The_impacts_of_urbanisation_and_climate_change_on_.pdf

Science of The Total Environment, 2016

Using historical data of climate, land-use, hydrology and water quality from four catchments located in the south of England, this study identifies the impact of climate and land-use change on selected water quantity and water quality indicators. The study utilises a paired catchment approach, with two catchments that have experienced a high degree of urbanisation over the past five decades and two nearby, hydrologically similar, but undeveloped catchments. Multivariate regression models were used to assess the influence of rainfall and urbanisation on runoff (annual and seasonal), dissolved oxygen levels and temperature. Results indicate: (i) no trend in annual or seasonal rainfall totals, (ii) upward trend in runoff totals in the two urban catchments but not in the rural catchments, (iii) upward trend in dissolved oxygen and temperature in the urban catchments, but not in the rural catchments, and (iv) changes in temperature and dissolved oxygen in the urban catchments are not driven by climatic variables.

Urban Areas and Global Climate Change, 2012

Frequency and intensity of floods and droughts are increased across the world due to global climate change. However, the responses of water quality in urban and non-urban areas to extreme weather events are not well understood. The heavy and extensive precipitation during the summer of 2011 and 2012 caused two severe floods in Beijing of China. This work evaluated the impacts of these two floods on the water quality of 10 urban lakes, 3 non-urban reservoirs, and 8 non-urban rivers through comparing the pre-flood and post-flood water quality as well as those in reference period (2006 ~ 2010). Results indicated that the lagging response of water quality to flood is more significant in non-urban areas than the urban areas. In addition, comprehensive pollutant index (CPI) during the first flood period in most sites were much higher than the reference values with the average increasing rate of 46%. The values of chemical and biological oxygen demand were elevated in most sites; total nitrogen in the non-urban areas and total phosphorous in the urban areas were higher than those in the reference period. The different responses of nitrogen and phosphorus to the flood events of the two areas were mainly due to the high nitrogen contents in non-urban soils and high phosphorus contents in the urban soils. Whereas, most pollutant concentrations during the second flood period were lower than the first flood period, or even lower than the reference period. This can be explained by that the first flood, belonging to the post-drought flood, scoured the land surface and brought plenty of pollutants into the aquatic environments, and the non-point source pollution caused by the second flood was less effective and mainly reflected as dilution effect. This study suggests that the response of surface water quality to floods caused by climate change will differ between urban and non-urban areas, as well as among different flood events.

Water Science and Technology, 2005

Engineering infrastructure is provided at high cost and is expected to have a useful operational life of decades. However, it is clear that the future is uncertain. Traditional approaches to designing and operating urban storm drainage assets have relied on past performance of natural systems and the ability to extrapolate this performance, together with that of the assets across the usable lifetime. Whether or not climate change is going to significantly alter future weather patterns in Europe, it is clear that it is now incumbent on designers and operators of storm drainage systems to prepare for greater uncertainty in the effectiveness of storm drainage systems. A recent UK Government study considered the potential effects of climate and socio-economic change in the UK in terms of four future scenarios and what the implications are for the performance of existing storm drainage facilities. In this paper the modelling that was undertaken to try to quantify the changes in risk, tog...

Water Research, 2018

Climate change and urbanization are key factors affecting the future of water quality in urbanized catchments. The work reported in this paper is an evaluation of the combined and relative impact of climate change and urbanization on the water quality of receiving water bodies in the context of a highly urbanized watershed served by a combined sewer system (CSS) in northern Italy. The impact is determined by an integrated modeling study involving two years of field campaigns. The results obtained from the case study show that impervious urban surfaces and rainfall intensity are significant predictors of combined sewer overflows (CSOs) and consequently of the water quality of the receiving water body. Scenarios for the year 2100 demonstrate that

Computers, Environment and Urban Systems, 2019

In order to assess the potential future impacts of climate change on urban areas, tools to assist decision-makers to understand future patterns of risk are required. This paper presents a modelling framework to allow the downscaling of national-and regional-scale population and employment projections to local scale land-use changes, providing scenarios of future socioeconomic change. A coupled spatial interaction population model and cellular automata land development model produces future urbanisation maps based on planning policy scenarios. The framework is demonstrated on Greater London, UK, with a set of future population and land-use scenarios being tested against flood risk under climate change. The framework is developed in Python using open-source databases and is designed to be transferable to other cities worldwide.

2009

Preface Contents 1. Introduction…..4 2. The ecological issue…..7 2.1. Urban runoff waters…..8 2.2. Northern conditions…..10 2.3. Impacts of climate change on urban hydrology…..13 2.3.1. Quantitative impacts…..13 2.3.2. Qualitative impacts…..14 2.4. Impacts of land use on runoff quality and ecosystem services…..15 3. Economic issues related to urban land-use, productivity and climate…..16 3.1. Productivity and urban form…..17 3.2. Examples of factors affecting urban structures…..18 3.3. Remarks on Finland and the Helsinki Region…..18 3.4. Urban structures, climate change and runoff waters…..20 4. Social issues in the context of the Helsinki Metropolitan Area.....22 4.1. The planning apparatus: structure, ethos and previous results…..23 4.2. Metropolisation as a structural change…..24 4.3. New differentiation…..27 5. Synthesis: the paradoxes in ecological, economic and social terms in relation to climate change, urbanization and hydrological cycles…..29 VACCIA/Action 6 working group members and their contributions to this report…..31 Tiivistelmä…..32 References…..34

2004

Effective urban resource planning and management entails the mitigation of the impacts of urbanisation on the water environment. The significance stems from the fact that water environments are greatly valued in urban areas as environmental, aesthetic and recreational resources and hence are important community assets. Urbanisation has a profound influence on stormwater runoff quality. This is due to changes to the hydrology of the catchment and the introduction of pollutants resulting from various anthropogenic activities common to urban areas. Though the sources and causes of stormwater pollution are known, its control constitutes an intractable challenge in the drive towards sustainable human settlements.

2012

Climate change is expected to affect precipitation patterns and may therefore impact upon water resource availability. The city of Birmingham in central England receives its public water supply from a catchment in the Elan Valley, mid-Wales. Baseline and future climate projections generated from a stochastic weather generator within the United Kingdom Climate Projections 2009 and a daily soil water balance model (WaSim) were used to determine the potential impacts of climate change on hydrologically effective rainfall (HER). Annual HER is likely to decrease from baseline conditions (> 90% likelihood that HER will be reduced), with more frequent and persistent very dry spells and increasing seasonality. It is concluded that climate change will put additional stress on water resources for the city of Birmingham so that, coupled with expected increases in demand, adaptation measures to increase supply and/or reduce demand are likely to be needed.

Pipelines 2011: A Sound Conduit for Sharing Solutions - Proceedings of the Pipelines 2011 Conference, 2011

It has been widely recognized that global climate change will have negative impacts not only on the natural environment but also on the human-built environment. This paper describes the framework developed to assess the potential impacts of climate change and urbanization on drainage systems of Australian urban cities. One of real concerns is how the flooding risk will change over the next 5-25 years under such possible impacts. In this study, the assessment method is explored with regards to two major effects of climate change (i.e. changed pattern of storm event and rising sea level), two effects of urbanization (i.e. increasing impervious area and storm water harvesting) and two effects of hydraulic deterioration (i.e. reduced cross-sectional area and increased internal surface roughness of conduits). The framework is demonstrated on a simulation study at street. The outcomes of this study will provide preliminary understanding on how drainage systems respond to changing climate inputs and also guided steps to implement the framework on real-world problems.

This report is the first in a series of reports focussing on the water quality impacts of urbanisation. The primary objectives of this report has been to critically review relevant published research, to identify important areas where there is a current lack of in-depth knowledge and to define future research directions. It is common knowledge that urbanisation can lead to significant water quantity and quality impacts. Past research into quantity impacts have resulted in an in-depth understanding of these issues and acceptable reliability in commonly available predictive approaches. However this is not the case for water quality impacts. The underlying processes and concepts relating to urban water quality are well known in a qualitative sense. However their quantification has proved to be extremely difficult. This is a major failure in most research studies. As a result, attempts to correlate land use to pollutant loadings have been inconclusive. A limitation in current urban wate...