关键词: 黄土台塬, 地面塌陷, 成因, 生态环境

Abstract: Soil sink is a new problem of ecological environment in middle Gansu province. Based on survey and test, the cause mechanism of soil sink has been analyzed in this paper. The key factor is irrational irrigation besides the soil physical and chemical characters. The salinity and clay particle in soil loss along with flood irrigation, and the structure of soil is distracted. As the seep water increasing, the holes and fissures are created in the soil, so the loess plat from is sinking in the process of water seep. Research results has provide important basis for harnessing the process of soil sink and rebuilding the ecological environment.

Key words: loess platform, soil sink, cause, ecological environment