摘要
利用川渝地区193个雨量站2016~2017年小时降水数据,采用降水发生率和贡献率两个指标,分析了川渝地区降水结构基本特征及其空间分布规律。研究结果表明:(1) 随着降水历时的增加,发生率呈幂指数递减下降趋势,贡献率呈增加趋势,但各分区降水贡献率在中部和东部盆地区域表现为先增后减。(2) 1~3 h历时降水的发生率从东向西呈增加趋势,其余降水历时的正好相反。1~3 h和大于12 h历时降水贡献率与发生率基本一致,而4~6 h降水贡献率从东往西呈增加趋势。(3) 随降水等级增加,发生率呈现显著下降趋势,贡献率在西部高原区呈下降趋势,而在东部和中部盆地区增加趋势。(4) 小雨发生率在西部高原区和中部盆地区较高,中雨发生率和贡献率均表现为从东南向西北增加的趋势,大雨发生率最大值出现在川渝南部地区,最小值出现在西北区域和中部四川盆地区域。暴雨和大暴雨的发生率和贡献率均表现为从东南向西北逐渐减小。
On basis of hourly precipitation data from 193 rain-gauge stations in Sichuan-Chongqing region from 2016-2017, the basic characteristics of precipitation structure and its spatial distribution pattern are analyzed with the two indexes-incidence rate and contribution rate of precipitation. The results show that: 1) The incidence rate of precipitation events for different durations decreases power-exponentially with the increase of precipitation durations, and the corresponding contribution rate shows a decreasing trend, while the contribution rate of precipitation firstly increases and then decreases;(2) The incidence rate of precipitation for 1 - 3 h duration shows an increasing trend from the east area to west area, which is opposite to the other precipitation durations. The spatial distribution pattern of contribution rate of precipitation for 1 - 3 h and >12 h duration is consistent with that of incidence rate of precipitation, and the contribution rate of precipitation for 4 - 6 h duration shows an increasing trend from the east area to the west area. (3) The incidence rate for different grades decreases significantly with the increase of precipitation grades, while the corresponding contribution rate is decreasing in the western plateau area and increasing in the central basin and east basin area. (4) The incidence rate of light rain is larger in the western plateau area and the central basin area, and the incidence rate and contribution rate of moderate rain both show an increasing trend from southeast to northwest area. The maximum incidence rate of heavy rain occurs in the southern Sichuan and Chongqing region, with the minimum incidence rate in the northwestern Sichuan and Chongqing region and the Sichuan Basin. The incidence rate and contribution rate of both rainstorm and heavy rainstorm gradually decrease from southeast to northwest area in Sichuan-Chongqing region.
出处
《自然科学》
2020年第5期442-449,共8页
Open Journal of Nature Science
关键词
降水结构
降水历时
降水等级
川渝地区
Precipitation Structure
Precipitation Duration
Precipitation Grades
Sichuan-Chongqing Region
