Includes bibliographical references.

Model selection based on sectoral application scale for increased value of hydroclimate-prediction information -- Cost-benefit framework for optimal design of water transfer systems -- Computer-aided decision-making model for multiphase upgrading of aged water distribution mains -- Intertemporal preferences of potable water supply consumers -- Derivation of hydropower rules for multireservoir systems and its apllication for optimal reservoir storage allocation -- Estimating profit, orice, and productivity changes in water industry using bennet-bowley indicator -- Cost model for pumps as turbines in run-of-river and in-pipe microhydropower applications -- Simulation-optimization model to derive operation rules of multiple cascaded reservoirs for nash equilibrium -- Model reduction and outer approximation for optimizing the placement of control valves in complex water networks -- Comparison of surrogate models based on different sampling methods for groundwater remediation -- Reservoir operations under changing climate conditions: hydropower-production perspective -- Machine learning for modeling water demand -- Using seasonal forecasts to inform water market-scale option contracts -- Benefits of cooperation in transnational water-energy systems.

[Article Title: Model Selection Based on Sectoral Application Scale for Increased Value of Hydroclimate-Prediction Information / Sarah Alexander, Shu Wu, and Paul Block, p. 1-11]

Abstract: Advance predictions of seasonal precipitation may provide information to aid water resource management decisions in various sectors. Yet, a disconnect between the spatial scale upon which skillful predictions are issued and the sectoral decision-making scale renders current predictive information inadequate in many cases. This study explores season-ahead precipitation prediction skill for a local region in the Blue Nile basin, Ethiopia, to better understand how model structure may serve to provide more skillful and valuable predictive information to the end user.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001044

[Article Title: Cost-Benefit Framework for Optimal Design of Water Transfer Systems / Chi Zhang, Wei Ding, Yu Li, Fanlin Meng, and Guangtao Fu, p. 1-14]

Abstract: Water transfer systems are increasingly seen as a response to regional water stresses. The expensive capital cost of such massive projects calls for satisfying the desired requirements with a minimum investment, i.e., achieving a high rate of return on investment. This paper develops a new theoretical cost-benefit analysis framework considering the tradeoffs between investment cost and expected water shortage loss to determine the optimal water transfer capacity for water transfer systems.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001059

[Article Title: Computer-Aided Decision-Making Model for Multiphase Upgrading of Aged Water Distribution Mains / Amin Minaei, Ali Haghighi, and Hamid Reza Ghafouri, p. 1-11]

Abstract: This study introduces a decision support system for upgrading aged water distribution mains. The network hydraulics is simulated and evaluated by a hybrid reliability measure, and the design period is divided into multiple upgrade phases. In each phase, a multiobjective optimization problem is solved to derive the trade-off between construction cost and network performance reliability. Subject to budget constraints, upgrade decisions, including those related to pipe replacement and laying parallel pipe, are made, leading to a more robust hydraulic performance of the network over time.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001070

[Article Title: Intertemporal Preferences of Potable Water Supply Consumers / Anna Robak and Henning Bjornlund, p. 1-11]

Abstract: This research explores potable water consumers’ willingness to pay to fund up-front investments in their potable water supply services (PWSSs), which will reduce rates in the longer term. An online survey of 1,970 New Zealand PWSS consumers was carried out in 2011 to identify factors that influence individual discount rates (IDRs) related to PWSS investments—a first of its kind—using dichotomous choice questions. Constrained latent class models (LCMs)—an established technique—were used to test the presence of a class of respondents that is unwilling to invest—a phenomenon that has not yet been tested for PWSS consumers.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001058

[Article Title: Derivation of Hydropower Rules for Multireservoir Systems and Its Application for Optimal Reservoir Storage Allocation / Xiaoqi Zhang, Pan Liu, Chong-Yu Xu, Shenglian Guo, Yu Gong, and He Li, p. 1-10]

Abstract: Hydropower operating rules can guide reservoir release and storage for maximizing hydropower generation. The optimal hydropower operating rules are usually derived by numerical hydropower simulation methods. This study focuses on the analytical solution to optimal hydropower rules for storage allocation of a multireservoir system.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001056

[Article Title: Estimating Profit, Price, and Productivity Changes in Water Industry Using Bennet-Bowley Indicator / María Molinos-Senante, Alexandros Maziotis, and Ramon Sala-Garrido, p. 1-9]

Abstract: The assessment of profit, productivity, and price change over time is valuable for regulators and companies when setting tariffs. This paper innovates by comparing profit, price, and productivity changes for English and Welsh water services between water and sewerage companies (WaSCs) and water-only companies (WoCs) over the period of 2001–2009. The Bennet-Bowley indicator (BBI) was used to estimate productivity change over time at industry and company levels.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001065

[Article Title: Cost Model for Pumps as Turbines in Run-of-River and In-Pipe Microhydropower Applications / D. Novara, A. Carravetta, A. McNabola, and H. M. Ramos, p. 1-9]

Abstract: Pumps as Turbines (PATs) are standard water pumps utilized as hydraulic turbines by reversing the flow direction across them. The off-the-shelf availability of water pumps and their reduced purchase price with respect to conventional hydro turbines makes them an ideal technology for exploiting large portions of uncapped hydro potential that is technically viable but not financially convenient. Such low-cost technology could help to expand hydropower exploitation in water resources worldwide, helping to reduce climate change greenhouse gas emissions.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001063

[Article Title: Simulation-Optimization Model to Derive Operation Rules of Multiple Cascaded Reservoirs for Nash Equilibrium / Xinyu Wu, Shuming Li, Chuntian Cheng, Shumin Miao, and Qilin Ying, p. 1-11]

Abstract: Operation rules are commonly used to make decisions for cascaded hydropower reservoirs for profit maximization, given the energy price of current and future periods. For large-scale cascaded hydropower reservoirs whose decisions can affect market price, the operation optimization models are transformed into game models to get Nash equilibriums.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001057

[Article Title: Model Reduction and Outer Approximation for Optimizing the Placement of Control Valves in Complex Water Networks / Filippo Pecci, Edo Abraham, and Ivan Stoianov, p. 1-13]

Abstract: The optimal placement and operation of pressure control valves in water distribution networks is a challenging engineering problem. When formulated in a mathematical optimization framework, this problem results in a nonconvex mixed integer nonlinear program (MINLP), which has combinatorial computational complexity. As a result, the considered MINLP becomes particularly difficult to solve for large-scale looped operational networks. We extend and combine network model reduction techniques with the proposed optimization framework in order to lower the computational burden and enable the optimal placement and operation of control valves in these complex water distribution networks.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001055

[Article Title: Comparison of Surrogate Models Based on Different Sampling Methods for Groundwater Remediation / Jiannan Luo, Yefei Ji, and Wenxi Lu, p. 1-9]

Abstract: To assess the influence of sampling methods on surrogate models’ accuracy, using two test problems and a nitrobenzene-contaminated aquifer remediation problem, several sampling methods were adopted to collect sample data sets and a Kriging method was adopted to construct surrogate models. The sampling methods adopted include Latin hypercube sampling (LHS), space-filling-based LHS (SFLHS), orthogonal-array-based LHS (OALHS), and space-filling and orthogonal-array-based LHS (SFOALHS).

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001062

[Article Title: Reservoir Operations under Changing Climate Conditions: Hydropower-Production Perspective / Sohom Mandal, R. Arunkumar, Patrick A. Breach, and Slobodan P. Simonovic, p. 1-12]

Abstract: Climate change has significant effects on the management of complex water resource systems. The objective of this study was to assess climate change effects on reservoir system operations. The assessment was performed using three greenhouse gas emission scenarios, four global climate models (GCMs), six downscaling methods, one hydrologic model, and a system dynamics simulation model (SDM). The analyses were conducted for a future time period (2036–2065) and results were compared with the historical time period (1984–2013).

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001061

[Article Title: Machine Learning for Modeling Water Demand / Maria C. Villarin and Victor F. Rodriguez-Galiano, p. 1-15]

Abstract: This work shows the application of machine learning (ML) methods to the modeling of water demand for the first time. Classification and regression trees (CART) and random forest (RF), a multivariate, spatially nonstationary and nonlinear ML approach, were used to build a predictive model of water demand in the city of Seville, Spain, at the census tract level. Regression trees (RT) allowed estimation of water demand with an error of 22  L/day/inhabitant and determination of the main driving variables.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001067

[Article Title: Using Seasonal Forecasts to Inform Water Market-Scale Option Contracts / Justin D. Delorit and Paul J. Block, p. 1-12]

Abstract: Option contracts have been successfully established in water-scare regions to facilitate temporary transfers of water between users. The benefits are clear when the contract water quantity can be guaranteed by the seller. Where water right allocations are subject to interannual variability, guaranteed delivery may not be feasible. Skillful season-ahead forecasts of water right allocations and crop market prices have the potential to inform option contracts in such circumstances.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001068

[Article Title: Benefits of Cooperation in Transnational Water-Energy Systems / Jakob Luchner, Niels D. Riegel, and Peter Bauer-Gottwein, p. 1-11]

Abstract: Cooperation in international river basins is often challenged by upstream–downstream conflicts over water allocation. In many cases, water allocation is linked to the energy sector through hydropower. In this study, the water value method was used to simulate reservoir operations in an international basin under different assumptions about national priorities and regional energy cooperation. Benefits in the water sector and the power sector were compared considering both cooperative and noncooperative behavior by national players. The approach is demonstrated for a semiarid international river basin characterized by conflict between upstream hydropower production and downstream irrigated agriculture.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001047

[Article Title: Assessing Conjunctive Use Opportunities with Stakeholders in the Murray-Darling Basin, Australia / Jenifer L. Ticehurst and Allan L. Curtis, p. 1-12]

Abstract: The management of global water resources is increasingly contested. Australia’s Murray-Darling Basin (MDB) is an example relevant to many semiarid basins around the world. In the MDB, government has recovered substantial volumes of water to support environmental values, but irrigators and the industries and communities they support have opposed the objectives and process of water reform. Initiatives have been implemented to minimize the impact of these reforms on agriculture, but little attention has been given to opportunities that better integrate surface and groundwater resources [i.e., conjunctive use (CU)].

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001069

[Article Title: Optimal Irrigation with Perfect Weekly Forecasts versus Imperfect Seasonal Forecasts / Alaa Jamal, Raphael Linker, and Mashor Housh, p. 1-6]

Abstract: his study examines the impact of weekly and seasonal weather forecasts on the optimal irrigation scheduling problem. We compare stochastic and deterministic simulation-optimization frameworks for irrigation scheduling using perfect weekly (deterministic) and imperfect seasonal (stochastic) forecasts. The analysis is performed on a case study of irrigated chickpeas in Kibbutz HaZore’a in northern Israel. The results demonstrate that, for the case study area and crop, the optimization with seasonal stochastic forecasts outperforms the deterministic optimization that uses perfect weekly forecast.

https://doi.org/10.1061/(ASCE)WR.1943-5452.0001066