From the late June to the early August, 1932, there was a set of wet and rainy days, the number of the rainy days over 20 in July. There was a flood in the areas of Nen River and its tributaries such as Nuoming River, Alun river, Yin River, Yalu River, Chuoer River, and both the main stream and branches of Songhua River. And the west branches of Wusuli River like Muleng River, Naoli River and some tributaries of Suifen River and Eergunai River like Hailaer River, Wuersun River, occurred spates also. The rainfall of the second Songhua River was more than the normal year. And the stream from the branches of Nengjiang River and Songhua River formed the catastrophic flooding in the main stream of Songhua River.
The rainland is 117°~134°E, 43°~51°N. There are Zhangguangcai Range, Laoye Range and Changbaishan Range in the east and southeast, Lesser Khingan Mountains in the north, and Great Khingan through the west of this rainy area. The terrain is surrounded by three sides of the green mountains on both sides, and the terrain is flat and is conducive to a long and large range of the rainfall.
The measured hydro-meteorological information of 1932 is rather less. In the only 17 precipitation stations, the stations in Hailong, Dehui, Changchun, Qiqihaer, Zhaonan, Haerbing, Dunhua, Manzhouli and Aihui have daily precipitation information, and the other 8 stations like Angangxi, Boketu, Zhalantun, Anda, Yimianpo, Mudanjiang, Meilaer and Tailing only have the information of the monthly rainfall and the maximum daily rainfall in each month. There are 11 Hydrological (water level) stations-Qiqihaer, Fulaerji, Baijikuibao, Haerbin, Xiaogudong, Sanxing, Jilin, Songhuajiang iron bridge, Yinma River, Changchun, Caijiagou. These 11 stations all have the information of daily average water level and highest flood level. Besides, there are some investigation and analytical data in the period of puppet Japanese. The water department had a lot of field investigations after the founding of the People's Republic of China and summarized 116 areas'survey data of flooding.
Precipitation process
From the early of July to the beginning of August, 1932, nearly 40 days, it was been raining all the time in the whole Songhua River , the west branches of Wusuli River and some tributaries of Eergunai River, it was raining almost every day in July. The number of rainy days reached at 26 in July in Haerbin, and the number of rainy days in other stations aslo over 20 days.
And there are three processes of rainstorm below: The first one took place between 17th and 21st in July, 1932, this rain covered the area of Haerbin, Hulan River and the most of the Nenjiang River area, the rainfall in Haerbin for 5 days is 205.2 millimeter. The second one took place at 26th, July, the main area of rain is located in Nengjiang basin, and the rainfall is 152.1 millimeter in Qihaer and 128.7 millimeter in Angangxi. The third one took place at 31st, July, the main area of the rain is in the Suifen River, Mule River, Mudan River, Mayi River and Lalin River sytem. The center of the rain is in the Mule River and the middle and downstream of Mudan River.
The rain in 1932 covered a lot of places. The acreage of where rainfall exceeds 200 millimeter overed 500000 square kilometers in July, and the acreage of where rainfall exceed 300 millimeter overed 120000 square kilometers.
The rain in 1932 lasted a long time, covered a large areas and it was aslo very strong. The daily rainfall of Qiqihaer and Angangxi execeeded their average amount in July of many years, the rainfall in Qiqihaer in July is 1.13 times as much as the average amount, and the rainfall in Angangxi is 1.27 times as much as the average amount. The rain in station Mudan River is 137.4 millimeter in 31st, July, 1932, which is 1.21 times as much as average amount of many years. The rainfall in Haerbin station is 204.9 millimeter in the 18th to 21st four days in July, 1932, which is 1.27 times as much as the average amount.
There are two high-value region of monthly rainfall in July. The first one’s center is the Zranton, on the south slope of Daxing'anling, and the mothly rainfall is 480.4 millimeter which is closed to the average amount 485.8 millimeter. Another one’s center is Haerbing and the monthly rainfall is 500.7 millimeter which is a little less than the average of 545.7 millimeter. The rainfalls in other stations are at least 1 time as much as the average amount of the same time in July. A catastrophic flood was caused in Nengjiang and Songhua River by the rainstorm in 1932. The largest peak discharage in Haerbin is 11500 cubic meters per second, reduction value is 16200 cubic meters per second. This is worst flooding in nearly a century in Haerbin. And the flooding in 1932 is still listed in the top few in the middle and downstream of Nengjiang (such as Lalin River, the downstream of Mudan, and Suifen River) .
The information is provided by Disaster Risk Reduction Knowledge Service.
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