Managing uncertainty in integrated environmental modelling:the UncertWeb framework

Web-based distributed modelling architectures are gaining increasing recognition as potentially useful tools to build holistic environmental models, combining individual components in complex workflows. However, existing web-based modelling frameworks currently offer no support for managing uncertainty. On the other hand, the rich array of modelling frameworks and simulation tools which support uncertainty propagation in complex and chained models typically lack the benefits of web based solutions such as ready publication, discoverability and easy access. In this article we describe the developments within the UncertWeb project which are designed to provide uncertainty support in the context of the proposed ‘Model Web’. We give an overview of uncertainty in modelling, review uncertainty management in existing modelling frameworks and consider the semantic and interoperability issues raised by integrated modelling. We describe the scope and architecture required to support uncertainty management as developed in UncertWeb. This includes tools which support elicitation, aggregation/disaggregation, visualisation and uncertainty/sensitivity analysis. We conclude by highlighting areas that require further research and development in UncertWeb, such as model calibration and inference within complex environmental models

Accessibility to green space in the Melbourne metropolitan area.

Demand for green space by the public is becoming stronger for aesthetic enjoyment, recreation, clean air and quiet environment. Green space can protect biodiversity, absorb pollutants, adjust urban temperature and increase urban residents’ longevity. Accessibility to green spaces has been regarded as a useful measure of the quality of life in urban areas. Adequate and equitable accessibility to green space for all residents in urban areas is an important planning objective in many urban areas in the world, including the Melbourne Metropolitan Area (MMA), to sustain urban residents’ quality of life and well-being. The relative contributions of different kinds of facilities to the attractiveness of a green space have been weighted in relation to four population groups, determined from the 2011 ABS census data, including young (aged 0-15), adult (aged 16-64), aged (aged 65+), and total (aged 0-115). The accessibility values to neighbourhood green spaces for the four groups of population from each Mesh block (MB) across the MMA are measured with the following four different methods: M2SFCA_G, the 2-step floating catchment area modified by the Gaussion function; M2SFCA_B, the 2-step floating catchment area modified by the Butterworth filter; M3SFCA_G, the 3-step floating catchment area modified by the Gaussion function; and M3SFCA_B, the 3-step floating catchment area modified by the Butterworth filter.. According to MB level accessibility measured with the modified floating catchment area method, on average, the percentage of population with relatively high, Medium +, Medium, Medium -, and low accessibility to green space is about 21.2%, 18.5%, 25.6%, 18.7%, and 16.2%, These findings should provide valuable evidence for urban planners and public policy makers as well as the general public for formulating future urban plans. The methodology developed in this study should be applicable to other metropolitan areas within and even beyond Australia, should the required datasets are readily available and accessible. The thesis also includes some discussions about the relative merits of the four different floating catchment area based methods and some recommendations for future researches