Journal of Water and Soil Conservation
Year:2019 | Volume:26 | Issue:1 |Papers Count:19

Background and Objectives: Climate change has changed meteorological parameters in different parts of the world. Drought and water scarcity may lead to crisis in many countries. Therefore, the study of the past meteorological parameters changes and their effect on river flow which is a key element of water supply is important. The purpose of this study was to investigate the relationship between temperature and rainfall parameters with base flow index using continuous wavelet transform and wavelet coherence in Gorganroud River Basin. Materials and Methods: At first, we used the base flow indices resulting from the Eckhart's two-parameter method and then the base flow index which is the portion of groundwater in river surface flow, was calculated at six gauge stations (Tamar, Lazoreh, Nodeh, Arazkooseh, Gorgan Dam and Taghiabad). The results illustrated that the lowest annual index found at Taghiabad gauge station with a value of 0. 30 and the highest yearly baseflow index found at Tamer gauge station with a value of 0. 66. Then, the annual trend of temperature and rainfall were investigated with base flow index of each station in Gorganroud River Basin during a period of 33 years (1981 to 2013) using continuous wavelet transform and wavelet Coherence. An analysis of wavelet coherence analysis showed a strong relation between temperature and rainfall with base flow. Results: Our analysis reveals the impact of yearly temperature and rainfall on the base flow index. Investigation of wavelet coherence between rainfall and base flow index showed that there is the highest correlation between 1-4 year period length, which indirect correlation was observed in the middle years of Gorgan dam and Taghiabad stations and positive correlation in other stations and the early and the end years of Taqiabad station. Similarly, a direct relationship exists between the rainfall and the base flow index in the 4-8 year period length, which are direct at Lazooreh and Nodeh gauge stations and indirect correlation in Tamer gauge station. Also, in the period length of 8 to 10 years, the high correlation between rainfall and base flow index were found at Arzokesh and Nodeh gauge stations with lower correlation at Sadgegran gauge station, which arrows direction indicated direct relationship. The analysis of the wavelet coherence between temperature and base flow index exhibit positive and high strength correlation at Gorgan dam gauge station in 2005 to 2009 in 3-4 year period length, at Lazorah gauge station in 2002 to 2006 with 4 year period length and at Taghiabad gauge station in 1984 to 1989 with period length of 1 to 5 years. Indirect correlations were found at Nodeh and Tamer gauge stations between 1987 to 1990 and 2011 to 2013, respectively, with a short 2-year and 3-year period length and Taqiabad gauge station between 1993 to 2000 and between 1992 to 2013 with a long-term period of 8 to 10 years. Conclusion: The rainfall relationship with the base flow index can be direct or indirect due to the watershed characteristics (e. g., human activities, soil, land-use, climate, hydrology, and geology). Also, in some stations there is a direct relationship in the periods and indirect relationship in the rest of the period. The relationship between the base flow index and temperature is also indirect in some of the stations.

Background and Objectives: The loss of water and soil resources are the consequences of unbalanced exploitation of production resources. Optimal land management leads to sustainable exploitation of water and soil resources and hence reduces the depletion of these resources. The aim of this research is to develop a list of vegetation-based management activities and to predict the impacts of the activities on surface runoff characteristics and soil erosion in the Bonekooh Watershed using a modeling exercise. The predictions can assist watershed planners and managers to make appropriate decisions solving the problems in the watershed. Materials and Methods: In this research, considering the type and extent of the environmental problems in the Bonekooh Watershed (about 3300 km2) and determining their relative importance, 11 management activities including rangeland exclusion, afforestation, forage cultivation, riparian restoration, terracing, agro-forestry, orchard development, pitting, contour furrow, seeding, and pile seeding were chosen to solve the watershed problems. The mean annual precipitation and air temperature of this river catchment are 318 mm and 7. 8 oC, respectively. The height of the highest point is 4053 meters above sea level. The L-THIA model and the Global Soil Loss Equation (RUSLE) model within the framework of the GIS were used to estimate the surface runoff characteristics (runoff, phosphorus and nitrate) and the amount of soil erosion, respectively. The RUSLE factors include R, K, LS, C, and P, which are calculated from rainfall data, regional soil maps, digital elevation models, and remote sensing techniques, respectively. The values of P and C factors in the RUSLE were estimated according to the standard tables provided in the relevant literature and based on expert judgment. Statistical criteria of RMSE and MAE were used to evaluate the efficiency of the models for the current status of the watershed. Subsequent to model evaluation, the models were used to predict the possible impacts of various management activities on surface runoff characteristics and soil erosion. Results: Soil erosion map shows that the amount of soil erosion changes from an insignificant value to 33. 49 (tons per hectare per year) in the region. Also, 11. 12 percent of the total area is located in the high and very high erosion classes. Annual runoff varies from 1. 12 to 9. 27 cm with an average of 6. 74 cm. The analysis indicates that rangeland exclusion and pile seeding management activities in the watershed will have the most impact considering all indices (surface runoff, soil erosion, Phosphorus, Nitrate). But per unit of management activities, forage cultivation, afforestation, and orchard development have the most impact on runoff depth index, respectively. Additionally, considering both soil erosion and phosphorus indices, orchard development, afforestation, and forage cultivation activities will have the best performance, respectively. In addition, in terms of nitrate index, orchard development, afforestation and riparian activities will present maximum differences with the index value for the current status of the watershed. Implementing of all management activities will result a decrease of runoff depth by about 13. 20% and a reduction of soil erosion by 8. 30% in the watershed. The results of model evaluation using RMSE and MAE tests show that the simulation of surface runoff and sediment components has the least error, which indicates the high accuracy of the model in the simulation; but the simulation of phosphorus and nitrate components have more error. Conclusion: Given the topographic and morphologic conditions of the Bonekooh watershed, and also natural and human-made erosion factors for the watershed, critical areas should be considered in order to prevent the loss of soil and water resources. Because of existing water and soil resources problems in the Bonekooh Watershed, it is required to implement appropriate management activities to fix the problem. Due to the vast extent of areas being suitable for implementing rangeland exclusion and pile seeding activities in the watershed, these activities have the greatest impact on improvement of surface runoff characteristics and soil erosion. To make an improved decision in choosing the best management activities, it is suggested to consider other impacts arising from implementing the activities at the watershed scale from economic, social and ecological point of views.

Background and Objectives: Occurrence of extreme rainfalls specifically in short-time scales causes heavy damages to human communities, municipal crowd regions and natural ecosystems. The studying and precise identifying of extreme rainfalls is essential and crucial in different agriculture and natural resources, meteorology and hydrology, engineering and natural environment aspects. The intensity damage of extreme rainfalls does not equally act in different regions and it is essential to assess the risk extent of such hazardeous rainfalls in regions with different climatic conditions. Therefore, the aim of this study is to identify and zonning of extreme rainfall occurrence risk in different 6, 12 and 24-hour time scales for west parts of Iran, where has a noticeable diversity in terms of the climatic and topographic conditions. Materials and Methods: To perform this research, about 27 synoptic stations located in five provinces including Kurdistan, Kermanshah, Hamedan, Ilam and Lorestan were selected, and the maximum annual values of extreme rainfalls in three time scales of 6, 12 and 24-hours in a 25 year time period (1992-2016) were extracted and by fitting different statistically distributions to each of these time series and by adopting the Chi-square test, the statistical distributions with best fit were regoized and were used to performing propabilitistic analyses. The 30, 40 and 50 mm thresholds were used to defining the torrential extreme rainfalls in 6, 12 and 24-hours time scales, respectively and after calculating the risk extents of the mentioned torrential extreme rainfalls for all of the studied stations, the risk zoning of torrential extreme rainfalls occurrence was performed by applying the multiple linear regression models between the risk extents and geographical properties (longitude, latitude and elevation) for all of the studied region. To enhancing the models accuracy, the long-term average of the number of days per year with precipitation greater than 1 mm was employed in the structure of the regression models as auxiliary variable in some cases and to achieve higher accuracy of regression models, the studied region was divided into three distinct regions. Results: The results showed that among different fitted statistical distributions to the time series of extreme rainfalls of 6, 12 and 24-hours in the studied region, three distributions including Log-Logistic, Pearson and Gama were recognized as the best fit distributions. In terms of the accuracy of the multiple linear regression models, the results showed the high accuracy of these models for all of the three distinct regions and whole of three time scales of 6, 12 and 24-hours. The overall results of this research showed that the risk occurrence of the torrential extreme rainfalls in the west part of Iran has a notable diversity so that this risk is very low in some centarl parts and very high in some west and south parts of the studied region. Conclusion: The overall results of this research revealed that the general applied algorithm of this research to estimating spatial distribution of torrential extreme rainfalls ocuurence risk led to obtain the appropriate and acceptable accuracy in regional estimation and to generalize the stational point results to the regional scale. Therefore, it is essential to adopt appropriate tasks and more attention in contrast to the negative consequences of the extreme rainfalls in the parts with high degree of probability occurence.

Background and Objectives: Soil moisture is a major factor determining the plant growth in rainfed lands. Lack of soil water content causes drought stress at plant growth stages. Soil water content temporally varies due to variations of precipitation, evaporation and other environmental factors. There are different methods to hold soil water content during the growth period. Knowledge of temporal variations in soil water content during wheat growth period can be effective in identifying the critical times of drought stress. Therefore, this study was carried out to investigate temporal variations of soil water content under the influence of straw mulch and tillage direction in rainfed system in semi-arid region. Materials and Methods: The study was conducted in a rainfed land with 10% slope steepness in University of Zanjan during winter wheat growth period from December 2015 to June 2016. Experiments were carried out in four levels of wheat straw mulch (0, 200, 400, 600 g/m2 equal to 0, 33, 66 and 100% covering surface) in two tillage directions (up to down slope and on counter line) in a factorial arrangement as completely randomized design at three replications. A total of 24 experimental plots with 2m × 5m in dimensions were designed to investigate the soil water content. Soil water content during the growth period, was determined by a Time-Domain Reflectometry (TDR) at 10-day interval. Monthly variations in soil water content were determined for different treatments during the growth period. The temporal variation of soil water content at different straw mulch levels and tillage direction were determined using the Duncan's tests and t-pair test. Results: Based on the result, soil water content was affected by straw mulch level in all months of wheat growth period (P<0. 05) and the highest value was observed in April. In April, the amount soil water content in 100% straw mulch level was significantly increased by 30 and 100% compared to control treatment in along slope tillage and contour tillage, respectively. Mean annual soil water content for along slope tillage at the mulch level of 33, 66 and 100% was 11, 13 and 21% higher than the control treatment (P<0. 01), respectively. Mean annual soil water content for the contour tillage was also at the mulch level of 33, 66 and 100% was increased 6, 8 and 18% higher than the control treatment, respectively (P<0. 01). Study of temporal variations of soil water content in two tillage directions showed that soil water content was significantly increased during growth period except on January, February and May. The reasons for this difference can be expressed by changes in the type of precipitation (snow) and the weakness of the vegetation. The mean soil water content in contour tillage was about 6% more than along slope tillage (P<0. 05). The highest difference in soil water content was observed in March (14%) and the lowest one was in May (2%). No interaction was found between straw mulch level and tillage direction in terms of soil water content in any months during the growth period. Conclusion: This study showed, both management methods had independent effects on soil water content in rain-fed wheat land. The roles of the two management methods in reservation of rain water are obvious in the early stages of growth and in spring when rainfalls frequently occur in the area. Application of at least 33% wheat straw mulch equivalent to 2 tons per hectare and tillage on contour lines are essential for improving soil water content in rain-fed system.

Background and Objectives: Spillways are a simple and practical hydraulic structure in water conveyance systems and irrigation drainage channels which used to measure the flow, transfer excess water and control the water surface of the reservoir. The Piano Key Weir (PKW) is a rectangular-labyrinth-type weir that used to maximize the allowable weir length that can fit in a given weir channel width, while reducing the required structural footprint. Piano key weirs is a new form of long crest weirs that have a relatively simple structure and high economic efficiency structures. Due to the advantages of this weirs, we need to study and investigate the downstream scouring of this structures. In this research, the downstream scour of piano key weir has been studied. Materials and Methods: To study the downstream scouring, two different physical models of piano key weirs in different hydraulic conditions have been used. The experiments were carried out in a flume with a 10 meters length and 50 cm width and height. Two type of piano key weir with 5 and 9 keys were used in this experiments. In order to compare the scour hole area a linear weir with a height of 20cm and a width of 50 cm were used in comparison with linear weirs, the corresponding hydraulic conditions was also studied. The scour hole dimensions were measured with a point gauge with ± 1 millimeter reading accuracy which has located on top of the channel that can moving along to the channel. The effect of the particle number on the maximum scour depth and location of maximum scour hole was investigated. Results: The results show that in piano key weirs, with increasing effective crest length, water depth decreases over weir crest and so on decreases the amount of scour depth by decreasing the flow velocity at downstream of weir. Bed profile shape at eroded area is completely three dimensional. Increasing rate of Scour hole depth is related to number the of piano keys. By increasing the number of keys the maximum depth, length and location of the scour hole as well increased. The results show that even at the low level downstream water depth, scouring of this weir is less than the sharp crested linear weirs. The profile of the scour hole in the piano key weir is almost similar to the linear weir but the only difference is in the height of the dune at the downstream of scour hole. The height of the dune generated at higher downstream water depth of piano key weir is even lower than sharp crested linear weir and also, with increasing the particle Froude number, the maximum scour depth parameter and length of occurrence was increased. The maximum scour depth at the 9 key spillway and in 10, 15 and 25 l/s were 30. 7% more than the 5-key spillway and 7% less than the sharp linear spillway. Conclusion: In piano key weirs reducing downstream water depth increases scour depth and far it away from downstream apron. Also, by increasing the particle Froude number, the maximum scour depth, the location of the maximum scour depth and the maximum length of the scour hole was increased. The rate of increase in the scour depth is also dependent on the number of overflow keys, and in a fixed Froude number and downstream water depth, increasing the number of keys, the maximum depth and location of maximum scour depth also increase.

Background and Objectives: The removal of sand and gravel from the bed and the banks of the rivers causes change in the hydraulic and hydrology conditions, increased erosion of the bedding and the banks of the river, also the destruction of existing structures along the river. The purpose of the present study is to investigate the maximum depth and length of the created pits migration due to the river material removal. Materials and Methods: For this research, a rectangular flume with length, width and height of (5, 0. 3, 0. 45) meters with a constant slope was used. The pit holes with different sizes and under the relative velocities of 0. 83, 0. 89, 0. 94 and 1 have been operated for the state of with or without gate by using two sediments mean dimensions of the 0. 15, 0. 6 mm. In this study, the duration of the experiments, were fixed to 1 and 1. 5 hours respectively for state of with and without gate, that the equilibrium time for both of them was the last 15 minutes. A 3D laser scanner was used to take data from a three-dimensional profile of the bed in both state, after disconnecting water and recording the depth of water in different places. Also, from the side view of the experimental flume, the digital photos were taken to view the conditions of the pits migration at different time intervals. Afterward, using the MATLAB, Tec-Plot 360, Excel and Grapher software tried to rearrange and reconfigured data and drawn graphs were taken. During the experiments, the bedforms at the up and downstream of the Created pits were observed and their temporal variations were recorded. Results: The results of the experiments showed that with decreasing of the Froude number, pits depth and also by creation of the secondary flow inside the holes, the dimensionless ratio of the y H decreases and reversely, the dimensionless parameters of the y L and y B increases. On the other hand, it was concluded that by increasing the shear stress and Froude number, the dimensionless ratio of the V u*cr will increase. The longitudinal profiles and 3D view of the pits migration at the all of the Hydraulic and sediment conditions were observed and depicted. At the end, the experimental equations for the maximum of scouring length and depth for the rectangular pit were presented along with the sensitivity analysis. In general, it was shown that the submerged angle of repose of materials ( ) has the greatest effect on the increase and y H has the greatest effect on reducing the length and depth of the scouring pit. Conclusion: The results of the experiments have been illustrated by presenting the dimensionless relationships for maximum depth and length of the pits for both state of with and without gate in both sediments mean dimensions of the 0. 15, 0. 6 mm under subcritical flow conditions and showing the maximum and minimum effect of parameters and the use of sensitivity analysis for the obtained relationships. It was proved that the lowest error percent for maximum scour depth was observed in the 0. 15 mm mean sediment particles in state of without gate, having the relative error of 2. 98% and RMSE of 0. 23. Also, the lowest error percent of the maximum scour length is related to a 0. 6 mm mean sediment particles with a relative error of 4. 75% and an RMSE of 0. 5.

Background and Objectives: Prediction of dam break flood flow characteristic such as water depth and velocities component has always been of interest for hydraulic engineers because of its impact on the severity of the terrible dam break. In the past, many studies have been conducted to investigate the dam-break flood waves hydraulic properties by using numerical methods. Present study performed in order to expand research dominate in numerical solution and factors influencing the dam break phenomenon. In this research, a comprehensive computer model has been developed on curvilinear coordinate in which using the explicit finite difference method and simultaneous use of Leap-Frog and Lax algorithms on the staggered mesh the shallow water equations were solved to simulated dam break problem. The number of involved points in discretization scheme increase by using this method therefore the sharp geometric and hydraulic gradients smooth and the probability of oscillation and divergence decrease without the use of artificial viscosity. Materials and Methods: The governing equations in the present research are the shallow water equations. Due to the inability of the Cartesian coordinate system to reflect the physical irregular boundaries of domain, the governing equations were discretized on the curvilinear coordinate system. The explicit method and simultaneously utilize of Leap-Frog and Lax algorithms were used to discretization of the governing equations. Results: In order to validate the present model, the model results were compared to experimental data and the results of other numerical models have been proposed by pervious researchers in several case studies. One of these cases is the ideal dam break in rectangular wide channel with length of 100 m including tail water, the results indicated the water surface profile and flow discharge along the channel at 10 second after dam break, was simulated with a high accuracy. The second case was simulation of the dam break of a trapezoidal reservoir with a large side of 2. 04 m, a small side of 0. 51 m and a length of 2. 02 m connected to dry bed downstream channel with length of 9. 3 m and wide of 0. 51. The calculated flow and stage hydrographs at dam location were closed to the experimental measured data with reasonable accuracy. The partial asymmetric dam break in wet bed is another case investigated in this study, simulation of stage and discharge hydrographs in asymmetric dam break in a reservoir with a length and width of one meter for three different shape factor of 1, 1. 25 and 1. 5 was performed in this case. The result indicated that by increasing the shape factor, peak points of stage and discharge hydrographs increase due to increasing of reservoir volume. Conclusion: In this research, a numerical model has been developed on curvilinear coordinate in which using simultaneous Leap-Frog and Lax algorithms on the staggered mesh the shallow water equations were solved to simulated dam break phenomenon. In the simulation of the ideal dam break with tail water, the present model ability to approximate the analytical solution is highly accurate. In the simulation of dam break in trapezoidal reservoirs on the dry bed, the results of the present numerical model are in agreement with experimental results, also in studying the main objective of the research, the results of the present numerical model for simulating partial asymmetric dam break with different shape factor (1, 1. 25 and 1. 5) of reservoir in dry bed have been investigated. It was observed that water surface profile changes by changing the shape factor to 1. 25 and 1. 5 after changing the shape of the walls of the reservoir compared to the reservoir with the coefficient of 1, it increases by 17. 98% and 28. 26%, respectively. Also, the amount of discharge flow per unit width for the reservoir with a coefficient of 1. 25 and 1. 5, compared to the reservoir with coefficient 1 was increased by 27. 24% and 41. 32%, respectively.

Background and Objectives: In Golestan province, the suitability of climatic condition to produce most of the agricultural products has led to high diversity in crop production, so this province has the first rank in terms of cultivating and producing oilseeds, especially soybean, in Iran. This research was carried out at four major watershed basins of Golestan province, Mohammad Abad, Qaresoo, Zaringol, and Gharnabad. This study was aimed to estimate the area under rice-and soybeans-cultivation in the aforementioned watershed basins. For this, Sentinel2 satellite images were used for the first time using different supervised classification methods (Maximum likelihood, the minimum distance of average and the Mahalanobis distance). Materials and Methods: In this study, two Sentinel-2 satellite images of August and September of 2016 were used to identify, detect and evaluate the cultivated area of rice and soybean as two summer crops. This research was carried out at four watershed basins of Golestan Province (Mohammad Abad, Qaresoo, Zaringol, and Gharnabad). Radiometric, atmospheric, and geometric corrections were made after downloading the images of the study area. Then, band compounds, pseudo-color combinations, image mosaics and rational band calculations were carried out, and the NDVI vegetation index was used to detect vegetation cover from other land uses, and finally, a land use map and crop layer was produced. Results: Results of this study showed that the soybean cultivation area which is an alternative plant for rice in summer cropping, has decreased compared to past years. In the present study, two Sentinel-2 satellite images of August and September of 2016 were used to identify, detect and evaluate the cultivated area of rice and soybean as two summer crops in four watershed basins of Golestan province. To compare the outputs of the three classification methods, training and test samples were used. In order to evaluate the accuracy of the classification results, the generated map was analyzed using the GPS-registered ground control point. The Maximum likelihood classification with kappa coefficient and overall accuracy of 92% and 95. 5% was selected as the superior method for rice. In this method, the rice cultivation area was estimated 32911 hectares with an 18% bias compared to the Agricultural Jihad statistics (27839 hectares). Whereas for soybean, the minimum distance method with kappa coefficient and the overall accuracy of 88% and 95. 2% was selected as a superior classification method. Based on the results, the soybean cultivation area was estimated as 28359 hectares, with a bias of 13%, compared to the Agricultural Jihad statistics (25083 hectares). Conclusion: Sentinel2 satellite images have a high potential for quick land detection and providing crops cultivation area maps in a regional scale. Also, the rice cultivation area has been increased compared to past years, while has been decreased for soybean.

Background and Objectives: Unstable exploitation of groundwater resources is one of the main problems of water management in the country. While, international sources consider that partnership ownership and its dimensions as an institutional approach are solution to the tragedy of shared resources, there are approaches based on full information and wise collective behavior in the country, in the context of problems related to groundwater resources. The purpose of this study is to critique the existing approach and provide an alternative approach. Materials and Methods: In this research, with the focus on the problems of Rafsanjan underground water resources, the foundations of institutional approach have been described and the implementation of these approaches has been extracted in Rafsanjan. The three levels of analysis in this study are considered. At the individual level, the "qualitative" research method and the "planned behavior" theory were used. At the local level, the quantitative research methodology for ecological effectiveness and the qualitative research method have been used to examine the organizational acceptability level. The macro level was also carried out using the qualitative research method and the analysis of the content of the written documents, and the pathology of the plan for the rehabilitation and equilibrium of groundwater resources was also carried out using the above mentioned items. Results: The results indicate a decrease in the level of per capita income, which is due to the plan for the restoration and balance of groundwater resources in the study area. So, as long as no plans are made to replace the livelihood of the exploiters, it cannot be expected that the objectives of the plan will become operational in the current context. It is a concern that resilience and social welfare to such plans will lead to its failure. The reason for this concern is the low level of social acceptance against the drought of their gardens. Conclusion: At present, the cultivated area is 80000 hectares and has a considerable difference in the amount of 40, 000 hectares. The destruction of half of the gardens in Rafsanjan has been accompanied by the loss of capital and employment of a large part of the social system in the study area. Consequently, if a solution is proposed to replace economic activity with low water requirements and with regard to the condition of the water resources of the region, it would be possible to propose a social acceptance of the plan for the restoration and balance of groundwater resources. After that, the implementation of the options can be done. The elimination of inconsistencies between individual and local levels is one of the main priorities along with the plan for the restoration and balance of underground resources in the study area. Reducing the inter-surface and inter-level inconsistencies will increase coordination and, as a result, increase the level of participation in implementation of measures related to the conservation of groundwater resources.

Background and Objectives: Population growth, agricultural and industrial development, degradation of surface water resources, groundwater levels drop are among the major factor causing water scarcity. The integrated management of groundwater and surface waters could serves as a solution to solve these challenges. In other words, sustainable water resources can be achieved through Integrated Water Resources Management, which is the comprehensive approach to all the components that affect and influences the status of water resources. With this approach, the importance of management tools such as integrated water resource simulation models to help planners and managers of this sector is increasingly evident. Connecting the WEAP model to MODFLOW allows the values calculated by WEAP to be sent to the MODFLOW for input on groundwater influxes, river levels, groundwater withdrawals (pumping) and surface runoffs. After it, the groundwater level, sub-streams between the aquifers and the flow between surface and underground water are sent to the WEAP as input of the next step of the calculation. The purpose of this research was to investigate the effects of scenarios related to demand and available water resources, integrated water management in the urban sector and sewage system application in Bojnourd region. Materials and Methods: In this study, with using a water resources simulation model (WEAP) and its connection to groundwater simulation model (MODFLOW), water consumptions for Bojnourd basin was evaluated. Calibration and validation of both models has done under taken data based on 6 (from 2005-06 to 2010-11) and 2 years (from 2011-12 to 2012-13) respectively. Then different management scenarios, including current state water resources scenario, dam's drinking water supply for Bojnord city via transferring water from Shirin Dareh dam, developing sewage systems and finally combination of 2 last scenarios were considered. Under these scenarios, projections for a period of 28 years (from 2013-14 to 2040-41) and its effects on water resources of Bojnord basin were studied. The hydrometric station data of Babaaman at the outlet of the Bojnourd basin, which is the only hydrometric station representing this basin, was used to calibrate the WEAP model. Also, data from four rain-sensing stations, one evaporation station and one synoptic station were obtained from the year 2001 to 2011. Demographic data and urban water demand and rural demand, population and consumption per person was assessed. Industry sector Water demand is estimated monthly. According to geological studies, the Bojnourd basin has two types of alluvial and limestone aquifers, both of which are defined in the model. Then, sensitive and effective parameters were determined by calculating the sensitivity percentage of the mode. Finally, the results of calibration and validation of the model were done from three indicators of Nash-Sutcliff (Ef), Coefficient of determination (R2) and Root Mean Square Error (RMSE), respectively, and the reliability index were used to evaluate the scenarios. Results: The results showed that Simultaneous applying multiple water management strategies seems to be better than any of its individual states, reducing water withdrawing on various resources. Reliability of water supply in the whole complex scenario, for urban drinking water, rural and industry purposes were estimated around 100, 100 and 65. 3 percent, respectively. As a result of this scenario, the annual recharge of the aquifer with 5. 39 million cubic meters per year can be relative balance between harvesting and recharge. Conclusion: It can be concluded that reliable results will be obtained from simultaneous simulation of drinking and industry water management.

Background and Objectives: Despite the importance of litter quality in soil conservation and stability, improvement of soil chemical properties, and increasing forage production in the rangeland ecosystem, very few studies have been carried out on the litter quality of range plant species in Iran and most studies on plant quality are limited to forage quality of plants in rangeland. This study aimed to measure and compare the litter quality of three range plant species, i. e., Artemisia aucheri, Centaurea virgata and Scariola orientalis and its relationship with some physico-chemical characteristics of soils in Hajibeyggi rangeland, Torbat Heidarieh, eastern Iran. Materials and Methods: Plant litter was sampled based on systematic-randomize sampling method on three transects with a length of 200 meters and 1 m2 quadrat. One litter sample of plant species along with one soil sample was collected from 0-15 cm depth in each plot. Parameters related to litter quality including phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), phenol and lignin were measured by standard methods. Also, soil characteristics including texture, lime percentage, EC, bulk density, pH, phosphorus (P), potassium (K) and organic carbon were measured by standard methods. One-way ANOVA was used to compare the litter quality of species and Duncan test was used to separate means with significant difference. The relationship between litter quality and soil characteristics was investigated using Pearson correlation. Results: The highest amount of P was in litter and dead materials of C. virgata, the highest amount of K was in A. aucheri and the highest amount of lignin was in S. orientalis. The highest amount of soil P, lime, silt, clay, clay+silt, pH, organic carbon and bulk density was found under A. aucheri canopy and the highest amount of K and gravel under S. orientalis canopy. The amount of calcium in A. aucheri litter was significantly correlated with soil lime, and its Mg content was related to soil EC and pH. The amount of P in C. virgata litter was significantly correlated with soil pH, and its K content was related with soil gravel, silt and clay + soil silt. The amount of P in S. orientalis litter was significantly correlated with soil K, organic carbon, lime, clay, silt, sand and silt. Conclusion: Lignin and phenol are anti-quality chemical consitituents in plant litter and dead materials. Mean values of lignin in all plant species were similar, but the quantity of phenol in the litter of A. aucheri was higher than that in other two species. The amount of Mg and Ca were also similar in all plant species, but mean value of P in C. virgate was greater than that in other two species. In this study, there was no significant relationship between the chemical composition of plant species litters and the physico-chemical variables.

Background and Objectives: Satureja hortensis plant is a medicinal, annual, Herbaceous belonging to the family Lamiaceae, which is used as a medicinal plant and spice, as well as fresh vegetable. Various plant species show a wide range of resistance to drought due to their physiological, morphological and biochemical adaptations. The use of various organic fertilizers, including humic acid, has been widely used to improve the quality and quantity of crops and gardens without harmful environmental effects. Hormonal effects and enhancement of the absorption of nutrients to enhance performance, especially under stress conditions, are the effects of humus derived humic acid and other natural sources and growth stimulating bacteria. Considering the dry and semi-dry nature of a large area of Iran, it is necessary to save water; on the other hand, nutrition is important in the yield and quality of the effective materials of medicinal plants. Therefore, the purpose of this study was to investigate the effects of drought stress and humic acid on morphological and physiological characteristics of Satureja hortensis. Materials and Methods: The experiment was conducted as a factorial based on a completely randomized design with four replications in greenhouse conditions in 2017. The moisture regimes were applied at four levels of 40, 60, 80 and 100% irrigation, based on the weighing system of pots and humic acid solution in four concentrations of 0, 150, 300 and 450 mg/l. In the 6 to 8 leaves stage, Drought treatments were applied to the pots. Humic acid was applied in two stages in the desired concentrations. The first stage of spraying was when the plants were in the 4 to 6 leaves stage and the second stage was done two weeks after the first spraying. About 7 weeks after application of drought treatments, traits such as plant height, number of branches, number of leaves, leaf length, plant dry weight, proline, chlorophyll a, b and total, carotenoid and carbohydrates were measured. Results: The results showed that the highest plant height, leaf number, number of branches and plant dry weight were obtained under irrigation conditions at 100% FC and spraying with 450 mg/l humic acid; While the highest leaf length, chlorophyll a, b and total, carotenoid and carbohydrate were obtained from irrigation treatment at 100% FC and 300 mg/l humic acid. Also, the highest proline content was obtained from irrigation treatments at 40% FC without humic acid application. Conclusion: Along with increasing stress and reaching 40% of FC, decrease in the amount of physiological and morphological traits of Satureja hortensis occured. Meanwhile, humic acid had a positive and significant effect on these traits. Finally, by improving the absorption of nutrients and the development of vegetative and reproductive parts, the physiological and morphological traits increased. The highest effect of humic acid treatment on drought stress of Satureja hortensis was in 450 mg/l treatment. Therefore, using of humic acid may improve morphological and physiological characteristics of Satureja hortensis.

Background and Objectives: Weirs are always one of the most important components of water transmission networks, due to its simple structure and function. These components are important hydraulic structures for controlling flow and water level adjustment, which increase the height of the water surface and thereby provide the required water heights to divert the flow to the lateral channels. Also, these structures are used as flow measuring devices of the important applications of overflows, the secure flow of floods behind the dams. The purpose of this study is to investigate investigate the effect of positive variation of weir in cross section on discharge coefficient of triangle weirs structures and provide a relationship for estimating the discharge coefficient based on geometrical hydraulic parameters. Materials and Methods: The discharge coefficient is defined as a function of Froude number (Fr), angle of vertex, ratio of water head to height of weir (H/P) and ratio of water head to effective length (H/Le). To achieve this aim, several experiments were done in the water and sediment laboratory, located in Gorgan University of Agricultural Sciences and Natural Resources. The experiments were compacted by 4 different angles of vertexes and three different slopes. Finally, an equation was set by using Gene Expression Programming (GEP) to evaluate the discharge coefficient of triangle weirs. Findings showed that this equation has more accurate result compare experimental findings. Results: The findings showed that the discharge coefficient would decrease by increasing trend in the side slopes in the constant Froude number. Also, by increasing the ratio of H/P a decreasing and increasing trend in the discharge coefficient was observed, respectively. The results show that GEP predicted the coefficient of triangle weirs structures with R2 of 0. 9676 and 0. 8591 and RMSE of 0. 0706 and 0. 0247 for training and testing stages, respectively. This model gave better results compared by regression equation with R2 of 0. 9253 and 0. 8029 and RMSE of 0. 0467 and 0. 084 for training and testing parts, respectively. In the other words, the error of coefficient triangle weirs structures prediction was decreased about 47. 10% using GEP approach. Conclusion: The results showed that GEP intelligence approach is an adequate model for the coefficient triangle weirs structures. Also, the results of traditional regression equations were improved using this method. In the other words, these results indicated that GEP was reliable to evaluate the coefficient discharge of triangle weirs structures by more accurate estimation. So; use of this way is suggested in future studies related to this topic.

Background and Objectives: The common Purslane (Portulaca oleracea) is a plant that is known more as weed, However, considering the wide use as herb and spice as well as the high quality of oil in the side, there are various aspects for researchers to investigate the use of this valuable plant in human nutrition, livestock and aquatic animals nutrition. Materials and Methods: The effects of different levels of irrigation and fertilizer regimes on the quantity and quality parameters of Purslane (Portulaca oleracea) were assessed in a trial at the Institute of Agriculture, University of Zabol. The experiment was carried out in a split plot as randomized complete block design with three replications. The treatments were three irrigation levels [80% (no stress), 60% (mild stress) and 40% (severe)] of available water in main plots and five fertilizer levels [Control (no fertilizer), cow manure (20 tones. ha-1), vermicompost (15 tones. ha-1), Urea (150 kg. ha-1) and NPK (100 kg. ha-1) in subplots. The quantitative and qualitative traits were measured and analyzed by SAS 9. 1 software. Results: Quantitative characteristics included: number of leaves per plant, wet and dry weight of leaf, wet and dry weight of root, 1000 seed weight, and also the measurement of chlorophyll a and b and anthocyanin in leaf as qualitative characteristics. The results of the analysis of variance revealed significant effects of drought stress, fertilizer and their interactions on all measured traits. Conclusion: Application of fertilizer treatments had a significant effect on quantitative and qualitative traits. Besides achieving higher quantitative and qualitative yields than chemical fertilizers, the treatment with organic fertilizers (vermicompost and cow manure in this case), increased water utilization efficiency (WUE) and modified the negative effects of drought stress on the measured characteristics.

Background and Objectives: Investigate how to movement, transport, distribution and transport pollution of the liquid phase of urban wastes (leachate) is one of the important problems of urban and environmental community. On the other hand, soil with complex biophysical-chemical properties is a natural refining for a variety of pollutants. The aim of this study was to investigate the rate of variation of soil reaction, salinity, total nitrogen and nickel pollutant in landfill anaerobic refined leachate in soil columns with clay loam, loam and sandy loam textures. Materials and Methods: This research was carried out in a completely randomized design in polyethylene columns in five periods of 20 days. Then, the amount of applied leachate were calculated taking into account the amount of leachate flow rate derived from the stored waste, and the 10-year rainfall data of the area, and were added to the columns of the mentioned soil in alternate waterlogging conditions. Results: The results of this study showed that the changes in the mean values of acidity in all three types of soil texture decreased over time and application of higher amount of leachate. However, the texture of clay loam soil showed more changes. Also, mean values of electrical conductivity (EC) increased in loamy soil and decreased in other soils, but the decreasing trend in clay loam soil was more intense. The mean total nitrogen content of drainage reduced in clay loam and loam soils but increased in sandy loam soil. The mean changes in the amounts of nickel pollutant in drainage of waste leachate decreased over time in clay loam soil and increased in loam and sandy loam soils. However, changes in the amounts of nickel pollutant in drainage of waste leachate were not statistically significant. Conclusion: Although, with the continuation of leachate application, the amount of each of the desired parameters (nickel in loam and sandy loam soils, electrical conductivity in loam soil and total nitrogen in sandy loam soil) has been added to the outlet drainage of waste leachate, however, soil played a very effective role in improvement of leachate quality, so that the mean values of other parameters (soil salinity and soil reaction in clay loam and sandy loam soils, Ni in sandy loam soil and total nitrogen in clay loam and loam soils) in outlet drainage were always lower in all treatments than the entrance leachate to soil columns. Finally, it seems that the effect of clay loam soil on reducing the values of the mentioned parameters was higher and has a more effective role in the refining of the leachate pollution load.