Keywords

Water quality modelling; WEAP; WQSAM; Buffalo River; South Africa

Location

Session H2: Water Resources Management and Planning - Modeling and Software for Improving Dcisions and Engaging Stakeholders

Start Date

17-6-2014 2:00 PM

End Date

17-6-2014 3:20 PM

Description

The water quality degradation of fresh water resources has become an increasingly urgent global problem which is predicted to be exacerbated by future development and climate change. Since water quality is to a large extent driven by water quantity, it is useful for a model to incorporate a rainfall-runoff component (natural hydrology), reservoir storage, return flows and abstractions (systems modelling), and a water quality component. One such model that meets these requirements is the Water Evaluation and Planning (WEAP) Model. During 2012, WEAP was applied to the Buffalo River within the Eastern Cape, South Africa, to investigate the effect on water availability of future development impacts, as well as potential climate change for the near future (2046–2065) under the A2 emission scenario. It was found that WEAP does not simulate water quality within reservoirs and water quality simulation facilities within WEAP are too simple. A new model was developed: the Water Quality Systems Assessment Model (WQSAM). WQSAM accepts water quantity data from a routinely used systems model, simulates water quality in a simplified manner, and also simulates water quality for reservoirs. WQSAM was applied to the Buffalo River to investigate climate change and development impacts on water quality, using the same Global Climate Model output and development data as were used within the WEAP study. The water quality results provided by the two models are compared, with the suitability of use of both WEAP and WQSAM to investigate future water quality discussed. WQSAM demonstrated the following advantages to water quality modelling compared to WEAP: 1) modelling of water quality in reservoirs; 2) consideration of water temperature effects on water quality; 3) consideration of transient events by modelling on a daily time step; 4) a more comprehensive and realistic conceptual model of water quality processes.

 
Jun 17th, 2:00 PM Jun 17th, 3:20 PM

Investigating possible climate change and development effects on water quality within an arid catchment in South Africa: a comparison of two models

Session H2: Water Resources Management and Planning - Modeling and Software for Improving Dcisions and Engaging Stakeholders

The water quality degradation of fresh water resources has become an increasingly urgent global problem which is predicted to be exacerbated by future development and climate change. Since water quality is to a large extent driven by water quantity, it is useful for a model to incorporate a rainfall-runoff component (natural hydrology), reservoir storage, return flows and abstractions (systems modelling), and a water quality component. One such model that meets these requirements is the Water Evaluation and Planning (WEAP) Model. During 2012, WEAP was applied to the Buffalo River within the Eastern Cape, South Africa, to investigate the effect on water availability of future development impacts, as well as potential climate change for the near future (2046–2065) under the A2 emission scenario. It was found that WEAP does not simulate water quality within reservoirs and water quality simulation facilities within WEAP are too simple. A new model was developed: the Water Quality Systems Assessment Model (WQSAM). WQSAM accepts water quantity data from a routinely used systems model, simulates water quality in a simplified manner, and also simulates water quality for reservoirs. WQSAM was applied to the Buffalo River to investigate climate change and development impacts on water quality, using the same Global Climate Model output and development data as were used within the WEAP study. The water quality results provided by the two models are compared, with the suitability of use of both WEAP and WQSAM to investigate future water quality discussed. WQSAM demonstrated the following advantages to water quality modelling compared to WEAP: 1) modelling of water quality in reservoirs; 2) consideration of water temperature effects on water quality; 3) consideration of transient events by modelling on a daily time step; 4) a more comprehensive and realistic conceptual model of water quality processes.