在次生盐碱区設計排水系统的原则,应該保证地下水位为土壤不致发生盐渍化的水位,一般以临界深度为准。但是这深度在原生盐碱区(濱海盐碱区)未被采纳运用,主要是該数值嫌大。如在盘锦灌区测定潜水蒸发强度资料,当潜水埋藏深度在二米时,潜水蒸发量趋于零。要認为这是抑制土壤返盐的深度,作为排水設計中的依据,则会造成施工和管理上的困 The principle of designing drainage system in secondary saline-alkali areas should ensure that groundwater level is not salinized water level of the soil, generally the critical depth shall prevail. However, this depth was not adopted in the primary saline-alkali region (coastal saline-alkali zone), mainly because the value is too large. As measured in the Panjin irrigation area diving intensity data, when the diving buried depth of two meters, the diving evaporation tends to zero. To think that this is to inhibit the depth of the soil back to salt, drainage design as the basis, it will cause construction and management difficulties