The river mouth delta process is affected by river dynamics and coastal dynamics . the process of river delta is estimated by empirical model , analytical model and minimum stream power method . the three models are verified with field data of the yellow river mouth . the computed results are compared with field data . the demerits of the three models are pointed out 采用经验模型、分析模型和最小功率方法研究河口三角洲演变过程.根据黄河河口三角洲资料,利用三个模型计算了河口三角洲岸线或沙咀宽度及岸线的平均延伸情况及对河口近口段河道水位的影响,比较分析了各模型的计算结果,指出了模型不足之处
First of all , the algorithm base on the boundary problem of helmholtz equation and finite - difference technique , calculate the field in “ cold ” cavity and disperse the helmholtz equation , as a result of the formula : ax = x . secondly , according to the eigenvalue of matrix theory and applied iterative methods , eigenmode adopt a numerical approach which allows the improved chebyshev polynomial iteration which based on the power method to extract the isolated eigenmode in the spectrum . finally , we resolve the problem of compatibility in software and insert the eigenmode module into the chipic which will have the function of eigenmode analysis 具体的说: ( 1 )首先以电磁理论中的亥姆霍兹方程的边值问题理论和计算电磁学中的有限差分法为基础,计算冷腔中的场分布并离散亥姆霍兹方程,得到标准的本征值问题: ax = x ; ( 2 )然后根据矩阵理论中的eigenvalue问题和数值计算中的迭代方法,采用改进后的chebyshev多项式,在power迭代法的基础上对ax = x进行多项式迭代,实现对频谱中孤立本征模的萃取; ( 3 )最后将用fortran语言编制的eigenmode模块加入到chipic软件中,解决了eigenmode模块与chipic主代码的兼容问题,从而实现了chipic软件的模式分析功能。
This paper combines the critical rainfall in the typical areas of yunnan province , and carries on the analysis to the critical rainfall situation , and carries on a research to the variety regulation of the critical rainfall of the mountain flood disasters in yunnan province by the application of spacial variogram theory , and the kringing of spacial gridding methods , the inverse distance to a power method , the radial basis function method , and then draws up each isoline maps 采用空间变异理论,应用克里金空间插值分析法、反距离加权插值法、径向基函数插值法对云南省山洪灾害典型区的临界雨量的情况进行对比分析,对其变化规律进行研究,并绘制相应等值线图。