Journal of East China Normal University(Natural Science) ›› 2020, Vol. 2020 ›› Issue (3): 88-97.doi: 10.3969/j.issn.1000-5641.201941006

• Estuary and Coastal Research • Previous Articles     Next Articles

Material flux variation and mechanism analysis of different rivers originating from the Tibetan Plateau

ZHANG Xiaocheng1, JIANG Xuezhong2,3   

  1. 1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China;
    2. Institute for Global Innovation and Development, East China Normal University, Shanghai 200062, China;
    3. School of Urban and Regional Science, East China Normal University, Shanghai 200241, China
  • Received:2019-02-01 Published:2020-05-22

Abstract: Many large rivers in Asia originate from the Tibetan Plateau. Changes in the rivers reflect not only changes in the Tibetan Plateau itself, but also relate closely to water resource utilization in the respective basin countries. Changes in terrestrial materials entering the sea reveal the impact of human activities on land-sea interactions in the basin. With changes in natural conditions and socio-economics, material flux from the basin has evolved over time. In this resarch, material flux was compared quantitatively by analysis of the water discharge, sediment load, and nutrient volumes for elements such as nitrogen, phosphorus, and silicon in the Yangtze, Yellow, Mekong, Indus, Ganges, and Brahmaputra Rivers. In addition, the mechanism of variation was discussed by comparison of two phases of land use and land cover in 1995 and 2015, which were extracted from remote sensed image mapping. The results revealed that the runoff of the Yangtze, Indus, and Brahmaputra Rivers decreased significantly from 1995 to 2015, but the Ganges increased over the same period. The Mekong River runoff changed slightly and fluctuated year to year. However, the sediment transportation from river to sea in the Yangtze, Yellow, and Indus Rivers reduced substantially at a statistically significant level (p < 0.05). In terms of nutrient element flux, the dissolved inorganic nitrogen (DIN) of the Yellow and Mekong Rivers showed an upward trend and the Yangtze River DIN decreased by about 26.5%. The total phosphorus and silicon flux in the Yangtze and Mekong Rivers did not change much, while the dissolved inorganic phosphorus (DIP) in the Yellow River decreased. The nitrogen and phosphorus flux was mainly affected by runoff, and the silicate flux was influenced by variations in sediment loads. Furthermore, dam construction, usage of pesticides and fertilizers, and changes in land use have changed the proportion of nutrient elements. An increase in industrial activity, agricultural development, and water conservancy facilities, resulted in a higher total nitrogen and phosphorus flux and more significant reduction in sediment loads. Understanding the material flux data of each basin is of great significance for management departments to build basins with common goals and use water resources reasonably and effectively.

Key words: basin, material flux, land use change, mechanism analysis

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