浙江宁波市地质灾害的雨量阈值及预报分析

山体滑坡、崩塌、泥石流等地质灾害主要由强降水或连续性降水引发产生,根据最近七年来宁波市国土资源局和宁波市气象台联合制作的地质灾害气象预报预警和地质灾害实况资料分析,结果发现:在最近七年里出现的159处地质灾害中,由热带气旋强降水引发的地质灾害有142处,约占89%;宁波市绝大多数地质灾害是由强降水引发,而强降水中又以热带气旋强降水为主要诱因,引发宁波市地质灾害的有效雨量大多数在100mm以上,因此,100mm有效雨量可作为预报引发宁波市地质灾害的雨量阈值,而200mm有效雨量可引发多处地质灾害产生。统计结果为以后地质灾害气象预报预警及强降水的临近监测提供参考依据。

Analysis on rainfall thresholds associated with geological disaster forecasts in Ningbo city

Geological disasters,such as landslides,collapses,mud-rock flows and so on,are mainly caused by heavy or continuous precipitations.Based on disaster warnings and practical cases issued by Ningbo Meteorological Observatory and Ningbo Municipal Bureau of national land and resources over the last 7 years across Ningbo city,analysis is done and results show： out of the total 159 cases,142 geological disasters were caused by tropical cyclones,taking a percentage around 89%.Most geological disasters in Ningbo were caused by heavy downpours,while tropical cyclone rainfalls were blamed for the main reason.Rainfall amount associated with geological disasters is above 100mm,which can be set as a rainfall threshold relating to natural disasters in Ningbo,whereas rainfall amount over 200mm can lead to multi geologic hazards.The statistics can be as reference for geological disaster warnings and now-casting rainfall monitoring.