塔里木河流域绿洲边缘土壤蒸发与积盐的初步分析

ANALYSIS ON SOIL EVAPORATION AND SALT ACCUMULATION IN THE MARGINAL ZONE OF THE OASES IN TARIM RIVER BASIN

本文通过对塔里木河流域土壤盐分的分析测定，初步研究了盐分积累的特点及其与蒸发的关系：盐分含量高、累积速度快、表聚性强。初步探讨了流域内农田土壤次生盐渍化问题以及减缓和控制其继续发展应采取的决策；兴修水利排灌工程、抑制蒸发等措施。

Secondary salinization of farmland is serious in Xinjiang. Measured from the Soil Map of Xinjiang in Scale of 1: 1, 000,000, salinized farmland area in the whole Xinjiang is 1.263 ×106hm2,and occupies 31. 1 % of the total farmland area of 4. 067 ×106ha, in which the areas of serious salinized farmland, mesosalinized farmland and slight salinized farm land occupy 18%, 33% and 49% respectively. Tarim Basin is surrounded by mountains,and the original soil here contains salt universally. Thus, salt accumulation is violent due to the shortage of pathways for groundwater and salt, extremely arid climate, less precipi tation and violent evaporation.This paper analyzes the relationship between salt accumulation in soil and evaporation of the marginal zone in the oases in Tarim River basin. The features of salt accumulation in the soil are as follows: (1 ) Salinization or alkalinization of soil here is universal, the area of saline soil is vast, and the degree of salinization or alkalinization is high. In the ir reclaimed desert regions, salt content is universally high in the surface soil, and generally,hard salty surface in a thickness of 5~15cm is formed in some part of the region and its salt content is as high as 50~80%. Even is in the irrigatied areas, secondary salinization of soil exists to varying degrees. (2) The speed of salt accumulation in soil is rapid. Some measures are put forward for controlling the salinization of soil in the paper.