Modelling the role of SuDS management trains to minimise the flood risk of new-build housing developments in the UK

In a changing climate with an increasing risk of flooding, developing a sustainable approach to flood management is paramount. Sustainable Drainage Systems (SuDS) present a change in thinking with regards to drainage; storing water in the urban environment as opposed to rapidly removing it to outflows. The Non-Statutory Standards for SuDS (DEFRA 2015a) presented a requirement for all developments to integrate SuDS in their design to reduce runoff. This research models the impact on water quantity of combining different SuDS devices to demonstrate their success as a flood management system, as compared to conventional pipe based drainage. The research uses MicroDrainage®, the UK industry standard flood modelling tool which has an integrated SuDS function, to simulate the role of SuDS in a management train. As space is often cited as the primary reason for rejecting SuDS, determining the most effective technique at reducing runoff is critical. Detention basins were concluded as being highly effective at reducing peak flow (150 l/s when combined with swales), however Porous Pavement Systems (PPS) was nearly twice as effective per m3, reducing peak flow by up to 0.075 l/s/m3 compared to 0.025 l/s/m3. This therefore suggests that both detention basins and PPS should be high priority devices when developing new sites, but that no matter what combination of modelled SuDS are installed a reduction in runoff in comparison to conventional drainage can be achieved. A SuDS decision support tool was developed to assist design in MicroDrainage® by reducing the time spent determining the number of SuDS required for a site. The tool uses outputs from MicroDrainage® to rapidly predict the minimum and maximum peak flow for a site, in comparison to greenfield runoff, based on the site parameters of area, rainfall rate, infiltration, combined with the planned SuDS. The tool was underpinned by a model analysis for each site parameter and each SuDS device, which produced r2 values >0.8, with 70% above 0.9. This ensured a high level of confidence in the outputs, enabling a regression analysis between runoff and each site parameter and SuDS device at the 99% confidence level, with the outputs combined to create the tool. The final aspect of the research validated MicroDrainage® to analyse the accuracy of the software at predicting runoff. Using field data from Hamilton, Leicester, and laboratory data for PPS and filter drains, a comparison could be made with the output from MicroDrainage®. The field data created a Nash-Sutcliffe Efficiency (NSE) of 0.88, with filter drains and PPS providing an NSE of 0.98 and 0.94 respectively. This demonstrates the success with which MicroDrainage® predicts runoff and provides credibility to the outputs of the research. Furthermore, it offers SuDS specialists the confidence to use MicroDrainage® to predict runoff when using SuDS

Innovative Concepts and Applications for Smart Water Cities

Smart cities are emerging worldwide, including economic, institutional, social, and technical concepts in interaction with existing infrastructure to achieve sustainability and increase quality of life. Additionally, digitalisation projects in the field of urban water infrastructure (UWI) aim to increase capacity of existing infrastructure to deal with future challenges caused by climate change, growing of urban population, and maintenance. Therefore, efficient and reliable information- and communication technologies (ICT) represent a key factor for the exchange of measurement data (e.g., monitoring environmental parameters) and interconnections between different participants. However, ICT and system-wide management are not yet widely deployed and mainly concentrated on main points in network-based UWI (e.g., combined sewer overflows, inlet point of district meter areas). In this context, especially the Internet of Things (IoT) concepts enables a large-scale implementation of measurement devices even at underground and remote structures, increasing data availability significantly. Following, new possibilities in the management of network-based UWI are emerging. The research aim of this doctoral dissertation is to contribute to the ongoing development of smart water cities by developing innovative concepts in the field of urban drainage and water distribution network including nature-based solutions

Optimizing Low Impact Development Controls for Sustainable Urban Flood Risk Management

Increased urbanization and a changing climate are contributing to an increased urban flood risk. Low Impact Development (LID) is a green infrastructure approach to help mitigate this risk. Analysis of flooding potential and socioeconomic factors of an urban area are essential in determining how to best implement these controls. The objectives of the study was to identify the most prominent areas for LID implementation and develop a framework for identifying LID controls within a multiobjective optimization framework. Coupled risk assessment and socioeconomic analysis was used to determine the potential areas to implement LID controls to achieve continuous benefits. A risk assessment methodology was developed to delineate the greatest flooding risk areas in sewersheds. A socioeconomic analysis framework was then adapted to assess the areas that would be most likely to adopt and successfully maintain LID controls. A simulation-optimization framework was then developed by coupling Stormwater Management Model (SWMM 5) with the Borg Multiobjective Evolutionary Algorithm (MOEA). This methodology analyzed different LID implementation solutions with a cost function to determine the most cost effective LID solutions. The PCSWMM interface was used to create the model for a large urban sewershed in Windsor, Ontario, Canada. The model tested LID measures against eight different scenarios consisting of both historical climate data and future predicted climate change data with the objectives of reducing peak flows in the sewer system, reducing total runoff across the sewershed and minimizing the cost of LID implementation. The results provide stormwater management professionals and decision makers cost-benefit information for different LID implementation scenarios to help assess the feasibility of LID in this area and to make infrastructure investment decisions

Hydronomic zones for developing basin water conservation strategies

Water conservation / River basins / Groundwater / Case studies / Irrigation / Water management / Water use efficiency / Sri Lanka / India / Egypt / Turkey / Kirindi Oya / Nile River / Bhakra Irrigation System / Gediz Basin

Modelling data of an urban drainage design using a Geographic Information System (GIS)database

This paper describes the development of a model to interface a planned urban drainage system with Geographic Information System (GIS)through the introduction of open-source tools; Auto Numbering and Get Elevation to extract essential data from GIS and Excel2GIS to bridge the output data between GIS and the drainage design program. Creating a range of essential data from digital database repositories aids the development of decision-support tools for urban planners in a simulation of different urban drainage scheme scenarios and moderates the interference with other infrastructure utilities. These tools, modelled with design software and GIS platform, are tested in two case studies; the results revealing essential improvements in accuracy of output, time taken to prepare and run the model and model presentation which visualised the hydraulic design results and global location of the drainage layout on an urban master plan. © 2019 Elsevier B.V

Doctor of Philosophy

dissertationThere is a need to improve the methods involved with targeted implementation and design of distributed, watershed-scale low impact development (LID) practices. The goal of this dissertation was to improve the targeted implementation and design of distrib

Impacts of land developments and land use changes on urban stormwater management

With the rapid urbanization happening around the world, the nature of the natural hydrological cycle has been changed and it causes many adverse effects like urban flooding, erosion and degradation of water quality in urban areas. Due to the increasing population, urbanization will continue rapidly and this increases impervious lands which generate more runoff. Anthropogenic climate change has influenced the strength of storm events and reduced the recurrent intervals. Current urban stormwater management systems are becoming increasingly lacking with rapidly increasing demands and climatic effects. Groundwater has been found as a key factor in creating inadequacy in urban drainage to carry stormwater runoff in catchments having a shallow groundwater table. Water sensitive urban design (WSUD) and modifications to urban stormwater management systems (USWMSs) according to the best management practices (BMP) should be implemented after systematic analysis to overcome the situation.This study has focused on assessing urban land development activities and changing patterns of land use in urban areas as the main anthropogenic stress on urban hydrology. In addition, the adaptation to natural phenomenon such as climate change has been studied. A numerical hydrological model was used to analyse the behaviour of catchments and their characteristics. Urban flood identification and prevention was one of the major concerns of this study. Several urban stormwater drainage systems have been assessed under three case studies.The stormwater drainage system of Canning Vale Central catchment, which is one of the urban catchments in Western Australia, has been assessed by using numerical modelling in case study number one. The model was developed by using existing mapped data and data collected from an ongoing telemetric observation system and several field visits. Surface runoff has been routed by using different modelling techniques such as hydrological surface runoff and two-dimensional (2D) surface runoff modelling. Groundwater has been treated as a critical issue during the modelling. The effects of land use changes and their sensitivity to the USWMS have been assessed. Necessary recommendations to improve the USWMS and mitigate localised flood issues have been given. Flood vulnerability maps have been developed to identify the critical areas where there is the potential to be flooded under different Average Recurrent Interval (ARI) events. These flood vulnerability maps will be used by the local authorities to develop recommendations and guidelines for future developments of infrastructure during land development and subdivision works.The urban ungauged catchment of Victoria Park in Western Australia has been assessed by using a 2D surface runoff routing model. The catchment has built flood storage areas (stormwater basins) and the inadequacy of them in protecting against recent storm events has caused local concern. The area has been developed rapidly in recent decades and land use has been changed to more impervious surfaces than was expected at the time the basins were designed. These changes to the land use—together with anthropogenic climate change—has caused runoff from rapid storms to exceed the basin top water level. The catchment‘s existing stormwater basins‘ capacities were assessed against different ARI events during case study number two. Flood vulnerability maps and water level contours have been developed to identify the possible inundations and flood depths of basins and surrounding areas.The overall study is based on hydrological modelling of different USWMSs and urban hydrology. Land use change was considered as the main anthropogenic stress upon urban hydrological catchments. Factors such as encountering groundwater in stormwater drainage have been analysed to support the study. Recommendations based on WSUD and BMPs have been given to mitigate the adverse effects of urban land use changes to urban stormwater management