砾石覆盖层截留降雨的模拟实验研究

砾石覆盖技术可减少土壤水分蒸发，在世界的一些干旱半干旱地区得到了不同程度的应用。但在降雨时，雨水通过覆盖层进入土壤的过程中，覆盖层也会截留一定的降雨量。此文通过模拟降雨实验，表明：在降雨强度、降雨历时和铺设方式等相同的条件下，烘干砾石的吸水量随着降雨历时的延长而增大，并逐渐达到饱和吸水量；烘干砾石达到吸水饱和所需的降雨历时随着砾石平均等效粒径的减小而缩短；随着砾石平均等效粒径的增加，覆盖层砾石颗粒间的滞留水量逐渐减少；饱和砾石覆盖层的截留水量也逐渐减小，用指数衰减拟合模型进行拟合，具有高度的显著性。

Rainfall Simulation Experimental Study on Rainfall Interception by Gravel Mulch

Gravel mulch technique can reduce soil moisture evaporation, some of the world’s arid and semi-arid areas have been varying degrees of application. However, the mulch will also retain a certain degree of rainfall when raining and rain water into the soil passing through the gravel mulch. The simulated rainfall experiments were carried out. The results indicated that the amount of water absorption of baked gravel increasing as the rainfall duration prolonging, and gradually reached the saturated water adsorptive value under the same conditions with the same rainfall intensity, rainfall duration prolonging, gravel paving pattern. The rainfall duration of baked gravel gotten to the saturated water adsorptive value was shortened as the gravel average equivalent diameter reducing. Rainfall interception and water retention among particles in gravel mulch gradually reduced with the gravel average equivalent diameter increasing. The relation between rainfall interception and gravel average equivalent diameter was fitted by exponential decay model as the gravel average equivalent diameter increasing. The data fitted was highly significant.