جستجوی مقالات مرتبط با کلیدواژه « non » در نشریات گروه « آب و خاک »

An important factor in increasing the scour around bridge piers is the accumulation of debris and trees. The effect of discharge¡ water depth¡ location of the debris¡ thickness¡ diameter and shape of the debris on pier scour been studied experimentally. 45 samples in the laboratory hydraulic and hydraulic structures¡ water engineering shahid Bahonar University of Kerman. The results showed that the maximum scour depth increases with increasing water depth less discharge occurs. The thickness and diameter debris on pier scour effective and maximum scour depth increases. The location of debris on the scouring effect. If the water level up to the debris hsub ¡ Water depth is ¡ In the range 00.3 scour reduced by increasing the submergence. The shape of the debris can affect scour¡ debris rectangular¡ cylindrical and triangular respectively scour more. Accumulation of debris such as branches and trunks of trees around the pier of the bridge scour increases about 90%.

Wave attack is the main source of irreparable damages to the sea coast line. The coastal protection techniques are now improved from structural protection to biological ones. This includes plantation of trees and development of vegetation canopy (called green belt) along the shorelines and protection of coastal structures against the waves created by tsunami. For this¡ the application of green belt has been studied and effect of vegetation density and wave height on wave force is evaluated for waves in broken condition. Experiments were conducted in a flume with 8.3m length¡ 0.8m width¡ and 0.55m height. Experimental variables include four bed slopes¡ four vegetation densities¡ and 110 wave heights. The results show that absorption of wave force increase with increase of wave height and density of vegetation. At the highest vegetation density the wave force effect was reduced by about 75% compared to the case without vegetation.

Weirs are one of important hydraulic structures that are constructed to regulate water surface, flow measurement and flood discharge in canals, rivers and reservoirs. According to the shape of crest across river, weirs are divided to two direct and indirect groups. Using labyrinth weir is an effective and economical way to increase discharge capacity. Main goal of labyrinth design of weirs is increase the length of weir by making the shape of it nonlinear. Effective factors on labyrinth weir’s discharge coefficient are important which should be considered. Different parameters affect this characteristic of flow and any change in one of these factors affect the flow condition and discharge coefficient. One of these parameters is downstream and upstream ramps slope of labyrinth weir. This study is concentrated on experimental investigation of simultaneous slope of downstream and upstream ramps’ effect on hydraulic performance of rectangular labyrinth weir.
In this study 5 models of rectangular labyrinth weir in 4 different ramp slopes were investigated in hydraulic laboratory. Effective parameters on system were obtained by dimensionless indexes using Buckingham theory. Experiments are carried out in flume with rectangular profile, it’s length, width and height are 12, 0.5 and 0.8 meters, respectively and discharge range of 10 to 70 l/s. Weirs under experiments were made of Plexiglas with 10 mm thickness and 2 cycles. Weirs including different heights of 15, 20, 25 cm and different crest’s length of 1.075, 1.275 and 1.675 cm were investigated. In this study 4 different slopes were considered for rectangular labyrinth weir including without slope, 15, 30 and 45 degrees.
Results indicated that in the case of upstream and downstream ramp's simultaneous slope, discharge coefficient decreased up to 7 percent compared to without slope condition. Increasing dimensionless parameter Ht/P leads to decrease discharge coefficient reduction. In the high discharge range, rectangular labyrinth discharge coefficient with upstream and downstream ramp's simultaneous slope is more than without slope condition. Furthermore, results showed that increase of weir height in rectangular labyrinth weir with upstream and downstream ramp's simultaneous slope results in discharge coefficient increase up to 13%. Increase of weir's effective length reduces the discharge coefficient up to 9% in Ht/P ratios that are more than 0.3.
With regard to the conclusion of this study, upstream and downstream ramps simultaneous slope plays an important role in efficiency of rectangular labyrinth weir. So, two ramps simultaneous slope can be used for high discharge in order to improvement of rectangular labyrinth weir's hydraulic efficiency.

Pollutants are considered the disturbing factors of environment, and among them the heavy metals are more important considering their non-degradability and physiological effects on organisms in low concentrations. The goal of this research was to investigate the effect of industrial landuse on Cd and Pb concentrations in surface soils of the southwest Isfahan. According to satellite images and topographic maps (1:50000) of the study area, soil samples (depth: 0–20 cm) were collected using random sampling. A total of 38 surface soil samples were obtained from industrial areas (lowest distance = 1480 m) in the area of 73481 ha. Total concentrations of Cd and Pb in the digested solution were measured by Atomic Absorption Spectrophotometry (AAS). Using Arc GIS, the spatial distribution patterns and Cd and Pb variography of samples were analysed and finally the best models of spatial distribution of heavy metals were achieved. The primary results showed that the mean concentrations of Cd, and Pb of surface soil samples in industrial areas were 1.8 to 31.5 mg Kg-1 higher than the world’s mean values, respectively. Although the mean concentrations of Cd and Pb were respectively 8 to 700 mg Kg-1 lower than the standard of Iranian Department of Environment for industrial landuse.

Potassium is an essential element for plant growth and exists as four forms in soils: soluble, exchangeable, non-exchangeable, and mineral. Soluble and exchangeable K are considered as readily available and non-exchangeable K as slowly available. Organic matters and acids play an important role in increasing the bioavailability of nutrients especially potassium in the soils. Organic acids are low-molecular weight CHO containing compounds which are found in all organisms and which are characterized by the possession of one or more carboxyl groups. Depending on the dissociation properties and number of these carboxylic groups, organic acids can carry varying negative charge, thereby allowing the complexation of metal cations in solution and the displacement of anions from the soil matrix.The ability of an organic acid to release K from soils depends on some factors such as: diffusion rate of the organic acid in soil, the diffusion capability of organic acid-element complexes, the contact time of the organic acid on a mineral surface, the ionization of the organic acid, the functional group of the organic acid and its position, and the chemical affinity between the organic acid and the mineral elements. This study was conducted in order to evaluate the effect of organic acids and vermicompost on transformation of K in some selected soils of Fars Province, southern Iran.
In this study, nine soils with enough diversity were selected from different parts of Fars Province. The experiment was done as a completely randomized design with three replications, consisting of three incubation times (5, 15 and 60 days) and four organic compounds (including 2% vermicompost, three acids of citric, malic and oxalic acid eachat a concentration of 250 mmolkg-1and one control). The samples were incubated at 50% of saturation moisture at 22°C. Routine physicochemical analyses and clay mineralogy were performed on soil samples. Soil reaction, texture, electrical conductivity, calcium carbonate, and gypsum were identified. Soluble, exchangeable, non-exchangeable and mineral potassium were measured. The amounts of K forms in each sample were determined. Total K was determined following digestion of soil (110°C) with 48 % HF and 6 M HCl. Water soluble K was measured in the saturated extract. Exchangeable K was extracted with 20 ml 1.0 M NH4OAc (pH 7.0) for 5 min. Nitric acid-extractable K was measured by extraction of a soil sample with boiling 1.0 M HNO3 for 1 h. Potassium was measured on all filtrated extracts by flame photometer. The content of clay minerals was determined semi-quantitatively, using peak areas on the diffractograms of ethylene glycol solvated specimens. Statistical analysis was accomplished using the SPSS 16.0 software and the comparison of mean values was done using the Duncan test at the 5% level of significance.
The amount of different forms of K including water soluble, exchangeable, HNO3-extractable, and mineral K are relatively high in the studied soils. Mineralogical analysis indicated that smectite, illite, palygorskite and chlorite were the major minerals in the clay fractions. The results also showed that exchangeable, non-exchangeable and total potassium were in the range of 166 to 378, 282 to 1694, and 2312 to 8437 mg/kg-1, respectively.Organic acids and vermicompostwere led toa significant increase in soluble K at all times compared to control and vermicompost treatment exhibited greater effect. These treatments also significantly increased exchangeable potassium compared to control. Significant differences between exchangeable potassium of organic acids and vermicompost treatments were not observed at 5 and 15 days, but significant differences were observed between treatments of mallic and oxalic acids at 60 days. Compared to the control, the non exchancheable K showed significant increase in all three organic acid treatments and vermicompost at 15 and 60 days.
Based on the results, while exchangeable and non-exchangeable (NEK) potassium showed a clear trend in treatments, solution potassium was first increased and then showed a decreasing trend due to the rapid changes in liquid phase compared to the solid phase. All treatments significantly increased soluble potassium in each 3 times. The greatest potassium increase associated with vermicompost. In general, oxalic acid> malic acid>vermicompost> citric acid, were increased exchangeable potassium, while the trend for NEK was in the order of oxalic acid> malic acid> citric acid>vermicompost, respectively. All treatments at all times (except for treatment 5 days of NEK), showed a significant increase in the exchange and NEK potassium compared to the control. The results also reflect the effect of the dominant soil clay mineral on transformation of exchangeable and NEK, so that the highest and lowest rate of increase was related to the soils with dominant palygorskite and illite, respectively. In general, it seems that the use of organic acids and organic matter leads to a rapid increase of potassium, which must be properly managed in the soils with high leaching. Due to the complexity of soil environment in terms of soil physical, chemical and biological aspects and the role of these factors on potassium transformation, repeating of this experiment in other soils is recommended.

Desertification defines land degredation in the arid, semi arid and subhumid dry regions in consequence of some parameters such as climate change, and human activities. Assessment of sensitivity of a region to desertification by combination of indeces and utilization of methods and standard analysis, leading us to understanding more about desertefication. Many studies have done to assess desertification by combination of desertification indicators. Kasmas et al (2014), analysised correlation between some variables and DESIRE project to considere desertification of a region and found significant correlation between some of such variables. Salvati et al. (2014), studied risk assessment of soil degradation and desertification in the Mediterranean by using nonparametric Kruskal-Wallis test and found that 20 variables from 47 variables have greatest impacts on desertification. Kairis et al. (2013) found that indicators with correlation coefficient of greater than 0.4 (P value = 0.05) are most effective indicators to evaluate risk assessment of desertification and land degredation.
This study aim to evaluate statistical correlation of indicators, effecting desertification by using nonparametric analysis in Khorasan e Razavi province at eastern Iran.
In this study, six indecators include Vegetation cover, Precipitation, Surface temperature, Soil moisture, soil temperature at 0-100 cm underground and Evaporation (evapotranspiration, soil evaporation) for four periods of 2001, 2005, 2009 and 2013 were used. These indeces were products of MODIS, MERRA and TRMM sensors onboard on TERRA satellite. In order to do statistical analysis of the variables, the Spearman correlation tests were used between vegetation index and the other indicators. Nonparametric analysis of Kruskal-Wallis tests were also used to determine variance in different indicators at the four periods,
High correlation between the vegetation index and the evapotranspiration in 2009 shows that increase in vegetation cover causes increasing in evapotranspiration due to a specific climate condition over this area. The same but converse correlation showed less vegetation consequence increase humidity in the subsurface depths to 2013. Kruskal-Wallis test results also showed that there are significant differences in the study time periods for rainfall, evapotranspiration and vegetation due to different climatic conditions prevailing in the region. Highest significant difference is for evapotranspiration in 2001 -2013 due to transition of drought period to a normal climate.
Since a large part of Khorasan e Razavi province is at desertification risk, combination indicators is an appropriate method to estimate potential relationships among of factors contributing to desertification. Methods used in this study may be an effective method to 1) choice appropriate variables associated to desertification 2) Identify spatiotemporal changes of variables by using remote sensing for different periods 3) analysis between variables Based on statistical test. Statistical analysis of variables can be identified the most influence and sensitive variables to desertification

The increase in water demand and its services due to population growth and the raising of the standards of living, health, and hygiene along with the limitation of water resources, droughts, and climate change has attracted water specialists and planners to explore the use of unconventional water resources, such as sewage and saline waters. Moreover, industrial and rural wastewater disposal and the penetration of their pollutants to the surface- and ground-water resources is an important concern in many countries, including Iran. Wastewater treatment and its application for various uses reduces the negative externalities of wastewater release on the environment and human health. Accordingly, in this paper the methodology for economic and environmental evaluation of wastewater collection and treatment, and the necessary holistic view taking into account the issues that must be considered in this regard has been addressed. Furthermore, the steps and framework of a modified cost-benefit analysis of the Tehran wastewater collection and treatment plan have been discussed.

To be safe from the risks of drought and water crisis in the future, it is necessary to follow the guidelines and rules for proper utilization of limit water resources. In this regard, using deficit irrigation strategies creates a balance between water use and the available resources (rivers, groundwater and dams) and also causes the optimization of water use in agriculture. In this study, in order to assess the effects of deficit irrigation on cropping patterns and farmers’ gross profit in Qazvin province, first, agricultural production functions based on three techniques of full irrigation, 5% deficit irrigation and 10% deficit irrigation were estimated. Then, optimal cropping patterns were determined by using a non-linear programming model in Qazvin province. In the end, the effects of deficit irrigation with irrigation water reduction under scenarios of 10%, 20%, 30% and 40% were investigated on cropping pattern and farmer's gross profit simultaneously. Agricultural production functions were estimated by using Ordinary Least Squares method and Eviews software. Also, the non-linear programming model in GAMS software was solved. Results of the estimation of production functions showed that 5% deficit irrigation technique creates a slight decrease in crops yield. But, 10% deficit irrigation technique has negative impact on yield of most crops. The results of non-linear programming model showed that, although simultaneous application of deficit irrigation technique and irrigation water reduction policy reduces the farmer's gross profit, but it helps to maintain the sustainability of groundwater and surface water resources in Qazvin province.

To derive optimal operation policies from multi-reservoir systems, applying the conflict multiple goals simultaneously is very important. In order to, this paper presents a multi-objective optimization-simulation model, which is consist of agriculture and minimum flow goals in a three dam water resources system. For this purpose, a discrete hedging rule with a non-dominated sorting genetic algorithm has been coupled to minimize the modified shortage index over a series of hydrological record of 48 years. The evaluation metrics are diversity metric and standard deviation, which obtained values of each are equal to 0.357 and 0.0111 respectively. The results show the efficient performance of this algorithm to obtain Pareto frontier. Also, multi-objective algorithms present a set of optimum solutions for users instead of a solution, thus it helps to make decision in supplying the conflict goals of agriculture and minimum flow in different and complicate operation conditions such as drought periods easily.

Changes in soil potassium pools including soluble, exchangeable and non-exchangeable forms at various growth stages of wheat (Triticum aestivum L.) may be important in management of this macronutrient and knowledge of its dynamic process. To study that issue, an experiment was done in a completely randomized design on a 9-ha field during 2012-2013. Soil samples were taken from depths of 0-15 and 15-30 cm before sowing wheat, and at its various growth stages until ripening. Also, at various growth stages, plant samples were collected and different K forms in soil including soluble, exchangeable and non-exchangeable, and total plant K were determined. Results indicated that soluble K in surface soil decreased severely during early growth stages until stem elongation, and thereafter continued constantly. But, changes in subsurface soil were slower. Significant decreases in exchangeable K in surface soil occurred at stem elongation and ripening stages, but this reduction in subsurface soil occurred at grain milk stage. Non-exchangeable K changes in surface soil were observed at ripening stage, while changes in subsurface soil were not significant. Sum of soluble, exchangeable and non-exchangeable decreased from759 mg kg-1 to 720 and 680 mg kg-1 at stem elongation and ripening stages, respectively. Generally, HNO3-extractable K decreased in surface soil five times more than subsurface soil. Potassium concentration in shoots increased at tillering stage and reached 6.8 %, followed by a decrease to 1.1% and 0.8 % in shoot and seed, respectively, at ripening stage. Generally, results indicated a maximum K uptake by wheat at stem elongation stage that may be considered as a key tool in K fertilizer management. On the other hand, the role of non-exchangeable K and K in subsurface soil may be considered in available K estimation.

Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.

Using simulation models is a strategy in agricultural water use management and in predicting effect of saline water on crop yield and soil salinity. In this study, soil salinity and forage maize yield were evaluated under alternating application of saline water with fresh water using SWAP and SALTMED models. For this purpose, field experiments were carried out under different treatments of fixed and cyclic use of saline (salinity levels of 3.5 and 5.7 dS.m-1) and non-saline water (non-saline water application in every one, three, and five saline water application) in Karaj region. Electrical conductivity of the non-saline water was 0.4 dS.m-1. Crop yield and soil salinity were simulated via both models and compared with their corresponding measured values. In SWAP model, coefficient of determination (R2) values were 0.754 and 0.587 for soil salinity and crop yield, respectively, while these values were 0.758 and 0.846, respectively, for SALTMED model. Absolute Relative error (|RE|) of SWAP model varied between 1.7% and 26.3% in crop yield estimation and varied between 2.5% and 32.4% in soil salinity estimation. Also, |RE| of SALTMED model ranged from 0.9% to 24.7% in estimation of crop yield, and ranged from 2.2% to 38.2% in case of soil salinity estimation.

Agh Emam(2) Watershed is one of the watersheds in the Golestan Province with an area of 2595 hectares and has considerable problems with soil erosion, particularly gully erosion. In order to carry out this study, at first, the total number of linear gullies in the study area (eleven gullies) was determined. Then, different physical soil properties (sand, clay, silt, and moisture saturation percentage) and chemical soil properties (electrical conductivity, bio- carbon, lime, cation exchange capacity, sodium adsorption ratio, and exchangeable sodium percentage) were investigated by soil sampling (eleven samples) inside the gullies and in the watershed upstream of the gullies at two depths (0-20 centimeters and 20-50 cm). Non- soil effective factors in development of linear gullies including slope classes, altitude classes, land use, and lithology were also evaluated. The results showed that, among soil characteristics, clay percentage (surface), silt percentage (surface), saturated moisture percentage (sub- surface), electrical conductivity (sub- surface), bio- carbon (surface and subsurface), lime (surface and sub- surface) and also lithology from non- soil factors had significant role in development of linear gully erosion in the study area.

The Mont Carlo simulation is widely used for data generation based on specified distribution. However, generation of correlated data is only possible for specific distributions (bivariate normal), while it is required to deal with non-normal distributions, e.g. in regional frequency analysis. To tackle the problem, an innovative approach was proposed by using the genetic algorithm. Since it is possible only to change the order of numbers in an array, our problem is not completely in agreement with the classic genetic algorithm. Therefore, we reordered the algorithm; the internal of each chromosome was changed instead of crossing two different ones. The proposed method was applied for one random variable, and it was shown that the genetic algorithm produces multi-solutions, while unique solution is obtained using the Mont Carlo simulation procedure. We presented an appropriate objective function to include any bivariate distribution and showed its hither versatility as compared with the Mont Carlo simulation (only for the bivariate normal distribution). The multi-solutions in our proposed methodology is due to the fact that any array can be reordered in different possible combinations, each of which having a unique correlation coefficient with another fixed array. It was shown that these different combinations increase as the correlation coefficient decreases.

A free overfall offers a simple device for flow discharge measuring by a single measurement of depth at the end of the channel yb which is known as the end depth or brink depth. When the bottom of a channel drops suddenly, the flow separates from sharp edge of the brink and the pressure distribution is not hydrostatic because of the curvature of the flow. In channels with subcritical flow regime, control section occurs at the upstream with a critical depth (yc). Although pressure distribution at the critical depth is hydrostatic, the location of the critical depth can vary with respect to the discharge value. So, the end depth at brink is offered to estimate the discharge. A unique relationship between the brink depth (yb) and critical depth (yc), known as end-depth ratio (EDR = yb/yc), exist. Since a relationship between the discharge and critical depth exists, the discharge can ultimately be related to yb. However, when the approaching flow is supercritical, critical section does not exist. Therefore, the discharge will be a function of end depth and channel longitudinal slope.
In current study, an analytical model is presented for a circular free overfall with different flat base height in subcritical and supercritical flow regimes. The flow over a drop in a free overfall is simulated by applying the energy to calculate the EDR and end depth-discharge (EDD) relationship.
End-depth-discharge relationship: The flow of a free overfall in a channel can be assumed that is similar to the flow over a sharp-crested weir by taking weir height equal to zero. It is assumed that pressure at the end section is atmospheric, and also streamlines at the end section are parallel. To account for the curvature of streamlines, the deflection of jet due to gravity, the coefficient of contraction, Cc, is considered. At a short distance upstream the end section, the pressure is hydrostatic. By applying the energy equation between end section and control section which is at upstream the end section, the flow depth at the end of the channel yb in terms of depth at the control section can be determined.
Subcritical flow regime: In this case, the approach flow to the brink is subcritical for negative, zero and mild bed slopes with critical depth at the control section. Using the definition of the Froude number at critical depth, the discharge can be determined. As the explicit relationship between discharge and depth at the brink don’t exist, a relationship should be presented through regression analysis between discharge and yb using the different values of yc over the practical range of 0.01 to 0.84. In this study, below explicit equation is presented for computing Q*(dimensionless discharge) in terms of ( ): Where d is channel diameter, is the ratio of bottom elevation to the channel diameter and . This equation can be used for different values of over the practical range of 0.06–0.6.
Supercritical flow regime: A critical flow occurs upstream of the free overfall under the subcritical approach flow. However, no such critical flow occurs in the vicinity of the overfall under supercritical flow regime. Therefore, the Manning equation for known value of channel bed slope and Manning’s coefficient is exercised to derive the discharge relationship under the supercritical flow regime. Since an explicit equation for discharge in term of yb is impossible, a direct graphical solution for discharge for known end depth, channel bed slope, and ratio of bottom elevation has been provided for supercritical flow regime.
The free overfall in a circular channel with flat base has been simulated by the flow over a sharp-crested weir to calculate the end-depth ratio. This method also eliminates the need of an empirical pressure coefficient. The method estimates the discharge from the known end-depth. In subcritical flows, the EDR has been related to the critical-depth. On the other hand, in supercritical flows, the end-depth has been expressed as a function of the longitudinal slope of the channel using the Manning equation. The mathematical solutions allow estimation of discharge from the known end-depth in subcritical and supercritical flows. The comparisons of the experimental data with this model have been satisfactory for subcritical flows and acceptable for supercritical flows.

Diffusion processes of contaminants are important processes in channel because of their effect on environmental pollution and health. In the present research, the effect of different levels of bed roughness coefficient and discharge rate on transverse diffusion coefficient and on the maximum solute diffusion length was studied in a non-rectangle channel. Three levels of bed roughness coefficient of about 0.2, 0.04 and 0.06 along with three levels of discharge of about 5, 10 and 15 L/s were tested: Sodium chloride was used as the soluble tracer. It was injected in to the water at the upstream cross section. In the water tracer concentration as well as the velocity profile were mined at eight cross sections of 3, 4, 5, 6, 7, 8, 9, 9.5 meter from upstream. The results indicated that the values of the transverse diffusion coefficient varied between 0.23 and 0.56 (cm2/s) and diffusion length values ranged from 108 to 170 (m) for different treatments. As regards constant bed roughness coefficient, increasing the value of discharge can increase diffusion length. Therefore, in constant input flow, roughness coefficient is shown to exert subtractive effect on diffusion lengths. The shape of channel affects the velocity profile, and this is why nonlinear equation was considered to calculate transverse mixing coefficient at different levels of bed roughness coefficient and discharge. In addition, an equation was also developed to explain the maximum diffusion length in a parabolic channel.

From ancient times, flood and its mitigation methods have been important to human in order to reduce damages threatening people and nature. Detention rockfill dams which are from the structural methods can control the flood risks in downstream by decreasing the maximum discharge of the flood and increasing the total time of its hydrograph. In order to have an efficient design of these dams, the important conditions of sediment transportation through dam body and also the optimum thickness of the dam should be known. The optimum thickness of detention rockfill dam leads into the maximum reduction in flood peak discharge and also causes the increment of flood duration to get minimized. To find this optimum thickness, some experiments were done on a simulated porous media in a lab. Then, the experimental results were utilized in Monte Carlo probabilistic method in order to find the percentage of sediment transportation probability. Results depict that by using mixed sediment with non-cohesive mean diameter of 0.6 mm within the water flow, optimum thickness would be 7 to 8 times greater than the rockfills with mean diameter of 2 cm in the dam body; while using non cohesive sediment with mean diameter of 0.2 mm in the flow causes the optimum thickness of the detention rockfill dam to be 7 times greater than body rockfills with diameter of 5 cm.

In the present study first the agricultural production functions was estimated based on three techniques of full irrigation and deficit irrigation 5 and 10 percent in order to presentation of the practical solution to conservation of surface and underground water resources in Qazvin plain. The optimal amounts of cropping pattern were determined in Qazvin province by a non-linear programming model. Then, the effects of deficit irrigation was investigated on cropping pattern, water used and farmer’s gross marginal simultaneously with reduced available water under scenarios 10, 20, 30 and 40 percent. To estimating of the agricultural production functions was used Ordinary Least Squares method and Eviews software. The non-linear programming model was solved in GAMS software. The results of estimated production functions showed that deficit irrigation 5 percent creates a slight decrease in products yield. But, deficit irrigation 10 percent has the negative effect on yield of most products. The results of non-linear programming model showed although use of deficit irrigation 5 percent simultaneously with reduced available water policy creates the slight decrease in farmer’s gross marginal but this technique helps to maintain and sustainability of surface and underground water resources of Qazvin plain strongly.

Generally, a moment that sediment particles start moving in stream is called incipient motion. A lot of research has been recently done to determine the conditions of incipient motion velocity of uniform and non-cohesive sediment in open channels and many Relationships or graphs are presented. But studies on non-cohesive and non uniform sediments are very little. With regard to the channel sediments are mostly non-uniform, Determination of the flow rate for prevent of sediment deposition can be an effective role in increasing of transmission efficiency and which reduced costs.
In this study, incipient motion of non-cohesive and non-uniform sediment was investigated by Laboratory modeling and dimensional analysis. In this study 9 non-cohesive and non-uniform sediment has been tested with different dimensions and uniformity coefficient in 0.0005, 0.001 and 0.002 slopes.
Results showed that increasing channel slopes from 0.0005 to 0.002 for sediments with different size, stability parameter on average decreases 45 percent. Also increasing particle size parameter from 0.12 to 0.35 for different slope, stability parameter on average decreases 15 percent. Results showed that with increasing uniformity coefficient from 4.5 to 7.5 for different size of sediment and channel slope, stability parameter on average increases 6 percent.
With increasing the slope and particle size parameters, decrease stability parameter and stability parameter, will increase with increasing uniformity coefficient.

Global warming, due to greenhouse gas increase in the earth atmosphere, caused an increase of about 0.8 oC in global mean air temperature since the early 20th century. The long-term heat energy deposition, both in atmosphere and in soil depths, affect physical and biological processes. Climate change detection statistically is a process which could reveal significant changes that might not be related to natural variations. Long-term thermal energy deposition in soil depths could play an important role in detecting climate change. Thus, the aims of this study were to fill the gaps in soil temperature data and determination of the effect of global warming on long term soil temperature trend.
Kerman synoptic station was chosen to collect data for 1951-200 interval. This station is located at 30o 15’ north latitude and 56o58’ east longitude with 1754 m above Sea level. The long-term annual mean temperature and mean annual total precipitation are 15.8 oC and 150 mm, respectively. For detection of climate change the long-term annual rainfall and cloudiness, daily air temperatures for 1951-2009 interval and daily soil temperatures at 3, 9 and 15 GMT at different depths (5, 10, 20, 30, 50 and 100 cm) for 1992-2009 interval were collected. The parametric methods of Pearson and regression techniques, along with nonparametric techniques of Spearman and Mann-Kendall were employed to detect temperature trends.
The results of these study indicated that Mann-Kendall test could reveal soil and air temperature trends more accurately. The mean annual, spring and summer air temperature trends significantly increased (P≤0.01). The mean annual, summer and autumn soil temperatures also had increasing and significant trends (P≤0.01). These findings also show significant negative trends in both cloudiness and rainfall (P≤0.05).
It is concluded that there is a pronounced similarity in Kerman air and soil temperature trends with global temperature trend and soil temperature could be used to detect climate change.