海洋地质与第四纪地质2018，Vol.38Issue(1)：11-22,12.DOI:10.16562/j.cnki.0256-1492.2018.01.002
全新世以来亚洲七个主要河口三角洲的生长极限
Modeling the growth limit of seven major Holocene river deltas in Asia
摘要
Abstract
River deltas grow in response to sediment discharge from the land,and there is a limit of growth.A conceptual geometric model is used in this paper,based on the principle of mass conservation,to investigate the impact of the significant decrease in sediment supply to the growth of deltas taking seven large Asian river deltas as examples.Furthermore,the sediment retention index for the Holocene period,the critical river input for maintenance of a delta and the growth limit without human interferences are discussed.Preliminary analyses of these deltas indicate that the area of delta plain is roughly in an order of 103～ 104 km2,and the volumes of 10～ 103 km3,and both are significantly positively correlated with the fluvial flux before the large numbers of dams being constructed.The range of the Holocene retention index varies between 36％ ～54％,with an average of 45％,indicating that more than half of the sediment escaped offshore and supported the deposition of shelf mud or deep sea fan.For the Yangtze,the Pearl,the Red,the Mekong and the Indus rivers,their sediment discharges are now below the level required to maintain the area of the sub-aerial deltaic plain and the volume of the entire dcltaic deposits,except for the Irrawaddy and the Ganges-Brahmaputra rivers,of which the river discharges are higher than the critical level required to maintain their total volumes,but lower than the critical level required to maintain deltaic plain areas.Without coastal protection projects,the area and volume for the former five deltas would drop sharply,but increase for the latter two.The present study has established the interrelationships between the growth magnitude,Holocene sediment retention index,the critical fluvial sediment flux and the growth limit of the seven Asian major river deltas,demonstrating that the method based on the conceptual geometric model has a great potential to predict the long-term evolution of river deltas.关键词
河口三角洲/概念几何模型/滞留指数/生长极限/亚洲地区Key words
river delta/geometric conceptual model/retention index/growth limit/Asia分类
天文与地球科学引用本文复制引用
李高聪,高抒,高建华..全新世以来亚洲七个主要河口三角洲的生长极限[J].海洋地质与第四纪地质,2018,38(1):11-22,12.基金项目
国家重大科学研究计划项目“扬子大三角洲演化与陆海交互作用过程及效应研究”(2013CB956501) （2013CB956501）
江苏省科技计划项目“古扬子大三角洲沉积体系研究”(BK130056) （BK130056）
国家自然科学基金重点项目“海岸风暴频率-强度关系的沉积记录分析”(41530962) （41530962）
