勐海灌区供水水库多时间尺度入库径流丰枯遭遇下调水分析

Analysis of down-regulation of multi-time scale inflow runoff encountering wet and dry conditions in the wet supply reservoir of Menghai Irrigation District

摘要

通过Copula函数进行建模，采用水文上常用的5种边缘函数对勐海灌区内三座重要水库在不同时间尺度下的入库径流进行边缘分布拟合，并由Copula函数对三座水库不同时间尺度下的最优边缘分布进行联合分布的构建，由最佳Copula函数求解两两水库在不同时间尺度下的入库径流丰枯遭遇概率，最后通过最小月平均流量法计算的径流量经Tennant法评价后，将其作为灌区内水库调水的标准。主要得出：三座水库在同一时间尺度下的最佳Copula函数均为Clayton Copula函数。同一时间尺度下三座水库两两丰枯遭遇概率组合中，丰枯同步的概率均大于丰枯异步的概率。在所有丰枯遭遇概率组合中所有时间尺度下三座水库两两均为同枯的概率最大，表明灌区内三座水库在丰枯遭遇组合中同为枯水年的可能性最大。非汛期和汛期三座水库由最小月平均流量法计算的径流量在Tennant法评价标准中基本符合生态需求，其结果可作为灌区水库调水的标准。在这一标准下，曼满水库在上一年12月份和2010年1月份无法向灌区进行大量供水，只能通过曼桂和那达勐水库向灌区进行供水调度。2011年非汛期三座水库均可向灌区进行供水调度。2010年、2011年汛期7月和8月三座水库均为丰丰遭遇，可以向灌区进行大量供水调度。除2010年、2011年7月和8月外，三座水库均为枯枯遭遇，在满足入库河流河道生态系统条件下，三座水库均可以对灌区适当进行供水调度。该研究成果可为勐海灌区供水水库群调水提供参考依据。

Abstract

Copula function is used to model, and five kinds of edge functions commonly used in hydrology are used to fit the edge distribution of the inflow runoff of three important reservoirs in Menghai Irrigation area at different time scales. The Copula function is used to construct the optimal edge distribution of the three reservoirs at different time scales. The optimal Copula function is used to solve the probability of the inflow runoff of the two reservoirs at different time scales. Finally, the runoff calculated by the minimum monthly average flow method is evaluated by the Tennant method and used as the standard for reservoir water transfer in the irrigation area. It is mainly concluded that the best Copula function of the three reservoirs at the same time scale is Clayton Copula function. Under the same time scale, the probability of abundance and dryness synchronization is greater than the probability of abundance and dryness asynchronous in the combination of abundance and dryness encounter probability of three reservoirs. In all the probability combinations of wet and dry encounters, the probability of the three reservoirs being dry in all time scales is the largest, indicating that the three reservoirs in the irrigation area are the most likely to be dry years in the combination of wet and dry encounters. The runoff of the three reservoirs calculated by the minimum monthly average flow method in the non-flood season and the flood season basically meets the ecological needs in the Tennant method evaluation criteria, and the result can be used as the standard for reservoir water transfer in irrigation areas. Under this standard, Manman Reservoir can't supply a large amount of water to the irrigation area in December of last year and January of 2010, and can only supply water to the irrigation area through Mangui and Nadameng Reservoirs. In the non-flood season of 2011, the three reservoirs can be dispatched to the irrigation area. In July and August of the flood season in 2010 and 2011, the three reservoirs were all wet and abundant, and a large amount of water supply could be dispatched to the irrigation area. Except for July and August in 2010 and 2011, the three reservoirs are all dry encounters. Under the condition of satisfying the river ecosystem of the inflow river, the three reservoirs can properly regulate the water supply in the irrigation area. The research result can provide reference for water diversion of water supply reservoirs in Menghai Irrigation area.

关键词

边缘函数 / Copula函数 / 丰枯遭遇 / 生态径流 / 调水分析

Key words

edge function / Copula function / dry encounter / ecological flow / analysis of water diversion

Author summay

刀海娅(1983—), 女, 高级工程师, 硕士, 主要从事水文水资源方面的研究。E-mail: [e-mail]

基金资助

国家重点研发计划项目(2021YFC3000205-06)