摘要
沙坡头地区降水是水份的主要补给来源,占补给总量的98.3％;凝结水仅对一年生短命植物有作用,无明显实际意义,尤其对灌木和半灌木。沙地蒸发散量是主要的消耗项,其占年降水的89.7—112.8％,有负亏缺现象,特别是固沙年代较长地区,人工防护体系发生变化和演替,水分不足是主要原因。热量变化是沙地水分运动的主要动力条件,容积热容量、导热系数、热扩散量是沙地热力学运动的基础参数,它与土壤水分和干容重相互制约,壤中热流和壤中水流耦合运动研究将进一步揭示水分运动规律的实质。
Precipitation is the main replenishing source of water supply in the Shapotou area, it accounts for 98. 3% of the total water supply source. Compared with precipitation condensation water counts for nothing in water supply although it is good for the annual ephemeral plants. Evapotranspiration of sandy land is the main consumptive term, it constitutes 89. 7-92. 8% for different afforested structure with different sand-fixing ages. Sometimes, there occur deficits of evaporation, especially in the sand-fixing areas with a onger period. The biological crusts could retain rain water, this will increase evaporation loss, decrease effective infiltration and finally lead to the changes and succession of artificial protective system.
Thermal change is the main dynamic condition for water movement in sandy land, while the volumetric heat capacity, heat conductivity and heat diffusivity are the basic parameters of thermodynamic movement in sandy land . All these factors are interacted with soil moisture and dry bulk density. A further study on the coupling movement of heat flow and water flow will contribute to reveal the nature of water movement laws.
出处
《中国沙漠》
CSCD
北大核心
1991年第2期1-10,共10页
Journal of Desert Research
