摘要: |
以灰数的白色函数生成为基础,建立白化形式的微分方程,来预测坝址每年丰水期、枯水期平均流量,结合三峡工程建库前后不同时空边界条件的分析计算,从而预测出三峡工程对洞庭湖区洲滩面积变化趋势的影响.灰色系统的预测简称灰色预测,它的特点是基于灰色系统的模型进行未来系统变化的预估.本文对洞庭湖洲滩面积的预测,采用灰色拓扑预测.其基本思路是将样本信息作成曲线,在曲线上按某个定值找出许多发生时刻数据,然后用时刻数据分别建立GM(1,1)模型群以预测这些定值未来出现的时刻,将各个未来发生的定值联成曲线,以了解整个数据曲线未来的发展变化. |
关键词: 灰色预测 流量过程 洞庭湖 洲滩面积 |
DOI:10.18307/1998.0414 |
分类号: |
基金项目:国家自然科学基金,9479022 |
|
Influence of the Three Gorge Project on Marshland in Dongting-Lake Area by Grey System Theory |
Wang Xiang-san, Li Da-mei
|
Wuhan University of Hydraulic and Electric Engineering, Wuhan 430072
|
Abstract: |
Based on the grey white function generation of Grey System Theory, a whitened differential equation has been established. It can be applied to forecast the discharge regime at the Three-Gorge Project (TOP) Dam site under flood and dry seasons. According to the variations of discharge with/without building TOP, the corresponding influence upon the marshland around Dongting Lake has been forecasted. In the Grey Syetem Theory a sample information curve is plotted first. After finding a series of time parameters at the curve on the basis of definite values, the GM (1.1) model group of the time parameters is set up. Different regimes such as 1974-type and 2000 year are considered. Based on the forecasted discharges before/after building TOP in Chenglinji Hydrological Station, the marshland decreases in East,West, South Dongting Lake areas are predicted respectively. Preliminary results show that there will be a 12. 1%-24. 9% decrease for the 1974-typo,a 17. 7. 1 %-26. 0% decrease for the 2000 year. Further analysis reveals that the decreases of marshland turns out to be greater in West Dongting Lake area than those in East Dongting Lake area. |
Key words: Grey Forecasting Three-Gorge Project Dongting Lake marshland |