干旱地区环境治理的动力学过程研究

Considering the environment management of arid areas in the Northwest China, we have established a dynamic model suitable for soil erosion prediction on the Loess Plateau of China. The simulated results for runoff generation, rill formation and soil erosion are found in good agreement with long-term observations in this region.; We have also analyzed the structure and characteristics of wind-driven sand flows in order to reveal the mechanism of sand storms formation; A coupling turbulent model and TSF subgrid model are proposed. The statistical features and coherent structures of buoyancy turbulence in vegetated layers are obtained based on LES. By comparing water motion in soil under the windbreak planted in different years, we have found that the formation of biological crust skin layer is the major cause responsible for deep rooted bush degeneration, shallow rooted weeds flourishing and the speed up of ecological succession. Finally, we have accumulated two databases for typical observations and experiments of soil erosion and terrestrial processes on the Loess Plateau. Essential progresses in the study of dynamic processes of arid environment management are made during the last four years, thus deepening understanding the turbulence in natural environment, promoting the study of soil erosion by dynamic approach. Very probably, a few results we yielded may directly be applied in the environment management in the Northwest China.

应用湍流、渗流、两相流新成果研究干旱地区土壤侵蚀和陆面过程的机理，建立土壤侵蚀和陆气湍流交换的动力学模式，预测干旱地区的环境演化；由植被、土壤和环境的关系揭示人类活动对土地荒漠化的影响，提出防治土地荒漠化的生态与工程措施，探讨黄河中游治理方案；促进学科交叉与发展，为我国中西部地区干旱环境治理和经济可持续发展作出贡献。