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一、晋中汾河灌区次生盐渍化发生原因 (一)次生盐渍化发展的规律:晋中汾河灌区次生盐渍化的严重性,已引起普遍的注意。就汾西一至四支渠一九六一年土壤调查统计,盐渍土及盐土盐土占总土地面积的86％。次生盐渍化的发展规律非常明显,新灌溉渠投入使用后一、二年内沿干、支渠两侧土壤迅速盐渍化或盐渍沼泽化,继而波及全灌区普遍盐渍化。汾河灌区目前正在这一阶段的初始,其特点是盐斑扩大和大量新盐斑出现。 (二)次生盐渍化发生的原因:半干旱气候及地堑式河流冲积的晋中盆地是该盆地汾河灌区土壤盐渍化的自然环境因素。因此该灌区是在自然盐渍上的次生盐渍化。灌区次
I. Causes of Secondary Salinization in Fenhe Irrigation District in Jinzhong (I) Rules of secondary salinization development: The severity of secondary salinization in Fenhe irrigation district in Jinzhong has caused widespread attention. On the Fenxi one to four branch canal 1961 soil survey statistics, salt soil and salt soil salt accounted for 86% of the total land area. The development of secondary salinization is very obvious. After the new irrigation canal is put into operation, soil salinization or salinization on both sides of the dry and branch channels within a year or two is followed by widespread salinization of the whole irrigation area. Fen River Irrigation is currently at this stage of the initial, which is characterized by the expansion of a large number of salt spots and new spots appear. (B) secondary salinization causes: the semi-arid climate and graben river alluvial Jinzhong Basin is the basin of Fen River irrigation soil salinization of the natural environmental factors. Therefore, the irrigation area is secondary salinization on natural salted soil. Irrigation area times