Moderator

Paul Osmond - Associate Professor - University of New South Wales, Sydney

S11.1 - Scenario-based digital modeling of sustainable transformation processes of urban eco and material systems towards closed cycle

If we want to transform today's world towards closed circular systems, we cannot start from zero. Our world is built and it is therefore a question of transforming these existing material resources into closed cycles. This requires new processes and tools. The project initiators are of the opinion that this requires a comprehensive use of innovative, digital instruments and the virtualization of the built and designed (cultural) as well as the natural environment. Digital models of urban living spaces allow scenario-based modeling of sustainable transformation processes of urban eco and material systems, towards closed cycle systems. The first partial results of the GeoBIM project should therefore be presented as part of the event. The focus of the presentation is on the use case modeling of material resources in buildings to a comprehensive circular life cycle management of real estate, but on an urban scale. The presented GeoBIM project aims to develop, use and optimize a method for collaborative, scientific collaboration using a virtual GeoBIM-based 3D area model of the built and designed environment, which also includes all natural environmental and Vegetation elements can be modeled virtually. To create a virtual representation model of the Campus Wädenswil, all digital sources and instruments available on campus are integrated, be they existing CAD / CAFM plans, BIM models and geodata, as well as additionally generated 3D models and geodata from various 3D scanners and drone-based sensors with different imaging methods. Based on the developed GeoBIM Campus N model, this is tested in a further step via various use cases for its applicability. The range of use cases includes the following topics addressed in the funding program: Circular Economy and Life Cycle Management (material quantities and qualities represented in buildings, recyclability), SmartCity and UrbanFM applications (mobility, accessibility and accessibility) and biodiversity (presentation of the degree near-natural areas). Possible development scenarios are also modeled and simulated in the use cases. The process logic developed in the project framework intends to help municipalities and cities systematically model all important resources in a suitable level of abstraction, in order to be able to model all necessary transformation steps towards a decarbonised, sustainable and circular society. This is also the basis for the participatory and collaborative development design in the modeled virtual representation space.

Speaker

Heinz J. Bernegger - ZHAW

S11.2 - A tool to generate sanitation system planning options considering novel technologies and to quantify their resource recovery potential

Sustainable sanitation not only protects and promotes human health; it covers the entire sanitation chain from toilet to final reuse or disposal, is socially, institutionally, and financially appropriate, and closes water, nutrient, and carbon cycles. Currently, half of the global population does not have access even to safe sanitation. The situation is particular challenging in urban areas of developing countries where most of the current population growth is taking place. In these areas, conventional solutions are not viable, because they depend on costly sewer networks, long planning horizons, and stable institutions. This has triggered massive investments in the development of novel technology and system configurations (e.g. container-based sanitation). These innovations are more appropriate (independent from sewer, water, and energy) and more sustainable (adaptable to socio-demographic and environmental changes, allowing for resource recovery). These advantages are also being recognized in high-income countries which are facing aging infrastructure and limited capacity. But more technologies, also increases planning complexity: How can they be assembled into entire systems and what is their performance in different situations? To address such questions, we have developed the SANITation system Option GeneratOr (Santiago) a tool that enables the consideration of novel technologies when generating sanitation system options for strategic planning. Santiago contains several algorithms and a library characterising over 41 technologies based on literature and expert knowledge. The required user inputs, developed as part of the planning process, are a (i) list of objective screening criteria (e.g. water availability) and (ii) the desired number of sanitation options depending on the capacity of the planning process (e.g. 3 to 30). Santiago then assists with four steps: it (1) identifies all appropriate technologies by comparing the profiles of potential technologies to the application case profile; (2) generates all possible system configurations (typically more than 100’000); (3) selects a divers set of locally appropriate sanitation system options of manageable size; and (4) quantifies resource recovery potentials and losses as input into further evaluation using e.g. using multi-criteria analysis. Several case studies revealed that Santiago bring a number of advantages. It is automated and can therefor deal with a very diverse and large set of options. It applies a systematic evaluation method, maintaining transparency and accountability. It explicitly considers uncertainties related to technologies and the application case. It matches international expert and literature data with local conditions. And it is flexible for future technology innovations. To make Santiago available to practice, we are in process of equipping it with an interactive user interface and data management system. This can be complemented with a full-scale reference application, a training package, and a business model for its dissemination. To reach the SDG 6, sustainable sanitation for all, city sanitation plans that provide a mix of different sanitation system options appropriate to the different urban zones (e.g. centre, informal dense, peri-urban) and optimizing the use of natural resources. This tool could provide a starting point for such a city-wide inclusive sanitation (CWIS) planning framework.

Speaker

Dorothee Spuhler - Researcher - Eawag

S11.3 - Swimming in urban rivers: development of a Bayesian belief network to predict public health risk to recreational users

The Parramatta River in Sydney, Australia is the focus of a coordinated effort between local governments, state agencies, and community groups to transform this waterway into a recreational asset by 2025. Impaired water quality, community receptivity and physical site constraints are being addressed via interdisciplinary research projects and planning initiatives. These include advancing methods for assessing recreational water quality and investigating the treatment performance of green infrastructure for microorganisms of concern to public health. This paper presents lessons from one such collaborative research project, currently underway, between the University of New South Wales, Sydney Water, and Beachwatch NSW to develop a predictive model for use as a tool within the assessment of recreational water quality at several riverine locations proposed for urban swimming. A ‘swimmable’ river has become the desired outcome for urban river restoration projects, globally. Pathogens, such as viruses, protozoa, and bacteria have several potential sources in the river. As such, establishing new bathing locations along this urban river corridor requires compliance with existing recreational water quality guidelines. A key limitation of the current approach is a safety classification system that does not account for dynamic changes in water quality. This is largely owing to the time it takes to carry out routine sampling, analysis, and reporting of Faecal Indicator Bacteria (FIB). The alternative approach proposed in this study involves the use of Bayesian networks to predict the risk to public health in real-time, based on the so-called indicator bacteria, Enterococci. This study implemented the use of Bayesian networks (BN) for reporting of water quality in three estuarine locations, planned to be opened to the public by 2021-2022. Spatial and temporal analysis of meteorological data, wet weather overflow frequencies, and enterococci data were undertaken to characterise relationships between wet weather events and enterococci levels, in sites proposed for recreation. This observed data was combined with site-specific stakeholder knowledge to inform the structure of the network. A singular Bayesian network was constructed and used to model different scenarios (wet-weather events) across the proposed swimming sites. The model was evaluated in terms of its ability to predict enterococci levels in comparison to observed data collected using the existing method. The model demonstrated capacity as a tool to complement and reduce the frequency of routine monitoring and provide more timely information to both managers and users of recreational surface waters. The ‘easy to understand’ diagrammatic interface of the model has given stakeholders insight into relationships between different real-world components of the network. Also, the BN has been designed as a foundational structure, meaning new types of data can be added, and scenarios modelled, such as the impact of green infrastructure or sewer network upgrades on swimming sites’ water quality. This accessibility and flexibility of BNs are important features for the future uptake of this approach by waterway managers.

Speaker

Simon Lloyd - PhD Candidate - University of New South Wales