JOURNAL OF NATURAL RESOURCES ›› 2019, Vol. 34 ›› Issue (12): 2701-2716.doi: 10.31497/zrzyxb.20191217

• Resource Ecology • Previous Articles     Next Articles

Sediment transport variation and its response to climate and human activities in Tongzi River Basin

TIAN Yi-chao1,2,3,4(), WANG Shi-jie2, BAI Xiao-yong2(), ZHANG Qiang1, TAO Jin1, ZHANG Ya-li1, HUANG Hu4, LIANG Ming-zhong4, ZHOU Guo-qing5, LAO Yan-ling1   

  1. 1. College of Resources and Environment, Qinzhou 535000, Guangxi, China
    2. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
    3. Key Laboratory of Marine Geographic Information Resources Development and Utilization, Qinzhou 535000, Guangxi, China
    4. Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Beibu Gulf University, Qinzhou 535000, Guangxi, China
    5. Guangxi Key Laboratory for Geospatial Informatics and Geomatics Engineering, Guilin University of Technology, Guilin 541004, Guangxi, China
  • Received:2019-05-31 Revised:2019-09-10 Online:2019-12-28 Published:2019-12-28

Abstract:

Based on the long time series data of annual precipitation, evapotranspiration and sediment transport of Erlangba Hydrological Station in Tongzi River Basin from 1975 to 2015, the evolution process and future trend of sediment transport in the past 40 years were quantitatively analyzed by the methods of cumulative anomaly, Morlet wavelet analysis and Hurst index, and the contribution rates of climate change and human activities to sediment transport in the study area were quantitatively assessed by the cumulative slope rate change comparison method. The results indicated that: (1) In the past 40 years, the precipitation in the basin ranged from 608.10 mm to 1132.70 mm, with an average of 829.00 mm. And the precipitation showed no significant decreasing trend, with an average annual decrease of -3.10 mm/a. (2) The annual sediment transport in the basin ranged from 0.44 to 478.01 million tons, with an average of 646.8 million tons. And it showed a very significant decreasing trend, with a reduction rate of -413000 t/a. In the future, sediment transport in the basin will continue to decrease, but it is likely to increase after 10 years. (3) In 1989, the sediment discharge in the basin changed abruptly. Before 1989, it showed an upward trend. After 1989, it showed a significant downward trend. The sediment discharge after the abrupt year decreased by 76.82% compared with that before the abrupt year. (4) The sediment discharge had a 12-year interdecadal oscillation period, forming two high oscillation periods and a low oscillation center. The high oscillation period was observed in 1976-1979 and 1986-1992, and the low oscillation period was found in 1979-1985. (5) The sediment transport in summer showed an increasing trend after 8 years, while there was no continuous cycle in other seasons. (6) Based on the period from 1975 to 1989, the contributions of precipitation and human activities to the sediment transport of Tongzi River Basin reached 4.8651% and 95.1385%, respectively in the period from 1989 to 2015. If the influence of evaporation on the sediment transport of the study area was taken into account, the contribution of human activities to the change of runoff of this basin would increase to 98.65% from 1989 to 2015. The decrease of sediment transport in the basin from 1990 to 2015 was mainly controlled by human activities, which reduced sediment transport by 157 thousand tons annually.

Key words: sediment transport, climate change, human activities, response, Tongzi River Basin