| 引用本文: | 黄宇云,余明辉,陆晶,孙昭华,田浩永.三峡建库后东洞庭湖适宜生态水位需求分析.湖泊科学,2020,32(2):417-427. DOI:10.18307/2020.0211 |
| HUANG Yuyun,YU Minghui,LU Jing,SUN Zhaohua,TIAN Haoyong.Suitable ecological water level of the East Lake Dongting after the Three Gorges Project operation. J. Lake Sci.2020,32(2):417-427. DOI:10.18307/2020.0211 |
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| 摘要: |
| 三峡水库的修建改变了水库下游的水沙条件，影响了洞庭湖湖区的生态平衡，进而引发相关生态问题.本文以城陵矶站水位代表东洞庭湖水位，基于其1953-2018年的逐日水位资料，采用滑动t检验法对年平均水位序列进行突变检验，发现因强人类活动导致城陵矶水位发生突变的时间为2004年，考虑为三峡蓄水的影响.借鉴IHA （Indicators of Hydrological Alteration，水文变化指标）及RVA （Range of Variability Approach，变化范围法）方法提出了一种同时考虑年内月平均水位过程、水位波动范围、高低水位发生情况以及水位涨落情况的适宜生态水位计算指标体系，能够直观和全面地描述生态系统健康发展对水位的要求，包括1-12月水位分别为：17.07~18.34、17.15~18.89、17.65~22.23、20.25~22.15、22.85~24.90、24.31~26.44、26.88~29.16、25.79~28.32、25.12~27.56、23.59~25.88、20.65~22.81、18.58~19.88 m；年最低水位：16.21~17.86 m，发生时间为第16~51天（年积日）；年最高水位：28.54~31.48 m，发生时间为第187~211天（年积日）；高水位平均持续时间为32.62~81.32 d/次，低水位平均持续时间为52.13~107.65 d/次；涨水次数为21.9~26.45次，涨水速率为0.17~0.21 m/d；落水次数为23.17~27.6次，落水速率为0.12~0.14 m/d.基于上述结果分析三峡建库后城陵矶水位发现，其在1、2月月平均水位分别较适宜生态水位需求高0.83、0.27 m；10月月平均水位较需求低0.83 m；年最低水位高出需求0.39 m，发生时间先于需求6天；涨水次数高于阈值要求4次，涨水速率低于阈值要求0.01 m/d；落水次数高于阈值要求2次.研究成果可为三峡及上游梯级水库群联合调度提供依据. |
| 关键词: 三峡工程 东洞庭湖 城陵矶 适宜生态水位 突变检验 IHA法 |
| DOI：10.18307/2020.0211 |
| 分类号: |
| 基金项目:国家重点研发计划项目（2016YFC0402303）和国家自然科学基金项目（11972265）联合资助. |
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| Suitable ecological water level of the East Lake Dongting after the Three Gorges Project operation |
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HUANG Yuyun, YU Minghui, LU Jing, SUN Zhaohua, TIAN Haoyong
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State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, P. R. China
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| Abstract: |
| The operation of the Three Gorges Dam has changed the flow and sediment conditions in the lower reaches of the reservoir, and it affected the ecological balance of the Lake Dongting and resulted in corresponding ecological problems. T-test was adopted for testing the consistency of the annual average water level based on the daily water level data of 1953-2018 at Chenglingji Station which is taken as the water level of the East Lake Dongting. The results show that the year of 2004 is an abrupt change point, indicating that the operation of Three Gorges Dam has resulted in the dramatic variation of water level at Chenglingji Station. Drawing on the IHA (Indicators of Hydrological Alteration) and RVA (Range of Variability Approach), an index system for calculating suitable ecological water level was presented in consideration of the range of monthly mean water level, the fluctuation range of annual water level, frequency and duration of high and low water level, and rate and frequency of water level condition changes. This index system can represent the requirements of the original ecological system intuitively and comprehensively. Using this index system, the suitable ecological water level of East Lake Dongting before the operation of the Three Gorges Dam was calculated for the following variables:1) the range of monthly mean water level (from January to December):17.07-18.34 m, 17.15-18.89 m, 17.65-22.23 m, 20.25-22.15 m, 22.85-24.90 m, 24.31-26.44 m, 26.88-29.16 m, 25.79-28.32 m, 25.12-27.56 m, 23.59-25.88 m, 20.65-22.81 m, 18.58-19.88 m, respectively; 2) annual acminimum water level:16.21-17.86 m, occurring from day 16 to day 51 (annual accumulative day); 3) annual maximum water level:28.54-31.48 m, occurring from day 187 to day 211 (annual accumulated day); 4) the high water level lasts 32.62-81.32 days at one time, the low water level lasts 52.13-107.65 days at one time, water level rises 21.9-26.45 times, the rate of water rising is 0.17-0.21 m/d, water level falls 23.17-27.6 times, the rate of water falling is 0.12-0.14 m/d. The results indicate that the monthly mean water level in January and February is 0.83 m and 0.27 m lower than the demand for suitable ecological water level, the monthly average water level in October is 0.83 m higher than the demand, the annual minimum water level is 0.39 m higher than the demand, occurring 6 days earlier than demand. The research results can provide a basis for the joint operation of Three Gorges and upstream cascade reservoirs. |
| Key words: Three Gorges Project East Lake Dongting Chenglingji Station suitable ecological water level mutation test IHA |
