Zhejiang Volume - China Meteorological Disaster Dictionary

Author: Editorial Committee of the "Comprehensive Catalog of China's Meteorological Disasters"
Publisher:
Publishing Date: 2006-11-01
Features: Zhejiang Province is located in the southeastern coastal area of China and belongs to a typical subtropical monsoon climate. In winter, under the control of the Mongolian cold high-pressure system, northwesterly winds prevail, with clear, cold, and dry weather, marking a season of low temperatures and little rainfall. Cold waves, heavy snow, strong winds, and severe icing are the main disastrous weather conditions. In spring and autumn, the region is influenced by the Pacific subtropical high-pressure system, with southeasterly winds bringing abundant moisture from the ocean, resulting in humid air and a season of high temperatures and strong sunlight. In early summer, cold and warm air masses often converge in the region's upper atmosphere, leading to the season, where heavy rain and flood disasters frequently occur. In midsummer, it is a period of high temperatures and drought, with drought and typhoons being the main disastrous weather conditions. Spring and autumn are transitional seasons between winter and summer, with frequent cyclone activities in spring, abundant precipitation, and significant temperature fluctuations, earning the saying "children's faces in spring change three times a day." Main disastrous weather conditions include low temperatures, continuous overcast rain, hail, and heavy rain. In autumn, the climate is generally mild and rainy, described as "autumn sky high and weather clear," with drought, typhoons, and autumn cold being the main disastrous weather conditions. Due to the instability of the monsoon, the varying intensity and timing of the winter and spring monsoons each year lead to abnormal low and high temperatures, or irregular rainfall, resulting in droughts and floods. Moreover, due to Zhejiang's location in the transitional zone between mid- and low latitudes, at the junction of the Jiangnan mountainous region and the Yangtze River Delta plain, and its reliance on both land and sea, it is exposed to both Siberian cold currents and tropical systems from the ocean. As a result, the province experiences frequent and diverse disastrous weather conditions throughout the year, including typhoons, heavy rain, floods, droughts, cold waves, heavy snow, strong winds, and hail, all of which bring severe disasters. The rivers in Zhejiang Province have short sources, rapid flow, and significant drops, making it difficult to store water. During dry periods, droughts are prone to occur. The lower reaches of the rivers directly flow into the sea and are often blocked by tidal surges. During rainy periods, poor drainage leads to frequent flood disasters. The terrain of Zhejiang Province is high in the southwest and low in the northeast, with mountain ranges oriented perpendicular or obliquely to the monsoon circulation direction. These mountains act as a certain barrier against cold currents from the north and typhoons from the southeast. However, when typhoons strike, the mountains slow their movement and obstruct the airflow, causing it to rise and intensify rainfall, further exacerbating the wind and flood disasters in coastal areas caused by typhoons. Additionally, after landing, typhoons often turn northeast or