绿洲—沙漠交错带沙漠扩散预测模型——以新疆民丰县为例

近年来,沙漠化问题日益受到关注,虽然各学科有关沙漠化的研究很多,也取得了显著的成果,但是在微分方程领域中有关沙漠化的研究却相对很少,在国内几乎空白。通过讨论绿洲—沙漠交错带中沙漠与绿洲之间的相互作用关系,参考传染病模型,根据数学物理原理建立了沙漠扩散预测模型,最后以民丰县为例验证了模型的正确性。利用龙格-库塔方法对数学模型进行了数值模拟,并与遥感图像处理技术相结合对民丰县绿洲进行了沙漠动态变化分析与预测,得到了较理想的结果,预测得到的结果与实际数据之间的偏差合理。提出的数学模型简单且实用,在预测和治理沙漠扩散工作中具有较大意义。

绿洲-沙漠交错带沙漠扩散预测模型的改进

近年来,沙漠化问题日益受到关注,虽然各科学有关沙漠化的研究较多,也取得了显著的成果,但是在微分方程领域中有关沙漠化的研究却相对很少.通过讨论绿洲-沙漠交错带中沙漠与绿洲之间的相互作用关系,参考传染病模型,根据前人提出的非线性项为乘积形式的沙漠扩散预测模型的基础上建立了新的非线性项为比例依赖函数的沙漠化预测模型,最后以民丰县为例验证了模型的正确性.利用龙格-库塔方法对数学模型进行了数值模拟,并与遥感图像处理技术相结合对民丰县绿洲进行了沙漠动态变化分析与预测,得到了较理想的结果,预测得到的结果比前人得到的结果好,与实际数据之间的偏差更合理.提出的数学模型简单且实用,进一步更好地反映了研究区域的环境变化,在预测和治理沙漠扩散工作中具有较大意义.

Investigations on Several Mechanical Problems in Windblown Sand Movement

It is very necessary for investigation on mechanism of windblown sand movement to understand and find out effective measures of preventing and reducing windblown sand, This also deals with some general features and hot spots in the scientific forelands. such as multi-scale problems. interactions among. multi-physical-fields, randomness and nonlinearity as well as complex systems. In recent years, a series of experiments in wind tunnels and theoretical modeling as well as computer simulation have been taken by our research group （the Laboratory of Environmental Mechanics on Windblown Sand Movement in Lanzhou University ）in a cross-disciplinary （mechanics and geography） viewpoint. Several original and essential studies were explored such as the main regularities of charges on sand particles, the mechanisms of electric field in windblown sand flux, the effects induced by the electric field on the flux, the microwave propagations, the evolution process of windblown and flux under mutual couple interations among several physical fields, and the simulation of the main features of Aeolian sand ripples.