فصلنامه حفاظت منابع آب و خاک
سال پنجم شماره 3 (پیاپی 19، بهار 1395)

In reservoir operation, there are various decision makers and stakeholders with different and varied utilities. In this paper, investigates the conflicts among decision makers and stakeholders and water quality simulation model and Genetic Algorithm (GA) optimization model combined to find the trade-off curve between qualitative and quantitative issues. The group n person conflict resolution theory is used for selecting the best point on trade-off curve. The Bayesian networks as a novel type of learning model is used to develop real-time operating rules. To evaluate the efficiency of the proposed methodology, it is applied to the 15-Khordad dam located in the central part of Iran. The 15-Khordad dam supplies the water demands of three main sectors: domestic, agriculture and environment. These sectors have conflicting interests about the quantity and quality of the allocated water to their demands the test results show that the both conflict resolution model and Bayesian network model can significantly calculate real-time reservoir operating policies.

Non-scientific and unconscious changes in land use have negative impacts on ýthe soil physical and chemical properties. In this research, the effect of land use ýchanges on some soil physical and chemical properties was investigated. For this propose, three sites in three ýýýadjacent land use ýtypes including pasture, forest andþ þagriculturalþ þlands were randomly selected in region of Baneh, ýýýýýKurdistan ýprovince. Disturbed and undisturbed soil samples were collected from three sites at each of the different land use types from depths of 0–15 and 15–30 cm ýand were analysed in the laboratoryý. The results indicated that land use changes have no significant effects on the percentage of sand, silt and clay. Change in the land use type caused increase in bulk density and decrease in total porosity, soil hydraulic conductivity and aggregate stability. The ýmost percentage of coarse aggregates (0.25-8 mm) and fine aggregates (0.053-0.25 mm) was found in forest ýand ýagricultural land, respectively. Land use change caused increase in electrical conductivity and ýsoil reaction which increases with depth too. The results also indicated that land use change significantly decreases the amount of soil organic carbon. The average of soil organic carbon in forest, agricultural land and pastures were 4.99, 2.26 and 1.79%, respectively. In general, the results of this research showed that changes in land use has adverse effects on the soil physical and chemical properties that can result in reducing soil quality and increasing its degradation.

The salinity of water and soil is called white death in many countries, because of its importance. Generally, the quantity of leaching water, energy consumption and time usage of soil remediation procedure are important factors which affect suitable method of soil reclamation. Electrokinetic (EK) is a physical method for salt extraction such as chemical, Organic and inorganic compounds. In this study, the horizontal placement of electrodes along with leaching procedure was used in Electrokinetic remediation of a saline-alkaline soil. For this purpose, two aluminum and reticular electrodes was placed above and under the soil column as anode and cathode, respectively. The soil columns heights were 10, 20, 30 and 45 cm. Then leaching water (30 mm) every day and totally Equivalent to Four times pore water was entered to soil and properties of drain water was measured. Although, leaching procedure without applying electrokinetic technique was done as control treatment. The results showed that Electrical Conductivity (EC) of drain water and current rate was changed sinusoidal in EK. Although, PH and temperature of drain water was changed between 6.8 to 9 and 23 to 35 centigrade, respectively. Leaching of cations increased in EK technique significantly (p

In this paper climate change impacts on hydrological regime of a mountainous river basin is assessed. In order to do that, scenarios of global climate models are downscaled by using change factor method. The climate scenarios are used as inputs of a rainfall-runoff model, which is well calibrated for the basin, and daily stream-flow series for present condition and future scenarios (2067-93) are simulated. By comparison of river-flow characteristics for present condition and future scenarios, the climate change impacts on hydrologic regime of the basin are assessed. for analysis of the emission scenarios uncertainty, scenarios of A2, A1B, and B1, which relevant to high, medium, and low emission scenarios, respectively. Based on the results, basin temperature will increase between 3 to 5 Celsius degrees and potential evapotranspiration will increase for all month of the year. Despite uncertainty of emission scenarios, under all emission scenarios, annual average of rainfall and stream flow will raise; however, seasonal cycle of rainfall and river flow will change, too. Average river flow in the autumn and winter will increase, while the average river flow in spring and summer will decrease. Decreasing of the river flow in the second half of the water year, Implies the importance of considering of the climate change impacts on the river-flow for designing of dam’s reservoir.

For assessing of soil quality, the sensitive indicators can be used in land use managements. Monitoring all soil characteristics is costly and laborious therefore, limited soil characteristics for this mean are recommended. The purposes of this study were comparing several soil attributes of different land use types and determination of minimum effective soil characteristics on soil quality in Chughakhor Basin, Chaharmahal va Bakhtiari Province, Iran. To fulfill the objectives slope, land use and soil maps and Latin Hypercube strategy were used and locations of 125 composite and surficial soil samples were determined. After pretreatment of soil samples, 29 soil physical and chemical characteristics were measured using appropriate methods. The mean comparison of different land uses showed that mean weighted aggregate diameter, available water content, air content, Dexter index, organic carbon, particle organic carbon in macro aggregate, the proportion of particle organic carbon in macro to in micro aggregates, P, Fe and Cu contents values of land use types were in the order Orchards>cultivated areas>Good rangelands>Dry land areas>Weak rangelands. For determination of effective indicators in soil quality assessing, the principle component analysis and stepwise discriminant analysis are used. The soil characters like water stable aggregates, soil texture elements, proportion of particle organic carbon in macro to in micro aggregates and soil Cu and Zn concentrations as minimum data set for soil quality assessment.

The simulation models of yield response to water are expected to play an increasingly important role in the optimization of water productivity (WP) in agriculture. In this study, the CERES-Wheat model was used to simulate of wheat yield response under different irrigation-cultivar treatments with three irrigation treatments in main plots and Five wheat cultivars in sub plots consisted of C1:C-75-5, C2: C-78-4, C3:C-78-8, C4: C-79-6 and C5: C-79-16 in Mashhad region during the years of 2002-2003 and 2003-2004. According to the results, the relative root mean square error of grain yield simulation by CERES-Wheat model was 7 and 10 % for 2002-2003 and 2003-2004 years, respectively. Because, the relative root mean square error was less than 10 percent, so done well simulation. Also, the root mean square error calculated for grain yield for both years was less than 10 percent of the observed mean. The results are indicating a good match to the simulation results of the model. The value water productivity based on crop evapotranspiration and irrigation water value in I3-C-79-6 treatment has the value highest for both years of 2002-2003 and 2003-2004. Therefore, the noted irrigation management (I3) and wheat cultivar (C-79-6) can be recommended in the study area. The overall findings of this study to confirm the optimal performance of the model CERES-Wheat in the growth process simulation and the water impact on yield in the study area.