摘要
变化环境下湄公河径流正在改变,科学认识澜湄流域干旱和澜沧江梯级水库调度的作用,有利于跨境水资源的管理和澜湄合作的开展。为了探究澜沧江梯级电站运行对湄公河枯水期的影响,基于景洪电站出库流量和湄公河4个水文站实测流量,以及SPEI指数、气温、降水资料,进行统计分析。结果表明,近40 a来,湄公河发生气象干旱的频率为25.6%,其中枯水期干旱频率为21.4%,丰水期干旱频率高达35.7%,SPEI下降趋势0.14/(10 a);2000年后持续升温和降水的年际不稳定易导致湄公河气象干旱频发。2010年以来经过澜沧江梯级电站调节,景洪电站枯水期平均出库较多年平均增加92.9%,景洪出库流量在清盛、万象、巴色、桔井4个水文站中占比分别为83.5%、68.1%、37.3%和35.0%,流量最小的3—4月份对下游桔井站的补水占比还可达45%左右;特别是在澜湄流域遭遇干旱期间,通过对下游补水,可有效缓解干旱期间用水需求。澜沧江梯级电站运行对枯水期湄公河的补水效果非常显著,充分体现出电站巨大的调节作用和对下游的积极影响。
The runoff of the Mekong River is undergoing transformation under the influence of environmental changes.Enhancing the scientific understanding of Mekong River drought and the role of cascade reservoir operations on the Lancang River contributes to the effective management of cross-border water resources and the development of the Lancang-Mekong Cooperation.Based on the discharge data from Jinghong Hydropower Station and runoff measurements from hydrological stations along the Mekong River,as well as the Standardized Precipitation Evapotranspiration Index(SPEI),temperature,and precipitation data,this study examines the impact of cascade hydropower stations on the Lancang River during the dry season.Results reveal that over the past 40 years,the meteorological drought frequency in the Mekong River was 25.6%,with higher frequency in flood season reaching 35.7%,and 21.4%in dry season.SPEI during flood season exhibited a decreasing trend of 0.14 per decade.Persistent warming and interannual precipitation variability since 2000 have resulted in sustained meteorological droughts in the Mekong River.Following the operational adjustments of cascade hydropower stations since 2010,the average discharge from Jinghong Hydropower Station during dry season has increased by 92.9%compared to the multi-year average.The discharge from Jinghong accounts for significant proportions of the runoff at key hydrological stations along the Mekong River,specifically 83.5%at Chiang Saen,68.1%at Vientiane,37.3%at Pakse,and 35.0%at Kratie.Notably,the proportion of water replenishment to Kratie can reach approximately 45%during the lowest runoff period from March to April.Particularly during drought conditions in the Lancang-Mekong Basin,these replenishments effectively alleviate water demand downstream.The operations of the Lancang River cascade hydropower stations significantly enhance water replenishment in the Mekong River during dry season,highlighting their substantial regulatory role and positive impact on downstream regions.
作者
张攀全
管镇
李红刚
杨庆
ZHANG Pan-quan;GUAN Zhen;LI Hong-gang;YANG Qing(Cascade Control Center of Huaneng Lancang River Hydropower Co.,Ltd.,Kunming 650214,China)
出处
《长江科学院院报》
北大核心
2025年第1期35-43,共9页
Journal of Changjiang River Scientific Research Institute
关键词
干旱
枯水期
电站运行
影响分析
澜沧江—湄公河
drought
dry season
reservoir operation
influence analysis
Lancang-Mekong River
