通过对不同发育年限结皮的生态调查和水文物理试验分析以及天然降雨后土壤水分动态的连续监测,分析了不同发育年限的结皮对于包括降雨截留、入渗、土壤水分再分配及土面蒸发在内的土壤水文过程的影响。结果表明,除容重外,结皮厚度、紧实度、粘粉粒含量、有机质、全氮含量均按21世纪初〈1990s〈1980s〈1970s〈1960s中期〈1960s初期的顺序依次增加;结皮层截留降雨和土面蒸发随着结皮发育年限的增加而呈增加趋势,而降雨入渗深度随结皮发育年限的增加呈下降趋势;与上述水文过程的年代演替规律不同的是,结皮对土壤水分再分配的影响具有一定的时空异质性,0—20cm水分入渗占入渗总量的90%以上,且0—10cm和10—20cm水分补给活跃层水分规律不具有同步性;随着土壤水分再分配阶段的不同,各年代样地表土水分先随着固沙年代的增加而增加,而后以80年代为分界土壤水分向两侧递减。
This paper synthetically analyzed the effects of soil crusts of different development years on soil hydrological processes including rainfall interception, infiltration, soil water redistribution, and surface evaporation, based on a series of field ecological investigation and experimental analysis of soil crusts and their hydrological properties, as well as continuous dynamic monitoring of soil water content after natural rainfall. The results showed that for soil crusts of different decades, except bulk density, soil crust properties such as thickness, compaction, clay and silt particle content, organic matter content and total nitrogen content all listed according to the following sequence: early 21^st century〈1990s〈1980s〈1970s〈mid 1960s〈early 1960s. Rainfall interception and surface evaporation of crust layer increased, while depth of rainfall infiltration decreased, with the increasing years of soil crust development. However, the impacts of soil crusts on soil moisture redistribution showed spatial and temporal heterogeneity, with 90% of water infiltration amount in 0-20 cm soil layer. Besides, the change law of soil water did not synchronize in 0-10 cm and 10-20 cm soil layer. Across different stages of soil water redistribution, the surface soil water content increased with the increasing duration of dune fixation at first, then peaked in 1980s and finally decreased.