A flow path model for regional water distribution optimization

Abstract

[1] We develop a flow path model for the optimization of a regional water distribution system. The model simultaneously describes a water distribution system in two parts: (1) the water delivery relationship between suppliers and receivers and (2) the physical water delivery network. In the first part, the model considers waters from different suppliers as multiple commodities. This helps the model clearly describe water deliveries by identifying the relationship between suppliers and receivers. The physical part characterizes a physical water distribution network by all possible flow paths. The flow path model can be used to optimize not only the suppliers to each receiver but also their associated flow paths for supplying water. This characteristic leads to the optimum solution that contains the optimal scheduling results and detailed information concerning water distribution in the physical system. That is, the water rights owner, water quantity, water location, and associated flow path of each delivery action are represented explicitly in the results rather than merely as an optimized total flow quantity in each arc of a distribution network. We first verify the proposed methodology on a hypothetical water distribution system. Then we apply the methodology to the water distribution system associated with the Tou-Qian River basin in northern Taiwan. The results show that the flow path model can be used to optimize the quantity of each water delivery, the associated flow path, and the water trade and transfer strategy.

Coordinating Model Predictive Control of Transport and Supply Water Systems

“…Before that, a node-arc representation method for a regional water network is provided, where a node represents a source, reservoir, demand or junction and an arc represents a transfer or trade [6]. In a regional water network, all flow paths can be obtained from node-arc incidence matrices because water always flows from upstream sources to downstream.…”

“…2. In the upper level, the daily model of the supply system is used in order to estimate the aggregated prices (which include both water and electricity costs) by means of the optimal path method (OPM) in [6] [8]. Detailed algorithms for this temporal coordination mechanism will be provided in detail in the following section.…”

Protecting environmental flows through enhanced water licensing and water markets

“…Hydroeconomic models that incorporate hydrology, institutions and economics are particularly relevant (Harou et al, 2009). Traditional hydroeconomic models can simulate aggregate regional results of water trading (Draper et al, 2003;Ward et al, 2006). To determine market outcomes at the scale of individual water diverters, however, it is important to simulate the transactions between individual water users.…”

“…To determine market outcomes at the scale of individual water diverters, however, it is important to simulate the transactions between individual water users. Cheng et al (2009) developed a flow-path model formulation that allows tracking transactions between users. Erfani et al (2013) presented an efficient variant used by Erfani et al (2014) to model a surface water spot market.…”

Determination of cost coefficients of a priority-based water allocation linear programming model – a network flow approach

“…For models that allocate water across multiple time steps, links connect reservoir nodes in different time periods to represent carryover storage. These models have been applied in reservoir sizing (Kuczera, 1989;Khaliquzzaman and Chander, 1997), capacity expansion (Martin, 1987;Gondolfi et al, 1997), the derivation of reservoir operating rules (Lund and Ferreira, 1996;Bessler et al, 2003), water transfer during droughts (Cheng et al, 2009), and the optimal real-time flood control operation of reservoirs (Braga and Barbosa, 2001). Single time step models allocate water only within an operational unit period, but the allocation is sequentially solved in every step during the simulation time horizon.…”