Wednesday, July 18, 2018

Yellow River Decade (2) from Delta to Dongbatou

Green Earth Volunteers (GEV) is one of China's oldest local environmental NGOs. They organized Yellow River Decade trip every year since 2009. In 2017, they arrived at Dongbatou on a bus tour. 

When we stopped at Lankao, a new member joined our team. He was from the Water Resources Research Institute of the Yellow River and his name was Pu Qi. His arrival led us to the discussion of the Yellow River Hydropower Stations. In Pu Qi’s view, as long as floods continued removing sediment from the stations, the task of managing the Yellow River looked optimistic. Yongchen Wang disagreed with Pu Qi's argument and stated that there was no water left to remove sediment.  Which one of these differing views was correct? It was difficult for the reporters and volunteers on the bus to decide. They had only just begun learning about the Yellow River. However, our journey passed through most of the hydropower stations built on the Yellow River so they had more opportunities to learn about the situation later on. We believed that after investigating and discussing the issues of several of the hydropower stations, they would gradually develop an answer.


On our journey from Heze, Shandong to Lankao, Henan, we spent more than an hour in a big rainstorm. The heavy rain obscured the view through the bus windows. After the intense summer heat in Beijing that year, the rain brought with it a cool draft along with landslides, debris flows, and other natural disasters.  These serious disasters and thunderstorms left us feeling worried about the safety of the locals.

When we arrived at Lankao County, we travelled along the Yellow River to Dongbatou. Along the way we saw Paulownia trees which were planted by a group led by the famous Yulu Jiao. When we got to Dongbatou, Pu Qi and the local water authority officials told us about their situation.
 
The Yellow River often silts up and floods. Also, it tends to change courses. There is a saying that says that the yellow river "floods twice every three years and changes course once every century". The middle and upper reaches of the Yellow River flow through valleys among high plateaus. The water there flows very rapidly and sediment is carried downstream by the whitewater. This stretch of the Yellow River hasn't changed much throughout history. The natural diversion of the Yellow River only occurs in the lower reaches of the river past Mengjin, Henan. Due to the large amounts of sediment carried by the Yellow River's upstream portion's rapidly flowing current, heavy silting occurs in the downstream stretches of the river. The mainstream of the Yellow River slows down and causes flooding around its lower reaches and people have started building dams for flood protection. The deposition of silt in these areas have elevated the water level of the river above the surrounding villages. Because of this, the Yellow River usually overflows during the flooding season, which often creates new waterways in low-lying areas, changing the course of the Yellow River. 
Since the beginning of written documentation, there have been numerous records of the Yellow River's activities and natural diversions. According to the statistics from the book, "People of the Yellow River,” written by the Yellow River Conservancy Commission, 1593 floods and 26 major diversions have been recorded throughout history. The most northern diversion of the Yellow River connected with the Hai River and flowed into the ocean. Its most southern diversion connected with the Huai River and flowed into the Yangtze River. Overall, the Yellow River's floodplain covers a vast area  spanning more than 250,000 square kilometers.   Most of the Yellow River's diversions during the Song dynasty around 1128 occurred in the lower reaches of Hua County in Henan and flowed into the Bo Sea in the northeast.  In 1128, in order to prevent a Jin invasion, the Song emperor rerouted the Yellow River's flow from Hua County to the Si River and then into the Huai River. In the following 700 years, the estuary of the Yellow River opened into the East China Sea (now the Yellow Sea). In 1855, the Yellow River burst at Gangwa Xiang around modern day Dongbatou and flowed into North Bank, back to its original course again. After this diversion, the Yellow River flowed northeast through changyuan, Puyang, Fanxian, and Taiqian into Shandong and then flowed past Lijin into the Bo Sea. That is the Yellow River that we know today. On June 27, 1938, the Republic of China attempted to stop the Japanese invasion by rerouting the Yellow River. On June 5, they dug through the Zhaokou embankment in Zhongmu County. However, there wasn't enough water to block the japanese so they destroyed the Huayuankou dike in Zhengzhou. On the 9th ,water flowed though the Huayuankou embankment. After three days, "the river rolled through the embankment, flowing through the mouth of the dam widening it by a hundred meters." Most of the water flowed from the Lu River into the Yen River and then from the Gu River into the Huai River. A small portion of the river flowed through the Wo River into the Huai River. In the 36th year of the Republic (1947) the Yellow River burst at Huayuankou and finally went back to its original course.