蒋家沟泥石流输沙年际变化及其灾变预测

Variation Property of Annual Sediment Yield of Debris Flow along Jiangjia Ravine and Catastrophe Forecast

根据云南东川蒋家沟泥石流年输沙量的时序资料,分析了蒋家沟泥石流输沙的年际变化特征,发现历年输沙量变动幅度大,波动明显且年际变化频繁,用灰色系统理论的灾变预测方法,建立泥石流年输沙量的等维新息灾变预测模型,能够对未来可能出现的灾变年份进行较好的预测。在前期研究基础上,补充最新观测资料,建立了新的灾变时间序列和相应的等维新息灾变预测模型,使蒋家沟泥石流的年输沙量灾变预测得以连续进行,并对预测结果进行了检验,效果较为理想。

Annual sediment yield of debris flow is an important physical index that reflects both the forming condition, carrying ability and potential danger degree. Thus the sediment yield of debris flow is of great significance to the design of prevention and mitigation projects against debris flow hazard. Based on the sequential data of the annual sediment yield of debris flow along Jiangjia ravine, it can be found that the annual sediment yield has been changing year by year with large scope and high frequency. Several fitting methods such as linear fitting, logarithmie fitting, polynomial fitting and exponential fitting had been tried, but all the results were unsatisfied with R^2 〈 0. 1. In this paper, based on the sequential data of the annual sediment yield of debris flow along Jiangjia ravine, the variation property of the annual sediment yield was analyzed and then was forecasted according to the equal dimension-new information model of grey theory, which makes the short-term catastrophe forecast for the annual sediment yield of debris flow can be done continuously. This research provides some useful results for the forecast of occurrence year with large magnitude of debris flow in Jiangjia ravine.