Threshold sediment flux for the formation of river deltas in Hainan Island, southern China  

华南海南岛河口三角洲形成的沉积物通量阈值（英文）

作　　者：LI Gaocong ZHOU Liang QI Yali GAO Shu 李高聪;周亮;祁雅莉;高抒

机构地区：[1]Collaborative Innovation Center of South China Sea Studies, Nanjing University [2]State Key Laboratory for Estuarine and Coastal Research, East China Normal University [3]College of Electronics and Information Engineering, Guangdong Ocean University

出　　处：《Journal of Geographical Sciences》2019年第1期146-160,共15页地理学报（英文版）

基　　金：National Natural Science Foundation of China,No.41530962,No.41706096;supports in part by the China Scholarship Council,No.201606190151

摘　　要：The knowledge of geomorphological evolution from an estuary to a river delta is necessary to form the formulation of comprehensive land-ocean interaction management strategies. In this study, the dominant factor controlling the geomorphological variability and the threshold sediment flux (TSF) to form a river delta in Hainan Island, southern China, including accommodation space, sediment supply, and reworking forces, was investigated by the method of big data analytics. The results indicated the 25 estuaries in consideration can be divided into three geographical groups, i.e. the multi-factors-controlled northern mixed estuaries, wave-dominated western estuaries with river deltas, and typhoon-dominated eastern coastal lagoon estuaries. For alluvial plain (AP) estuaries, the order of magnitude of TSFs is the smallest (10¹ kt·yr^-1), for barrier-lagoon (BL) ones is the highest (> 10² kt·yr^-1), and for drowned valley (DV) ones is moderate (10² kt·yr^-1). The river deltas associated with DV systems should be relatively large, and those related to BLs should be small, with the AP deltas being between the above mentioned types. The present study provides a technique to evaluate the role played by TSF for the formation of river deltas in micro-tidal and wave-dominated and typhoon-influenced coastal environments.The knowledge of geomorphological evolution from an estuary to a river delta is necessary to form the formulation of comprehensive land-ocean interaction management strategies. In this study, the dominant factor controlling the geomorphological variability and the threshold sediment flux(TSF) to form a river delta in Hainan Island, southern China, including accommodation space, sediment supply, and reworking forces, was investigated by the method of big data analytics. The results indicated the 25 estuaries in consideration can be divided into three geographical groups, i.e. the multi-factors-controlled northern mixed estuaries, wave-dominated western estuaries with river deltas, and typhoon-dominated eastern coastal lagoon estuaries. For alluvial plain(AP) estuaries, the order of magnitude of TSFs is the smallest(10~1 kt·yr^(–1)), for barrier-lagoon(BL) ones is the highest(>10~2 kt·yr^(–1)), and for drowned valley(DV) ones is moderate(10~2 kt·yr^(–1)). The river deltas associated with DV systems should be relatively large, and those related to BLs should be small, with the AP deltas being between the above mentioned types. The present study provides a technique to evaluate the role played by TSF for the formation of river deltas in micro-tidal and wave-dominated and typhoon-influenced coastal environments.

关 键 词：ESTUARINE GEOMORPHOLOGY DOMINANT factor TYPHOON processes THRESHOLD sediment flux river delta HainanIsland 

分 类 号：P343.5[天文地球—水文科学] P512.2[天文地球—地球物理学]