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Utz R.M.,Chatham University | Hopkins K.G.,National United University | Beesley L.,University of Western Australia | Beesley L.,Cooperative Research Center for Water Sensitive Cities | And 5 more authors.
Freshwater Science | Year: 2016

Urbanization substantially changes the physicochemical and biological characteristics of streams. The trajectory of negative effect is broadly similar around the world, but the nature and magnitude of ecological responses to urban growth differ among locations. Some heterogeneity in response arises from differences in the level of urban development and attributes of urban water management. However, the heterogeneity also may arise from variation in hydrologic, biological, and physicochemical templates that shaped stream ecosystems before urban development. We present a framework to develop hypotheses that predict how natural watershed and channel attributes in the pre-urban-development state may confer ecological resistance to urbanization. We present 6 testable hypotheses that explore the expression of such attributes under our framework: 1) greater water storage capacity mitigates hydrologic regime shifts, 2) coarse substrates and a balance between erosive forces and sediment supply buffer morphological changes, 3) naturally high ionic concentrations and pH pre-adapt biota to waterquality stress, 4) metapopulation connectivity results in retention of species richness, 5) high functional redundancy buffers trophic function from species loss, and 6) landuse history mutes or reverses the expected trajectory of eutrophication. Data from past comparative analyses support these hypotheses, but rigorous testing will require targeted investigations that account for confounDing or interacting factors, such as diversity in urban infrastructure attributes. Improved understanDing of the susceptibility or resistance of stream ecosystems could substantially strengthen conservation, management, and monitoring efforts in urban streams. We hope that these preliminary, conceptual hypotheses will encourage others to explore these ideas further and generate additional explanations for the heterogeneity observed in urban streams. © 2016 by The Society for Freshwater Science.

Cardell-Oliver R.,Cooperative Research Center for Water Sensitive Cities | Cardell-Oliver R.,University of Western Australia
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Conserving water is a critical problem and characterising how households in communities use water is a first step for reducing consumption. This paper introduces a method for discovering habits in smart water meter time series. Habits are household activities that recur in a predictable way, such as watering the garden at 6 am twice a week. Discovering habit patterns automatically is a challenging data mining task. Habit patterns are not only periodic, nor only seasonal, and they may not be frequent. Their recurrences are partial periodic patterns with a very large number of candidates. Further, the recurrences in real data are imperfect, making accurate matching of observations with proposed patterns difficult. The main contribution of this paper is an efficient, robust and accurate Habit Detection Algorithm (HDA) for discovering regular activities in smart meter time series with evaluation the performance of the algorithm and its ability to discover valuable insights from real-world data sets. © Springer International Publishing Switzerland 2016.

Zhang K.,Monash University | Zhang K.,Cooperative Research Center for Water Sensitive Cities | Randelovic A.,University of Belgrade | Page D.,CSIRO | And 4 more authors.
Ecological Engineering | Year: 2014

Stormwater harvesting is becoming a popular alternative water resource in water stressed regions. Stormwater biofilters have been recognized as being among the most promising pre-treatment technologies. In this study, a series of challenge tests were conducted as part of a validation framework of stormwater biofilters for selected micropollutants. Two biofilter configurations were studied: a configuration with loamy sand and no submerged zone (LS-noSZ) and another configuration that uses sand and a submerged zone (S-SZ). Biofilter challenge conditions were: (i) treatment volume set at 95th percentile of all treated events and (ii) the maximum and minimum durations of dry period between two events, both based on hydrology simulations using 30 years rainfall data for Melbourne. The hydraulic performance of S-SZ was stable and not affected by either prolonged wet or dry periods, while the outflow rate of LS-noSZ was largely reduced during prolonged wet periods. Biofilters had a removal efficiency of >80% for total petroleum hydrocarbons (TPHs), glyphosate, dibutyl phthalate (DBP), bis-(2-ethylhexyl) phthalate (DEHP), pyrene and naphthalene loads by both configurations under the most challenge conditions; the removal of pentachlorophenol (PCP) and phenol loads was >80% in LS-noSZ and 50-80% in S-SZ, while chloroform had load removal rates between 20% and 50%. Biofilters were less effective in removing atrazine and simazine with load removal 20-50% in LS-noSZ and <20% in S-SZ. Prolonged dry periods benefited the removal of micropollutants while very short dry periods adversely affected micropollutants removal. The study contributes to the development of the overall framework for validation of stormwater biofilters, which is required if these systems are to be applied in stormwater treatment systems for higher end water uses such as drinking water. © 2014 Elsevier B.V.

Sun J.,University of Queensland | Hu S.,University of Queensland | Sharma K.R.,University of Queensland | Sharma K.R.,Cooperative Research Center for Water Sensitive Cities | And 3 more authors.
Applied and Environmental Microbiology | Year: 2014

Simultaneous production of sulfide and methane by anaerobic sewer biofilms has recently been observed, suggesting that sulfate-reducing bacteria (SRB) and methanogenic archaea (MA), microorganisms known to compete for the same substrates, can coexist in this environment. This study investigated the community structures and activities of SRB and MA in anaerobic sewer biofilms (average thickness of 800 μm) using a combination of microelectrode measurements, molecular techniques, and mathematical modeling. It was seen that sulfide was mainly produced in the outer layer of the biofilm, between the depths of 0 and 300 μm, which is in good agreement with the distribution of SRB population as revealed by cryosection-fluorescence in situ hybridization (FISH). SRB had a higher relative abundance of 20% on the surface layer, which decreased gradually to below 3% at a depth of 400 μm. In contrast, MA mainly inhabited the inner layer of the biofilm. Their relative abundances increased from 10% to 75% at depths of 200 μm and 700 μm, respectively, from the biofilm surface layer. High-throughput pyrosequencing of 16S rRNA amplicons showed that SRB in the biofilm were mainly affiliated with five genera, Desulfobulbus, Desulfomicrobium, Desulfovibrio, Desulfatiferula, and Desulforegula, while about 90% of the MA population belonged to the genus Methanosaeta. The spatial organizations of SRB and MA revealed by pyrosequencing were consistent with the FISH results. A biofilm model was constructed to simulate the SRB and MA distributions in the anaerobic sewer biofilm. The good fit between model predictions and the experimental data indicate that the coexistence and spatial structure of SRB and MA in the biofilm resulted from the microbial types and their metabolic transformations and interactions with substrates. © 2014, American Society for Microbiology.

Dobbie M.F.,Monash University | Dobbie M.F.,Cooperative Research Center for Water Sensitive Cities | Brown R.R.,Cooperative Research Center for Water Sensitive Cities | Brown R.R.,Monash Sustainability Institute | And 2 more authors.
Environmental Science and Policy | Year: 2016

In the water sensitive city, a hybrid mix of centralised and decentralised water systems and sources will operate at a range of scales to provide sustainable fit-for-purpose water services that will safeguard environmental quality, intergenerational equity and landscape amenity. Governance of these systems is likely to differ from the traditional arrangement, involving multiple stakeholders who must work together to manage risk. Trust will be essential to effective governance. This study explored attitudes of Australian urban water practitioners towards ownership and management of different water systems that might comprise the water sensitive city, including who they would trust to manage the associated risk. Results support the status quo, in which risk management responsibilities lie with state and local government or corporatised water utilities. Although practitioners support ownership and management of lot-scale water systems by homeowners, they trust them only to manage the risks associated with rainwater tanks. These results can be interpreted as risk perceptions, which are influenced by trust and knowledge. Implementation of decentralised water systems should be accompanied by governance arrangements that include strategies to enhance trust between stakeholders and to facilitate the co-production of knowledge to inform shared decision-making. © 2015 Elsevier Ltd.

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