Optimizing the Runoff Estimation with HEC-HMS Model Using Spatial Evapotranspiration by the SEBS Model

Most of the commonly used hydrological models do not account for the actual evapotranspiration (ETa) as a key contributor to water loss in semi-arid/arid regions. In this study, the HEC-HMS (Hydrologic Engineering Center Hydrologic Modeling System) model was calibrated, modified, and its performance in simulating runoff resulting from short-duration rainfall events was evaluated. The model modifications included integrating spatially distributed ETa, calculated using the surface energy balance system (SEBS), into the model. Evaluating the model’s performance in simulating runoff showed that the default HEC-HMS model underestimated the runoff with root mean squared error (RMSE) of 0.14 m³/s (R²?=?0.92) while incorporating SEBS ETa into the model reduced RMSE to 0.01 m³/s (R²?=?0.99). The integration of HECHMS and SEBS resulted in smaller and more realistic latent heat flux estimates translated into a lower water loss rate and a higher magnitude of runoff simulated by the HECHMS model. The difference between runoff simulations using the default and modified model translated into an average of 95,000 m³ runoff per rainfall event (equal to seasonal water requirement of ten-hectare winter wheat) that could be planned and triggered for agricultural purposes, flood harvesting, and groundwater recharge in the region. The effect of ETa on the simulated runoff volume is expected to be more pronounced during high evaporative demand periods, longer rainfall events, and larger catchments. The outcome of this study signifies the importance of implementing accurate estimates of evapotranspiration into a hydrological model.

     

Performance Assessment of a Coupled Particle Swarm Optimization and Network Flow Programming Model for Optimum Water Allocation

Water resources allocation problems are mainly categorized in two classes of simulation and optimization. In most cases, optimization problems due to the number of variables, constraints and nonlinear feasible search space are known as a challenging subject in the literature. In this research, by coupling particle swarm optimization (PSO) algorithm and a network flow programming (NFP) based river basin simulation model, a PSO-NFP hybrid structure is constructed for optimum water allocation planning. In the PSO-NFP model, the NFP core roles as the fast inner simulation engine for finding optimum values for a large number of water discharges in the network links (rivers and canals) and nodes (reservoirs and demands) while the heuristic PSO algorithm forms the outer optimization cover to search for the optimum values of reservoirs capacities and their storage priorities. In order to assess the performance of the PSO-NFP model, three hypothetical test problems are defined, and their equivalent nonlinear mathematical programs are developed in LINGO and the results are compared. Finally, the PSO-NFP model is applied in solving a real river basin water allocation problem. Results indicate that the applied method of coupling PSO and NFP has an efficient ability for handling river basin-scale water resources optimization problems.     

Large Scale Reservoirs System Operation Optimization: the Interior Search Algorithm (ISA) Approach

Reservoirs are built to provide a powerful tool to control and manage surface water resources in order to cover inconsistency between water resources and demands. Due to finite available water and the increasing demands for water especially in arid and semi-arid regions like Iran, reservoirs must be optimally operated in order to use water in the most efficient way. This study applies the Interior Search Algorithm (ISA) to solve large scale reservoirs system operation optimization problems. The ISA is a meta-heuristic algorithm inspired from a systematic methodology of architecture process and mirror work utilized by Persian designers for decoration. Unlike other meta-heuristic algorithms, the ISA just have one parameter to tune which is a great advantage. In this study the parameter of the ISA tuned automatically using a linear equation. A real-world one-reservoir operation problem (i.e. Karun-4) and two large scale benchmark problems (i.e. four-reservoir and ten-reservoir operation problem) were employed to show the effectiveness of the ISA. The results shows the high ability of the ISA to solve reservoirs system operation problems as it achieved solutions 99.97, 99.99 and 99.95 % of global optimum for Karun-4 reservoir, four-reservoir and ten-reservoir system operation problems, respectively. These results are the best results reported so far in the studied problems. Comparing results of the ISA with those of non-linear programming (NLP), linear programming (LP), genetic algorithm (GA) and other meta-heuristic algorithms indicates fast convergence to global optimum. Considering the results, it can be stated that the ISA is a powerful tool to optimize complex large scale reservoir system operation problems.     

Optimal Inter-Basin Water Allocation Using Crisp and Fuzzy Shapley Games

In recent years, uneven distribution of available water resources as well as increasing water demands and overexploiting the water resources have brought severe need for transferring water from basins having sufficient water to basins facing water shortages. Therefore, optimal allocation of shared water resources in water transfer projects, considering the utilities of different stakeholders, physical limitations of the system and socioeconomic criteria is an important task. In this paper, a new methodology based on crisp and fuzzy Shapley games is developed for optimal allocation of inter-basin water resources. In the proposed methodology, initial water allocations are obtained using an optimization model considering an equity criterion. In the second step, the stakeholders form crisp coalitions to increase the total net benefit of the system as well as their own benefits and a crisp Shapley Value game is used to reallocate the benefits produced in the crisp coalitions. Lastly, to provide maximum total net benefit, fuzzy coalitions are constituted and the participation rates of water users to fuzzy coalitions are optimized. Then, the total net benefit is reallocated to water users in a rational and equitable way using Fuzzy Shapley Value game. The effectiveness of this method is examined by applying it to a large scale case study of water transfer from the Karoon river basin in southern Iran to the Rafsanjan plain in central Iran.     

Social Planner’s Solution for the Caspian Sea Conflict

This paper evaluates the proposed alternatives for sharing the Caspian Sea from the social planner’s or systems-level perspective with respect to the stakeholders’ utilities from the oil and natural gas resources of the sea. Different multi-criteria decision-making methods, namely dominance, maximin, lexicography, simple additive weighting, and TOPSIS are applied to determine the social planner’s ranking of these alternatives. Results suggest the Condominium governance regime as the most promising division method. Bankruptcy rules and cooperative game theory methods can be considered as the other socially optimal resolutions to the conflict over sharing the Caspian Sea energy resources among its five littoral countries. Consideration of these methods in negotiations may help with resolving the existing deadlock, which has been in place for two decades.     

Determination of the Optimal River Basin-Wide Agricultural Water Demand Quantities Meeting Satisfactory Reliability Levels

Water Resources Management - The unbridled increase in water demands and beyond-sustainable water withdrawals have led to decrease reliable supply levels, particularly for agricultural purposes in...     

An application of the theory of planned behaviour to understand compliance with daytime running headlights law among motorcycle riders

Abstract

Fatal motorcycle crashes are a persistent problem in Southeast Asia. In many respects, road safety experts have acknowledged conspicuity issue as one of the main causes of such accidents. To mitigate this deficiency, daytime running headlights (DRHs) law has been documented among the widely exercised countermeasures. The present study aimed to explore socio-psychological factors shaping intentions towards use of DRHs among Malaysian motorcyclists, because compliance level with this rule has remained constant since 1996 (80%). For this purpose, a model was constructed through the Theory of Planned Behaviour (TPB) to evaluate factors affecting motorcyclists’ intentions towards compliance with DRHs law. A series of statistical analyses were performed to explain the effect of these factors and to predict degree of compliance with this rule. The model applied on a sample of university students (N?=?398) demonstrated that the TPB components could significantly predict motorcycle riders’ behaviours and degree of compliance with DRHs law. Moreover, it would be of assistance to policy-makers to recognize groups of motorcyclists more likely to cause an increase in traffic accidents. In general, regular educational campaigns were recommended to raise awareness regarding consequences of not using DRHs and also to nurture factors influencing motorcyclists’ attitudes towards DRHs.     

A Multi-Model Nonstationary Rainfall-Runoff Modeling Framework: Analysis and Toolbox

Water Resources Management - We present a framework and toolbox for multi-model (one at a time) nonstationary modeling of rainfall-runoff (RR) transformation. The designed time-varying nature of...     

Optimal Reservoir Operation with Water Supply Enhancement and Flood Mitigation Objectives Using an Optimization-Simulation Approach

Floods are one of the most destructive natural disasters which compensation of their effects inflicts immense costs especially in areas with human developments such as cities. Moreover, supplying water for demands particularly during the drought period is a challenging issue in water resource planning. The aim of this study is to propose a model for optimal operation of a reservoir with enhancing downstream demands supply and flood damage mitigation objectives. The model is developed by coupling MODSIM, river network simulation DSS with the imperialist competitive optimization algorithm (ICA). Gotvand Dam in southwestern Iran is the case of study and amounts of water storage in the reservoir in daily time-steps are the decision variable. Results indicate efficiency of the proposed optimization-simulation approach, suggesting that flood damages can be controlled with proper planning while ensuring that downstream water demands are satisfied. As an instance of results, the optimum reservoir rule curve obtained by the proposed model is able to manage a flood entering to the reservoir 11 times greater than the safe flow in the downstream reach and release it lower than the safe flow rate.     

Evaluation of the Bankruptcy Approach for Water Resources Allocation Conflict Resolution at Basin Scale,Iran’s Lake Urmia Experience

Water conflicts appear when there are insufficient and less available water resources than water demands claimed by different agents. In this study, a new bankruptcy approach is investigated to resolve water conflicts in the Zarrinehroud River Basin, the largest and most important sub-basin of Lake Urmia’s Basin in the northwest of Iran. The new bankruptcy method is compared with the proportional rule (PRO) and another alternative based on the cessation of irrigated agriculture in the region proposed to supply and save environmentally in danger Lake Urmia. Four scenarios consisting of the current situation, optimistic, average and pessimistic scenarios regarding the future of water resources of the basin and agricultural developments were considered. According to the results, both bankruptcy rules helped Lake Urmia to receive more water, but neither could utterly overcome the water shortage of the Lake, so can be used as supplementary actions alongside other solutions. The cessation of irrigated agriculture throughout the basin overcame the average annual shortage of Lake Urmia in the first and second scenarios equal to 137 and 148 million cubic meters respectively. It showed disability to fully supply the lake in the third and fourth scenarios. These three methods must be combined with a social-economic policy like the purchase of decreased water allocations to farmers to be socially acceptable.