珠江三角洲网河区顶点河道断面侵蚀形态的演变

Variation of River Section Erosion Morphology in Pearl River Delta

[目的]研究断面形态的演变特征,给上游来水来沙、人类活动影响的分析提供检验,也为下游水文地貌的演变提供科学依据。[方法]利用珠江三角州网河区三水站和马口站资料,通过提取反映河道断面侵蚀形态的指标,采用模拟退火算法优化的投影寻踪模型,综合解析河道断面侵蚀形态的演变特征。[结果]由于三水站2009年的虚实比远大于其他年份的虚实比,2009年三水站断面侵蚀形态异于其他年份外,其他年份侵蚀形态的变化较为缓和;对于马口站而言,尽管该断面的侵蚀形态变化较多,但综合5项反映河道断面侵蚀形态指标来看,该断面形态的变化类型总体上可以划分成2种侵蚀类别。[结论]总体上,21世纪初马口和三水站断面比20世纪90年代过水断面增大,断面的过水能力有加大的趋势。

[Objective]To research the erosion morphology characteristics of river section in order to provide a scientific basis for the evolution of landform hydrological of downstream,the analysis of the impact of human activities and the rationality of the runoff（sediment）of upstream.[Methods]Based on the data of Shanshui and Makou stations in Pearl River dalta,Indices of the river section erosion morphology were derived.By using simulated annealing algorithm to optimize the projection pursuit model,we analyzed the evolution characteristics of river erosion morphology.[Results]As the actual ratio in 2009 of the Sanshui station was much higher than that in other years,the river section erosion in 2009 was completely different from other years.Changes in erosion patterns of other years were stable in Sanshui station.For Makou station,in spite of more erosion morphology changes,according to 5indicators which reflect the erosion morphology of river section,the variation types of the section shape can be divided into 2types of erosion morphology.[Conclusion]In summary,the sectional area in Makou and Sanshui station increased since 1990 s,and the water capacity showed an increasing trend.