Losing stormwater: 60 years of urbanisation and reduced downstream flow

The potential for stormwater to supplement traditional water supplies from upstream catchments or groundwater is high, with claims that the quantity of additional runoff from impervious surfaces in a modern city in a temperate climate is greater than the total potable water demand. To ensure the success of Integrated Urban Water Management, it must consider the broad context of catchment management and the cumulative effect of all factors including river health. Ballarat, an inland city of approximately 100,000 people in south-eastern Australia, has many attributes necessary to potentially exploit stormwater. Given the doubling of population, tripling of residences and 90% increase in average residence size over the past 60 years, over which time flow data is available for the downstream waterway, it might be expected that the flow in the river downstream of the city within the catchment would reflect additional stormwater runoff. However, no increase in flow was detected between 1957 and 1996 while flow over the past 20 years has reduced by 60%. A water balance shows this decrease was not due to extractions as the stream has been a consistent net receiver of water from other catchments. Modelling data from the Australian Water Resources Assessment indicates that the reduction in streamflow is double what might be expected due to climatic variations. Between 1957 and 1996 there was no significant difference between modelled runoff and actual flow, however from 1997 onwards there is a significant divergence. While lower runoff may be expected during the period of drought, the rainfall-runoff relationship does not return to previous levels during latter years of rainfall. The effect is greater during higher flow months, which has significance when identifying potential additional water resources. Base flow has been reduced to the point where dry weather flow is reliant on waste water treatment plant and mine discharge. This study indicates that while impervious surfaces generate higher runoff which can cause environmental damage, making stormwater an attractive water source, consideration must be given to the impacts on the whole catchment when assessing alternative supply options

Exploring a flow regime and its historical changes downstream of an urbanised catchment

The rapid growth of Ballarat's urban area, an inland city of approximately 100,000 people in south-eastern Australia, suggests that it is suitable for stormwater capture and reuse. With a threefold increase in the number of dwellings in recent decades, along with a 90% increase in their average size, it should follow that there is evidence of more flow being generated from the urban areas. However, while additional runoff from the growth of impervious areas may be occurring, the overall flow in the receiving river has dramatically reduced with a 60% decrease in the rainfall-runoff relationship since 1997. This reduction in river flow seems disproportionate to any association with the Millennium Drought which occurred during 1997 to 2009. The evidence of river flow has been complicated by other changes in the catchment. A change in the rainfall-runoff relationship has been identified in other similar catchments, and may lead to significant impacts on water resource management over the long term. To better understand the impacts on river flow downstream of an urbanised catchment, the flow has been partitioned into various components over time using the daily stream flow data available from 1957. Base flow, calculated as the stream flow after periods of four or more days without rain, has decreased. Transfers, predominantly from other catchments for use as potable supply and entering the river via the waste water treatment plant, have remained steady, but now make up the vast majority of dry weather flow. While climatic variations have impacted the river significantly the actual streamflow reduction has been twice that predicted by data from the Australian Water Resources Assessment. A significant increase in the number of small farm dams due to the expansion of peri-urban living around Ballarat explains a further portion of the flow reduction. This paper highlights multiple factors which influence river flow and demonstrates how increases in urbanised area do not necessarily create additional river flow at larger aggregate scales. The investigation therefore provides a cautionary tale around assumptions of stormwater harvesting and any perceived benefit to river flow, and provides insights into the importance of collecting water information of the correct type and scale to help inform future integrated urban water management efforts

Patient, general practitioner and oncologist views regarding long-term cancer shared care

Background: The rising incidence of cancer and increasing number of cancer survivors place competing demands on specialist oncology clinics. This has led to a need to consider collaborative care between primary and secondary care for the long-term post-treatment care of cancer survivors. Objective: To explore the views of breast and colorectal cancer survivors, their oncologist and GP about GPs taking a more active role in long-term cancer follow-up care. Methods: Semi-structured interviews using a thematic analysis framework. Respondents were asked their views on the specialist hospital-based model for cancer follow-up care and their views on their GP taking a greater or leading role in follow-up care. Researcher triangulation was used to refine the coding framework and emergent themes; source triangulation and participant validation were used to increase credibility. Results: Fifty-six interviews were conducted (22 patients, 16 oncologists, 18 GPs). Respondents highlighted the importance of GPs needing specialist cancer knowledge; the need for GPs to have an interest in and time for cancer follow-up care; the GPs role in providing psychosocial care; and the reassurance that was provided from a specialist overseeing care. A staged, shared care team arrangement with both GPs and specialists flexibly providing continuing care was found to be acceptable for most. Conclusion: Collaborative care of cancer survivors may lessen the load on specialist oncology clinics. The findings suggest that building this model will require early and ongoing shared care processes

When Two Become One: The Limits of Causality Analysis of Brain Dynamics

Biological systems often consist of multiple interacting subsystems, the brain being a prominent example. To understand the functions of such systems it is important to analyze if and how the subsystems interact and to describe the effect of these interactions. In this work we investigate the extent to which the cause-and-effect framework is applicable to such interacting subsystems. We base our work on a standard notion of causal effects and define a new concept called natural causal effect. This new concept takes into account that when studying interactions in biological systems, one is often not interested in the effect of perturbations that alter the dynamics. The interest is instead in how the causal connections participate in the generation of the observed natural dynamics. We identify the constraints on the structure of the causal connections that determine the existence of natural causal effects. In particular, we show that the influence of the causal connections on the natural dynamics of the system often cannot be analyzed in terms of the causal effect of one subsystem on another. Only when the causing subsystem is autonomous with respect to the rest can this interpretation be made. We note that subsystems in the brain are often bidirectionally connected, which means that interactions rarely should be quantified in terms of cause-and-effect. We furthermore introduce a framework for how natural causal effects can be characterized when they exist. Our work also has important consequences for the interpretation of other approaches commonly applied to study causality in the brain. Specifically, we discuss how the notion of natural causal effects can be combined with Granger causality and Dynamic Causal Modeling (DCM). Our results are generic and the concept of natural causal effects is relevant in all areas where the effects of interactions between subsystems are of interest

Comparing Notes: Recording and Criticism

This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edison’s Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice

Wider Still and Wider: British Music Criticism since the Second World War

This chapter provides the first historical examination of music criticism in Britain since the Second World War. In the process, it also challenges the simplistic prevailing view of this being a period of decline from a golden age in music criticism

The journey to a water sensitive city - a case study of Ballarat, Victoria, Australia

Water security is a vital part of ensuring a sustainable future. This is particularly true for many cities in Australia where relatively low rainfall, population growth and climate change places communities under water stress. The 'Water Sensitive City' is one in which water is drawn from a range of water supplies and that sustainably interacts with its surrounding environment. Every city has a unique water history in which the economic, environmental and social history have impacted on the development of water management. Tracking the evolution of water management of a city from its initial stages can provide information regarding the journey towards a Water Sensitive City. Water management in Ballarat has been tracked from the establishment of the first water supply to the city in the 1850's until 2015 using historical records from the local water authority. These records show that Ballarat generally followed the classical water development model with the introduction of water supply, sewerage and water treatment. Water use in Ballarat increased dramatically from 1941 until 1980, in line with increased standards of living as expected. However, after this time water use decreased despite continued population growth, and commercial water use decreased as a percentage of total use and external water use also declined. The reasons behind the decline in water use since 1980 may contain lessons that can be used in the establishment of Water Sensitive Cities

An unexpected decrease in urban water demand : Making discoveries possible by taking a long-term view

Forecasting supply and demand is fundamental to the sustainability of the water system. Demand for urban water seems on an ever-upward trajectory, with use increasing twice as quickly as population throughout the 20th century. However, data from Ballarat, a city in south-eastern Australia, show that despite this conventionally held wisdom, total water usage actually peaked over 30 years ago. While the 1997–2009 ‘Millennium Drought’ had some effect, the decline commenced many years before. Initially, this was due to a reduction in external domestic water use, which correlates well with an increase in water price. However, the effect was found to not be purely economic as the price was not volumetric-based. Internal water use seems more affected by technological advances and regulatory controls. Interestingly, there was no relationship found between rainfall and water demand. The role of price, water-reduction education programmes, water-efficient technology and regulation supports previous research that a multifaceted approach is required when developing demand-reduction policies and strategies. This finding emphasises the importance of understanding the component of consumptive behaviour being targeted, and ensuring that policies being implemented are appropriate for the desired behavioural change