Environmental demand effects on the energy generation of Karkheh reservoir: Base and climate change conditions

Environment, Development and Sustainability - Reservoir is a hydraulic structure that regulates river water to supply different sectors’ demands such as municipal, agricultural, and...     

Environmental water demand assessment under climate change conditions

Measures taken to cope with the possible effects of climate change on water resources management are key for the successful adaptation to such change. This work assesses the environmental water demand of the Karkheh river in the reach comprising Karkheh dam to the Hoor-al-Azim wetland, Iran, under climate change during the period 2010–2059. The assessment of the environmental demand applies (1) representative concentration pathways (RCPs) and (2) downscaling methods. The first phase of this work projects temperature and rainfall in the period 2010–2059 under three RCPs and with two downscaling methods. Thus, six climatic scenarios are generated. The results showed that temperature and rainfall average would increase in the range of 1.7–5.2 and 1.9–9.2%, respectively. Subsequently, flows corresponding to the six different climatic scenarios are simulated with the unit hydrographs and component flows from rainfall, evaporation, and stream flow data (IHACRES) rainfall-runoff model and are input to the Karkheh reservoir. The simulation results indicated increases of 0.9–7.7% in the average flow under the six simulation scenarios during the period of analysis. The second phase of this paper’s methodology determines the monthly minimum environmental water demands of the Karkheh river associated with the six simulation scenarios using a hydrological method. The determined environmental demands are compared with historical ones. The results show that the temporal variation of monthly environmental demand would change under climate change conditions. Furthermore, some climatic scenarios project environmental water demand larger than and some of them project less than the baseline one.     

Developing a sustainability assessment framework for integrated management of water resources systems using distributed zoning and system dynamics approaches

The management of large-scale water resources systems requires including of different stakeholders and users from municipal, agricultural, industrial and environmental sectors. This has baffled the process of decision making for integrated water resource systems. In such systems, the interactions between various stakeholders must be carefully taken into account with the goal of aggregating interests around the sustainability concept. In this study, first, the integrated water resources systems of Big Karun Watershed, Iran, have been modeled using the system dynamics approach. The system dynamics model represents the interactions between different components of the system, including water transfer projects, dams, urban, industry, agriculture and fish farming, and environmental demands. Vensim software has been used for the system dynamics modeling. Vensim simulates the dynamics behavior of the sub-systems and overall performance of the system by comparing the current operation policies with the future management scenarios. A wide range of performance indices, such as quantitative and qualitative water stress, income, cost, and productivity, have been used here to represent different aspects of sustainability goals. Finally, the performance of the systems has been evaluated by developing a sustainability index using distributed zoning model in order to identify proper management policies for this watershed. The results indicate that downstream users demand cannot be fully met by solely considering inter-basin water transfer and agricultural development projects. The sustainable and integrated management of the whole system ties into enhancement in both infrastructure systems and the operation of the whole system. It is expected that the sustainability of the basin improves if a water market schema exists and the gained money would be used to enhance the efficiency of existing irrigation networks.

     

A review of 20-year applications of multi-attribute decision-making in environmental and water resources planning and management

Environment, Development and Sustainability - Multi-attribute decision-making (MADM) is an umbrella term to describe a series of mathematical frameworks that, in essence, enable the decision-makers...     

Optimal water resources allocation in transboundary river basins according to hydropolitical consideration

Environment, Development and Sustainability - Water resources allocation policies can create cooperation or tension among different stakeholders in a large basin. Thus, integrated water resources...     

Upstream flood pattern recognition based on downstream events

Reverse stream flood routing determines the upstream hydrograph in a stream reach given the downstream hydrograph. The Muskingum model of flood routing involves parameters that govern the routed hydrograph. These parameters are herein estimated using simulation methods coupled with optimization tools to achieve optimized parameters. Different simulation methods are shown to perform unequally in the estimation of nonlinear Muskingum parameters. This paper presents two simulation methods for nonlinear Muskingum reverse flood routing: (1) Euler equations and (2) Runge-Kutta 4th order equations. Moreover, the generalized reduced gradient (GRG) is used as the optimization tool that minimized the sum of the squared deviations (SSQ) between observed and routed inflows in a benchmark flood routing problem. Results show the Runge-Kutta 4th order equations yield better routed hydrographs with smaller SSQ than obtained in previous research and with the first simulation method (Euler equations).