Scenarios analysis using water-sensitive urban design principles: a case study of the Cape Flats Aquifer in South Africa
- PDF / 2,551,124 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 22 Downloads / 198 Views
REPORT
Scenarios analysis using water-sensitive urban design principles: a case study of the Cape Flats Aquifer in South Africa Siyamthanda Gxokwe 1 & Yongxin Xu 1 & Thokozani Kanyerere 1 Received: 29 May 2019 / Accepted: 19 May 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract A feasibility assessment was undertaken on the application of water-sensitive urban design (WSUD) for the Cape Flats Aquifer in Cape Town, South Africa, at the local scale. The study contributes towards the planning of water-sensitive cities in the future. A three-dimensional steady-state groundwater flow model was applied to the Cape Flats Aquifer to predict WSUD scenarios by incorporating managed aquifer recharge (MAR). Analysis of the scenarios of varying recharge estimates and groundwater abstraction rates, predicted using the model, indicated that the water-table distribution and outflows from identified groundwater balance components show direct proportionality to the varying recharge scenarios. A notable increase in these outflows was observed when the recharge rate was increased by 50%. Varying groundwater abstraction scenarios indicated that with increasing abstraction rates, water levels and outflows from groundwater balance components also decreased accordingly. A notable decline in water levels and outflows was established at an abstraction rate of 2.5 and 5 L/s, respectively. Similar to the previous regional studies in the area, the results from the predicted scenarios show that there is a potential for applying WSUD, particularly MAR, at site-specific scale within the Cape Flats Aquifer. However, shallow groundwater levels during wet seasons limit the opportunities for application of WSUD in the area. This finding would provide an important reference to the ongoing debate on the Cape Town water crisis and similar environmental conditions where WSUD is considered. Keywords South Africa . Conceptual model . Groundwater abstraction . Numerical modelling . Groundwater flow
Introduction Water-sensitive urban design (WSUD) as defined by Wong (2006) is an approach that integrates urban planning with the management, protection and conservation of the urban water cycle. The approach is aimed at ensuring that water is given due prominence during the urban design process, through the integration of interlinked approaches functioning to achieve the objective of water conservation, wastewater minimisation and stormwater quality improvement, as well as flow control in an urban area (Ward et al. 2012). Water conservation is achieved through potable-water demand management using an alternative water source for different purposes, stormwater or rain water reuse, aquifer storage and recovery, and
* Yongxin Xu [email protected] 1
Department of Earth Science, Faculty of Natural Science, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
greywater reuse. Wastewater minimisation is achieved through demand management, grey water reuse and effective infiltration inflows. The stormwater quality impr
Data Loading...
