Assessing the sustainability of water companies: A synthetic indicator approach

Performance indicators (PIs) are essential in the benchmarking process used to rate and rank water companies. However, a set of individual PIs does not provide a holistic assessment of company performance from multiple perspectives. A multidimensional evaluation of the performance of water companies can be achieved by aggregating the PIs into a synthetic indicator. Although the concept of sustainability involves economic, environmental and social criteria, most of the previous studies have not considered these three dimensions simultaneously. This paper discusses a process of indicator aggregation using two approaches based on multi-criteria decision analysis to evaluate and compare the sustainability of water companies from a holistic perspective. A synthetic indicator embracing economic, environmental and social PIs was computed for a sample of 154 Portuguese water companies. Both methods yielded similar rankings of water company sustainability. The techniques and results presented in this paper may be utilized as a means of improving the benchmarking process in regulated water industries, as well as providing valuable contributions to decision-makers on the most efficient steps for improving the sustainability of urban water services.     

A sensitivity analysis to methodological variation in indicator-based urban sustainability assessment: a Quebec case study

Methodological factors are often acknowledged for their impact on the urban sustainability assessment outcomes. The significance of this impact, however, divides those who assign it great importance; to the point of compromising any attempt at sustainability benchmarking using indicators, from those who regard it as having a relatively limited role. In this paper, we aim to contribute to this debate by assessing how methodological choices could influence the variation in the outcomes of indicator-based urban sustainability benchmarking. The paper starts with a literature review outlining the evolution of the approaches adopted since the pioneering experiences in the ‘90s to show a convergence in indicators and data over time. Subsequently, by using the data of the 25 most populous cities in Quebec, we empirically analyse the sensitivity of the cities’ sustainability scores to 18 combinations of estimation techniques, and observe consistency within the outcomes while maintaining general patterns regardless of the approach used. The results suggest that methodological choices play a limited role in the urban sustainability assessment outcomes. Thus, other determinants beyond the evaluation methods are most likely involved and therefore should be a major focus in future research agendas.     

Evaluating dynamics of national economies through cluster analysis within the input-state-output sustainability framework

In this paper a cluster analysis is applied to an input-state-output indicator framework that represents the interconnection of the three aspects of sustainability, namely environmental, social and economic. This framework is a useful and comprehensive tool for assessing country performances over time and improving guidelines for the classification of countries under a sustainability perspective. The method enables identification of trends and traps that characterize the evolution of countries over time. The analysis is performed for 83 countries in 2000 and 2008 in order to observe system behaviour and development patterns.     

Benchmarking the environmental performance of specialized milk production systems: selection of a set of indicators

Dairy production across the world contributes to environmental impacts such as eutrophication, acidification, loss of biodiversity, and use of resources, such as land, fossil energy and water. Benchmarking the environmental performance of farms can help to reduce these environmental impacts and improve resource use efficiency. Indicators to quantify and benchmark environmental performances are generally derived from a nutrient balance (NB) or a life cycle assessment (LCA). An NB is relatively easy to quantify, whereas an LCA provides more detailed insight into the type of losses and associated environmental impacts. In this study, we explored correlations between NB and LCA indicators, in order to identify an effective set of indicators that can be used as a proxy for benchmarking the environmental performance of dairy farms. We selected 55 specialised dairy farms from western European countries and determined their environmental performance based on eight commonly used NB and LCA indicators from cradle-to-farm gate. Indicators included N surplus, P surplus, land use, fossil energy use, global warming potential (GWP), acidification potential (AP), freshwater eutrophication potential (FEP) and marine eutrophication potential (MEP) for 2010. All indicators are expressed per kg of fat-and-protein-corrected milk. Pearson and Spearman Rho’s correlation analyses were performed to determine the correlations between the indicators. Subsequently, multiple regression and canonical correlation analyses were performed to select the set of indicators to be used as a proxy. Results show that the set of selected indicator, including N surplus, P surplus, energy use and land use, is strongly correlated with the eliminated set of indicators, including FEP (r = 0.95), MEP (r = 0.91), GWP (r = 0. 83) and AP (r = 0.79). The canonical correlation between the two sets is high as well (r = 0.97). Therefore, N surplus, P surplus, energy use and land use can be used as a proxy to benchmark the environmental performance of dairy farms, also representing GWP, AP, FEP and MEP. The set of selected indicators can be monitored and collected in a time and cost-effective way, and can be interpreted easily by decision makers. Other important environmental impacts, such as biodiversity and water use, however, should not be overlooked.     

城市生态韧性水平空间评估及其驱动力——以北京市通州区为例

随着城镇化水平的提高、城镇化进程的发展,城市生态系统逐渐变得脆弱不堪,增强城市生态韧性水平对城市发展起关键性作用。以韧性的核心内涵为基础评估城市生态韧性水平,探究城市防范化解生态风险能力在空间上的差异,从而制定分区生态治理制度,是提升城市防范化解生态风险能力的有效办法。从抵抗力、适应力和恢复力三方面构建了城市生态韧性水平空间评估模型,以2020年北京市通州区行政边界、土地利用、重点排污单位、人口等数据为例,评估了2020年北京市通州区生态韧性空间格局,并利用空间自相关模型对其分区生态治理进行研究。最后利用地理加权回归分析模型（Geographical weighted regression,GWR）进行驱动力分析,探讨社会经济层面对城市生态韧性水平空间的影响,并提出建设性建议。主要得到以下结论：（1）在空间结构上,通州区生态韧性低值区域最多,占比为52.80%,主要分布于通州区北部、东北部、中部偏西及东南部;高值区域最少,占比0.83%,零星分布于偏西部地区和偏南部地区。通州区由于缺乏相对适宜的整体规划和统筹安排,使城市生态系统的循环体系受到了负面影响,从而导致东南地区抵抗力弱。同时,近年来降水点的南移使得大量水资源在城市热岛效应的作用下流失,通州区东南部及通州大运河沿线区域内恢复力呈现出大范围低值水平。（2）通州区中心偏西北地区为副中心的核心地带,呈现低韧性水平-高排污企业密度的集聚分布情况,且生态韧性低值区域主要集聚于新华街、中仓街、玉桥街等区域,说明这些区域的环境生态风险防范化解能力比较低,需要因地制宜地对生态危机做出可持续的分区生态治理,增强区域对生态风险的调节能力。（3）结合GWR模型的驱动力分析,城市生态韧性水平主要被城市功能多样性驱动,且城市功能多样性越强,城市生态韧性水平越低,在通州区西北部的城市副中心负向影响最为显著。研究结果为城市生态韧性水平发展优化提供了理论依据,为促进国土空间合理利用和有效保护发挥积极作用。