Effect of calcium carbonate on wind erosion: A wind tunnel experiment
,2, Ping Yan1
,2, Xiaonan Meng1
,2, Jinrui Guo1, Yao Qian1
,2, Wei Wu1
1State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China, 2Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing, China
Wind erosion of soil is an important part and primary link of land desertification, has become one of the main ecological environment problems of the world. Impact factor of soil wind erosion mainly focused on the wind velocity, water moisture, vegetation and human activities, etc. Calcium carbonate widely distributes in the soil of arid and semiarid regions and plays an important role in soil physical, chemical and biological properties, and acts as important factor impact soil wind erosion. Some researches show that add different proportions calcium carbonate to different kinds of soil has different influence on soil structure and erodibility, add a certain amount of calcium carbonate in the soil can increase the clay particles and aggregate, so as to improving the capability of wind erosion resistance. But when the amount of calcium carbonate content is higher, it can destroy the mechanical stability of the soil, enlarge soil erodibility. Little is known about the relationship between calcium carbonate content and wind erosion of soil. In this paper, we collected two chestnut soils of eastern Inner Mongolia, and prepared two sets of soil sample with calcium carbonate content of 0, 2, 5, 8 and 12% into the wind tunnel experiment to analyze the relationship between calcium carbonate content and wind erosion. We concluded that: (1) As increase of calcium carbonate content, the threshold velocity increased then decreased, when the calcium carbonate content is around 5%, the threshold velocity is largest; (2) No matter how change of calcium carbonate content in the soil, wind erosion rate were increased as wind speed increased. Under different wind speed, when the calcium carbonate content is 5%, wind erosion rate is smallest, the intensity of wind erosion rate change flat along with the wind velocity; (3) The relationship between wind erosion rates and calcium carbonate content accords with quadratic function, accumulated wind erosion rates of two soil samples are lowest when calcium carbonate content is about 5~7%, the variation of wind erosion rates and threshold value of calcium carbonate content differ with soil properties; (4) Maintaining the calcium carbonate content around 5% may have a significant effect on prevention and control of wind erosion. This article explored the effect of calcium carbonate content on soil wind erosion, and put forward the strategy of prevent and control of wind erosion into practice, so as to provide important theoretical basis for preventing and controlling wind erosion.