清江流域地质灾害气象预警预报模型及数值模拟研究

Geohazard early warning and forecast is one of the most effective ways to protect against geohazards and reduce economic loss and casualties, and thus has long been the hot topic in the field of geological disaster research worldwide. From the viewpoint of systematic evolution, geohazards are affected by interactions of the rainfall and the ecological geo-environment that are characterized by openness, nonlinearity and uncertainty. Based on the dynamic principles, the geohazards induced by the different rainfall scales can be studied by analyzing the processes of rainfall duration, rainfall intensity, rainfall biggest initial time and rainfall intensity of different rainfall scales. In this study, the Hunshui River, one tributary of Qing River, is selected for the geohazard meteorological warning and forecast research. On the basis of field investigation and meteorological data, the characteristics of different rainfall scales are analyzed and simulation experiment is performed to inverse the formation process of geohazards induced by the rainfall. According to the coupled analysis of the interaction between the rainfall scales and the ecological geo-environment, the models and numerical simulation of the meteorological warning and forecast are completed. It provides technical support for the geohazard meteorological early warning and forecast in the Qing River Basin and the Three Gorges Region.

地质灾害预警预报是全球地质灾害研究的重要课题之一，是进行地质灾害预防、减少或避免人员伤亡最有效的手段之一。从系统演化的角度来看，地质灾害系统的发展和演化受降雨及生态地质环境的相互作用影响，具有很大的开放性、非线性和不确定性等特点。基于动力学原理，分析不同降雨尺度的降雨历时、降雨最大强度、降雨初始时间和降雨强度等与生态地质环境的相互作用，进行不同尺度降雨诱发地质灾害的致灾机理研究。本项目选取清江流域典型支流浑水河流域进行地质灾害气象预警预报研究，以野外调查资料和气象数据为基础，分析不同降雨尺度特征，进行不同尺度降雨模拟实验；反演地质灾害形成过程，进行不同尺度降雨与生态地质环境相互作用的致灾机理耦合分析，实现气象预警预报模型及数值模拟研究，为清江流域乃至三峡地区地质灾害致灾机理研究及气象预警预报提供技术支撑。

在恩施市浑水河流域开展地质调查测绘、岩土测试及野外试验等工作，完成区域地质及成灾规律背景条件调查。地质灾害受中部志留系页岩顺向坡，三叠系巴东组一、二段泥岩顺向坡，三叠系大冶组一、二段薄层灰岩，受三叠系栖霞组、梁山组、石炭系黄龙组、大埔组等岩性组合控制；土质滑坡灾害总有效降雨量时间可能稍长于碎块石滑坡灾害的有效降雨量时间。选取4天作为过程降雨量的特征值和24h降雨量值作为气象预警预报，建立了滑坡灾害点在不同易发分区的发生概率，采用Bayes综合模型，实现地质灾害气象预警预报。