论文部分内容阅读
以西藏喜马拉雅山地区的冰湖为研究对象,基于现有的冰湖溃决预测方法,提出了建立冰湖溃决预测方法的关键点,即选取的指标必须能够体现冰湖的动态变化特征.在定量分析的建模过程中应该采用不确定性的数学理论,对于冰湖溃决可能性的等级划分需要进行合理性及实用性验证.选取坝顶宽度、湖水面距坝顶高度与坝高之比、冰湖面积和补给冰川面积为预测指标,通过对西藏喜马拉雅山地区29个冰湖样本进行逻辑回归分析,建立了冰湖溃决的预测模型,并用所有样本进行了交叉验证.结果表明:该模型能够在分类应用中取得较好效果,根据溃决冰湖累积百分数随冰湖溃决可能性大小的变化曲线,将冰湖溃决的可能性划分为四个等级.以黄湖为例,把湖水面距坝顶高度与坝高之比作为冰湖溃决的诱变指标,分析了冰湖溃决可能性大小的变化规律.结合现有的冰湖溃决预测的定性方法,讨论了所建立的冰湖溃决预测模型的优点和缺点.
Taking the glacier in the Tibet Himalayas region as the research object, the key point of establishing the predicting method for the glacial lake collapse is proposed based on the existing prediction methods of the glacial lake collapse prediction. That is, the index selected must reflect the dynamic characteristics of glacial lake. The mathematical model of uncertainty analysis should be adopted in the process of modeling and the rationality and practicability verification should be carried out for the grade classification of glacial lake probability of failure.Choosing the width of dam top and the ratio of dam height to dam height, Ice lake area and recharge glacier area as prediction indexes, a prediction model of glacial lake collapse was established by logistic regression analysis of 29 ice-lake samples in the Tibet Himalayas region and cross-validation was performed with all the samples.The results show that this model can According to the change curve of cumulative percentage of ice-lake collapse with the possibility of ice-lake collapse, the possibility of ice-lake collapse was divided into four grades.With Huanghu Lake as an example, The ratio of the height of the roof to the height of the dam is taken as a mutagenic index of the glacial lake rupture and the changing law of the possibility of the glacial lake rupture is analyzed. The qualitative and quantitative methods are discussed, and the advantages and disadvantages of the ice-lake prediction model are discussed.