从陆地移入水体后增强的线状中尺度对流系统常引发雷暴大风、短时强降水等灾害性强对流天气。由于对水上线状中尺度对流系统的强度变化特征和主要影响因子缺乏系统认识，目前仍是业务预报工作中的难点。本项目拟以杭州湾为例，挑选近10年移入杭州湾的线状中尺度对流系统，统计分析其强度变化特征；利用流型识别法和基于构成要素的强天气分析法分析入海线状中尺度对流系统的环境条件，初步区分增强类和减弱类的特征流型配置和环境参数；利用VDRAS同化分析系统，研究典型个例中杭州湾陆水两侧的中小尺度热力和动力条件对入海对流海上部分的局地影响；进一步利用高分辨率中尺度数值模式对典型个例进行数值模拟和敏感性试验，研究杭州湾对线状中尺度对流系统入海强度所起的作用。项目研究结果将有助于系统认识我国杭州湾地区入海线状中尺度对流系统的强度变化特征和主要影响因子，并为提高我国陆水交界区域强对流天气的预报准确率和预警能力提供参考依据。

The mesoscale convective systems (MCSs) crossing from land to water always cause disastrous severe convective weather like strong thunderstorm wind, short-time severe precipitation, etc. Due to the lack of systematic understanding the characteristics of strength variations and the main influencing factors, the strength variations of linear MCSs entering the water are very difficult to be predicted accurately. In this project, the Hangzhou Bay is chosen as research region and the cases of linear MCSs entering the Hangzhou Bay during the recent 10 years are selected. Then the characteristics of strength variations are statistically analyzed. Besides, the ambient conditions of these cases are analyzed by using the pattern identification method and the severe weather analysis method, and then the typical synoptic patterns and environmental parameters are worked out, which help to identify the increased and decreased categories. Using the Variational Doppler Radar Analysis System (VDRAS), the effects of dynamical and thermodynamical factors over the land-water boundary region to the convections over the Hangzhou Bay is studied. Furthermore, high-resolution mesoscale numerical model is utilized to simulate typical cases and do sensitivity tests, and how the Hangzhou Bay impacts the strength of MCSs when they entering the Hangzhou Bay is investigated. The successful implementing of this project will help to increase the understanding of the characteristics of strength variation and their main influential factors for the coastal linear MCSs when they entering the Hangzhou Bay, and provide scientific references for improving the forecasting accuracy and warning capability of severe convective weathers in the land-water boundary regions in China.