Extraordinary flood events occurred recently in northwest England, with several severe floods in Cumbria, Lancashire and the Manchester area in 2004, 2009 and 2015. These clustered extraordinary events have raised the question of whether any changes in the magnitude and frequency of river flows in the region can be detected. For this purpose, the annual maximum series of 39 river gauging stations in the study area are analysed. In particular, non-stationary models that include time, annual rainfall and annual temperature as predictors are investigated. Most records demonstrate a marked non-stationary behaviour and an increase of up to 75% in flood quantile estimates during the study period. Annual rainfall explains the largest proportion of variability in the peak flow series relative to other predictors considered in our study, providing practitioners with a useful framework for updating flood quantile estimates based on the dynamics of this highly accessible and informative climate indicator.

Life cycle assessment (LCA) tools have been used by governments and city administrators to support the decision-making process toward creating a more sustainable society. Since LCA is strongly influenced by local conditions and may vary according to various factors, several institutions have launched cooperation projects to achieve sustainable development goals. In this study, we assessed the potential environmental enhancements within the production of road materials applied to the road network of Münster, Germany. We also compared traditional pavement structures used in Münster and alternative options containing asphalt mixtures with larger amounts of reclaimed asphalt pavement (RAP). Although the case study was conducted in Münster, the data collected and the results obtained in this study can be used for comparison purposes in other investigations. In the analysis, we considered all environmental impacts from raw material extraction to the finished product at the asphalt plant. Two environmental indicators were used: non-renewable cumulative energy demand (nr-CED) and global warming potential (GWP). The results show that using RAP increases the consumption of energy but potentially decreases the environmental impacts in terms of the nr-CED and GWP associated with the production of asphalt materials.

This study proposes an algorithm for the improvement of water distribution networks (WDNs) performance using system dynamics. In the first part, the hydraulic and environmental performance of WDNs is investigated. The hydraulic performance is assessed based on the pressure of nodes and the flow velocity in pipes. Furthermore, using life cycle assessment, an environmental performance index is proposed to examine the environmental impacts of WDNs. Moreover, in order to evaluate the overall performance in regards to the costs, a value index in the system dynamics framework is proposed. Then, based on the developed framework, improvement strategies for a WDN are assessed by applying scenarios according to constraints and requirements of the network. The considered scenarios are as follows: (1) reducing per capita water demand of the WDN; (2) decreasing the average pressure in the WDN; (3) reducing the mean age of the system by its renewing; and (4) a combination of reducing the per capita water demand and average pressure in the WDN. The results indicate that the best solutions for increasing the value index in this network are: (a) to reduce the pressure of the pressure reducing valves (PRV) from 30 to 28 m; (b) to reduce the per capita water demand by the annual rate of 0.5% and 1% and decreasing the pressure of the PRV valves together. Therefore, it is shown how the developed algorithm is a purposeful approach for evaluating and improving the performance of WDNs based on the value index.