基于高分辨率格点数据集的中国气温与降水时空分布及变化趋势分析

Spatio Temporal Distribution and Variation Trend of Temperature and Precipitation over China Based on High Resolution Gridded Datasets

基于LZU0025高分辨率格点数据集,对1951—2012年中国区域气温和降水量的时空分布特征,以及气候变化趋势进行了初步分析。结果表明:中国的年平均气温自1980年开始显著增暖,年降水量在1960年出现由湿润到干燥的突变。中国的整体降水量变化趋势不如气温的变化趋势具有一致性。中国年平均气温增温趋势为0.26℃/(10a),局部的最大增温趋势超过0.6℃/(10a);中国年降水量减少趋势为6.7 mm/(10a),局部地区的降水减少趋势超过了30 mm/(10a),而有些地区的降水增加趋势却可达30 mm/(10a)。大兴安岭—黄土高原西北缘—黄河长江上游以北—冈底斯山脉东部为大致的平均400 mm等降水量线,可用于划分中国的半干旱与半湿润区。1951—2010年中国400 mm等降水量线位置的年代际变化情况复杂,但总体呈现不断南移的趋势,表明中国干旱、半干旱区面积在不断扩大。

Based on the LZU0025 dataset,the spatio-temporal distribution and variation trend of temperature and precipitation over China during 1951-2012 are primarily analyzed.The results show that the annual temperature has a significant warming trend since 1980,and the average precipitation presented a sudden decrease in1960,which shows a different change trend with temperature.The annual average temperature increases 0.26 ℃/decades,with the largest more than 0.6 ℃/decades;and the annual precipitation decreases 6.7 mm/decades,with the largest more than30.0 mm/decades,while in some region,the annual precipitation may increases 30.0 mm/decades.Along Daxinganling-northwestern margin of the Loess Plateau-the upper of the Yellow River and Yangtze River-the eastern part of Mountain Gangdisi is the 400 mm isohyetal line,which could be used to divide semi-arid and sub-humid areas.Inter-decadal variation of 400 mm isohyetal line over China during 1951-2010 moved southward,which meant that the arid and semi-aird area in China expands constantly.