TY - JOUR
T1 - Water diversion and sea-level rise
T2 - Potential threats to freshwater supplies in the Changjiang River estuary
AU - Li, Maotian
AU - Chen, Zhongyuan
AU - Finlayson, Brian
AU - Wei, Taoyuan
AU - Chen, Jing
AU - Wu, Xiaodan
AU - Xu, Hao
AU - Webber, Michael
AU - Barnett, Jon
AU - Wang, Mark
N1 - Publisher Copyright:
© 2014 Elsevier Ltd.
PY - 2015
Y1 - 2015
N2 - The densely-populated mega-city of Shanghai relies increasingly on freshwater from the Changjiang estuary (70% now). However, this strategy is facing potential threats due to extensive water diversion in the lower Changjiang basin and future sea-level rise. Given this, the present study evaluates the ability of Shanghai to source its water from the estuary, especially in the dry season. Flow <15,000 m3 s-1, which occurs for ca. 50% of dry seasons, represents the threshold for salinity 0.45psu (chloride 250 mg/L) above which the estuary is unusable for freshwater. Correlating discharge and salinity, maximum salinity and related time duration, and taking the future water diversions and sea-level rise into consideration, we extrapolated salinity events into the future at intervals of 10years until 2040. We estimate that water diversions of 56.2 × 109 m3 (1800 m3 s-1), 59.2 × 109 m3 (1900 m3 s-1) and 61.3 × 109 m3 (2000 m3 s-1) will occur in 2020, 2030 and 2040, and a rise of sea level of 0.12m by 2040 (from 2010), equivalent 506 m3 s-1, ca. 19.4% of the total reducing discharge of 2040 into the estuary (ca. 28% projected to the worst case of February of 2040). Based on scenario building, the pattern of salinity distribution would remain >0.45 for 20-65, 75-90 and 120-128days (in 2020, 2030, and 2040, respectively), for extreme low-flow conditions. These periods exceed the present 68-day maximum freshwater storage in Qingcaosha reservoir, which is meant to secure freshwater for Shanghai in the future. Urgently countermeasures are needed to secure the Shanghai's water in the future.
AB - The densely-populated mega-city of Shanghai relies increasingly on freshwater from the Changjiang estuary (70% now). However, this strategy is facing potential threats due to extensive water diversion in the lower Changjiang basin and future sea-level rise. Given this, the present study evaluates the ability of Shanghai to source its water from the estuary, especially in the dry season. Flow <15,000 m3 s-1, which occurs for ca. 50% of dry seasons, represents the threshold for salinity 0.45psu (chloride 250 mg/L) above which the estuary is unusable for freshwater. Correlating discharge and salinity, maximum salinity and related time duration, and taking the future water diversions and sea-level rise into consideration, we extrapolated salinity events into the future at intervals of 10years until 2040. We estimate that water diversions of 56.2 × 109 m3 (1800 m3 s-1), 59.2 × 109 m3 (1900 m3 s-1) and 61.3 × 109 m3 (2000 m3 s-1) will occur in 2020, 2030 and 2040, and a rise of sea level of 0.12m by 2040 (from 2010), equivalent 506 m3 s-1, ca. 19.4% of the total reducing discharge of 2040 into the estuary (ca. 28% projected to the worst case of February of 2040). Based on scenario building, the pattern of salinity distribution would remain >0.45 for 20-65, 75-90 and 120-128days (in 2020, 2030, and 2040, respectively), for extreme low-flow conditions. These periods exceed the present 68-day maximum freshwater storage in Qingcaosha reservoir, which is meant to secure freshwater for Shanghai in the future. Urgently countermeasures are needed to secure the Shanghai's water in the future.
KW - Discharge
KW - Salinity
KW - Sea-level rise
KW - The Changjiang estuary
KW - Water diversion
KW - Water supply
UR - https://www.scopus.com/pages/publications/85027935678
U2 - 10.1016/j.ecss.2014.07.007
DO - 10.1016/j.ecss.2014.07.007
M3 - 文章
AN - SCOPUS:85027935678
SN - 0272-7714
VL - 156
SP - 52
EP - 60
JO - Estuarine, Coastal and Shelf Science
JF - Estuarine, Coastal and Shelf Science
IS - 1
ER -