Ecohydrological effects of litter cover on the hillslope-scale infiltration-runoff patterns for layered soil in forest ecosystem

Abstract

The litter interception of rainfall have great effect on the water balance in the hydrological process, especially for the process of infiltration and runoff. Infiltration plays a significant role in soil erosion, evapotranspiration, and overland flow. Runoff generation is a main component of the hydrological cycle, and the simulations of soil moisture can improve infiltration process modeling. And hillslope is the basic unit of hydrological response and the key place of hydrological process. It is also the basis of distributed hydrological simulation to explore and understand the hillslope scale rainfall infiltration and runoff generation. A hillslope infiltration-runoff model in mountain area was established, including vegetation and litter interception. Field experiments on runoff yield and confluence of natural precipitation were carried out for model verification, and the simulation results of the present model were compared and analyzed with that of existing hillslope infiltration-runoff models. The results show that compared with existing models, the model proposed in this study can well simulate the runoff and infiltration amount, and the measured values are in good agreement with the simulated ones. However, during storm periods, the simulated infiltration rates are far less than the measured ones. A possible reason is that fragments in soils may cause the formation of fast flow paths in the earth-rock interface，which is neglected in the present model. This model needs to be further refined and improved to consider the priority flow paths inside the soil layers in the hillslope.