本文利用近30年热带气旋年鉴建立了西北太平洋热带气旋灾害数据库,以.NET和ArcGIS Engine搭建了二次开发平台(其包括登录界面、图查属性、属性查图、数据库分析处理等功能),分析了西北太平洋热带气旋的时间特征、空间特征,以及时空变化特征。结果表明,30年来西北太平洋共生成905次热带气旋,年均30.2次/年。其中,7-10月最容易发生热带气旋,占所有热带气旋的35.7%,8月份达到峰值,达21.5%,2月最不容易发生热带气旋,发生频率仅为0.6%,而8-10月是强台风和超强台风发生的月份。热带气旋源地集中区位于(10°~22°N,112°~120°E)、(8°~20°N,126°~134°E)和(6°~20°N,136°~150°E),具有纬度带和经度带的分布特性。源地的空间分布存在明显的季节变化和月变化特征,在季节尺度上,夏季主要集中在偏北偏西位置,并向南向东偏移,冬季向北向西偏移;在月尺度上,1-4月源地相对分散;5-6月相对于1-4月的源地位置发生向西向北方向转移;7月向东向北扩散,8-9月向西扩散,9月源地相对集中,10月热带气旋源地南移,11-12月热带气旋源地范围明显减小。
Tropical cyclones (TCs) over the Northwest Pacific play an important role on climate change. Based on the Yearbook of Tropical Cyclones during the period of 1981 - 2010 and the developer kit of Ar- cEngine 9.3, this paper analyses the TCs" time characteristics and space characteristics and spatio-temporal characteristics. We have constructed a typhoon disaster geographic information system, which includes typhoon information point database and line database. The function of the database includes, login inter- face, map search attribute, property search map, database analysis and processing function. Our main conclusions are as follows: firstly, the Northwest Pacific typhoon occurred 905 times and average 30. 2 times per year. The typhoons mainly occurred during the period from July to October that covered a pro- portion of 35.7 %. The frequency of typhoons in August reached the peak and covered the ratio of 21.5 %. February is the most difficult month of typhoon and the occurrence frequency is only 0.6 %. Powerful ty- phoon and super typhoon mainly focused on August to October. Secondly, the birthplace of typhoon showed a characteristic of with latitude and longitude band, mainly distributed over regions of (10°- 22°N, 112°-120°E), (8°-20°N, 126°-134°E) and (6°-20°N, 136°-150°E). Thirdly, the birthplaces of typhoon presented significant seasonal variation. In summer, typhoon distributed over north and west area, then gradually shifted south and east until to north and west in winter. Typhoon birthplace showed significant monthly variation that scattered in January-April, shifted to north and west from May to June, spread north and east in July, was westward in August-September and southward in October. In Septem- ber, the sources were relatively concentrated. In November-December, typhoon sources significantly reduced.