Dec. 04, 2023
Rainy days can’t extinguish our enthusiasm

Green Earth Volunteers, Eco-Water Tour:
Rainy days can’t extinguish our enthusiasm
July 10, 2010
Author: Lina Wang
Cameraman: Yongchen Wang

Today, we walked along the South Long River from the Purple Bamboo Court to Jishuitan. There are many dialects in Beijing which are relative to the Long River. Chen Zhou, the expert of the Happy Water Tour program, explained the relationship between the history of canals and Beijing. During the Qing dynasty, willows were planted along both sides of the river channel, and the sight of them along the gleaming blue Long River was an excellent scene at that time.
Shoujing Guo built the Tonghui Canal and created 24 water gates between Kunming Lake to the Imperial Palace. The Tonghui Canal became the main method of canal transport instead of the Xiba River because water gates are more convenient than dams in terms of controlling the river and because the Tonghui Canal was also connected to the Yuangong river system. The competition between dams and water gates stemmed from this. Additionally, the bricks and lumber used for the construction of wards in Yuan Dadu and Qing Beijing were transported from southern China through the Tonghui Canal.
The idiom, “Beijing city floated up from the south,” came from this event. The Long River was the water source for the palace during the Jin dynasty, and it was the royal river in the Ming and Qing dynasties. That river witnessed the prosperity of the royalty and underwent the humiliation of the Eight Power Allied Force. If you ever wondered about the rise and fall of Beijing, you only need to understand the history of the Long River.
There were some yachts passing by when we walked along the river. The royal river has been opened to the public now.

The Happy Water Tour group in the Purple Bamboo Court beside the South Long River


Professional Chen Zhou explains the drainage map and the South Long River map


The royal river channel

As usual, we invited the plant molecular biologist Dr. Nie from the agricultural university to impart some knowledge about botany to us. Why do many people say celery can darken our skin? Celery contains furocoumarin, which contains a substance sensitive to light. Furocoumarin helps people absorb ultraviolet radiation and stimulates the development of melanin. We don’t need to worry about this because the concentration of that substance is usually very low in our bodies. We should remember to wash our hands after trimming celery for cooking. In addition, we shouldn’t trim celery in the sun. Furocoumarin is also a potent agricultural defense. The insects that eat celery die faster in the sun, so celery doesn’t require the use of pesticides.
At this time, a passerby overheard and questioned Dr. Nie. Could we transfer the furocoumarin to cucumbers and cabbages, which are easily eaten by pests? If we could do this, we wouldn’t have to worry about using farm chemicals. That question provoked a debate among the participants of Happy Water Tour. Many people were concerned about the possible risk factors to their health, and others brought up how transgene crops could harm native vegetation. Some also mentioned that certain interest groups could exploit the farmers in order to get the transgene crops.
Yongchen Wang pointed out that once the hybrid crops are patented, some interest groups would try to monopolize their production. Once this happens, it would become difficult for people to avoid higher prices. However, we didn’t discuss this issue too thoroughly, as there are still many people in China who can’t get a decent meal every night. At the very least, her opinion reminded us that there are many ways of looking at a problem and that we shouldn't force our views on others.

The debate with the passerby

To our disappointment, the river channel we walked today has been lined with concrete on both the sides and bottom. The original intention of the concrete lining is good; it was intended to stop silt from accumulating, prevent water from soaking into the soil, and save water, but few people considered that the river itself already had those functions. What we need to do is return it to its former state.
If plants on both banks can be maintained, soil erosion won’t occur and the watercourse won’t become blocked. The natural sediment at the bottom of the river is abundant in nutrition, and plants can grew well there. The changes of depth in the river determine the proportions of air and illumination. In addition to the change in water velocity and the irregularities of the watercourse, the heterogeneous environment will cause all kinds of vegetation to grow: floating plants, submerged plants and phytoplankton. Those plants can assimilate nutrients and hold the dust down to keep the water high in quality.
Regarding the loss of water to soil absorption, there is a great misunderstanding. The loss of surface water actually supplements groundwater. What’s more, groundwater is an important drinking water source and necessary for underground flora. The decrease of water lies mostly in evaporation, not in absorption. If we line the river with concrete, the temperature of the water would go up more rapidly than before, and evaporation would speed up.
If we don’t understand the ecosystem before administering treatment, we will be unable to attend to everything at once, and we would produce exactly the opposite of the desired result.
The Green Earth Program paid attention to the problem of concrete lining from 1990s. During these years, we appealed to people not to line the river. In 2001, Yongchen Wang attended the Chinese Cultural Environment program of CCTV as an editor to discuss the problem of lining the Miyun-Beijing Canal.
Why does the Beijing Municipal Bureau of Water Resources adhere to this method of river control? Minister Guochang Chang said that reinforcing the river stops water from leaking out, and it is a convenient way to remove silt. Recently, Beijing has been short on rain and dry. The Miyun-Beijing Canal lost 1000 million cubic meters of water to soil absorption, which was approximately equal to one fifth of the canal. Adding concrete lining to the river banks could block the water from the soil and save water. In addition, the Miyun-Beijing Canal has been polluted severely, and marshy weeds breed in its waters. In order to guarantee high water quality, concrete linings could reduce silt, increase water velocity, and change unfavourable water quality.
Several experts have expressed  their professional opinions on this issue.
Xianfa Li, a professor from Beijing Environment Research Center, disagreed with the opinions stated above. Professor Li pointed out that loss of water is due to evaporation and that water absorption is not a loss but a way to preserve water. It is a conceptual mistake to see water absorption as a loss. Soil absorption is not a bad thing; rather, it is quite beneficial. Beijing has used up more than 4 billion cubic meters of water, and as a result, a 1200 square kilometer funnel formed under the ground. We should have dug channels down to help replenish the water level, but instead we reinforce the river.
Erhong Pang, a professor at the Beijing Planning Institute, thought that this river channel shouldn’t have been reinforced. Several waterworks sit on the bank of Kunyun reach. The river channel has been the runoff source for the waterworks since 1965. Lining it with concrete caused the groundwater to become surface water, and the high quality water became low quality water.
Is the reinforced river channel good for maintaining the water’s quality? Kongjian Yu, professor of Peking University and design science doctor of Harvard, thought that the urban water system, which acts as our stem, doesn’t have enough esteem or attendance. We made a mistake regarding the control of the urban water system. We put undue emphasis on draining off floodwater, sluice water, and pollution discharge. We even straightened the channel and lined it with armored concrete. We thought that we had made a great effort to shield the urban water system once and for all from future trouble. In reality, the natural water system is a living ecosystem. It needs a natural environment to keep it healthy.
Dihua Li, urban landscape and designing center instructor of Peking University, has worked on urban environment research for several years. As she put it, rivers have a self-purification capability from an ecological point of view. There are many plants and microorganisms in the water, which can help prevent pollution. Plants also supply oxygen to the river, which also helps protect the river from pollution. Lining it with armored concrete cuts off the relationship between the soil and the water, and it separates the water system from the earth and environment. As a result, some ecological functions would disappear. Rivers without their self-purification capability would experience aggravated pollution.
For the past few years, both the public and the government has realized the negative effects of concrete reinforcement on ecological systems. We noticed that many places found alternative means; for example, using vines, air-permeable bricks, or stones instead of concrete. In fact, developed countries like American, Germany, and Japan removed their river linings in the 1990s.
When we passed the zoo, the river had no reinforcements on the sides but still had one on the bottom, yet the water quality was visibly better than the entirely lined river. There was a cluster of yellow flags, which we call the pride of flowers, in the water. It is a pity that we missed its blossoms.


The river with both side and bottom linings

Plants have replaced the concrete

The river with no side reinforcement but retaining it on the bottom

The plants here may be dead

The river without any concrete lining

The yellow flags here have passed their flowering time

We stopped by the Five-pagoda Temple and the Beijing Art Museum of Stone Carving. Historically, regions have always prospered under the reign of ethnic minorities. Religion may be a means of governing the whole country. Five-pagoda Temple has been repaired several times, but the two maidenhair trees nearby, which are the same age as the pagoda, remain green and fresh. They grow within a foot of each other and haven’t separated for thousands of years. We saw the stone rubbings of Nalan Murong’s epitaph at the Art Museum of Stone Carving. That name may not be familiar to everyone, but many people know his poem: “if lovers live their lives blissfully like the day they first met, why do they still part in sorrow?” The number one composer of poetry in the Qing dynasty, Nalan had great literary talent, character, a good nature, wealth, power, high family status, and much kindness. There was no other like him in any time and in any land, but he died young due to the envy of God. In addition, Yijing Ni, who had researched comparative culture, said that Nalan had strong compassion and worried about other people’s suffering.

Five-pagoda Temple

The two maidenhair trees beside the repaired temple

A rubbing of Nalan Murong’s epitaph.

When we ended the activity, everyone expressed their feelings. Mr. Zu, who was a newcomer to the Happy Water Tour, was unwilling to come at the beginning, but he gained a lot from this tour. Mr. Zu also shared his musical knowledge with us. Yiking Ni said that she had focused on this activity for a long time, and it was also the first time for her to experience the water tour. She didn’t expect Happy Water Tour to combine the history with nature and to associate the past with the present. That was a shock to her. In consideration of the future, she was thinking about how to attract more people to this program and continue to spread natural and cultural topics. The white-collar worker Miss Wang wanted to become a full-time cameraman for Happy Water Tour. It made her calm down to come so close to nature. Learning about nature and social culture also inspired her. Our literary and history professional Chen Zhou came to understand Nalan Murong from another point of view under Master Ni Yijing’s directions. Our plant expert Nie said he got to know this city anew through the water tour, and that he didn’t expect Beijing, the city so full of tall buildings and large mansions, to have so many interesting places. We can’t explain the joy of sharing our knowledge unless we join the water tour. I came to know the importance of my major. The field of ecology contains great wisdom. I felt responsible for spreading the its theory to the public as a student of this major.
Everyone who took part in the Happy Water Tour was both a teacher and student. We inspired each other.

Translator: Tao Jiang
Proofreader: Judy Chiang