珠江三角洲地形不均匀变化对区域闸群适应性影响研究

Study on the influence of terrain uneven processes to the sluice group adaptability in the Pearl River Delta

近40年来,由于人类活动影响,珠江网河区地形大幅不均匀下切,径潮动力条件发生剧烈变化,水闸的实际运行效果需要多指标的综合定量评价。采用以区间数代替点值数构造判断矩阵的可拓层次分析法,引入精度更高的指数标度,建立多指标的闸群适应性综合评价体系,定量评估水闸防洪挡潮综合效应。以珠江河网七大代表水闸为例,评估了1977年、1999年和2008年地形变化前后闸群不同调度方式下的水闸防洪挡潮效果。结果表明:建闸后较建闸前适应性等级提升,建闸达到了“控支强干”目标,减轻了支流的防洪压力;河网地形下切导致水位降低,潮动力增强,地形不均匀下切后闸群适应性增强。研究成果可为河网水闸适应性评价、水闸建设及调度规划提供参考。

Due to the influences of human activities,the topography of the river network has been unevenly cut greatly,and the hydrodynamic conditions were changed seriously in the past 40 years.It is urgent to evaluate the actual operation influence of the sluice gate group.In this paper,the extension analytic hierarchy process,which replaced the number of point values with the number of interval values to construct the judgment matrix.The index scale with higher precision was introduced to establish multi-index evaluation system for the adaptability of sluice group to quantitatively evaluate the influence of flood control and tide prevention of sluice gate group.Seven sluices of the Pearl River Network were used as an example,the flood control and tidal prevention influences of different operation modes of sluice groups before and after topographic changes were evaluated in 1977,1999 and 2008.The results show that the adaptability score after the construction of the sluice gate is higher than that before the construction of the sluice gate,which achieves the purpose of"controlling tributaries and strengthening the trunk"and reduces the flood control pressure of the tributaries,topographic cutting of river network leaded to the decrease of water level and the enhancement of tidal dynamics,the gate group adaptability score increased after terrain cutting.