Acta Geographica Sinica ›› 2021, Vol. 76 ›› Issue (9): 2312-2328.doi: 10.11821/dlxb202109019

• Climate Change and Land Surface Process • Previous Articles     Next Articles

Spatiotemporal differentiation and development process of tidal creek network morphological characteristics in Yellow River Delta

MOU Kuinan1,2(), GONG Zhaoning1,2(), QIU Huachang1,2   

  1. 1. College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China
    2. MCA Key Laboratory of Disaster Assessment and Risk Prevention, Capital Normal University, Beijing 100048, China
  • Received:2020-10-22 Revised:2021-05-20 Online:2021-09-25 Published:2021-11-25
  • Contact: GONG Zhaoning E-mail:moukuinan@163.com;gongzhn@163.com
  • Supported by:
    National Key R&D Program of China(2017YFC0505903);National Natural Science Foundation of China(41971381)

Abstract:

The tidal creek is the main channel for the interaction of the land-sea ecosystem and has a high degree of spatiotemporal dynamics. Taking the old and new river courses in the Yellow River Delta as the boundary, the North Bank of the Yellow River (Area I), the East of the South Bank (Area II), and the West of the South Bank (Area III) are divided into comparative study areas. Remote-sensing images of five key time nodes from 1998 to 2018 are selected as the data source. Using the GIS spatial analysis function, the typical morphological characteristics of the tidal creek development degree are quantitatively characterized. The influence of factors such as the Yellow River diversion, wetland restoration project, and alien species invasion on the development process of tidal creeks is analyzed. Mining the temporal and spatial evolution of the tidal creek network through morphological parameters. Results are shown as follows. (1) The morphological characteristics of tidal creeks have obvious spatiotemporal heterogeneity. From the early stage of the Yellow River diversion in 1998 to the early stage of wetland restoration in 2004, the number of tidal creeks at all levels in Area I decreased significantly. Owing to the siltation of tidal flats and the effect of Spartina alterniflora, the number, density, and bifurcation ratio of tidal creeks in Area II showed an increasing trend. During the rapid expansion period of Spartina alterniflora in 2013, the curvature and bifurcation ratio of the tidal creek increased significantly. The level, length, and density of tidal creek development in Area III were the highest, as is the frequency of conversion between levels. The wetland restoration project has resulted in a significant reduction in the number and length of low-grade tidal creeks. Strong ocean dynamics inhibited the development of meanders in tidal creeks. (2) The diversion of the Yellow River and construction of side-curved spur dams have led to an increase in the overmarsh path length (OPL). This reduces the drainage density of the tidal creek network The rapid expansion of Spartina alterniflora increased the drainage density and the OPL continued to decrease. The degree of tidal creek development is Area III>Area II>Area I. (3) The tidal creek system changed rapidly from adolescence to middle age, and the development tended to be in dynamic equilibrium. The research results aid an understanding of the development process and evolution mechanism of large-scale tidal creeks, and provide scientific decision support for the development and utilization of coastal tidal flats.

Key words: tidal creek network, morphological characteristic parameter, spatiotemporal differentiation, development stage, Yellow River Delta