An agricultural heartland is sinking
The Hetao Plain is a vast, fertile agricultural area in Inner Mongolia, approximately 250 kilometers long and 50 kilometers wide. For over 2,200 years, since the Qin Dynasty, farmers have diverted water from the Yellow River to irrigate this arid region. The area receives only about 150-200 mm of rain annually but contends with evaporation rates as high as 2,200 mm per year. This climate makes irrigation essential. The modern Hetao Irrigation District covers more than 730,000 hectares and produces much of the grain and oil for China.
To meet the intense water demands of modern agriculture, extensive groundwater pumping supplements the water drawn from the Yellow River. This over-extraction is causing the ground itself to fall. When water is pumped from underground aquifers, the pressure that supports the overlying sediment drops. The fine-grained clays and silts in the aquifer system compact under the weight, leading to a gradual lowering of the land surface, a process called subsidence. The loss of underground water storage is permanent; once the clay layers have compressed, they cannot be refilled. This widespread subsidence now threatens infrastructure and the long-term viability of farming in the region.