School of Water, Energy and Environment (SWEE)

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Browsing School of Water, Energy and Environment (SWEE) by Course name "MSc in Advanced Water Management"

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    Impact of the Oxford canal on water quality and ecological status of the River Cherwell.
    (Cranfield University, 2021-09) Dowdeswell-Downey, Luke; Grabowski, Robert; Campo Moreno, Pablo
    Good quality water provides numerous ecosystem services and it is a legal requirement of the Water Framework Directive for all waterbodies to be achieving good status. Achieving good water quality and ecological status remains a critical issue throughout most waterbodies within the UK. Waterbodies can have an impact on one another, however, determining the impact of tributaries and canal interactions on rivers remains a challenge. This study aims to investigate whether the Oxford canal has had a negative impact upon water quality and ecological status of the River Cherwell. New water quality and sediment samples were collected, upstream and downstream of where the river and canal interact at two sections at 16 sampling locations. Historical invertebrate data was examined at three locations; upstream, between and downstream of these two sections along the River Cherwell and compared to the nearby River Windrush, which does not interact with any canals. Results showed no statistical decreases in river water quality downstream of where the canal joins the river. Conversely, there was evidence that interaction with the canal water may have decreased river nutrient levels, such as nitrate, by a dilution effect. Furthermore, mixing with river water may have significantly increased orthophosphate and conductivity in the canal (p< 0.05). Similarly, invertebrate data showed no negative impact from the canal on the river in terms of taxa richness, BMWP, ASPT, and diversity indices. However, results suggested that the River Cherwell has had higher invertebrate metrics and indices when compared to the River Windrush. Overall, this study found no evidence to indicate that the Oxford canal negatively impacted water quality and ecological status of the River Cherwell.
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    ItemOpen Access
    Modelling catchment scale response to drought risk, a case study in South Africa.
    (2021-09) Lulane, Zanele; Hess, Tim M.; Holman, Ian P.
    South Africa is a water scarce country with future water availability threatened by climate change, an increasing population leading to urbanization, increasing agricultural production, and industrialization. Past droughts have highlighted the country’s vulnerability to drought leading to economic losses in the Agricultural sector, inadequate water, and supply for basic domestic needs and failure to meet ecological water requirements. A case study was carried out in the water scarce, 4,937 km² agricultural intensive Groot Letaba catchment located in the Limpopo province. Water Evaluation and Planning (WEAP) model was used to simulate the water supply system in the catchment, from 1981 to 2016. The Nash–Sutcliffe Efficiency was used to validate the model’s accuracy providing a value of 0.91 and 0.86 during calibration (1981-2000) and 0.69 and 0.65 during validation (2001-2016) for streamflow and Tzaneen reservoir levels, respectively. A reference scenario to assess water resources and water demand sites’ vulnerability should droughts experienced between 1981 to 2016 be repeated under current demand was developed. 10% Agricultural water supply reduction, 50% per capita use rate reduction, Tzaneen reservoir storage increase and rerouting domestic return flow to the river were explored as drought adaptation measures. Drought response measures prevented reservoir drawdown in moderate droughts and delayed drawdown in severe droughts, reducing their temporal extents. Improvements in water resources availability correlated with improving demand coverage and reliability. Pairing drought response scenarios amplified benefits realized resulting in 100% demand coverage and reliability for two demand sites. All drought response measures were insufficient to fully circumvent droughts with a magnitude like the 1992-1996 drought. These findings show that effectiveness of response measures is dependent on the intensity and duration of the drought.