1961—2009年辽河流域水文气象要素变化特征

Characteristics of hydrological and meteorological elements from 1961 to 2009 in the Liaohe River areas

依据1961—2009年辽河流域5个气象观测站点逐日降水和气温观测资料,运用非参数检验方法(Mann-Kendall法),对辽河流域降水和气温的变化趋势进行了分析。利用2006—2010年夏季共162d降水日的铁岭站日降水量与铁岭水文站径流量资料,探讨了日降水量与径流量之间的相关关系。结果表明:辽河流域年降水量减少趋势明显,降水量偏少年份明显增加,其主要原因为占全年降水量65%的夏季降水以7.4 mm/10 a的气候趋势倾向率递减,呈现出明显的减少趋势;辽河流域的年平均气温是在波动中逐渐上升的,且升温趋势明显,春季呈明显的升温趋势,夏季略有下降,秋季变化不大,冬季是气温上升最明显的季节;日降水量与径流量存在正相关关系,且日降水量与降水第二日的径流量相关显著。

According to the daily precipitation and air temperature data from five typical meteorological stations from 1961 to 2009 along the Liaohe River areas,the changes in the precipitation and air temperature trends were analyzed with a Mann-Kendall method.The relationship between the daily precipitation and runoff was discussed based on data from 162 precipitation days in summer at Tieling weather station and runoff data at Tieling hydrological station from 2006 to 2010.The results show that the mean annual precipitation tends to decrease,and the years with less precipitation significantly increase because summer precipitation that accounts for 65% of the total precipitation decreases with the rate of 7.4 mm/decade.The annual mean air temperature fluctuates and increases gradually.The ascending trend is significant,especially in winter,then in spring,while it is in a decreasing trend in summer.The change in precipitation trend is small in autumn.The daily precipitation is in a positive correlation with the daily runoff,especially with runoff on the next day after the rainfall.