One of the important problems in watershed management and water resources planning is Maximum flood discharge estimation for small watersheds, due to a lack of hydrometric stations or data. In this study, two sets of methods were evaluated for determining the peak flood discharge, one is based on watershed area and another is based on physiographic and rain factors of the Watersheds. Watersheds were selected in North (Gorgan, Gilan and Mazandaran provinces as one region) and Azarbaiejan (East and West Azarbaiejan) as another region to determining rain depth efficient. The objective of this study was to find suitable methods for Maximum flood discharge estimation in small watersheds. The results indicated that the Horton method in area base methods and SCS Graphical method in physiographic base methods had lower error in two regions. The FHWA method showed the Maximum error for peak flood estimation in these regions. An error difference among area base methods wasn’t more in two regions, but in physiographic methods amount of error in North region was much more than the Azarbaijan region. The results indicate, that amount of rainfall was a major factor that it influenced on errors. Generally, SCS Graphical method was showed a minimum error in compared with other selected methods.

According to available statistics and information and given the population growth as well as the ever-increasing development of agriculture, there is an upward trend in withdrawals from surface water and groundwater resources in different regions of the country such as Mahabad to provide water for the region. The optimal conjunctive use of surface and groundwater resources is one way to providing the water demands in crisis and drought situations. In this study, a management model based on effective techniques of optimization and simulation has been developed to solve the optimization problem. Variation of groundwater table level in Mahabad plain was simulated using GMS software initially. Then based on the results of this simulation, artificial neural network was trained to use in simulate-optimization system. Genetic algorithm was used to solve the optimization problem. The results indicate that this model is powerful and effective for solving large-scale problems and optimal conjunctive use of surface water and groundwater resources of Mahabad. Based on the results obtained of the research and running of optimization conjunctive use quantitative model, the share of water supply of water resources, is respectively 13. 5 percent and 86. 5 percent of surface water and groundwater resource.

One of the simple and cheap ways for flow measurement in canals is to use flumes. In this study, the efficiency of trapezoidal flumes with prismatic piers for flow measurement in trapezoidal canals was investigated. Laboratory investigations on four prismatic piers installed in the trapezoidal canal floor with an adjustable side slope were conducted. Based on the results of conducting several experiments, in the first analysis, a relationship and graph to calculate the discharge for each side slop and a relationship for all of the investigated side slopes were separately presented using dimensional analysis. In the second analysis the relationship and graph to calculate the discharge coefficient for each side slope and a single relationship for all of the investigated side slopes were separately obtained through the simultaneous use of the concept of energy principle and dimensional analysis. To investigate the accuracy of the obtained relationships, the statistical parameter of Mean Absolute Relative Error (MARE) was used. In the first analysis the mean value of the relative error to estimate the discharge in the investigated side slopes (z=0.268, 0.4663, 0.7 and 1) were 8.8, 10, 7.7 and 8.3 percent, respectively. Also in the second analysis, the value of this statistical parameter to estimate the discharge in the investigated slopes were 6.5, 10, 1.8 and 3.4 percent respectively and based on the single relationship for all of the investigated side slopes was 9%. Therefore, to calculate the discharge, the second analysis was recognized to be more appropriate than the first.

We described the two-stage Maximum flow network interdiction problem under endogenous stochastic interdiction. Our model consists of two adversary agent playing a Stackelberg game. A smuggler who wishes to maximize the expected flow of some illicit commodities (same as drugs), can be transmitted between a source node and a sink node without being detected. On the other hand, an attacker tries to minimize the objective of the smugglers by installing some detectors or adding some security controls on critical arcs to increase the probability of detection. Most previous stochastic network interdiction problems in the literature deal with exogenous uncertainty, while we consider stochastic programs under endogenous uncertainty in which the interdictor’ s decisions can alter the probability measures. The problem can be formulated as a bi-level program, at the top level the attacker by a limited budget, choosing critical arcs to install detectors and enhance the interdiction probability of those arcs endogenously. The bottom level problem is a two-stage problem which is solved to find the Maximum flow in the network by smugglers. In the first stage, he chooses some links to transmit the flow. In the second stage an indicator variable is used to show if he would be detected under each scenario. The bi-level decomposition algorithm has been applied to solve the problem by adding some Benders’ cuts iteratively. We applied a successive method, to deal with non-linearity rise in the probability measure of each path. A case study of drug trafficking network is applied to recognize which countries have the most significant effect in interdicting the drug trafficking network. The police can concentrate on those areas to decline the amount of drug flow. Our results demonstrate that if the critical arcs are chosen wisely and the probability of drug seizers decreases slightly, a significant decrease in the expected total flow of drugs can be achieved.

We consider the Maximum flow network interdiction problem. We provide a new interpretation of the problem and define a concept called ”optimalcut”. We propose a heuristic algorithm to obtain an approximated cut, and we also obtain its error bound. Finally, we show that our heuristic is an α-approximation algorithm for a class of networks. By implementing it on three network types, we show the advantage of it over solving the model by CPLEX.

Considering the lack of hydrometrical stations in most small watersheds, determination of Maximum flood discharge requires a suitable method to estimate runoff and peak flow thats used in flood and erosion control management plans. One of such methods is the graphical method presented by Natural Resources Conservation Service of the United States Department of Agriculture. To evaluate the applicability of this method, 19 watersheds in three regions of Iran Vis Karaj-Ghazvin region (region 1), Shomal region (region 2) and Azarbaiejan region (region 3) were selected. Among the different types of rain, type II exhibits a minimum error. The results showed this method had better applicability for estimation of peak flood in Karaj-Ghazvin and Azarbaiejan regions, but was more erroneous in Shomal region.

Bottom intake is one of the most appropriate systems for diverting discharge in steep rivers. Bottom intake with porous media is a new system of diverting discharge which can be replaced by bottom rack intakes. To investigate the hydraulic flow characteristics on diverted discharge of this intake, an experimental model was designed in which the inflow, diverted discharge and remained flow of porous media intake can be measured. In the present research, measurements of the diverted discharge were performed for different rates of flow, grain size distributions as well as surface slopes of intake with clear water. According to the obtained results, by increasing the inflow discharge, the rate of diverted discharge increases gradually and then reaches to a constant value. Any increment of the surface slope above the intake also decrease the relation diverted flow. It is found that the grain size of the porous media has a great influence on the diverted flow. By increasing the grain size diverted flow increases, too. Dimensional analysis and experimental results were used to estimate the discharge coefficient of porous media. Analytical analysis on experimental data shows that the discharge coefficient of porous media intake is about 0.1. Also an empirical-theoretical relation is proposed to evaluate the diverted discharge of this kind of bottom intakes.

Some relations for flood design estimating in sub-catchments in east and west part of north basin (Khazer basin).are established using multiple regression and index flood method.There are 31 sub-catchments in east part and 22 in west part of this area as gauged catchments.Factor analysis approach has realized that amongst several factors affecting on instantneous peak discharge, area of watershed, length of main channel, mean slope of watershed, mean annual precipitation, drainage density and compactness coefficient harv the largest effects, thus they are used in regional flood estimation analysis. Four homogenous groups of catchments are classified for each part of whole area and also entire area as one group using cluster analysis, Anderw curves and discrimination test. Some relations have been established for each of these groups and also for entire area of both part of Khazer basin using flood index method as well as multiple regression analysis. The results are successful in comparison with previous works have been done by others in this area.