The rumor that the underground of Linyi is a sea is derived from the rumor that the underground of Linyi is not a sea, which is just a rumor. Linyi is not a coastal city, and there are indeed abundant groundwater resources in the depths of the land under its feet. Most of the water used by residents and industrial production comes from groundwater. Geological experts have never stopped studying the distribution of groundwater in Linyi.
The abundant groundwater in Linyi flows along different aquifers and water storage structures, or surges, permeates or accumulates. The border of country-specific mountains can generally reach the water-rich area about 2 meters underground. Water-rich areas are not groundwater that is customarily understood as rivers, but exist in underground strata in three states: pore water, fissure water and karst water.
Linyi landform
Linyi is surrounded by mountains in the west, north and east, and forms a fan-shaped alluvial plain to the south. The area ratio of mountains, hills and plains is 2: 4: 4. The mountainous areas are concentrated in Yishui, Yinan, Mengyin, Pingyi, Feixian and Junan counties. The terrain is relatively high, generally more than 4 meters above sea level. Mountain vegetation is dense, which is the main base for developing forestry, fruit industry and animal husbandry.
the hills are mainly distributed in the periphery of mountainous areas, such as Yishui, Yinan, Junan, Lanshan, Lanling, Linshu, Tancheng and Pingyi, with the widest distribution in the east of Shuhe River, which is generally 2-4 meters above sea level. There are three main mountain ranges in Linyi from north to south, namely Yishan, Mengshan and Nishan, and there are more than 1 peaks above 1 meters above sea level.
what are the above references? Baidu encyclopedia-Linyi