Soghra Andaryani; Mohammad Hosein Rezaei Moghadam; khalil Valizadeh Kamran; Farhad Almaspour
Abstract
Forecasting models of Land Use/ Cover changes are the main resources for managers and policy-makers in order to develop a sustainable land management plan. Changes of Orchard-lands have an effect on water resources as well as soil permeability. Thus simulation of this land use changes, in areas where ...
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Forecasting models of Land Use/ Cover changes are the main resources for managers and policy-makers in order to develop a sustainable land management plan. Changes of Orchard-lands have an effect on water resources as well as soil permeability. Thus simulation of this land use changes, in areas where there is a shortage of water resources, can provide more information about the occurred changes during a specified time scales along current management. The present study was carried out to simulate and predict the spatial-temporal changes of the orchard by 2026. For this purpose, Geomod method was used to simulate spatial changes of the orchard. Due to the lack of ability of this model in temporal simulation, Markov chain analysis method was used to solve the mentioned problem with the error proportional of 0.012. Orchard was extracted using Landsat 5, 7, and 8 satellite data after necessary corrections as well as SVM in 1987, 2000, and 2013. Then, to understand the impact of each of the criteria used to change this type of land use, instead of Delphi methods, logistic regression, Fuzzy standardization and, after all, WLC were used. The ROC index was used to validate the model. The results showed, this model has a good performance to simulate spatial changes because of area under Curve 0.91 for both of the 2000 and 2013. In the 26-years period, there are 294 hectares of orchard development, and the hybrid model showed that this land use will increase to 304 hectares till 2026
Hossein Azarnivand; Sedigh MOhammadi; Sadegh Hossein niyaee; Pouyan Dehghan
Abstract
One of the best methods to prevent or reduce soil erosion, it is preserving and restoring vegetation. So knowledge about the characteristics of the vegetation, including ecological features as the first and most important biological tool for soil conservation is essential. Coma (Ferula hausskenechtii) ...
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One of the best methods to prevent or reduce soil erosion, it is preserving and restoring vegetation. So knowledge about the characteristics of the vegetation, including ecological features as the first and most important biological tool for soil conservation is essential. Coma (Ferula hausskenechtii) Plant of Apiaceae family, which is abundant in the mountainous regions of Kurdistan. Regarding the importance this species to protect and prevent soil erosion that the proper species is to reform the mountainous rangelands. Therefore, Autecology studies is necessary. For this study, the main habitat of this species were determined by using vegetation maps with a scale of 1: 25,000 in Kurdistan province. Finally, five sites (Saral Divandarreh, Sarshiv Marivan, Buin-e Baneh, North West Dam Qshlagh, and Sarshiv Saqqez) were selected as sample. Then studies of vegetation, soil analysis, chemical analysis, root system and phenology of species was performed. The results showed that this species grows well at the altitude of 3000-1600 mask with 700-400 mm rainfall as well as its density decreases with increasing altitude. Its habitat soil has a neutral pH to slightly alkaline (7-8), is shallow or deep and medium texture. Vegetative growth starts of the first week of April and the plant is seeding in mid- June. This plant has multiple roots system, which average root length and the number of rootlet are 102 cm and 11 respectively. The highest amount of crude protein in the growth and the lowest is in seeding stage.
Elnaz Hassanzadeh Kuhsareh; ardavan ghorbani; Mehdi Moameri; kazem hashemi majd; Ardeshir pounemati
Abstract
The purpose of this study was to determine the effects of altitude, slope, aspect and topographic index on life forms and total net primary production (NPP) in mountains meadows in Fandoghlou in Namin county in Ardabil province. NPP in three altitude, slope, topographic index classes and four aspect ...
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The purpose of this study was to determine the effects of altitude, slope, aspect and topographic index on life forms and total net primary production (NPP) in mountains meadows in Fandoghlou in Namin county in Ardabil province. NPP in three altitude, slope, topographic index classes and four aspect classes was estimated using one m2 plots (totally 180 plots) by harvesting and weighting method. Correlation between life forms and total NPP with topographic factors were analyzed using stepwise multivariate regression method and using derived regression equations, the maps of NPP were derived. Results show that different topographic factors has significant effects on forbs (p<0.01) and grasses (p<0.01), however on total NPP have no significant effects. The highest NPP of forbs (1584/1 Kg/ha) and total NPP (2339/3 Kg/ha) were observed in the second altitude (1525-1564 m) but has no significant effect on grasses. The NPP of grasses show direct relationship with slope, however the NPP of forbs were decreased with the increase of slope and has no significant effect on total NPP. The highest amount of grasses (894/3 kg/ha) and forbs (1875/5 Kg/ha) were observed in the south and northwest aspect, respectively. According to the various classes of topographic index, the maximum amount of grasses (853/4 Kg/ha) were observed in the first classes and the highest NPP of forbs (1568/6 Kg/ha) on the third classes. The results of this study can be used to balance the amount of biomass, carbon, the supply and demand of and to plan for proper rangeland management.
Omid Rahmati; Aliakbar Nazari Samani; Mohammad Mahdavi
Abstract
Determination of groundwater potential in respect to increasing trend of water demand in Iran, is found to be an unavoidable and vital subject. The present research was aimed to assess the efficiency analytical hierarchical process (AHP) to identify potential groundwater zones. Initially, five parameters ...
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Determination of groundwater potential in respect to increasing trend of water demand in Iran, is found to be an unavoidable and vital subject. The present research was aimed to assess the efficiency analytical hierarchical process (AHP) to identify potential groundwater zones. Initially, five parameters (viz., lithology, annual rainfall, drainage density, lineament density and land slope) were used in Ghorveh-Dehgalan plain. Influencing groundwater potential were selected. A questionnaire was prepared to collect ten experts attitudes to paired comparison of such parameters. The normalized weights of criteria/parameters were determined based on Saaty’s 9 point scale and its importance in specifying groundwater potential zones using analytical hierarchy process (AHP) and eigenvector method. To prepare lineament distribution maps, ETM+ Landsat images and PCI Geomatica were applied. Finally, the set of criteria were integrated by weighted linear combination method using ArcGIS 9.3 software to generate groundwater potential prediction map. The pumping test results collected and overlaid with groundwater potential prediction map. The validation of the groundwater potential prediction map was conducted based on frequency ratio and results of pumping 20 wells in study area. Results from comparing predicted potential of groundwater and by the groundwater specific capacity (SPC) showed 85% accuracy. It was established in the study that the AHP technique is promising of make accurate and reliable prediction, specifically in no-data aquifers.
Shahab oddin Zarezade Mehrizi; Asadollah Khoorani; Javad Bazrafshan; Ommolbanin Bazrafshan
Abstract
Gamasiab River is one of the five main branches of the Karkheh River and plays a basic role in preserving the life and ecosystem of the region. The first step in the adoption of proper and sustainable methods for managing the water resources of the Gamasiyab river is to gain continuous knowledge of the ...
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Gamasiab River is one of the five main branches of the Karkheh River and plays a basic role in preserving the life and ecosystem of the region. The first step in the adoption of proper and sustainable methods for managing the water resources of the Gamasiyab river is to gain continuous knowledge of the quantitative and qualitative status of the water as well as its variations. The use of hydrological models is common to simulate quantitative and qualitative processes associated with the water cycle. One of the models that is widely used in the international level is the SWAT model. In this research, we evaluated the efficiency of SWAT model in simulation of Gamasiyab river flow. For running this model requires a DEM, soil map, land use map and slope classification. Initially, discharge data in daily step at Polchehr Hydrometric Station was calibration (1977-1995 AD) and then validation (1996-2005 AD) by using precipitation data of two synoptic stations and three weather stations and minimum and maximum temperature of two synoptic stations. Statistical coefficients including Nash-Sutcliff coefficient, R2, P-factor and R-factor for calibration period were 0.71, 0.73, 0.79, 1.36 respectively and for validation period were 0.57, 0.61, 0.71 and 1.34 respectively. These results indicate that the SWAT model has the ability to simulate the Gamasiyab River discharge and researchers can use this model to apply management scenarios in short time and low cost for better decision making.
Maryam Asadi
Abstract
In this research, was investigated the effect of grazing intensities on carbon and nitrogen allocation in aerial and belowground biomass of Artemisia austriaca in summer rangelands of Darvishchae (including Alvares, Aldeshin and Asbmarz villages) at southern slope of Sabalan. The study areas based on ...
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In this research, was investigated the effect of grazing intensities on carbon and nitrogen allocation in aerial and belowground biomass of Artemisia austriaca in summer rangelands of Darvishchae (including Alvares, Aldeshin and Asbmarz villages) at southern slope of Sabalan. The study areas based on grazing rate, rangeland condition, previous researches and department of Natural Resources and field survey in three grazing intensity low, medium and heavy was selected. Sampled in each grazing intensity, from vegetation and soil with randomized-systematic method on 3 transects parallel with the length of 200 meters and plot 1×1 m2 was carried out at intervals of 50 meters. Biomass was determined using cut and weighting method. After digging profiles at the base of the plant, roots were harvested. Then, allocation in aerial and underground plant was determined. The comparisonof allocation in plant was conducted using analysis of variance (ANOVA) and Tukey's test was performed to examine the differences between means. Results showed the effect of different grazing intensities (mostly sheep of Moghani breed) on biomass of A. austriaca was significant. Results of compare mean showed that the greatest amount of nitrogen allocation in the aerial biomass of A. austriaca (2.2 mg/kg) was observed in the moderate grazing intensity. Moreover, the greatest amount of carbon allocation in the roots of A. austriaca (22 mg/kg) was occurred in the moderate grazing intensity. In general, attention to effects of grazing different intensities on vegetation factors such as carbon and nitrogen allocation, is essential for rangelands correct management and protection.
Masoomeh Abbasi Khalaki; Ardavan Ghorbani; Sahar Samadi Khanghah
Abstract
Seed priming is a technique by which the seeds of the conditions before getting on their bed and ecological environment in terms of physiological and biochemical readiness to receive germination. Experiment was conducted using a completely randomized design in summer 2015 in rangeland laboratory– ...
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Seed priming is a technique by which the seeds of the conditions before getting on their bed and ecological environment in terms of physiological and biochemical readiness to receive germination. Experiment was conducted using a completely randomized design in summer 2015 in rangeland laboratory– University of Mohaghegh Ardebili. Treatments include: osmopriming (primed with KNO3 with the Concentration of 0.3 and 0.2 %), hormopriming (primed with GA3 with the concentration of 500 and 1000 ppm) and control (distilled water). Drought stress was applied by using solution of PEG-6000 with three levels of 0, -6 and -12 bar. Analysis of variance showed that the osmopriming and hormopriming treatments and levels of drought stress had significant difference (p<0.01) on germination and early seedling growth of F. ovina in germination percentage, germination rate, root and shoot length, vigor index, allometric coefficient and mean germination time. In general, osmopriming had more desirable performance compared with hormopriming and control. Except allometric coefficient in other Indicators, NO3 0.2 % in drought 0, has had the most impact on germination and early growth of these species.
ALIREZA Arabameri; kourosh shirani; khalil rezai; mojtaba yamani
Abstract
landslides situation recognized using interpreting the aerial photos and extensive field measurements. Among total number of 200 identified landslides, %70 (140 landslides) of them have been utilized for model executing and %30 (60 landslides) of them for verification randomly. This research criteria ...
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landslides situation recognized using interpreting the aerial photos and extensive field measurements. Among total number of 200 identified landslides, %70 (140 landslides) of them have been utilized for model executing and %30 (60 landslides) of them for verification randomly. This research criteria including geomorphological parameters, hydrological parameters , geological parameters and environmental parameters . The Shannon’s entropy model have been used for defining the criteria weight and Area density model for defining classes weight, then the regionalization map obtained by combining the criteria and classes weight in ArcGIS 10.2 software environment and classified to 5 classes very little, little , moderate, high and very high according to natural fractures. The Roc curve have been used for model verification. The clerical accuracy results indicated that the compound model have the high accuracy 0.877 (87.7%) for identifying the regions susceptible to landslide. According to the results, slope length, slope and topography wetness index have had the most effect in occurring the landslide. Among total area of region (168547 hectar), 27.39% (46165.02 hectar) have been placed in high and very high sensitive. The prepared regionalization map can be useful for planning land use and building the infrastructure installations such as road.
Bakhtiar Fattahi; Mohammad Jafari; Soheila Aghabeigi Amin; mahdieh salehi; ayoub karimi; Azad Karami
Abstract
Abstract This study aimed to investigate the effect of different intensities of grazing on soil chemical properties on Gonbad paired basins-Hamadan. The objective of this research was to characterize the impact of sheep grazing intensity on soil chemical behavior on mountainous in Hamadan rangelands ...
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Abstract This study aimed to investigate the effect of different intensities of grazing on soil chemical properties on Gonbad paired basins-Hamadan. The objective of this research was to characterize the impact of sheep grazing intensity on soil chemical behavior on mountainous in Hamadan rangelands (Gonbad paired basins). Grazing intensity was classified as light, moderate and heavy, then the soil samples from the three depths of 0-10, 10-20 and 20-30 cm were collected. The soil data was analyzed via SPSS (ANOVA). Results showed that the soil OC, total N content and organic matter decreased significantly with grazing intensity and they were greatest at the surface and decreased with depth. The amount of Calcium and Magnesium won't be affected by grazing intensity. The decreases in soil OC suggest Carbon storage in the soil of grassland declined as grazing intensity increased. Combined with the decreases in soil TN content, this also means heavy grazing could lead to decreases in soil quality and fertility. Uneven grazing intensity is an inherent feature of a season long-grazing system and there are risks to avoid quality and environmental health.
sadat feiznia; Meisam Samadi; Teimur Teimurian
Abstract
The age determination of sediments is usually performed by different methods, all of them need a lot of cost, effort and research facilities. The goal of this research is to compare the results of sediment granulometery with precipitation data to perform chronology of sediments. In this study four check ...
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The age determination of sediments is usually performed by different methods, all of them need a lot of cost, effort and research facilities. The goal of this research is to compare the results of sediment granulometery with precipitation data to perform chronology of sediments. In this study four check dams were selected and profiles were drilled in their sediments. Then sediment sampling was performed in different horizons based on texture and color of the sediments. Granolumetric analyses were performned on samples and the results were analyzed by Gradistat Software. Long-term (45 years) rainfall statistics of Zanjan Station was obtained from Zanjan Meteorological Office for determination of low-water and high-water periods using PNPI (Percent of Normal Precipitation Index). The results of granolumeteric analyses were compared with the results of rainfall analyses which showed that sandy texture relates to high-water and silty texture to low-water periods. The results showed that in thirteen samples from seventeen samples, there is complete conformity between granolumetric and climatic results and that accurate recognition of high-water and low-water periods can be reached using granolumetric characteristics.The age of sediments in four small dams is as follow: Sediments of profile one were deposited between 2005 to 2011, profile 2 between 2006 to 2011, profile 3 between 2008 to 2011 and profile 4 between 2008 to 2011 years. Using sediment chronology of each horizon in sediment profiles, sediment yield potential of upland drainage basin of each small dam in different temporal phases can be estimated.
Mohammad Golshan; Abazar Esmaili; ali afzali; Afshin Jahanshahi
Abstract
Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed ...
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Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed with area 67.8 square kilometers in Mazandaran province. To prepare the Requirements maps for running HEC-HMS model was used HEC-GeoHMS extension. Hyetograph data with 15 minutes time step and its related hydrograph was entered to two models based on 1 hour time step. Then simulation of the flood hydrograph was done based on 15 minutes time step. CP and RE% statistical coefficients was used for evaluation of models performance. Values of this coefficients using the HEC-HMS model for flood 26 November 1994 was calculated 0.72 and 118.26 respectively and for flood 6 October 1996, 0.89 and -24.63 respectively and using the implementation of IHACRES model these coefficients in the first flood was calculated 0.63 and 152.4 respectively and in the second flood 0.79 and -35.6 respectively. The results showed that both use models have acceptable performance for simulation of flood hydrograph in this area and HEC-HMS model has better performance in compared with IHACRES model.
sedigeh mohamadi; Ali Salajegheh; Hassan Ahmadi; Jamal Ghoddousi; Ali Kianirad
Abstract
Suspended sediment load is the biggest non-point pollution source and a major factor of degradation of surface water quality. Because of hydraulic models of sediment transport can not predict the suspended sediment load, sediment rating curves as usual hydrological methods are utilized spread for this ...
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Suspended sediment load is the biggest non-point pollution source and a major factor of degradation of surface water quality. Because of hydraulic models of sediment transport can not predict the suspended sediment load, sediment rating curves as usual hydrological methods are utilized spread for this goal. Cause of regression equations of rating curve have a lot of bias due to logarithmic convert, correction factors in optimization of sediment rating curve were used for eliminating of logarithmic conversion effect and bias of extrapolation in 20 hydrometric stations in up streams and major rivers of Sefidrood watershed. Comparing of 9 rating curve methods as one-linear, one-linear with correction factors as CF1, CF2, FAO, two-linear, mean loads within discharge classes, mean loads within discharge classes with correction factors as CF1, CF2 and FAO was conducted by RMSE and NASH criteria. Results showed that mean loads within discharge classes, mean loads within discharge classes with CF1 and CF2 correction factors have the most fitting to Sefidrood watershed stations. Our findings illustrated that CF1 and CF2 correction factors in majority of stations have compensated underestimation of rating curves and increased efficiency of models. Power of equation between sediment load and area was more than of one. According to results 30 million ton suspended sediment load enter to reservior of Sefidrood dam annually. Key words: sediment rating curve, Sefidrood, model efficiency, logarithmic conversion, NASH criteria.
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.
jamal mosaffaie; mohammad reza ekhtesasi; Amin Saleh pourjam
Abstract
Study of geological units is one of the basic studies in many different sciences such as natural resources. The use of geological maps produced by geological survey is now the basic of geological studies in detailed-operating and investigative studies of natural resources. On the other hand, during the ...
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Study of geological units is one of the basic studies in many different sciences such as natural resources. The use of geological maps produced by geological survey is now the basic of geological studies in detailed-operating and investigative studies of natural resources. On the other hand, during the last years, remote sensing technology has been introduced as a new and efficient tool for geological studies that in addition to proper precision, it has other benefits such as accessibility to impassable or inaccessible mountainous regions. In this study, comparing the accuracy of existing geological and remote sensing maps of Vartavan catchment of Qazvin province has been the object of the study which was evaluated with the ground realities. So first, maps of geological survey were examined. Then, various image processing techniques including False Color Composite (FCC), Principal Component Analysis (PCA), Optimum Index Factor (OIF) and Band Ratio (BR) were used to enhance different lithological units and finally, RS lithology map of the catchment was prepared. Considering the variety of rocks and formations of the study area, the FCC and OIF techniques have respectively the most capabilities for differentiation of the rocks. Kappa coefficient of 0.39 between the two maps indicates low agreement between them. Checking the accuracy of maps based on the ground realities showed that photo-lithological map is more accurate (97.1%) compared to geological map (52.5%).
Fatemeh Maghsoud; Mohammad Reza Yazdani; Mohammad Rahimi; Arash Malekian; ali asghar zolfaghari
Abstract
Overview, drought is effected an unusual dry period which is enough continued and causes imbalance in the hydrologic status, as depletion of surface water and groundwater resources. The purpose of this research is modeling meteorological drought prediction using Neural Network- Multi layer Perceptron, ...
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Overview, drought is effected an unusual dry period which is enough continued and causes imbalance in the hydrologic status, as depletion of surface water and groundwater resources. The purpose of this research is modeling meteorological drought prediction using Neural Network- Multi layer Perceptron, parameters and climatic signals in three time scales include short, middle and long term in a rain-gauge station located at south plain of Qazvin Province. Three different scenarios were tested as inputs model. Optimal combination of variables was determinate by Gamma-Test after identification of input variables using cross-correlation. Results showed, influence of climatic signals increased and against the influence of meteorological parameters decreased when time scale were increased from short-term to long-term. MEI (Multivariate ENSO Index) and rainfall were introduced as the most effective climatic signals and meteorological parameter for each scale, respectively. Neural Network modeling which has hidden layer with enough neurons, Sigmoid Function in middle layer and linear function at output layer was used. The most appropriate of the number neurons was determined in each scenario and wasn’t observed significant correlation between increasing or decreasing the error and number of neurons. Finally, the most appropriate network structure was determined based on evaluation indexes in three scenarios and each time scale.
kazem Nosrati; mohammad mehdi hossein zadeh
Abstract
Growing population and increasing water resources demand have caused to slump groundwater level in many plains. Therefore there is a necessary to improve the quantity and quality of the aquifers. One of the most important methods to increase water table in recent decade is groundwater artificial recharge. ...
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Growing population and increasing water resources demand have caused to slump groundwater level in many plains. Therefore there is a necessary to improve the quantity and quality of the aquifers. One of the most important methods to increase water table in recent decade is groundwater artificial recharge. The main objective of this study is to select sites more suitable for groundwater artificial recharge in Ravansar plain. In view of this, the raster map layers of criteria including geology, slope, alluvial thickness, infiltration rate, permeability, erodibility, land use, percent of silt and clay were prepared. Then each of these criteria was ranked using analytic hierarchy process (AHP) and weighting liner component (WLC) methods for two artificial recharge methods including flood spreading and spreading basin. The results showed that based on the selected indicators and the zonation map in two methods, the best sites located in northern, northeastern and southwestern of the study area and fluvial fans adapted with the best sites for groundwater artificial recharge.
mahboobeh moatamednia; ahmad nohegar; arash malekian; maryam saberi anari
Abstract
One of the most important of hydrological computing in ecosystem is estimation of the relationship between rainfall and runoff. So that investigation occurred processes in it and the estimate of important outputs such as flood and sediment is considered one the most important mission of a watershed project. ...
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One of the most important of hydrological computing in ecosystem is estimation of the relationship between rainfall and runoff. So that investigation occurred processes in it and the estimate of important outputs such as flood and sediment is considered one the most important mission of a watershed project. Because of variable spatial and temporal characteristics of incident in the water cycle and the nonlinear relationship and uncertainties, none of the statistical and conceptual models are able to be a better and capable model for that. But today using nonlinear networks as intelligent system for forecasting such complicated event can be efficient and effective in many problems of ecology. For this aim it is used variables such as precipitation, temperature, evartanspiration, relative humidity and discharges in daily scale over 42 years period and assessment 62 different suggested structures for surveying river flow in Amame representative watershed. For comparison it used Multi Layer Perceptoron (MLP) and Radial Basis Function (RBF).The results show that out of 6000 available models for estimation river flow model number 54 with 8-9-8-1 network structure and 8 types of input variable such as precipitation (Pt), precipitation with two lags (Pt-1 and Pt-2), temperature (Tt), evartanspiration (ETt), relative humidity (Rht), and discharge with two lags (Qt-1 and Qt-2) with Multi Layer Perceptoron method has the best function. The error of model was 0.03, 0.18 and 0.04 in training and 0.02, 0.14 and 0.02 for testing stage for MSE, RMSE and MAE, respectively.
parisa niknam; Reza Erfanzadeh
Abstract
In this study, the effect of cushion plants on spatial distribution of soil seed bank was studied in mountainous and hilly rangelands in Vaz watershed, Mazandaran province. Therefore, we selected randomly 20 Onobrychis cornuta individuals and sampled from soil at four positions around each individual ...
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In this study, the effect of cushion plants on spatial distribution of soil seed bank was studied in mountainous and hilly rangelands in Vaz watershed, Mazandaran province. Therefore, we selected randomly 20 Onobrychis cornuta individuals and sampled from soil at four positions around each individual (upslope, downslope, center and, outside as control). Soil samples spread out under natural conditions in greenhouse to germinate the seeds. Germinated seeds were identified then, the seed density per square meter and species richness were calculated and both of them were compared between the four sampling positions. Two and one-way ANOVA, T-test and Duncan test were used to compare the effect of location, depth and their interaction on soil seed bank characteristics. The results showed that the effect of the location and depth of the density and species richness at level of 0.01% were significant. The results of Duncan test showed that seed density in the upslope and center positions (average 5473 and 4099.5 seed/m2, respectively) was significantly higher than seed density in the downslope and outside positions (average 2685.5 and 2413.8 seed/m2, respectively). Similarly, species richness in the upslope and center positions (the average 9.7 and 9.5, respectively) was significantly higher than species richness in the downslope and outside positions (average 7 and 6.4, respectively). Density and species richness of soil seed bank at depth of 0-5cm was significantly greater than the depth of 5-10cm. This study clarified the positive significant effect of canopy of cushion plants on seed density and richness.
roya vazirian; hamid reza asgari
Abstract
Abstract: Soil particles are one of the most effective characteristics related to erodibility and main hydrological and physical aspects of soil. This is important to understand soil characteristics which control soil stability in the case of conservation of soil structure. Also, recognizing critical ...
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Abstract: Soil particles are one of the most effective characteristics related to erodibility and main hydrological and physical aspects of soil. This is important to understand soil characteristics which control soil stability in the case of conservation of soil structure. Also, recognizing critical soil properties such as organic matters in the regions, where soil erosion is resulted from natural patterns of aggregates will be fundamental key in conservation strategies. In this paper, organic matter measurement, discovery of particles stability and interactions between these two factors have been aimed. Sampling was done in three different densities (<200, 200-400 and >200 stand per hectare) and 30 replications. The results revealed that Atriplex spp. Increased soil organic matter and also soil stability. Different planting distances were not effective in level of 5%. Therefore; improvement of soil particles stability and controlling soil erosion in the study area depend on soil management and implication of soil conservation projects.
pooya hoshyar; Hossein Khademi; Shamsollah Ayoubi; Mehdi Norouzi
Abstract
Parent material and vegetation are two important and influential factors in the formation of soil. Type of elements in the soil and their availability to plants depends deeply on soil parent material. However, type and density of vegetation change with amount of organic matter and mechanism of element ...
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Parent material and vegetation are two important and influential factors in the formation of soil. Type of elements in the soil and their availability to plants depends deeply on soil parent material. However, type and density of vegetation change with amount of organic matter and mechanism of element cycle overshadowed the availability of element in rangeland ecosystem. This study were conducted to investigate profile distribution of nutritional elements affected by rangeland species and different parent material as a factorial trial and completely randomized design with three replications in rangelands around Kuhrang city. Therefore, in the study area, three different parent matter such as fossiliferous marl limestone, fossiliferous dolomitic limestone and red conglomerate and sandstone were selected. In each parent material, three places under Astragalus spp and Daphne and the bare part as a control profile to depth of 100 cm were dug. Then the soil physical and chemical properties and concentrations of nutritional elements in profiles were measured. The results of this study showed that type of parent material have significant effect on amount of soil element while the vegetation in some cases could not make a significant difference in concentration of elements. Red conglomerate parent material because of coarser texture, release fewer element compared to marl and dolomite limestone in soil. Soils in study area except soils derived from red conglomerate parent material, there is no shortage of potassium and phosphorous. Furthermore, concentration of elements in different depths of the profiles obeyed a similar pattern
