Journal of Water Resources Planning and Management

Detecting and localizing leakages in underground water pipelines continue to be challenging in large-scale water distribution networks (WDNs) having a low density of acoustic sensors per unit pipeline. Many previous acoustic research analyses have been restricted to either (1) lab-scale WDN setups having simulated leakage conditions, or (2) field-scale WDNs with high densities of acoustic sensors. To address the current challenges, this study develops a generic and practical acoustic data analysis framework to analyze acoustics signals for leakage detection and localization in large-scale WDNs, where the proposed framework encompasses multi-stage systematic analyses, namely: (1) data quality assessment; (2) acoustic features generation and analysis; (3) leakage event detection; and (4) leakage event localization. In collaboration with Public Utility Board (PUB), Singapore’s National Water Agency, our proposed framework has been verified in large-scale WDNs in Singapore having more than 1,100 km of underground water pipelines and 82 permanently installed monitoring stations, each of which is instrumented to measure acoustics, via hydrophone equipment, pressure, and water quality parameters, and by using historical data collected between August 1, 2019 and August 31, 2020, where numerous leakage events were reported to within 1,000 m, or less, connected pipelines from independent hydrophones.

Basin ecological compensation policy is a regulatory policy that coordinates environmental protection, economic construction, and social development in a watershed. The policy helps alleviate problems such as unequal responsibilities for environmental protection and large disparities in economic conditions in different basin regions, enabling better implementation of scientific and green development. Although different regions implement policies differently, studying the factors influencing the diffusion of these policies can help develop an understanding of the elements that promote or hinder policy implementation. Such work can provide a reference for different provinces to develop implementation plans suitable for their regions. Using watershed ecological compensation policy data from 31 provincial administrative regions in China from 2005 to 2018, an interprovincial event history analysis was conducted to study the factors influencing the diffusion of watershed ecological compensation policies. Our findings show that financial support, proximity diffusion, and vertical pressure significantly affect the diffusion of watershed compensation policies at the level of $p<0.01$; below the poor quality of Class 3 cross section, and regional watershed area are correlated with the diffusion of watershed compensation policies at the level of $p<0.05$. In contrast, water pollution events, forest cover, water resources per capita, and gross domestic product per capita were not directly correlated with national diffusion variables at the 0.05 level.

Abstract

Arid and semi-arid landscapes globally represent significant challenges in developing and managing regional water resources for human uses while simultaneously sustaining aquatic ecosystems. Allocation of water resources between these divergent purposes requires careful analysis of the variable nature of the water supply and the plurality of demands on that supply if economic and ecological values of water are to be sustained. Where water resources are limiting, sustainability management of short-lived fish species may depend on adjusting the timing and quantity of out-of-channel diversions of water to reduce mortality-causing flow intermittence. Such management efforts can include strategies for improved water transport efficiency to increase the amount of water available for environmental flow. This work addresses gaps in the published literature by formulating and applying an analytic process that integrates demography of an endangered freshwater fish species, hydrology for a river segment with a high frequency of seasonal flow intermittence, and measures of cost-saving water management strategies to achieve environmental and economic objectives. This process provides a useful context for adaptive water resource planning that focuses on promising management actions needed to limit flow intermittence while serving to sustain socioecological systems.

Practical Applications

Much of the theory underpinning of management for ecological restoration and species sustainability is founded on an understanding of population ecology and the identification of factors that regulate population growth. We present an analytic process that integrates hydrologic and demographic factors in estimating the amount of water needed to supplement in-channel flow and so maintain surface water conditions that are minimally needed for short-term species survival. Demographic simulation results reveal distinct patterns in problem-solution sets that provide managers with much needed insight in planning effective and flexible responses to management challenges arising from unstable hydrologic conditions. Where water resources are limiting, sustainability management of short-lived freshwater fish species may depend on adjusting the timing and quantity of out-of-channel diversion of water to reduce mortality-causing flow intermittence. Investments in water transport efficiency increase the amount of water available for environmental flow while reducing potential conflicts with and between concerned and/or affected constituencies.

Abstract

Translation of a system’s performance goals into measurable quantities is fundamental for water systems planning. Frequently, the selected metrics are the same threshold-based metrics that have been common in water systems analysis for four decades. These are single statistic measures that characterize failure characteristics (e.g., frequency, duration, and magnitude) for a given simulation period where the failure threshold is a target delivery. At the same time, our systems are increasingly challenged by shifting water availability due to climate change and other anthropogenic pressures. Preparing our water systems to be resilient to such changes is a major challenge faced by water resources planners and managers. In particular, shifting mismatches between availability and target deliveries mean that for optimal design and control problems, metric choice implicitly becomes a statement of preference of failure type (i.e., the magnitude and/or duration of failure events). This usually occurs without explicit discussion of failure preference, resulting in unintended consequences that are not well understood. This study addresses the issue of unintended consequences in two ways. First, we introduce an approach to detect the threshold at which the balance between availability and delivery is no longer stable. Second, we characterize the consequences of metric choice when this threshold is exceeded. We find that early warning signals, and specifically the L moment estimator of variance, are able to detect the system’s entry into a state of increasing failure. We also find that for target deliveries greater than this threshold there are increasing tradeoffs between failure frequency, duration, and magnitude and that the distributional characteristics of failure magnitude and duration are driven by metric selection, objective formulation, and where on the Pareto front the solution sets lies. This study establishes a way to detect critical system thresholds and characterizes the effects of metric and threshold selection on failure, both of which are requisite for analysts and decision makers to avoid unintended consequences of planning and management decisions in an uncertain and changing world.

Practical Applications

Metrics form the basis of comparison for water resources planning and management decisions. When availability and demand are mismatched, the use of the standard threshold-based metrics in optimization problems can easily lead to unintended consequences. This is of fundamental concern for water resources planning and management in a changing world. This study helps analysts and decision makers avoid unintended consequence of poor metric selection by (1) characterizing the influence of metric selection on the types of failure events the system may endure; and (2) introducing a measure to detect the threshold at which analysts and decision makers should begin to be cautious of such consequences.

This study uses a water-food-energy nexus model, which connects water-based productive activities and allocation policies, to simulate water resources management strategies for adapting the Maule Basin in Chile to climate change impacts. Two strategies are considered: introducing linear hedging rules to a reservoir and establishing adaptative water rights linked to irrigation efficiency of crops in the area. The simulations are run over 14 different climatic scenarios that project different water availability conditions. A multiobjective optimization of environmental, agricultural, and energy outcome indicators is conducted to generate noninferior portfolios that combine the strategies proposed. Simulation results, though limited to a deterministic approach and pessimistic climate scenarios, show that 79 out of the 84 combinations of objective-scenarios increase their performance because of the strategies, with notable increases in agricultural resilience (64%), outflow (92%), and total benefits (26%). We find considerable trade-offs between the food/energy production and water outflow, alongside agricultural vulnerability and resilience.

Various water distribution leak detection and localization methods have been proposed for supervisory control and data acquisition (SCADA) data collection systems. However, because their available numbers of measurements are limited, the SCADA systems are often insufficient to identify realistic sized leaks. A clear next step is to develop detection and localization methods for smart systems that collect advanced metering infrastructure (AMI) data (i.e., AMI systems); however, only the authors have proposed tools for the AMI data collection systems. To encourage the usage of AMI data, this study tested five types of data collection systems for leak detection and localization that measure (1) only source flows, (2) source flows and a few nodal pressures, (3) source flows and AMI demands, (4) AMI demands and a few nodal pressures, and (5) AMI pressures and AMI demands. An appropriate leak detection and localization tool for each data collection system is applied and tested for two water distribution networks: one located in Austin, TX, and the other in Tucson, AZ. Each system’s performance was evaluated using metrics of detection probability, false alarm rate, time to detect, and localization pipe distance. Overall, based on the obtained results, the SCADA systems were poor in detecting realistic-sized leaks, while the AMI systems successfully identified those small failures. Thus, the AMI systems were required to improve detection, and a pressure-supplemented AMI system was necessary to obtain high localization performance, particularly for a large network, such as Austin, Texas.

Frequent changes in the hydrological regime of rivers downstream of dams due to reservoir scheduling would lead to problems such as ecological degradation. This study proposes the ecological flow-process level (EFPL), a quantitative ecological benefits indicator of flow processes, to reduce hydrological regime variation. The EFPL considers dynamic evaluation criteria for ecological flows at different periods and the influence of excessive flow. Based on the EFPL, a multiobjective ecological scheduling model was developed to maximize EFPL and power generation. To validate the effectiveness of the proposed method, a case study on the ecological scheduling of the Hongjiadu hydropower station was conducted. The resulting scheduling scheme showed a significant reduction of 33.21% in the maximum difference between the inflow and discharge processes compared to the original scheme. The result demonstrates that the proposed method can effectively reduce the hydropower-induced hydrological regime variation. The superiority of the EFPL indicator is further supported through comparisons with other ecological indicators. The result shows that the EFPL-based scheduling scheme has relatively good indicator values compared to other schemes.

Identification and control of the pollutant load in sewer networks (SNs) are among the priorities for utilities to reduce the impact on water bodies and to individuate the presence of pathogens to prevent their further spread, sometimes through interventions on a social scale. This goal can be achieved essentially through the development of a monitoring system. This paper proposes a backtracking methodology for efficiently planning a monitoring system in SNs assuming steady-state conditions during the analysis. The methodology is based on the calculation of the impact coefficient, which is related to the dilution and decay of contaminants and pathogens in the network, to evaluate the impact of each possible contaminated node on a downstream one in terms of concentration. This information supports the identification of candidate monitoring points, i.e., where to place measurement sensors to ensure complete coverage and control of the network. Additional analysis has been performed considering unsteady conditions for comparing the impact coefficient values averaged over 24 h and those of the steady-state methodology. Results show a similar value between steady-state and unsteady conditions, thus justifying the use of steady-state conditions for the proposed methodology, and also for real practical applications, with a significant improvement in terms both of simplicity and computational time saving.

Food-energy-water (FEW) nexus research emphasizes the links among food, energy, and water resource systems and is introduced as an attempt to overcome independent single-sector approaches that dominate the governing of resources today. Focus on multiple sectors and links among them is a key concept to the systems approach and methodology for its implementation by identifying and quantifying the connections between food, energy, and water sectors; modeling the FEW nexus system; and simulation of future management scenarios for decision-making assistance. This paper investigates the FEW nexus methodology within the system context by comparing simulation results obtained by the fully integrated model of global change, named ANEMI, and its modification, ANEMI_FEW, obtained by isolating nexus sectors from the rest of the model. Developing ANEMI_FEW requires breaking multiple feedback relationships that define the dynamic behavior of the modeled systems. A comparison of the simulation results confirms that the nexus model structure generates misleading results due to the break of significant feedbacks between FEW nexus and other sectors of the global change model. Obtained results are strongly suggesting that the nexus approach should be replaced with a more comprehensive structure of the global change model. The global ANEMI model is used as an example to investigate the research question. The findings generated by simulations of ANEMI and ANEMI_FEW are applicable to modeling at any scale (global, regional, or local).

Lack of access to potable drinking water is a crucial problem faced by many communities globally, especially poverty-stricken rural regions and urban and peri-urban settlements. Consumption of contaminated drinking water leads to both chronic and acute health consequences, especially in the case of young children and immunocompromised individuals. The sixth UN Sustainable Development Goal (SDG) seeks to provide universal access to safe drinking water by the year 2030. Household water treatment systems (HWTSs), such as membrane filters and chlorination tablets, have been researched and proposed as solutions for water treatment in developing economies for decades because they can provide localized solutions that best fit the context of the community of intervention. Despite increased resources, funding, and effort, many HWTSs fail long-term, sustained implementation in developing economies. This study takes a holistic approach, considering factors from both the technical and operational environment to identify factors and circumstances that inhibit these treatment technologies. Results from an analysis of 30 articles show that studies predominantly focus on factors related to system design and performance (e.g., contaminant removal efficacy, system flow rate, impact of turbidity). Many studies also focus on factors surrounding user perception and behavior. Factors with lower coverage in the data set relate to operation and maintenance, financial sustainability, supply chain, and the legal and regulatory structures. These findings are situated within a holistic conceptual framework that serves as a resource for knowledge transfer and can be updated to fit a variety of contexts.

Intense disputes between companies and the local population have led to new governance regimes, raising concerns about the hydropower business’s sustainability, social instability, and violence in emerging economies. New approaches to these issues must go beyond a critical view to be more adaptative and result oriented. This paper explores how the hydropower business’s sustainability influences governance regimes on the territory. A cross-case study is applied in the Samaná River basin in the Colombian Andes through a qualitative-quantitative mixed methodology to generate a grounded theory of sustainability and governance in hydropower territories. A qualitative approach was used to produce a framework about territorial factors based on 45 in-depth interviews. The quantitative approach was used as a machine-learning data compression and prediction method. It served as an additional test to extend and reshape the prediction power of the coding. The results suggested three territorial factors of hydropower business as drivers of governance regimes: (1) context variation, (2) the spatial configuration of governance, and (3) the importance of long-term stakeholder interactions. Implications of findings involve addressing power asymmetries and adapting the collaborative dynamics to the territory. This analysis validated a previous interpretative model and proposed sustainability and governance patterns useful in similar hydropower territories in emerging countries.

Some recent studies have used actual water end-use data to inform the peak demand design of plumbing systems in residential buildings, addressing the problem of overestimation in many long-standing plumbing codes and standards. Vast amounts of fixture-specific data from each household are required to determine the frequency each fixture is used during peak water consumption periods (fixture-use probability). However, obtaining such data can be difficult, and the processing is costly and time-consuming. The current study presents a new approach for determining the fixture-use probability for peak water demand design of premise plumbing systems. A stochastic water demand model is developed using only the high-level statistical information from water end-use studies presented in the public domain, offsetting the need for the original water end-use data sets. The stochastic model is then used to form easy-to-use formulas for determining the probability of use for various fixture groups, which consider both the number of apartments and building occupancy. The approach is validated by comparing the estimated peak demand values with the corresponding values determined from actual water consumption observations in three Australian residential apartment buildings and one mixed-use building. The new approach enables a much more accurate estimation of the peak demand compared with the conventional approach suggested in the current Australian plumbing standard. The proposed approach can be used by researchers and practitioners in other countries to determine their region-specific fixture-use probability values for more accurate peak demand estimation, contributing to improved premise plumbing system design.

Abstract

The water-economy-innovation nexus is an integrated system that plays an important driving role in urban and regional sustainable development. To identify, evaluate, and measure the coupling-coordinated development of the regional water-economy-innovation nexus, this study selects China’s Grand Canal area as a typical case and constructs an integrated evaluation system of the water-economy-innovation nexus. Then, the coupling coordination model is used to evaluate the regional water-economy-innovation nexus’ development. Finally, grey correlation analysis is used to evaluate the influencing factors. The results find that the water-economy-innovation nexus’ overall development level is not high and that there are significant spatial differences. The coupling coordination level keeps rising, and the coupling coordination level of the central city is obviously better than other cities. Water accounts for the largest contribution to the coupling coordination of the water-economy-innovation nexus, followed by economy and innovation. This study contributes to the knowledge body of sustainable development and provides a scientific basis for the decision of coupling the development of the water-economy-innovation nexus in China’s Grand Canal area and other regions.

Practical Applications

Water, as a fundamental resource, plays an important role in achieving the sustainable development goals (SDGs). However, water needs to interact with other factors to effectively achieve regional sustainable development. Innovation and the economy are both important drivers of sustainable development, and water is closely linked and interacted with them. Currently, the mechanism and extent of the coupled development of regional water-economy-innovation nexus remains unclear. To address this challenge, this study takes the Grand Canal area in China as a typical case and constructs an evaluation model with multiple methods to explore the coupling development of the regional water-economy-innovation nexus. This study verified the importance of multifactor coupling for regional sustainable development and demonstrated that water contributed the most, but the overall coupling development of the water-economy-innovation nexus was not high. Promoting the coupling development of the water-economy-innovation nexus through targeted policies is an important task for local governments.

Maximizing reliability is imperative for water distribution network (WDN) design. Recent claims about providing adequate and operable isolation valves as a focal aspect of a reliable WDN design have attracted substantial interest. In this direction, this paper attempts to answer the question of which isolation valves in a WDN must be prioritized based on their criticality toward enhancing WDN reliability. Two novel algorithms are proposed, one for ranking every isolation valve in a WDN and the second to identify the location of a new isolation valve to reduce the criticality of a specific valve in a WDN. Unlike the prevailing methodologies, the proposed algorithms are entirely based on the topological attributes of a WDN and do not require a calibrated hydraulic model, which is often a limiting factor in WDN management. Our proof of concept has unveiled the capability of the methodology to deliver preliminary information to water utilities regarding the criticality of valves without any hydraulic simulation.