River Quality Improvements Research Articles

Assessing subjective preferences for river quality improvements: combining Q-methodology and choice experiment data

ABSTRACT Choice decisions are inherently subjective but capturing and explaining nuanced variation in respondents’ attitudes is difficult and needs more than the simple socio-demographic variables traditionally used in economic research. In recent years, environmental economists have been shifting towards a more holistic approach to economic valuation, making an increased use of psychology within behavioural economics, to better understand subjective preferences on the environment. This research applies a novel mixed-methods approach to integrate the results from a Q-methodological analysis, which reveals respondents’ latent traits and perceptions about river management, into a choice experiment which estimates respondents’ preferences for potential future improvements to river water quality. The purpose is to improve the quantification of subjectivity within stated preference experiments. Q-methodology reveals five statistically distinct narratives (characterised as Ecological, Financial, Leadership, Collaboration, Legislation) which define the main perspectives respondents hold for river management strategies. Choice experiment results suggest subjectivity causes significant differences in respondents’ choice behaviour. Statistically verified Q-methodological narratives provide plausible explanations for differences in respondents’ choice preferences regarding river water quality improvements. By triangulating between quantitative and qualitative research methods, we demonstrate a research strategy that can contribute to a better understanding of the impact socially contested perspectives have on respondents’ choice behaviour.

Protecting rivers by integrating supply-wastewater infrastructure planning and coordinating operational decisions

Placing water quality in rivers at the centre of water infrastructure planning and management is an important objective. In response there has been a range of ‘whole system’ analyses. Few studies, however, consider both abstraction (water removed from rivers) and discharge (water returned) to inform the future planning of water systems. In this work we present a systems approach to analysing future water planning options where system development prioritises the water quality of the receiving river. We provide a theoretical demonstration by integrating water supply and wastewater infrastructure, and downstream river water quality, on an open-source, stylised, systems model for London, UK, at a citywide scale. We show that models which consider either supply or wastewater separately will underestimate impacts of effluent on the water quality, in some cases by amounts that would require £1 billion worth of infrastructure equivalent to mitigate. We highlight the utility of the systems approach in evaluating integrated water infrastructure planning using both socio-economic and environmental indicators. Through this approach we find unintended impacts from planning options on downstream river quality; including benefits from water demand management and rainwater harvesting, and costs from wastewater reuse. Finally, we present a novel management planning option between supply and wastewater, which we refer to as ion-Effluent Dilution (AED), that is, to reduce river abstractions during high precipitation events to dilute untreated sewer spills. The AED option is found to provide up to £200 million worth of equivalent infrastructure in river quality improvements and has minimal impact on the reliability of water supply while requiring only a change in operational decision making. This proof-of-concept study highlights that seeing our water systems differently with this holistic approach could fundamentally change the way we think about future water infrastructure planning so that it works both for people and the environment.

Urban water security assessment in the context of sustainability and urban water management transitions: An empirical study in Shanghai

Despite the relevance of urban water security in protecting water resources and supporting sustainable urban development, the literature seldom addresses sustainability and the features of urban water management practices in the assessment. Hence, based on the four sustainability dimensions (environment, society, economy and institution) and the cumulative objectives of urban water management transitions (from facilitating water supply, sewage, drainage, pollution treatment, water utilization, to resilience), this study analyzed the water security condition in Shanghai during 2011–2017 and examined the progress of the sequence of the Three-Year Action Plan on Environmental Protection and Construction implemented in Shanghai. Besides, the Criteria Importance Through Intercriteria Correlation (CRITIC) method was performed to determine indicator weights without integration of value choices. The results showed that the water security condition in Shanghai has gently variated during 2011–2013 and distinctly improved from 2013 (the single score as 0.270) to 2017 (the single score as 0.859). The condition of abrupt environmental events, water use, river quality, and pollution discharge has significantly fluctuated during the investigated period. Policy analysis pointed out that river quality improvement, pollutant control, and wastewater treatment advancement have been the focus throughout the urban water policy measures in Shanghai. However, unstable water resource availability leads to a risk of water security deterioration in Shanghai in the long term and sewage infrastructure planning shall be refined to facilitate sufficient sewage collection. Furthermore, Shanghai shall notice incorporating water use and disaster management into water policy planning to better support water utilization efficiency and urban resilience. This study contributes to the framework development and comparative assessment practices in urban water security studies. The application of the suggested framework and assessment approach can allow policymakers to analyze the improvement needs of urban water security and favor policy design.

Urban water security of China’s municipalities: Comparison, features and challenges

Current urban water security studies failed to incorporate sustainability concerns and the objectives of urban water management practices. China’s municipalities, namely Shanghai, Beijing, Tianjin and Chongqing, have faced great pressure on water security, however, literature has not yet investigated their features and concerns of urban water security. To address these challenges, this study suggested a water security assessment framework which incorporates the features of urban water management transitions and sustainability aspects to analyze the urban water security condition of the four municipalities during 2011–2017. In addition, the Criteria Importance Through Intercriteria Correlation (CRITIC) method was employed to detect the weights of indicators without incorporating personal value judgements to enhance the results robustness. The results point out that Beijing has had the best water security condition, followed by Tianjin, Shanghai and Chongqing. In addition, Shanghai has had the largest improvement of water security condition among the municipalities during the investigated period. The condition of water use efficiency, river quality, pollutant discharge, wastewater treatment capacity, green covered area and crop area affected by droughts and floods has showed a great variation between the four municipalities. River quality improvement, and mitigation of droughts and floods damages have remained top priority in Tianjin and Beijing. The Shanghai government should lay a particular concern on water use reduction and the regulation of wastewater and pollutant discharges. The Chongqing government should reinforce the coverage of sewage and drainage infrastructure, advance water use efficiency and balance water intensity of economic activities to avoid long term damages on water security. The assessment framework and approach are conducive to investigate and communicate water security condition of cities and can assist tailoring policy measurements to cities in different water security contexts.

Multivariate statistical analyses for water and sediment quality index development: A study of susceptibility in an urban river

In this study, multivariate statistical analyses were performed to develop water and sediment quality indexes, allowing us (i) to select with reliability the most appropriate chemical variables for the evaluation of river quality susceptibility; (ii) to weight the influence of each variable based on monitored data; (iii) to consider possible synergism or antagonism derived from the combined effect of several pollutants; and (iv) to express the quality as a deviation from selected site-specific reference conditions. For the establishment of these threshold/maximum values, combining two biological indicators related to denitrifying bacteria in sediments turned out to be applicable to ensure compliance with the European water quality standard.The joint implementation of water and sediment quality indexes assisted us in the rapid detection of the deleterious effect of different anthropogenic contamination sources, as well as the influence of hydrological regime seasonality on river quality. In addition, metal-dependent water quality appeared to be coupled to sediment dynamics, since they were preferentially adsorbed onto sediments during low flow seasons, whereas there was potential for metal mobilization to water during sediment resuspension in high flow seasons. Therefore, an annual determination of sediment quality index was also recommended as suitable tool for prospective monitoring water quality, identifying those sites which could deserve special attention during certain periods, and planning future strategies for river quality improvement. However, two limitations were found: (1) sediment was not appropriate for water physicochemical quality early monitoring due to organic matter and nutrient continuous transformation; and (2) a multimetric index did not provide a concise and definitive quality information, thus a new tool for combining with quality index was proposed for specifically evaluate the water and sediment quality by identifying pollutant/s of concern at each location.

Decadal-scale export of nitrogen, phosphorus, and sediment from the Susquehanna River basin, USA: Analysis and synthesis of temporal and spatial patterns

The export of nitrogen (N), phosphorus (P), and suspended sediment (SS) is a long-standing management concern for the Chesapeake Bay watershed, USA. Here we present a comprehensive evaluation of nutrient and sediment loads over the last three decades at multiple locations in the Susquehanna River basin (SRB), Chesapeake's largest tributary watershed. Sediment and nutrient riverine loadings, including both dissolved and particulate fractions, have generally declined at all sites upstream of Conowingo Dam (non-tidal SRB outlet). Period-of-record declines in riverine yield are generally smaller than those in source input, suggesting the possibility of legacy contributions. Consistent with other watershed studies, these results reinforce the importance of considering lag time between the implementation of management actions and achievement of river quality improvement. Whereas flow-normalized loadings for particulate species have increased recently below Conowingo Reservoir, those for upstream sites have declined, thus substantiating conclusions from prior studies about decreased reservoir trapping efficiency. In regard to streamflow effects, statistically significant log-linear relationships between annual streamflow and annual constituent load suggest the dominance of hydrological control on the inter-annual variability of constituent export. Concentration-discharge relationships revealed general chemostasis and mobilization effects for dissolved and particulate species, respectively, both suggesting transport-limitation conditions. In addition to affecting annual export rates, streamflow has also modulated the relative importance of dissolved and particulate fractions, as reflected by its negative correlations with dissolved P/total P, dissolved N/total N, particulate P/SS, and total N/total P ratios. For land-use effects, period-of-record median annual yields of N, P, and SS all correlate positively with the area fraction of non-forested land but negatively with that of forested land under all hydrological conditions. Overall, this work has informed understanding with respect to four major factors affecting constituent export (i.e., source input, reservoir modulation, streamflow, and land use) and demonstrated the value of long-term river monitoring.

Predicting microbial pollution concentrations in UK rivers in response to land use change

The Water Framework Directive has caused a paradigm shift towards the integrated management of recreational water quality through the development of drainage basin-wide programmes of measures. This has increased the need for a cost-effective diagnostic tool capable of accurately predicting riverine faecal indicator organism (FIO) concentrations. This paper outlines the application of models developed to fulfil this need, which represent the first transferrable generic FIO models to be developed for the UK to incorporate direct measures of key FIO sources (namely human and livestock population data) as predictor variables. We apply a recently developed transfer methodology, which enables the quantification of geometric mean presumptive faecal coliforms and presumptive intestinal enterococci concentrations for base- and high-flow during the summer bathing season in unmonitored UK watercourses, to predict FIO concentrations in the Humber river basin district. Because the FIO models incorporate explanatory variables which allow the effects of policy measures which influence livestock stocking rates to be assessed, we carry out empirical analysis of the differential effects of seven land use management and policy instruments (fiscal constraint, production constraint, cost intervention, area intervention, demand-side constraint, input constraint, and micro-level land use management) all of which can be used to reduce riverine FIO concentrations. This research provides insights into FIO source apportionment, explores a selection of pollution remediation strategies and the spatial differentiation of land use policies which could be implemented to deliver river quality improvements. All of the policy tools we model reduce FIO concentrations in rivers but our research suggests that the installation of streamside fencing in intensive milk producing areas may be the single most effective land management strategy to reduce riverine microbial pollution.

MEASURING THE BENEFITS OF RIVER QUALITY IMPROVEMENT USING THE CONTINGENT VALUATION METHOD: THE CASE OF THE PING RIVER, CHIANG MAI, THAILAND

Rivers provide us with general life support, water supply, transportation, waste assimilation, and a wide array of recreation and tourism activities. However, due to undervaluation of the functions of rivers and river ecosystems, rivers of the world have been overexploited or degraded. To tackle the problem of undervaluation, this study measures the benefits of Ping River quality improvement using the contingent valuation method (CVM). The study estimates the lower-bound and higher-bound annual benefits gained by the residents of Chiang Mai District from the river quality improvement as 42,453,000 THB (1.25 million USD) and 102,835,317 THB (3 million USD), respectively. Moreover, in an attempt to explain the determinants of willingness to pay (WTP) statements, it was found that both behavioural and attitudinal factors affect WTP positively. The study also found distance decay, where WTP statements decreased with increased distance. And rather interestingly, male respondents tend to pay more than their female counterparts. Two other socioeconomic factors which affected WTP positively and significantly are education, partly because it can lead to a well paying and stable job, and normally raises the awareness of citizens towards environmental conservation, as well as income.

Clustering multidimensional sequences in spatial and temporal databases

Many environmental, scientific, technical or medical database applications require effective and efficient mining of time series, sequences or trajectories of measurements taken at different time points and positions forming large temporal or spatial databases. Particularly the analysis of concurrent and multidimensional sequences poses new challenges in finding clusters of arbitrary length and varying number of attributes. We present a novel algorithm capable of finding parallel clusters in different subspaces and demonstrate our results for temporal and spatial applications. Our analysis of structural quality parameters in rivers is successfully used by hydrologists to develop measures for river quality improvements.

Valuing environmental benefits from river quality improvements

A deficiency in current approaches to meeting environmental expectations is the lack of a sound, consistent methodology by which the environmental benefit may be quantified in economic terms thereby enabling cost benefit/cost ratios to be determined and included in the decision making process. This is being addressed in the UK through a programme of collaborative research involving the Dept of the Environment, the Water Services Association and the environmental and economic regulators. An Interim Benefit Assessment Manual has been produced and is being evaluated by case studies, reporting in 1995 with a revised version of the Manual planned to be available in 1996.

Valuing environmental benefits from river quality improvements

Current approaches to meeting environmental expectations lack a sound, consistent methodology by which the environmental benefit may be quantified in economic terms, thereby enabling cost benefit/cost ratios to be determined and included in the decision-making process. This is being addressed in the United Kingdom through a programme of collaborative research involving the Department of the Environment, the Water Services Association and the Environmental and Economic Regulators. An Interim Benefit Assessment Manual has been produced and is being evaluated by case studies, reporting in 1995 with a revised version of the manual planned to be available in 1996.

Valuing environmental benefits from river quality improvements

Current approaches to meeting environmental expectations lack a sound, consistent methodology by which the environmental benefit may be quantified in economic terms, thereby enabling cost benefit/cost ratios to be determined and included in the decision-making process. This is being addressed in the United Kingdom through a programme of collaborative research involving the Department of the Environment, the Water Services Association and the Environmental and Economic Regulators. An Interim Benefit Assessment Manual bas been produced and is being evaluated by case studies, reporting in 1995 with a revised version of the manual planned to be available in 1996.