根据小江流域1956~2002年的降水资料,运用Mann—Kendall(M—K)非参数检验法和自相关函数,发现1990代降水呈现显著增加的趋势,其降水年均值比前期年均值增加96.5mm(16.2%)。并结合37a气候变化下的蒋家沟高频率暴雨泥石流输沙量时序观测资料,分析了降雨变化与泥石流输沙量的关系,结果显示1990年代泥石流输沙量有显著增加的趋势,1990年代的年均输沙量比前期(1965~1989年)的年均输沙量多91×10^4m^3/a。反映了暴雨泥石流输沙年际变率对降水年际变化的旧应关系。本文已经初步揭示暴雨泥石流灾害活动年际变化的基本规律,并且为未来暴雨泥石流中、短期时间尺度的预测研究提供一条新路。
The result also showed that the average annual rainfall in 1990s was about 96.5 mm ( 16.2% ) larger than that in 1956 - 1989. The variation of annual rainfall and the variation of sediment transport by debris flows at Jiangjia Gully were studied, based on 37years observation data, in order to investigate the impact of climate change on annual sediment transport by debris flows. The result showed that there was significant increase of annual sediment transport in 1990s. Comparison with the annual sediment transport in the period of 1965 to 1989, the increase of average annual sediment transport in 1990s was about 910 000 m^3/yr. This showed that the increase of rainfall resulted in the increase of debris flow sediment transport. This study has revealed the preliminary trends of debris flow annual sediment transport and its relation with the annual rainfall variation at Jiangjia Gully.