After the Battle of Xuzhou in May 1938, the Japanese army began to advance along the banks of the Yangtze River to Wuhan, and the other Japanese army rushed south from north China. According to a book published by the War Department of the Base Camp published by Japan, the Japanese army hoped that all the main forces of China and the factories and enterprises that had retreated here from Shanghai and other places could be combined in Wuhan with these two routes.
On the other hand, the Japanese army will launch the Guangzhou Operation to cut off the supply line, only in this way can the Japanese army win a quick victory. Otherwise, since our geographical and demographic resources are sufficient for self-sufficiency, the war will enter a stage of war of attrition, thus weakening Japan's financial resources.
At that time, all the units in our country that had retreated from the Battle of Songhu, the Battle of Nanjing, the Defense Battle of the National Defense Line, and the Battle of Xuzhou were very tired after several months of marching and fighting, and they also urgently needed to replenish new soldiers, reorganize and replenish weapons and ammunition. New defensive positions and roads were also built in various locations in Hubei, centered on Wuhan.
The Japanese army is also rapidly increasing its strength, replenishing supplies, concentrating 14 divisions and regiments, as well as a large number of artillery, engineers, communications troops, hundreds of aircraft, thousands of artillery more than 300,000 troops ready to launch an offensive from both sides of the Yangtze River. More than 1 million people in the 14 main armies of our country are also concentrated here to prepare for battle.
At this time, in the north, there was no more troops sent in the Henan Great Plain to defend the Japanese army from the north, if the Japanese army successfully went south, then the Japanese army from the south and the 2nd Japanese army from the east formed a large encirclement in the entire Wuhan area, and a million troops were all encircled, which was also the last main force.
Therefore, on June 9, the levee on the south bank of the Yellow River was exploded at the garden mouth near Zhengzhou, directing the raging Yellow River water to a large plain in the southeast, and this catastrophic flood also broke the Attempt of the Japanese Army to take Luoyang directly along the Longhai Road, from Zhengzhou to the south along the Pinghan Road to capture Wuhan, and to annihilate our main force east of the Pinghan Road, although the flood only drowned less than 200 Japanese troops, but it made it impossible for the Japanese army to continue marching.