【摘要】 降水的大小与空间分布在迎风坡与背风坡处具有显著的差异。为分析宏观坡向对不同等级降水的影响,应用主次降水方位算法,利用地面降水观测资料,结合空间分辨率1km×1km的DEM数据,计算得到全国气象站点1961—2000年不同等级降水的主次方位降水日数差/总量差,并通过坡向影响系数、显著性检验、主次方位降水日数差/总量差绝对值三个指标进行对比分析。结果表明:坡向对不同等级降水的相对影响程度为暴雨>大雨>中雨>小雨。此外,坡向对不同等级降水的影响受地貌和干湿条件的共同作用,山地地区的影响最为显著,丘陵次之,平原最小,且坡向对不同山体的影响在降水日数与总量上具有不同的体现;在不同的干湿条件下,随着降水等级的减弱,最显著区由湿润区逐渐向半湿润区、半干旱区、干旱区移动。更多还原

【Abstract】 There is a significant difference in rainfall intensity and areal precipitation between windward slope and leeward slope.Using the algorithm of primary and secondary precipitation orientation and the data of surface observation rainfall,we analyzed how slope affects precipitation at different levels.Combining with DEM data,we calculated the day difference and total precipitation difference of national meteorological stations from 1961 to 2000,and then compared and analyzed its characteristics from the aspects of exposures,significance test and absolute value.The result shows that exposures have various effects on different precipitation levels.The effect decreases in the order:torrential rain>heavy rain>moderate rain>light rain.In addition,the effect of exposures on different precipitation levels is also determined by the combined impact of landform and the wet and dry conditions.The results show that it is most significantly correlated with mountain land,less correlated with hills and the least correlated with plains.In the meantime,it is most significantly correlated with sub-humid zone,less correlated with semi-arid zone,and the least correlated with arid zone.更多还原