灌溉对甘肃中部黄土台塬区地面塌陷及生态环境影响研究

甘肃中部黄土台塬地面塌陷实质上是由水利灌溉引起的新的生态环境问题。文章在深入调查、勘测和试验研究的基础上，综合分析了地面塌陷变形的成因机制，认为黄土台塬地面塌陷变形除了黄土母质理化性质和人类活动等因素外，主要是不合理灌溉引起的。过量大水漫灌使大量渗入的水体将土壤中起固结作用的盐分和粘粒矿物淋溶殆尽，使原始结构破坏，进而崩解、湿陷。随下渗水量的增加，犁底层及以下隔水层孔洞进一步发展为洞穴和陷缝，大面积塌陷变形随之出现，同时也成为台塬滑坡的诱导因素。研究为黄土台塬灌区突出的水利环境问题治理和生态重建方案提供了基础依据。

Soil Sink Caused by Irrigation and the Influence on Ecological Environment of Loess Platform in Middle Gansu Province

Abstract: Soil sink is a new problem of ecological environment in middle Gansu province. Based on surveyand test, the cause mechanism of soil sink has been analyzed in this paper. The key factor is irrational irri-gation besides the soil physical and chemical characters. The salinity and clay particle in soil loss alongwith flood irrigation, and the structure of soil is distracted. As the seep water increasing, the holes andfissures are created in the soil, so the loess platfrom is sinking in the process of water seep. Research re-sults has provide important basis for harnessing the process of soil sink and rebuilding the ecological envi-ronment.