During that period, the water level exceeded the danger line for more than two months, and the highest water level in history continued for more than a month. Sections of the Chang Jiang are prone to flooding. The river's total length is 6,300 km, and runs from the Tibetan Plateau and the Sanxia area in the high-altitude west, to the central plains area, where it suddenly begins to flow gently. According to survey results by experts, this incredible activity was caused mainly by the washout of sediments brought on by destructive deforestation, and by the reclamation of land in rivers, lakes, and marshes, which crippled the region's ability to accommodate occasional flooding. For thousands of years, the pressure of increasing population in China has forced reclamation that often plunders natural resources in the regions, especially the destruction of forests.
Forests are a scarcer resource than are arable land, fresh water, and minerals.
The destruction of forests not only caused the inability to retain water, but also the expansion of washouts. The area of washouts in the Chang Jiang river basin expanded from 36 million hectare in the 1950s to 56 million hectare in the 1990s, and accounted for a third of the drainage area. The annual amount of washouts has reached 2.24 billion tons, most of which are settled in river and lake beds. More serious topsoil washouts occur in Huangtu Kaoyuan, in the river basin of the Huang He, the second-largest river in China. Some experts fear that cities in the area will be buried like Pompeii in ancient Rome.