Delaram ziaei jazzi; rafat zare bidaki
Abstract
Soil erosion along environmental problems. The consequences of soil erosion can be examined from a variety of perspectives.the cost of soil erosion is divided into two categories of on-site and off-site costs. Soil erosion affects the production cycle and economics directly and indirectly. The purpose ...
Read More
Soil erosion along environmental problems. The consequences of soil erosion can be examined from a variety of perspectives.the cost of soil erosion is divided into two categories of on-site and off-site costs. Soil erosion affects the production cycle and economics directly and indirectly. The purpose of this study was to estimate and compare direct and indirect economic losses of soil erosion in different land uses in the Beheshtabad Basin.To achive this, first sediment production by each landuse was initially determined by using SWAT model. NS and R² model coefficients for calibration were 0.72,0.73, and 0.66,0.71 for validation. Then direct loss of erosion was calculated based on the method of replacing the main soil organic fertilizer (NPK) by chemical fertilizers and indirect loss of erosion based on the loss caused by sedimentation behind the check dams inside the basin and reservoir dams outside the basin. According to the results, the highest amount of economic loss of soil erosion was related to rainfed farms equivalent to 56 million Rials per hectare Due to the fact that these lands are located on high slopes and also incorrect agricultural operations .The least amount was related to gardens,equal to 4.5 million-rials/hectare that indicated the importance of trees crown covering and observing the proper slope in the construction of gardens in the soil conservation. In this basin,excess grazing and improper utilization of rangelands have led to high erosion rate and sediment production in upstream rangelands and 3.33 million-Rials/hectare economic losses of erosion in this land use.
N. Noura; A. Kabir
Volume 62, Issue 1 , June 2009, , Pages 153-166
Abstract
In this paper the utilization of GIS for the parameterization of rainfall- runoff process, physically based hydrological model components is described. The hytrogeneity of soil and vegetation in a catchment can be expressed with distribution functions of infiltration and soil storage capacities which ...
Read More
In this paper the utilization of GIS for the parameterization of rainfall- runoff process, physically based hydrological model components is described. The hytrogeneity of soil and vegetation in a catchment can be expressed with distribution functions of infiltration and soil storage capacities which derived efficiently by an overlay of a soil map with land use characteristics. These distribution functions are used to consider the non-linear distribution of actual saturation within a catchment with regard to their impacts on generation of excess rainfall and deep percolation during a storm event. The newly developed infiltration model components and its parametrization by GIS was successfully applied to Kechik catchment. To obtain the nesessory information a simple digital soil map of the catchment was constructed by discretizing the watershed into 1×1 km2 grid cells, and combined with the land use classification to estimate for each cell in a soil texture class the areal distribution function of infiltration model parameters consist of surface soil moisture content, maximum and minimum infiltration capacity rate (Sm, fo, fc), coefficients of model (K1, K2, K3 & K4) and excess rainfall. The results of the model application are shown that the rainfall-effective runoff relationships during storm events in catchment, by application of GIS technology, a new generation of hydrological model for micro and macro scale can be developed under consideration of catchment characteristics and their spatial heterogeneity.
maryam larijani; mostafa naderi; Seyed Mohamad Shobeiri; Lobat Zebardast
Abstract
This article tries to prioritize important criteria in the study the performance of environmental programs of the channel One by using exploratory factor analysis method with a questionnaire that was completed by 70 IRIB's experts. Finally, offer suggestions for improving the level of environmental programs. ...
Read More
This article tries to prioritize important criteria in the study the performance of environmental programs of the channel One by using exploratory factor analysis method with a questionnaire that was completed by 70 IRIB's experts. Finally, offer suggestions for improving the level of environmental programs. In this regard, the considered criteria are the main components of the environment, which include water, soil, air and biodiversity. Factors derived from the Sustainable Development Model with Exploratory Factor Analysis, which include six political, economic, social, technological, legal, and environmental dimensions, are independent variables and key components of the environment as dependent variables in the multivariate regression model. Linear was used using SPSS22 software. The results of this study show that in terms of water, environment Criterion with a score of 0/539 is the highest and technology criterion with a score of 0/036 is the lowest in evaluating the quality of the channel one according to sustainable development criteria. Also, in the soil dimension, the social criterion is the highest and the political criterion is the lowest, in the air dimension, the legal criterion is the highest and the economic criterion is the lowest. In the biodiversity dimension, environment criterion, it has the highest and the political criterion has the lowest score in evaluating the quality of the channel One according to criteria of sustainable development. Finally with a Confidence of ٩٥% according to experts opinion, the overall quality of the programs of the channel One in the field of environment has been low.
M. Navidi; F. Sarmadian; Sh. Mahmoudi
Volume 62, Issue 2 , October 2009, , Pages 299-309
Abstract
Sustainable exploitation of land resources is directly affected by considering soil quality which finally will also conclude environmental protection. Therefore, assessing different soil quality aspects which are sensitive to various land management practices seems too important. In this study, some ...
Read More
Sustainable exploitation of land resources is directly affected by considering soil quality which finally will also conclude environmental protection. Therefore, assessing different soil quality aspects which are sensitive to various land management practices seems too important. In this study, some selected soil quality indicators have been compared in five land use systems including untouched rangelands, semi degraded rangelands due to grazing, rangelands that converted to rainfed agriculture, abandoned rainfed agriculture and an irrigated wheat farm in eastern Qazvin province, Iran. Samples were taken from the surface layer (A horizon) of soils in a completely randomized design with four replications. Statistical comparisons of the results revealed highest decrease in soil organic matter and total nitrogen owing to abandoned rainfed agriculture that showed 74% and 70% decline, respectively. Eventually the abandoned rainfed agriculture meets the sharpest slump in some soil properties such as cation exchange capacity (CEC), available phosphorous, total porosity and thickness of A horizon. Meantime the most increase in bulk density was also in recent land use. According to the results, the negative effects of inappropriate land use changes were led to soil productivity decline and will cause undesirable consequences in soil quality. So maintenance of soil quality is critical to environmental sustainability and this should be done on the basis of recognition all features that reduce its quality.
Sadat Feiznia; Asghar Kouhpeima; Hasan Ahmadi; Ali Asghar Hashemi
Abstract
Due to successes of fingerprinting method in producing rapid and low-cost information of sediment sources, in this research this method was used in three sub-cathments of Chasht-Khoran Basin in Semnan Province: Amrovan, Atari and Ali-Abad. Samples below 63 μm were separated and 15 fingerprinting propertis ...
Read More
Due to successes of fingerprinting method in producing rapid and low-cost information of sediment sources, in this research this method was used in three sub-cathments of Chasht-Khoran Basin in Semnan Province: Amrovan, Atari and Ali-Abad. Samples below 63 μm were separated and 15 fingerprinting propertis was measured. In the first stage comparison of means and differentiation analysis were used for determination of the characteristics that can differentiate sediment source as well as possible. In second stage, by minimizing composite multivariate model by optimization methods, the share of each source was determined. The results shown that, in Amrovan Catchment, For properties consisting of Co, Ph , Kaolinite and K were recognized as optimum composition of sediment tracers which could differentiate sediment source completely. In Atary Catchment, the optimum composition of tracers are Na, Co, XLF and kaolinite which differentiate source by %91.7. In Ali-Abad Catchment five parameters were recognized as optimum composite which are :Na, XLF, Ca, Co and smectit which completely differentiated sediment sources. The results of calculated composite multivariate model have shown that Upper Red formation in Amrovan, Atari and Ali-Abad Sub-Catchment has the highest share in sediment production. The sediment production in these three sub catchment are as follows:35.9, 23.53 and 86.64% respectively. Therefore sediment management and control strategies should be performed on these sources.
Ghader Karimi; Hasan Yeganeh; Hasan Barati; Farhang Ghasriani
Abstract
Due to the growing trend of rangelands degradation, study effects of different harvesting intensities on species in order to gain a more fundamental utilization of ranglands can be effective for reclamation and improvement. The purpose of this research was to study effects of different harvesting intensities ...
Read More
Due to the growing trend of rangelands degradation, study effects of different harvesting intensities on species in order to gain a more fundamental utilization of ranglands can be effective for reclamation and improvement. The purpose of this research was to study effects of different harvesting intensities on key species Ajuga chamaecistus.This species has a forage value in the study area. In this first region and a key area of one hectare in area Kordan and in the first year and was grazed, and fencing. Selected and removed from any of 0, 25, 50, 75% and control is exercised (a basic 10 treatments). Monthly by the clipper and the area is grazing season. Effect of harvest was study with the changes in the characteristics the species treated, including; forage and seed production, vitality, mortality and growth of shoots. Finally, production data the combined analysis of data with a split plot design and seed production, vitality, mortality and growth of shoots data in SAS software was analysed. Results of studies of the effects on forage production and harvest of Ajuga chamaecistus species showed the effect of different levels, different years, and their interactions on the production level is a significant percentage. This shows that in different years with different weather conditions of production are different. Also results of the analysis data showed seed production, vitality, mortality and growth of shoots are affected different levels of harvest and weather conditions. In general according to results indicated the negative effects harvesting at the level 75% was observed. In other words, heavy grazing has a negative impact on the species treated. So harvesting up 75% endangering the survival of these species and in fact, harvesting 50 percent it is not a serious problem.
Seyedeh Zohreh Mirdeilami; Esmaeil Sheidai; Moosa Akbalou
Abstract
Considering the importance of vegetation changes and awareness of its destruction or improvement trends in programming and its proper managing of utilization, this study was conducted in order to survey the effects of grazing on the qualitative and quantitative components of vegetation (including life ...
Read More
Considering the importance of vegetation changes and awareness of its destruction or improvement trends in programming and its proper managing of utilization, this study was conducted in order to survey the effects of grazing on the qualitative and quantitative components of vegetation (including life form, growth form, palatability class, plant families and species diversity) and recognition their most important changes in both grazing and enclosed sites in Kalpush plain, Golestan provience. For this purpose, samples were taken via 78 plot 1 square meter in a randomly- systematic method. Mean comparison of the components and recognition of the most changeable components in consequent implementing grazing management were done with t-student test and principle component analysis (PCA) respectively using Spss software. According to the vegetation study, 13 species belong to Asteraceae family and 10 species to Poaceae family and there are 69 Herbaceous species, 13 Grass species and 5 shrubs species of plants in this region. The results of t-Student test indicate an increase in relative density of Therophytes and class I plants, and decrease in Cryptophytes and class III in the enclosed. Also the results point out that grazing has caused increasing in the relative canopy of Shrubs and Champhyte and decreasing in Therophytes, Forbs in the region. Comparison of relative density and canopy cover of plant species in two sites showed a relatively good effect of rangeland enclosing in increasing of the density, restoration and recovery of species composition and diversity. Principal component analysis also showed that the most changeable components in consequent of rangeland enclosing were Forbs, Hemicryphtophyte, Therophyte, Appiacea and Brassicacea families in positive and Shrubs in negative of first axis. Also the Papaveracea and Asteracea families have the most incremental changes in the second component.
sahebe Karimi; Sharareh Pourebrahim; Ali Salajegheh; Arash Malekian; Michael Strauch; martin volk; felix witing
Abstract
Environmental flow (EF) is the quantity, quality and timing of water needed for ensuring the sustainability of aquatic ecosystems. The Karaj River is one of the five protected rivers in Iran. It provides drinking water for the cities of Tehran and Alborz, water needed for agriculture, and is also an ...
Read More
Environmental flow (EF) is the quantity, quality and timing of water needed for ensuring the sustainability of aquatic ecosystems. The Karaj River is one of the five protected rivers in Iran. It provides drinking water for the cities of Tehran and Alborz, water needed for agriculture, and is also an important power supply source for the country. While the river has fulfilled for a long time environmental requirements of downstream areas, this has been threatened in recent years by increasing demands of the rapidly growing population in Tehran and Karaj. In the present study, we tried to find an acceptable environmental flow range by using Flow Duration Curve (FDC) and Indicators of Hydrological Alteration and compared the results with the Tennant method which has been officially used by the Energy Ministry of Iran. Results are presented in monthly resolution and at the scale of sub-watersheds to provide a spatio-temporal EF analysis that can be used in watershed management planning. Based on the results, highest and lowest amounts of EF were calculated by FDC-Q95 and Tennant methods, respectively. For instance, the monthly mean Q95 in last gauge (Sira-Karaj) equals 5.75 m3/s, while the mean value estimated by Tennant is just 2.35 m3/s. Eventually, this study suggests a range of the EF values obtained by the FDC method as the upper monthly threshold and the Indicators of Hydrological Alteration as lower monthly threshold for Environmental Flow in Karaj River.
Seyed Hamid Reza Sadeghi; Mohsen Zabihi; Mehdi Vafakh
Abstract
Regarding the undeniable role of rainfall erositivity factor in initiating water erosion, studying its different aspects is important in optimal soil and water resources management. It is taken in to account in many soil erosion estimation models which are used for soil and water conservation. However, ...
Read More
Regarding the undeniable role of rainfall erositivity factor in initiating water erosion, studying its different aspects is important in optimal soil and water resources management. It is taken in to account in many soil erosion estimation models which are used for soil and water conservation. However, the impact of data length, study span, and the number of stations on variability of rainfall erosivity factor has been understudied. The present study therefore is an attempt to investigate the temporal variation of Wischmeier and Smith’s rainfall erosivity factor at different time scales and also the effect of data length, study span, and number of stations upon rainfall erosivity factor is scrutinized. Accordingly, the results of the present study with 70 stations, data span of 20 years and different study periods were compared with those obtained for another study with 18 stations and 23 years of data span. Rainfall erosivity factor of over 12,000 storm events was calculated in present study and mean values for different time scales were compared using t-Test. Results showed that the maximum and the minimum values of monthly rainfall erosivity factor in the country were different from each other. Besides, the results of t-Test showed significant difference between the calculated values of rainfall erosivity factor in some months (p<0.05) and seasons (p<0.05). Nonetheless, the difference between annual rainfall erosivity factor was not significant (p<0.05).
Tayyebeh Mesbahzadeh; Hassan Ahmadi
Abstract
Sand dunes mobility is one of the serious problems in arid regions. Since wind regime is one of the important factors in sand dunes formation, its frequency, direction and magnitude can be effective. Amount of wind energy and its directional variability (wind regime) have significant control on the morphology ...
Read More
Sand dunes mobility is one of the serious problems in arid regions. Since wind regime is one of the important factors in sand dunes formation, its frequency, direction and magnitude can be effective. Amount of wind energy and its directional variability (wind regime) have significant control on the morphology and maintenance of aeolian landforms. By recognizing of morphometric and morphodynamic characteristics, it is possible to control soil erosion. Thus, statistical analysis of wind data using Tsoar index (sand dunes mobility index) in the study area was considered to understand wind regime role in volume and direction of transported sediments. Sand drift potential amount of the study area is 100.8 v.u. and sand flux is 2.358 m3/m.year resulted from Lettau – Lettau equation. Considering wind erosion power, the study area is in low class based on Fryberger & Dyne (1979) classification. In spring the wind blowing pattern has west direction and is different from other seasons. Also, the most frequency of blowing wind higher than threshold velocity occurs in this season. Unidirectional index value is 0.64 for this region that results formation of transverse dunes (barkhanoid).
somaye sharifi; fateme mohamadzade; Aliakbar Karimian; Seyyd Hamidreza Mirghaderi
Abstract
Population growth and more demand for food have imposed pressure on natural resources, one of which is conversion of lands to farming land. For example, in some areas people convert slope rangelands around their village to non irrigation farms since they receive enough rain. This factor accelerates the ...
Read More
Population growth and more demand for food have imposed pressure on natural resources, one of which is conversion of lands to farming land. For example, in some areas people convert slope rangelands around their village to non irrigation farms since they receive enough rain. This factor accelerates the decomposition of organic matter and changes other physical and chemical properties of the soil and impacts upon productivity of lands. To protect the soil of these areas, government has implemented many watershed management projects, one of which is conversion of non irrigation farming into the Amygdalus gardens. This study aimed to investigate the impact of non irrigation farming on some physical and chemical properties of soil and economic evaluation of non irrigation wheat and Amygdalus gardens was conducted. For this purpose, soil samples were selected out of three types of lands i.e. rangelands, non irrigation wheat land, and Amygdalus gardens and from the depths of 0-30 and 30-60 cm soil with 3 replications. The results showed that the plan of converting inefficient non irrigation farming to Amygdalus gardens improves soil quality (fertility) in this region. . The results of economic evaluation of different land uses showed that the benefit to cost ratio for non irrigation wheat is 0/57; while that of Amygdalus gardens project is from 2 to 3/7; that is about 4 to 7 times much more. So the project of Amygdalus gardens has increased rural financial power.
Seyed Hasan Kaboli; Farhad Fakhri; Ali ashraf Jafari; Parviz Bayat
Abstract
Different plants have different effects on the characteristics of their surroundings, especially on the soil. Soil properties also have the different effects of these plants on them. In this research, the effect of capparis spinosa on the soil characteristics of three areas with different soil characteristics ...
Read More
Different plants have different effects on the characteristics of their surroundings, especially on the soil. Soil properties also have the different effects of these plants on them. In this research, the effect of capparis spinosa on the soil characteristics of three areas with different soil characteristics was evaluated. The under-floor soils of the capper plant in three depths of 0-30, 60-30 and 60-90 cm, compared to the non-vegetation soils, were taken in three different geographic regions with six replicates and a total of 108 depth samples, and in The laboratory measured some of their physical and chemical properties. SPSS software was used to analyze the data and to compare the measured characteristics with non-pairs F and T tests. The results showed that the effect of capper plant on the characteristics of saline soils is a significant reduction of salinity and soil salts, reducing SAR and simultaneously improving some of the characteristics of fertility, such as increasing the potassium available in these areas. Also, in soils with light and medium non-saline texture, significant increase in available potassium levels and SAR reduction were observed in the lagging soil.
Ali Golkarian; Davoud Davoudi Moghaddam; Seyed Amir Naghibi; Masoud Eshghizadeh
Abstract
Soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. The present study was conducted to assess the ability of Rangeland Hydrology and Erosion Model for estimating sediment yield on rangeland’s hill slopes in dry regions ...
Read More
Soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. The present study was conducted to assess the ability of Rangeland Hydrology and Erosion Model for estimating sediment yield on rangeland’s hill slopes in dry regions at Shahid Noori paired watershed of Kakhk. RHEM is a mathematical, distribution and physical model that is capable to simulate hydrological and erosional processes with climatic data and hill slope’s characteristics. Measuring of sediment yield performed on 18 erosion plots in both disturbed and undisturbed rangeland conditions. In order to implement the model, the parameters of climate, soil texture, slope length, slope steepness, canopy cover and ground cover were measured and entered into the model to estimate amount of runoff and sediment yield in each year. The analysis showed no significant difference between observed and estimated values at 5% level in both all erosion plots and the average of measured values of all three different aspects. The results indicate that the model is capable to determine the quantity effects of rangeland conservation practices in hydrological and soil erosion processes. Overall, the present study suggested good potential for application of the model in the same rangelands of dry regions.
Sahar Samadi Khangah; Mehdi Moameri; Masoome Abbasi Khalaki
Abstract
The aim of this study was to investigate the ecological factors affecting the distribution of four Trifolium repense, T. pratense, T. micranthum and T. compestre species in Fandoghlou rangelands of Namin county in Ardabil province. Sampling was conducted in six sites with the presence and absence of ...
Read More
The aim of this study was to investigate the ecological factors affecting the distribution of four Trifolium repense, T. pratense, T. micranthum and T. compestre species in Fandoghlou rangelands of Namin county in Ardabil province. Sampling was conducted in six sites with the presence and absence of species at random. Topographic, climatic, land cover and density of selected species were recorded. From each transect, soil samples were taken from the root activity depth the parameters of acidity, electrical conductivity, soil texture, lime, calcium, magnesium, sodium, phosphorus, potassium, organic matter, propagated clay and soil moisture content were measured. A significant difference was observed between the environmental factors on presence and absence of studied species by one-way ANOVA and comparison of the mean of the measured characteristics with Duncan test. To determine the importance of the variables in different sites and the species distribution, Linear Discriminant Analysis (LDA) was used. Results showed that there were significant different between the factors of electrical conductivity, slope, sodium, organic matter (p<0.01) and factors of elevation, rainfall, temperature, acidity, potassium, phosphorus, clay, silt, dispersible clay and bare soil (p<0.05) in sites of presence and absence of species. According to the results of the LDA, four functions were justified as 78.50, 15.60, 5.80, 0.10 %, respectively and totally 100% of the total variance of the data were justified. Four factors (temperature, electrical conductivity, potassium and clay) were identified as the most important factors in the distribution of the T. repense, T. pratense, T. micranthum, T. compestre species.
Asghar Mosleh arany; Hamid Azimzadeh; Mohammad Reza Ekhtesasi; Neda imantalab; Ali Dolati
Abstract
This study aimed to investigate morphological changes of Capparis deciduas and C. spinosa and their effects on nebkha formation. In order to examine the morphological changes of these plants, nine C. spinosa nebkhas of varying ages were randomly selected and size and number of adventitious roots, number ...
Read More
This study aimed to investigate morphological changes of Capparis deciduas and C. spinosa and their effects on nebkha formation. In order to examine the morphological changes of these plants, nine C. spinosa nebkhas of varying ages were randomly selected and size and number of adventitious roots, number of shoot and buds were counted. Results showed that the dead and green parts of C. spinosa in nebkha were significantly more than control plants. These showed that nebkha in C. spinosa stimulated growth by increasing bud and shoot at first and then there was a steady mortality when the volume of nebkhas increased. In C. deciduas, nebkha caused stimulation of adventitious roots in buried shoots. Increasing nebkha volume did not increased the number of shoots and buds in C. decidua. Control plants did not produce adventitious roots. Formation of nebkha in C. decidua happened in two ways. In the first, C. decidua plants in middle age produced root stock in base of stems. Root stocks continued to grow, trap sand, and form nebkha. Root stock in nebkha produced adventitious root. In consecutive years root stocks continued to grow, trap sand, and form larger nebkha. In contrast, growth of main stems stopped and they were finally dried. C. decidua also formed nebkha like C. spinosa in the second way. It is concluded that C. decidua stimulated better adaptive morphological changes compared to C. spinosa in facing nebkh formation.
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 ...
Read More
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.
Nayereh Ghazanfarpour; Sadat Feiznia; Hassan Ahmadi; Mohammad Jafari; Masoud Nasri
Abstract
Estimation of the amount of soil loss measurement of field indicators is a low-cost method, is easy to learn and can be simply applied. In order to measure and make assessment of soil loss amount by field indicators method in Shahrak Watershed, first map of the work units was prepared and then, measurements ...
Read More
Estimation of the amount of soil loss measurement of field indicators is a low-cost method, is easy to learn and can be simply applied. In order to measure and make assessment of soil loss amount by field indicators method in Shahrak Watershed, first map of the work units was prepared and then, measurements of the relevant field indicators were carried out within these units. Then, EPM model was calibrated and verified. Then the measured data for the amount of the soil loss obtained by using field indicators were analysed and assessed using EPM experimental model. Mean of relative error and correlation coefficient between values from filed indicators method and EPM model were around 7.6 and 0.9, respectively which these results verify field indicators method for estimation of soil loss intensity. Estimation of the average of soil loss amounts relevant to each of the field indicators shows the following soil losses: Rock exposure indicator: 47.61 (ton/ha), Pedestal indicator: 22.61 (ton/ha), Rill indicator: 5.67 (ton/ha), Sediment in drains indicator: 2.21 (ton/ha), Gully indicator: 2.17 (ton/ha) and Build up against barriers indicator: 34.78 (ton/ha).
Fatemeh Hadian; Reza Jafari; Hossein Bashari; Saeed Soltani
Abstract
Because soil moisture condition affects vegetation changes hence, monitoring of drought and vegetation changes are among valuable management tools in these ecosystems. Nowadays, satellite images are used as a low-cost and fast method for vegetation study in different scales. Vegetation change is assessed ...
Read More
Because soil moisture condition affects vegetation changes hence, monitoring of drought and vegetation changes are among valuable management tools in these ecosystems. Nowadays, satellite images are used as a low-cost and fast method for vegetation study in different scales. Vegetation change is assessed using vegetation spectral characteristics. This study aimed to analyze and monitor the vegetation cover changes in 4 rangelands and one forest type site in south of Isfahan and southeastern of Chaharmahal and Bakhtiary province during 1997-2009 ّField sampling were used for measuring the percentage of canopy cover in all vegetation types using step-point method in radial direction (6000 points per vegetation type). Regression analysis technique was used to ensure if vegetation cover can be measured properly using a Landsat images from 2009. Then NDVI indices were derived from 12 Landsat images between 1997 to 2009 (all images were taken from 22th of May to 5th of Jun each year) to monitor vegetation changes. According to results, there was significant correlation between NDVI indices and canopy cover in all vegetation types. Evaluating the canopy cover changes indicated that the precipitation had various effects on different vegetation types based on their plant form and ecological condition. T
TAYYEBEH MESBAHZADEH
Abstract
This research was done in order to submit a model for salinity map made with TM satellite data and salinity values in a Buienzahra. The necessary processings such as principal component analysis and producing of different indices was done on the main bands. The 38 soil samples using random sampling (with ...
Read More
This research was done in order to submit a model for salinity map made with TM satellite data and salinity values in a Buienzahra. The necessary processings such as principal component analysis and producing of different indices was done on the main bands. The 38 soil samples using random sampling (with 10×10 km dimension) from different horizons were designed and performed on the study area. The position of each node was registered with global positioning system (GPS), and the surface electric conductivity of samples was measured using EC meter instrument in soil saturation extract. Correlation between spectral values (main bands, produced indices) with electrical conductivity values were investigated for 80% of the samples. The regression analysis of ECe showed that there is a significant correlation between ECe with spectral data in all of main bands and with BI, NDMI, SI1, SI2, SI3 indices in 99% levels. The accuracy assessment of estimations using validation 20% samples was done. Results showed the produced ECe model could predict the soil salinity with ME and RMSE of 0.08 and 2.53 dS/m respectively. At finally, Salinity map with different salinity classes ( 0-2, 2-4, 4-16, 16-32, 32< dS m-1) was produced.
Mostafa Firuzruz; Mahdi Ghorbani; Reza Erfanzadeh
Abstract
Indigenous knowledge of each land is the manner of understanding and attitude of people towards world that shows the outcome of ancestors' experiences for years on optimal utilization of resources around human beings. Emphasis on technology transition and disregard for indigenous knowledge cause not ...
Read More
Indigenous knowledge of each land is the manner of understanding and attitude of people towards world that shows the outcome of ancestors' experiences for years on optimal utilization of resources around human beings. Emphasis on technology transition and disregard for indigenous knowledge cause not only destroys the relationship between humans and the environment, but also causes disruption in sustainable development programs. This research with the overview of some part of indigenous knowledge of the Baladeh region of Noor city, emphasizes on local traditions on manufacture and management of sheep dairy products in Takor village. The study method of this research is based on filed studies, that qualitative methods including directs observations, cooperative observation and organized interviews with target groups have been used to generate information and data. The results of this research include analysis of pastoralists’ knowledge for livestock management and evaluation of different aspects of milk derivatives processing and dispensation in the form of traditional cooperatives named “Ayargiri” and “Shakhupi”. Based on the research results can be stated that pastoralists in the study village have found a social organization based on local traditions and customs toward dairy products management. This organization will be a kind of social capital for stakeholders. Eventually, it can be stated that stability of subsistence economy of residents in the study area depends on sustainability and improvement of social cohesion and capital in social network of rangeland utilizers
Omid Rahmati; Aliakbar Nazari Samani; Nariman Mahmoodi; bahram choubin
Abstract
One of the techniques to eliminate groundwater resources crisis is to carry out artificial recharge projects, which cause infiltration of water from the surface into the aquifer and balance of the water table. An appropriate site selection for artificial recharge is one of the most important steps in ...
Read More
One of the techniques to eliminate groundwater resources crisis is to carry out artificial recharge projects, which cause infiltration of water from the surface into the aquifer and balance of the water table. An appropriate site selection for artificial recharge is one of the most important steps in implementation of these projects, itself. In this study, capability of gridding technique and AHP method was evaluated for zonation of artificial recharge potential. Accordingly, a grid, with cell size 0.1 km2, was defined for rangelands of Chamshor watershed and geological parameters, slope, thickness of unsaturated layer, electrical conductivity and transmissivity were selected for entry into the model. Finally, potential zonation map of artificial recharge project, using gridding technique, Analytical Hierarchy Process (AHP) and weighting linear combination methods were produced for implementation of artificial recharge. In order to assess the model, the project of artificial recharge in the study area was used which has had a successful performance on balancing the water table level, reducing destructive floods and increasing vegetation. Finally, the accuracy of the gridding technique and AHP method was 87.5 percent. In conclusion, the zonation of artificial recharge potential which was obtained by gridding technique and AHP method was reliable and it is recommended to be used in the site selection of flood spreading systems to be able to carry out artificial recharge projects.
Yousef Azimi; Salman Zare; Hamid Sarkheil; Javad Bodaghjamali; Siayamac Heshmati
Abstract
Mulching on the ground surface is one of the common approaches for fixing the sandy dunes and controlling dust. Despite the frequent use of oil mulch, due to its heavy costs and environmental problems, researches are focused on producing new environmentally friendly mulches. In this research, different ...
Read More
Mulching on the ground surface is one of the common approaches for fixing the sandy dunes and controlling dust. Despite the frequent use of oil mulch, due to its heavy costs and environmental problems, researches are focused on producing new environmentally friendly mulches. In this research, different treatments of cement, lime, wind sands and steel-slag, as cement-slag mulch, have been used to fix the sand dunes samples prepared from Robat-Karim region. Steel-slag is added to the mulch composition because of the benefits of waste reduction from environment and replacement of a part of the cement in the mulch composition because of Steel-slag pozzolanic property. To reduce the number of tests and find the optimal composition of the mulch, statistical mixture design approach was used. Furthermore, the effect of different percentages of the ingredients on shear, compression and impact strength and moisture content of cement-slag treatments were investigated. Results show that the addition of steel-slag increases the compressive and shear strength as well as the ability to maintain soil moisture in the proposed mulch. Finally, developing the mathematical model of the experiments, six different objective functions were considered for optimizing the composition of the proposed cement-slage mulch. As a result combination of 68.731% sand, 27% cement, 2.979% steel-slag and 1.3% lime were the best mulch considering all the objective functions. To validate the results of the optimization, six optimal compositions were re-constructed and the tested again. Obtained results showed an acceptable consistency between the predicted and tested values.
Hossein Sarvi sadrabad; Iman Islami
Abstract
Water is one of the major sources of development in countries and one of the greatest challenges of the present century, which can be the source of many of the positive and negative developments in the world, and in fact destruction of water resources is the destruction of the foundations of development. ...
Read More
Water is one of the major sources of development in countries and one of the greatest challenges of the present century, which can be the source of many of the positive and negative developments in the world, and in fact destruction of water resources is the destruction of the foundations of development. Researches has shown that improved management of conservation, exploitation and distribution of water resources is possible by reducing Governmental Entrepreneurship and stakeholders' participation and community participation through participatory management. Accordingly, social network analysis is considered as an approach to analyzing the relationships of local stakeholders for sustainable water resources management. The purpose of this research is to survey social network of local stakeholders using social network analysis in Sadr Abad village in Nodoushan catchment of Yazd. This research has been done on the basis of two connections of trust and participation using network level and subgroup level indicators. The results indicate that the degree of cohesion and social capital is moderate, and the stability and equilibrium of the network is also high, which indicates the high level of transmission in the relationships of trust and participation. Also, the correlation between the two connection of trust and participation, based on the QAP index, is 64 percent and it is appropriate and high level. Water management network in Sadrabad has the potential of greater cohesion and social capital, that prerequisite of it is to utilize the appropriate state of trust to increase participation.
Jamal Mosaffaie; Davoud Akhzari; Saeed Rashvand; Javad Ataei
Abstract
One of the important parameters in the design of flood control structures is to determine flood peak discharge for various return periods. A primary issue of planners in the face with flood is lack of data or insufficient data. One of the most reliable strategies is generalizing the results from sites ...
Read More
One of the important parameters in the design of flood control structures is to determine flood peak discharge for various return periods. A primary issue of planners in the face with flood is lack of data or insufficient data. One of the most reliable strategies is generalizing the results from sites with observed data to ungauged locations. The main goal of this study is regional flood frequency analysis using multiple regression method for Qazvin province of Iran. 8 out of 23 existing hydrometric station were removed because of the short-term statistics and construction of storage dam at upstream. The results of factor analysis showed that perimeter, equivalent diameter, time of concentration, length of main waterway and area were the main variables affecting flood magnitude. The remaining 15 stations were divided into two homogenous regions using cluster analysis. Homogeneity of these two regions was confirmed using homogeneity and heterogeneity tests of L-moments. Based on the best-fit criteria of Zdist, GNO distribution with the statistic of 0.29 has the best fit for the entire region but for one and two homogeneous regions, GLO and GPA distributions with the statistics equal to 0.09 & 1.56 have the best fit respectively. After calculating parameter values for selected distributions, discharges with different return periods were estimated for all stations. Then, regression relations were obtained between peak discharge and factors affecting flood peak for each return periods at two homogeneous regions. Peak discharges at ungauged locations can be estimated for different recurrence interval using these relationships.
Khosro Shahbazi; ali salajagheh; mohammad jafari; hassan ahmadi; ali akbar nazari samani; mohammad khosro shahi
Abstract
Negative impacts of gully erosion in marl areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate hydraulic flow thresholds of gully erosion in the agriculture (AG), fair rangeland ...
Read More
Negative impacts of gully erosion in marl areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate hydraulic flow thresholds of gully erosion in the agriculture (AG), fair rangeland (FR) and poor rangeland (PR) areas in the Qasre-shirin, Kermanshah, Iran. Nine flumes were performed in the field to determine the critical values of hydraulic parameters including flow discharge, velocity, Froude and Reynolds numbers, Darsi resistance coefficient, shear tension, head-cut dimensions as well as vegetation cover. Results showed that respective critical value of discharge as the gulling thresholds for AG,FR and PR was 1.53, 12.0 and 4.49 li/s indicating significantly higher (p<0.05%) in the FR due to higher vegetation cover. In addition, there were no significant differences for flow disturbance based on Froude number, while the respective value of Rinuldze number in the AG, FR and WR were obtained 3113, 26092 and 9525 significantly higher in the FR. Furthermore, the critical level of shear tension for gully formation in the AG, FR and WR were found 12.12, 14.01 and 9.28 Nm-2, respectively showing significant differences among them. Finally, it is concluded that hydraulic flow parameters as the gully triggering are strongly affected by vegetation cover through landue practices so that higher plant cover in the FR was the key factor resulting in significant enhancement of gully.
