How China is destroying the Mekong

[Viva_Viet]

That is how a Vietnamese dishwasher or a workshop sweeper will responds I believe.
Most of the time they dare not to look at me in the eyes.
Normally working class will formally address me in a proper manner, protocol and very politely with a smile on their face.
Look at you. Just another crass proletariat from a communist society. A cadre from China in 1990 will be more disciplined than you.
Look at you. Tsk Tsk

Haha.but in 2014 VN-CN conflicts, we just thought Cnese-SG r as same as Cnese and beat them up badly on dirty streets.

Lessons for Cnese-SG : dont try to look and act like Cnese in VN, dont make trouble for us, keep focusing in washing dishes or u guys will learn another lesson on our dirty streets again

 

[ILC]

16% of Mekong's water comes from the Chinese upper basin, and 84% from the lower basin. China is not stealing water.

Further reading : General Hydrological Cycle of the Mekong Basin

With the Chinese section of the river significantly drier and the Laotian portion much wetter as seen in the water yield map, it is not fair to say that China holds the crucial lifeline of the river. The Chinese section experiences a far less precipitation variability profile, but the lower stretches fluctuate in high correlation with the SE Asia wet season, so that 16% now looks quite consistent. Flooding during the monsoon season is common along the lower stretches, in line with the SE Asia monsoon pattern.

So due to the monsoon, this river fluctuates quite wildly between seasons. Who would think this seasonality is impacted by China in light of all this hydrological data?

By the way, the Mekong River Commission just published a response to that "surface wetness" study in late April : http://www.mrcmekong.org/assets/Pub...Mekong-River-hydrological-conditions_2020.pdf

Some highlights :

The annual flow regimes at Chaing Saen, where the Mekong enters the Lower Mekong Basin
(LMB), have been altered by hydropower projects in China. These projects reduce wet
season flows and increase dry season flows. This situation brings both opportunities and
challenges.

The impact of these changes becomes less evident further downstream due to the inflows
from tributaries in the LMB and the operations of the tributary hydropower dams.

The Eyes on Earth Study draws its conclusions from calculated flows at Chaing Saen, the
most upstream point in the LMB. These calculations do not reflect the actual dry season
flows over the last two years. The actual flows recorded in the Mekong River Commission’s
Procedures for the Maintenance of Flows on the Mainstream (PMFM) in the 2019 and 2020
dry seasons showed that inflows from China were higher than typical for the dry season.
The record low flow at Vientiane in Lao PDR noted in the 2019 and 2020 dry seasons was
most likely due to the change in rainfall volume and pattern.

Dam development in the upper reaches of the Mekong has led to changes in
seasonal flows, with increased dry season flows and decreased wet season flows.
Both phenomena are observed in the LMB, with the impact on the flow regime
becoming progressively less noticeable further downstream.

The findings of the Eyes on Earth study have not yet well taken into account the complexities of rainfall and runoff, thus not reflecting the actual hydrological conditions in the Basin. The conclusions drawn are based on calculated flows and not an analysis of the actual flows at Chaing Saen set against the long term trends.

MRC report

Our preliminary analysis, using historical rainfall data (2008-2019) and observed water flows, showed that the 2019 drought in the basin was due largely to insufficient rainfall during the wet season with a delayed arrival and earlier departure of monsoon rains and an El Nino event that created an abnormally higher temperature and higher evapotranspiration.

While we know that the operation of dams in China causes impacts to the LMB (see MRC’s State of the Basin Report), it is not true that the lack of water in the LMB during 2019 and 2020 was influenced mainly by these dams. The water flow contributions across the whole basin must be analysed.

The Eyes on Earth study concludes that the “severe lack of water in the Lower Mekong during the wet season of 2019 was largely influenced by the restriction of water flowing from the Upper Mekong during that time” (Basist & Williams, 2020, p. 18). The study further notes that “cooperation between China and the Lower Mekong countries to simulate the natural flow cycle of the Mekong could have improved the low flow conditions experienced downstream between May and September of 2019” (ibid., p. 18). However, this conclusion should note the major contribution of rainfall in the Northern and Eastern catchments to the Mekong flows. By far the major contribution comes from the two major left-bank (eastern) tributaries between Vientiane and Nakhon Phanom, and Pakse and Steung Treng. Together they contribute more than 40% to the flow (see Figure 1). This means water infrastructures in the Lower Mekong tributaries – where some 73 out of 150 planned dams have been installed over the last 55 years – could have various degrees of impact on the flow.

On average, the rainfall from the left bank contributes to almost 60% of the flood season discharge in the Mekong at the Lao-Cambodian border, while the contribution from China is in the order of 15%. Hence, the conclusion holds only up to Chiang Saen, which is the most upstream station in the LMB (see Figure 2). Satellite data of rainfall over the basin showing a wetter condition in China and drier in the rest of the basin appears to be correct. However, the approach does not provide robust scientific evidence that the storing of water in Chinese reservoirs caused the exceptionally low flows in the LMB at Vientiane in 2019 and 2020.

In fact, the PMFM’s data showed the inflow from China was higher than typical for these dry seasons. The record low flow was most likely the result of much lower than normal rainfall in the LMB, and the shift in rainfall patterns (see Figure 7). The operations of the hydropower projects in Lao PDR have also increased dry season flows in the Mekong downstream of Vientiane, and flows into Cambodia were also higher than typical for the 2019 and 2020 dry seasons.