and factorial experiment in randomized complete block design was usedto compare preference values and their comparison in different times and places. The results showed that preference value between plant species and studied sites at five percent are significant but there was no significant difference among different months.The interaction of species and stage of grazing was not significant in this research. Moreover, the preference value of Stipa arabica andArtemisia sieberi for sheep grazing were different over different months. The results also reveald that Artemisia sieberi in Nadooshan site has the highest preference value.
M. Ghorbani; H. Azarnivand; A.A Mehrabi; S. Bastani; M Jafari; H. Nayebi
Abstract
Since last decades, there has been a growing interest in the human/social dimensions of natural resources governance especially the structure of social networks in achieving to successful co-management of natural resources. Network analysis as a suitable tool in optimum planning of the “network ...
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Since last decades, there has been a growing interest in the human/social dimensions of natural resources governance especially the structure of social networks in achieving to successful co-management of natural resources. Network analysis as a suitable tool in optimum planning of the “network management” of rangeland in regional scale, can improve inter-organizational decision-making and coordination among key actors. Trust development and mutual relations among various actors is a key factor in policy of rangeland co-management issue. In this study, trust and collaboration networks between informal and formal institutions and rangeland users in co-management process have been investigated. Social network analysis as a quantitative method has been implicated in this research. The results of this study indicate that “Veterinary Office of Taleghan” and “Village Council” can play a key role in policy and planning of rangeland co-management which is related to higher density of trust and collaboration ties. Moreover, trust and collaboration networks among the Veterinary Office and rangeland users have more sustainability than these in related to other institutions. However, the sustainability of networks among all of institutions and rangeland users has low level. Statistical results show there is a high correlation (70%) between trust and collaboration networks and also 50% of collaboration changes are related to trust factor. Also, it can be state that lack of trust and collaboration between the Natural Resources Office and rangeland users is a key challenge for initiating of rangeland co-management. Finally, social network analysis helps manager and planner in detecting of the challenges of rangeland co-management and policy in tune with solving these challenges.
M. Nabizadeh; A. Mosaedi; A. A. Dehghani
Abstract
River flow forecasting for a region has a special and important role for optimal allocation of water resources. In this research, for forecasting river flow process, Fuzzy Inference System (FIS) is used. Three parameters including precipitation, temperature and daily discharge are used for forecasting ...
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River flow forecasting for a region has a special and important role for optimal allocation of water resources. In this research, for forecasting river flow process, Fuzzy Inference System (FIS) is used. Three parameters including precipitation, temperature and daily discharge are used for forecasting of daily river flow of Lighvan River located in Lighvanchai watershed. For the initial preprocessing, the randomness of data was examined by return points test. Then, for determination of the optimum lags for input parameters, correlogram of data was considered. Finally to investigate the effects of temperature on river flow forecasting, the process were done for any months separately. Assessments of prediction by using various criteria such as Nash-Sutcliff coefficient showed that FIS model had high precision (CNS=0.9976) and low error (RMSE=0.0113) in prediction which shows that the FIS model can be employed successfully in river flow forecasting. Final assessment of the results was also revealed the effects of temperature on prediction in some months (April and December).