砾石覆盖固沙措施水土保持作用研究——以库布齐沙漠北缘为例

库布齐沙漠发展沙产业,风沙防护是必要举措。通过风洞试验与野外观测探讨了砾石覆盖固沙措施的风沙防护效益及其对土壤温湿度的影响,旨在为砾石覆盖在库布齐沙漠防风固沙中的应用提供科学依据。研究表明:3cm粒径砾石床面具有显著的防风固沙效应:10~16m/s试验风速下,10%~90%覆盖度砾石床面风蚀防护效应介于49.4%~100%,其中,50%覆盖度砾石床面空气动力学粗糙度达到最大值,风蚀防护效应在96%以上,已达到理想的防风固沙效果。鉴于库布齐沙漠风况特征,从工程防护角度讲,40%覆盖度砾石覆盖固沙措施能够达到防风蚀的目的,风蚀防护效应在93%以上,且能起到白天降温、夜间保温的作用,减少极端气温对作物的伤害,还能提高土壤含水量。本研究可为砾石覆盖固沙措施在干旱区风蚀防护中的应用提供借鉴作用。

Effect of Gravel Mulch on Soil and Water Conversation——A Case Study in the Northern Edge of Hobq Desert

The control of wind erosion is crucial to the development of deserticulture in the Hobq Desert.This study discussed the protective effect of gravel mulch against wind erosion as well as its influence on soil temperature and humidity through wind tunnel experiments and field observation,aiming to provide the scientific basis for the application of gravel mulch to wind erosion control in the Hobq Desert.The results show that gravel beds composed of gravels in 3 cm diameter have significant effect of wind-reducing and erosion control,and the inhibition ratio of wind erosion ranges 49.4~100％.Under experimental wind speeds of 10 to 16 m/s and as gravel coverage reaching 50％,gravel beds are aerodynamically stabile,and the inhibition ratio of wind erosion is more than 96％.In aeolian engineering,gravel mulch in coverage of 40％,with a wind erosion inhibition ratio of more than 93％,can achieve the purpose of preventing wind erosion in the Hobq Desert.Meantime,it can play a role of cooling in daytime and preserving heat at night,thus reducing the damage of extreme temperature to crops and also improving soil moisture content.This study can provide reference for the application of gravel mulch to wind erosion protection in the other arid areas.