TY - JOUR

T1 - Modelling the impact of future climate change on streamflow and water quality in Wales, UK

AU - Dallison, Richard

AU - Williams, Prysor

AU - Harris, Ian

AU - Patil, Sopan

PY - 2022/4/25

Y1 - 2022/4/25

N2 - Climate change is likely to have a major impact on future hydrological regimes, impacting numerous sectors reliant on surface waters. We use the Soil and Water Assessment Tool (SWAT) to model future (2021-2080) streamflow and water quality variables (nitrogen, phosphorus, suspended sediment, and dissolved oxygen), in five catchments in Wales, under a worst-case scenario of future greenhouse gas concentrations (RCP8.5). Results show a decline in annual average flows (-4% to -13%) but larger changes seasonally (spring, up to 41% increase; autumn, up to 52% reduction). The magnitude and frequency of high flow events increases in spring (magnitude: Sen’s slope range 0.165-0.589, p <0.01), with more low flows in autumn (Sen’s slope range 0.064-0.090, p <0.01). Water quality declines, with higher nitrogen, phosphorus, and sediment concentrations and lower dissolved oxygen levels. The findings have economic and environmental implications for abstractors, as water resources could become more unreliable, seasonal, and polluted.

AB - Climate change is likely to have a major impact on future hydrological regimes, impacting numerous sectors reliant on surface waters. We use the Soil and Water Assessment Tool (SWAT) to model future (2021-2080) streamflow and water quality variables (nitrogen, phosphorus, suspended sediment, and dissolved oxygen), in five catchments in Wales, under a worst-case scenario of future greenhouse gas concentrations (RCP8.5). Results show a decline in annual average flows (-4% to -13%) but larger changes seasonally (spring, up to 41% increase; autumn, up to 52% reduction). The magnitude and frequency of high flow events increases in spring (magnitude: Sen’s slope range 0.165-0.589, p <0.01), with more low flows in autumn (Sen’s slope range 0.064-0.090, p <0.01). Water quality declines, with higher nitrogen, phosphorus, and sediment concentrations and lower dissolved oxygen levels. The findings have economic and environmental implications for abstractors, as water resources could become more unreliable, seasonal, and polluted.

KW - UKCP18

KW - hydrological modelling

KW - particle swarm optimization

KW - trend analysis

KW - water resource management

KW - water supply

U2 - 10.1080/02626667.2022.2044045

DO - 10.1080/02626667.2022.2044045

M3 - Article

VL - 67

SP - 939

EP - 962

JO - Hydrological Sciences Journal

JF - Hydrological Sciences Journal

SN - 0262-6667

IS - 6

ER -