Maximising the value of natural capital in a changing climate through the integration of blue-green infrastructure

© 2020, International Centre for Sustainable Development of Energy, Water and Environment Systems SDEWES. All rights reserved. Australia’s natural capital is under growing cumulative pressure from land use change and intensive agriculture, fishery, forestry, and urban sprawl. This consequently reduces the benefits and services that it provides. This paper firstly assessed how current trends of land-use change have an impact on the natural capital loss in South Victoria, Australia during 2006-2016. Then in order to increase natural capital inherent value and to ensure that natural capital is multifunctional, a system of Blue-Green Infrastructure is designed within the current natural capital of Tarwin Lower, in Victoria. Given that natural capital area is declining in Australia, incorporating designed elements into existing natural capital to create multifunctional natural capital, enables maximising the supply and value of ecosystem services in order to meet the demands of a growing population. Here, three ecosystem services (stormwater abatement, water quality improvement, and water supply services) were compared in terms of existing natural capital or with integrated Blue-Green Infrastructure elements to create multifunctional natural capital system. The results indicate that planning Blue-Green Infrastructure will enhance multiple aspects of regional sustainability and resilience in the Tarwin catchment and will maximise the multifunctionality of the natural capital. Finally, the paper simulates the cost-benefit analysis for the implementation of Blue-Green Infrastructure to show that it is a cost-effective and sustainable solution to cope with the current demographic, economic and agricultural trends, which affect natural capital. This paper confirms that in order to provide ecosystem services for extra demands of growing inhabitants, Blue-Green Infrastructure networks require to be extended in the Victoria State of Australia to compensate natural capital and ecosystem service losses due to the regional and urban development.