Figure 1. Map of the Yangtze River, showing color variations along its length. Colors selected from Google maps. Click for detailed image

Recently an article in Slashdot revealed some alarming photos of the Yangtze River Turning Red, and apparently has “baffled officials” and caused people to start collecting samples. Speculation suggests that it may be red tide or pollution.
This article will explain exactly why it’s red..

Tracing the article’s history is somewhat revealing..
1) Slashdot’s article “China’s Yangtze River Turns Red”.. which refers to..
2) International Business Times article “Yangtze River Turns Red: Photos Of China’s Once Golden, Now Scarlet Pathway”.. which refers to..
3) Daily MailOnline article (UK source), “The river that DID run red: Residents of Chinese city left baffled after Yangtze turns scarlet”… which refers to..
4) Photos by ChinaFotoPress by Barcroft Medi..

Here is an example of one of the images of Chongqing city, where the Yangtze and Jialin River meet..

Chongqing city with exaggerated color, where Yangtze and Jialin River meet. Photo by ChinaFotoPress.

Shortly after these images were released, Slashdot readers discovered that several pictures had obvious artifact which revealed that the colors were painted in and manipulated. Certainly the amount of red was increased beyond what was actually photographed.

The photograph which was specifically identified as a hoax by Slashdot readers is here:

The white arrows indicate places where color bleeding is caused by a Photoshop user accidentally increasing the red color outside the area of the bottle.

Here is the location in the above photo of Chongqing as it appears in Google maps. The color in these google maps photos has not been manipulated in any way (overlay text was added for city names).

Notice the discoloration of the Yangtze river from the Jialin river photo is evident in this satellite picture, and the dramatic transition where they mix. Colors are as they appear in google maps.

Let’s zoom out and see how these rivers are colored across a larger length..

Here Chongqing is at the center, and the two rivers enter from the north (Jialin) and south (Yangtze). It is clear the difference in color is present even 20 miles upstream from Chongqing.
We can continue to trace the Yangtze river until we arrive at this point…

Here we see a clear transition in color on the Yangtze itself that takes place near the town of Longhuazhen. Downstream of the Yangtze is to the upper right (moving north), and upstream is to the lower left (coming from south west). Notice the fairly obvious change in color from blue to red. However, this location is not exactly at one of the nearest cities along the river. The color in the river change lies at point just downstream of Longhuazhen, which we can zoom into here.. and we find this..

This image is from the north bank of the Yangtze just above Longhuazhen.
Mystery solved!
What we find is a mining operation with very rich red soil. It is clear that the redness of the river is caused by discharge from mining. I don’t know what company is operating here, or what is being mined. These are interesting questions. However, it’s important to point out that this kind of blue-red transition happens several times along the Yangtze river – and in fact on most rivers in the world now. The cause is pollution.

From an environmental perspective, of course it is alarming that the Yangtze is polluted. The question here is, to what degree the river is naturally red versus polluted red by mining.. One should ask: How many tons of red soil is being released into the river by mining, and what effects does this have on fish and human health. More importantly, is anything being released which is not soil, but which are chemical additives resulting from the mining process?

It is much more alarming, in my opinion, that the article entered the mainstream because none of the major media sources bothered to investigate the validity of the original photographs. The authors saturated the red color to such a degree that they do indeed look alarming. These major media networks did not do even the minimum amount of investigative journalism.

A more interesting article would be one which reports on a scientific study of how much actual, measured pollution there is on the Yangtze compared to other rivers in the world. I’d like to know that.

So what of the news that the “Yangtze River Turns Red”? The idea itself is misleading. The Yangtze river is 3,918 miles long. Does this mean to imply the entire river has turned red? If not, then what makes this area so special? It seems none of the articles asked these rather basic questions. Most likely the redness is no more or less than it is at several blue-red transitions along the length of the river, where the cause of redness is clearly pollution after each city it passes through. The question, which I don’t know the answer to, is whether there is something unusual which is happening now with the Yangtze beyond the kind of pollution which occurs on most rivers throughout the world.

See my recent article in the Huffington Post for more details:
Yangtze River Turns Red – Biblical Curse or Industrial Pollution?