秦皇岛市近63年自然降水资源变化特征

The Characteristics of Natural Rainfall in Recent 63 Years in Qinhuangdao

利用秦皇岛市1954—2016年逐日降水资料,运用线性趋势法、累计距平、方差分析等数理统计方法,分析了近63 a来秦皇岛市年、季、月自然降水总量与雨日的气候变化特征。结果表明:秦皇岛市年降水量总体呈减少趋势,气候倾向率-15.5 mm/10 a;夏、秋季降水量呈减少趋势,春季呈增加趋势,冬季变化不明显;1月、2月降水变化趋势不明显,7月—10月呈减少趋势,2月—4月、11月—12月呈增多趋势。年雨日明显减少,平均每10 a减少3.05 d,雨日的减少主要表现为小雨日数的减少。年降水强度变化不大,夏、春季降水强度呈增加趋势,秋季呈减小趋势,冬季变化不大。由上可知,年降水量和雨日的同步减少是秦皇岛市近63 a降水变化的明显特征,因此,秦皇岛市自然降水资源呈减少趋势,夏、秋两季变干明显。

Based on the daily precipitation data from 1954 to 2016 in Qinhuangdao, using some mathematical statistics methods, such as the linear trend method, the cumulative departure method etc., the characteristics of the climate change have been analyzed on the total precipitation and rainy days for 63 years, and the total precipitation include annual rainfall, monthly precipitation, daily rainfall. The results are that the annual precipitation, in overall, shows a trend of decrease, being a -15.5 mm/10 a of the climate trend rate. The rainfall is decreasing trend in summer and autumn, the opposite situation in spring, no significant change during the winter. Specific to the annual condition, the change trend of precipitation is not obvious in January and February, being a decreasing trend from July to October, presenting an increasing trend in March and April, as well as in November and December. Annual rainfall days decrease significantly, and it will reduce 3.05 day every 10 years on average, and the decrease of light rain days is more obvious in 63 years. Annual precipitation intensity change little, the precipitation intensity increase in spring and summer, but decrease in autumn, there is no obvious change in winter. So it is concluded that the resource of the natural rainfall is tending to decrease, it will be more dry in summer and autumn.