小波分维估计法在三峡水库汛期 洪水分期中的应用

汛限水位分期控制能在不降低水库防洪标准的条件下提高水能资源利用效率，而洪水分期是汛限水位分期控制的前提.以三峡水库洪水资源高效利用为背景，在分析三峡水库上下游水文气象特征的基础上，根据水文序列的自相似性，由统计分析法确定了宜昌站洪水分期数目，并选择Db4为小波基，以Mallat算法为基础，提出了小波分维估计法计算模式并计算了宜昌站各分期的分维数，最后确定了三峡水库的汛期洪水分期。结果表明，以小波分维估计法划分的洪水分期与传统研究分期结果一致，但小波分维估计法计算简便，所得分维数结果稳定，表明小波分维估计法应用于洪水分期是可行的和有效的.

Application of wavelet fractal dimension estimation method to flood season staged of Three Gorges Reservoir

Adjusting flood control limited level in phases scientifically will improve water resources utilization ratio without abating the flood control standard of reservoir, and the reasonable partition of the stage in the flood season is the precondition of controlling the limited water level by stage. Therefore, on thebackground of Three Gorges Reservoir flood efficient utilization and on analyzing hydrological and meteorological characteristics of upstream and downstream of Three Gorges Reservoir, according to self-similarity of hydrological series, determining the number of flood season staged on the basis of statistical analytical method,choosing the Db4 wavelet and Mallat algorithm, the computation mode of wavelet fractal dimension estimation method is proposed and every stage's fractal dimension of Yichang gauging station is computed, then the final flood season staged is given. The resultsdemonstrate the periods of Three Gorges Reservoir determined by adopting wavelet fractal dimension method are consistent with that from traditional method, but the fractal dimension result by former method is easier and more stable which ensuring the feasibility and validity of the wavelet fractal dimension method applying to the flood season staged and need deep study.