Evolution of Hydrological Regime and Its Impact on the Guaranteed Rate of Saltwater Intrusion Suppression Flows in the Lower Reaches of the Minjiang River
Responding to the changes of the natural hydrological regime of the lower reaches estuary of the Minjiang River in recent years,resulting in a gradual increase in the phenomenon of upward salty tides,this paper selected the daily flow data from 1950 to 2018 at Zhuqi station in the lower reaches of the Minjiang River,and used Mann-Kendall method to analyze the trend and sudden change.The mutation year appeared in 1997.The range of variation of hydrological indi-cators method(IHA/RVA)was used to analyze 32 hydrological indicators for two time series before and after the muta-tion,1950-1996 and 1997-2018.All the indicators are moderate and low,except for the number of low-flow pulse occur-rences and duration and the number of reversals,which are highly altered.The overall hydrological alteration of the lower reaches of the Minjiang River is 38.16%,which is moderate.The guarantee rate analysis for two time series representa-tive years at two saltwater intrusion suppression flow scenarios was carried out.The minimum and total water demand of saltwater intrusion suppression flow process in scheme 1 is less than in scheme 2,and the guaranteed rate of saltwater in-trusion suppression flow is higher.The guaranteed rate of saltwater intrusion suppression flow increases overall after the mutation compared with that before the mutation.Especially in the dry year,the guaranteed rate of saltwater intrusion suppression flow increases substantially,but at the same time there is the problem of decreasing the guaranteed rate of saltwater intrusion suppression flow in the high flow year.It shows that the operation of the reservoir affects the down-stream runoff process,but it also makes the guaranteed rate of saltwater intrusion suppression flow rate in high flow year,normal flow year and low flow year converge.
the lower reaches of the Minjiang Riverhydrological regimeIHA/RVA methodhydrological alterationsaltwater intrusion suppression flowguarantee rate
万方数据
维普
