沙地地区水文过程及模拟——以秃尾河流域为例

根据气候条件的不同,沙漠可分为沙质荒漠和沙地两种类型.其中沙地地区降水相对丰富,具有降水、蒸发、下渗、产流及汇流等过程的相对完整的水文过程,但已有研究较少.以黄河中游沙地地区的秃尾河为例,分析了沙层水分分布及演化特性,进而将整个水文过程进行概化,得到物理意义明确,结构简单的概念性水文模型.该模型应用方便,精度较高.研究定量地阐明,研究区域沙层孔隙特征决定了沙层水分易保存而不易蒸发,使该地区径流深相对较大,而地下水丰富,调节能力强,是该地区河流径流年内分配均匀,年际变化小的重要原因.流域的非闭合性是该类地区水文研究中需要重点考虑的问题.

Hydrological Processes and Simulation in Sand Land: A Case Study of the Tuwei River Basin

Desert can be divided into two types of sandy wilderness and sand land, according to different climate conditions.Sand land has relatively rich precipitation and integrated hydrological processes in cluding precipitation, evaporation, infiltration,runoff yield and flew concentration. However, there is only a little research on the hydrologic processes in sand land. Takingthe Tuwei River in the middle reaches of the Yellow River as a case, this paper analyzed water distribution and dynamicevolution in sand layer, and then developed an explicit and simple conceptual hydrologic model. The model is of convenientapplication and high precision. The results indicated that pore characteristics enable the storage of water without easy evapora -tion; the runoff distribution is well-proportioned annually and inter-annual variation is slight in this area, which results fromplenty of the ground water and strong ability of modulation. The fact that the basin is usually unclosed in sand land must beconsidered.