Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap system
Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap system
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DOI：
10.5194/hess-18-4529-2014
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发表时间：
2014-01-01
影响因子：
6.3
通讯作者：
Piman, T.
中科院分区：
文献类型：
--
作者：
Cochrane, T. A.;Arias, M. E.;Piman, T.
湄公河流域水利基础设施的快速发展令人担忧，因为它对渔业和下游自然生态系统有潜在影响。在本文中，我们通过比较1991年前后湄公河干流沿线从清盛（泰国北部）到上丁（柬埔寨）的六个监测站以及洞里萨河上的Prek Kdam监测站的每日观测数据，分析了湄公河和洞里萨水系的历史水位。观察到的湄公河沿岸水位模式的变化与1960年至2010年水利基础设施发展的时空趋势有关。我们认为历史气候因素的变化很重要，但它们并不是观察到的与生态系统生产力相关的关键水文指标变化的主要原因。我们的分析表明，1991年后湄公河上游流域主流水坝的开发可能导致30天最低水位略有增加（+17%），但清盛观察到的下降率（+42%）和水位波动次数（+75%）显着增加。这种影响在下游逐渐减弱，直到在莫达汉（泰国东北部）变得可以忽略不计，该地区的流域面积占整个湄公河盆地的 50% 以上。在巴色（老挝南部）的更下游，1991年后波动次数和上升率的变化变得非常显着。观察到的变化在下游缓慢减少，但直到Prek Kdam为止，修改后的上升率、下降率和旱季水位仍然是可量化的和显着的。本文提供了湄公河上游中国大坝梯级之外湄公河水文变化的第一组证据。鉴于巴色及其下游的明显变化，1991 年之后的变化也可直接归因于泰国 Chi 和 Mun 流域的水利基础设施发展。 Prek Kdam 的水位上升率和下降率分别减少了 23% 和 11%，这证明 1991 年之后洞里萨湖洪水脉冲减弱。鉴于 1991 年至 2010 年由于水利基础设施开发而观察到的水位变化，我们可以推断，干流和主要跨界 Srepok、Sesan 和 Sekong 次流域的未来开发将对洞里萨湖洪水泛滥区、湄公河下游漫滩和三角洲产生更大的影响。
The rapid rate of water infrastructure development in the Mekong Basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper, we analyze the historical water levels of the Mekong River and Tonle Sap system by comparing pre-and post-1991 daily observations from six stations along the Mekong mainstream from Chiang Saen (northern Thailand), to Stung Treng (Cambodia), and the Prek Kdam station on the Tonle Sap River. Observed alterations in water level patterns along the Mekong are linked to temporal and spatial trends in water infrastructure development from 1960 to 2010. We argue that variations in historical climatic factors are important, but they are not the main cause of observed changes in key hydrological indicators related to ecosystem productivity. Our analysis shows that the development of mainstream dams in the upper Mekong Basin in the post-1991 period may have resulted in a modest increase of 30-day minimum levels (+17 %), but significant increases in fall rates (+42 %) and the number of water level fluctuations (+75 %) observed in Chiang Saen. This effect diminishes downstream until it becomes negligible at Mukdahan (northeast Thailand), which represents a drainage area of over 50 % of the total Mekong Basin. Further downstream at Pakse (southern Laos), alterations to the number of fluctuations and rise rate became strongly significant after 1991. The observed alterations slowly decrease downstream, but modified rise rates, fall rates, and dry season water levels were still quantifiable and significant as far as Prek Kdam. This paper provides the first set of evidence of hydrological alterations in the Mekong beyond the Chinese dam cascade in the upper Mekong. Given the evident alterations at Pakse and downstream, post-1991 changes could also be directly attributed to water infrastructure development in the Chi and Mun basins of Thailand. A reduction of 23 and 11% in the water raising and falling rates respectively at Prek Kdam provides evidence of a diminished Tonle Sap flood pulse in the post-1991 period. Given the observed water level alterations from 1991 to 2010 as a result of water infrastructure development, we can extrapolate that future development in the mainstream and the key transboundary Srepok, Sesan, and Sekong sub-basins will have an even greater effect on the Tonle Sap flood regime, the lower Mekong floodplain, and the delta.