The Four Mysteries of Daming Lake have been around for a long time. Wang Xiangchun, a great left-wing poet in the late Ming Dynasty, once recorded it in detail in his "Qiyin·Daming Lake" - "The lake is in the city, and there is nothing in it. The difference is that it never swells when it rains, and never dries up after a long drought." "As for the snakes not appearing and the frogs not croaking, it is strange." This article was later included in the "Licheng County Chronicle" by the Qing Dynasty. It should be the earliest written record of the four monsters of Minghu Lake. These are the "four strange things" in Daming Lake that are well-known to people in Jinan - frogs do not crow, snakes are hard to find, drought does not fall for a long time, and rain does not rise for a long time. Snakes do not appear: The so-called "snake does not appear" is because there are many water birds in Daming Lake, making it difficult for snakes to survive in it. Constant rain does not rise: The so-called "constant rain does not rise" is because Daming Lake has many water outlets. When the water rises, it will naturally flow out. The so-called "long-lasting drought never dries up" is because the bottom of Daming Lake is made of fine igneous rock, which prevents the spring water that continuously flows into the lake from flowing down. Frogs don’t crow: No one has been able to find a reasonable answer to the so-called “frog doesn’t crow” mystery in Daming Lake. There is a beautiful legend about the strange phenomenon of frogs not crowing and snakes not appearing in Daming Lake, but it has been proven to be fabricated by later generations. Around the time of Qianlong in the Qing Dynasty, Emperor Qianlong went to the south of the Yangtze River and passed by Jinan. After visiting Baotu Spring, Qianfo Mountain and other scenic spots, he came to the Lixia Pavilion on the bank of Daming Lake to rest at noon. When the True Dragon Emperor came to Daming Lake, it naturally alarmed all the gods in Daming Lake. So a hundred frogs chirped, snakes gathered, and birds and insects flew over Daming Lake. All living beings hoped to catch a glimpse of the Emperor Dragon. Yan. But Emperor Qianlong, who was already very tired, wanted to rest at this moment, but the snakes, frogs, and birds outside the window were not interested in joining in the fun. So Long Yan was furious, slapped the table, and issued an imperial edict, ordering: "Snake Returning to the cave, the frogs don't crow." Seeing Long Yan, the creatures were furious, so they immediately ran away in panic. Since then, snakes have never been seen in Daming Lake, and frogs can no longer be heard. Of course, this so-called folk saying is naturally made up by people. You must know that as early as the Wanli period of the Ming Dynasty, Wang Xiangchun had recorded the four monsters of Daming Lake. Therefore, this statement was only made by the Qing Dynasty to please Qianlong. It's just a fabrication made by people. People who have lived in Jinan for a long time almost all know that there are "four strange things" in Daming Lake - snakes never appear, frogs never crow, constant rain never rises, and prolonged drought never dries up.
With the advancement of science and technology, the natural ecological mystery of Daming Lake’s “no snakes and no frogs” has long been solved. It turns out that the reason why the "snake disappeared" is because there are many ospreys and other waterfowl in the lake, and they are the natural enemies of snakes. The frogs in Jinan City never crow. Although the frogs in the city don't crow, once you get outside the city, their croaking can keep you up all night. Comparing the two can't help but make people feel strange. Therefore, it has become an issue of concern and interest to people for many years. Legend has it that when Emperor Qianlong went to the south of the Yangtze River and passed through Jinan, he lived by Daming Lake. Because the noise of the frogs disturbed his sleep, he ordered that no frogs were allowed to cry again in the city. From then on, no frogs were heard in Jinan City until now. Therefore, whenever someone asks why the frogs in Jinan do not crow, the old people always answer this. In fact, this is just a legend and has no scientific basis. According to current scientific explanations, this is because the spring water that gushes out of the ground in Jinan City has a low water temperature. Frogs living here cannot go into estrus, so they do not scream. When the spring water flows out of the city and joins the ground, the water temperature increases, and the frogs live normally here. When they are in estrus, they will naturally scream. This has nothing to do with Emperor Qianlong who came to Jinan.
As for the fact that Daming Lake never swells when it rains and never dries up after long periods of drought, it is closely related to the special geographical environment and natural composition conditions of Daming Lake. Daming Lake is formed by the confluence of many springs in Jinan. The spring water flows in from the south bank. When the water overflows, it can flow out from the Beishui Gate built on the north bank in the Song Dynasty, flow into the Xiaoqing River, and pour into the Bohai Sea in the east. This excellent dredging channel is not available in many other natural lakes. The bottom of Daming Lake is impermeable igneous rock, which prevents the spring water that continuously flows into the lake from flowing down. This results in "constant rain does not rise and long drought does not dry up", allowing the lake to maintain a relatively fixed water level all year round.