中国降水演变趋势诊断及其新事实

Diagnose of precipitation evolution trend in China and new facts

  • 摘要: 利用动态泰森多边形模型,计算评价了中国1951-2006年全国尺度及各区域尺度的月、季、汛期、年等时段的降水量,并分析了年、季、汛期等降水量的时空分布、区域特征及其年际年内(月、季)变化等基本规律;分析诊断了年、季、汛期降水量的演变趋势、突变趋势、震荡周期等特性;对比分析了长期(1961-2006年)、近期(1980-2006年)以及近期与前期(1961-1979年)降水量的变化特征及其空间变化分布。结果表明,中国近期年降水量在环渤海湾600 mm等值线有所南移,100°E以西地区年降水量普遍增多;内蒙古中西部、海河沿海、黄河中部、淮河北部近期降水量比前期偏少10%以上,嫩江中部、长江下游、闽南沿海、西藏中北部、新疆中西部则偏多10%以上,而塔里木河、伊犁河上游偏多达30%以上。

     

    Abstract: Using dynamic segmentation and the Thiessen polygon method, precipitation amounts can be estimated for different spatial and temporal resolutions over the period 1951-2006. The resulting monthly, seasonal, flooding season and annual time series for both regional and national average precipitation are then analyzed. The spatial distributions, regional characteristics, variabilities, trends, abrupt changes, oscillation periods of monthly, flooding season and annual precipitation are examined. The temporal analysis is done for the three periods 1961-2006, 1980-2006 and 1961-1979, which represents the precipitation variabilities in long term, recent years and earlier term (or baseline). Compared to the earlier term values, the result shows that a recent southward trend is detected in the 600 mm of annual precipitation isoline in Bohai Bay. The annual amount of precipitation is on the rise recently in the west area of 110° E. The mean annual precipitation is down 10% in the mid-western part of Inner Mongolia, the coastal areas of the Haihe River, the middle part of the Yellow River and the northern part of the Huaihe River. In contrast, the mean annual precipitation is up 10% in the middle part of the Nenjiang River, the lower reach region of the Yangtse River, the coastal areas of South Fujian, the mid-northern part of Tibet and the middle part of Xinjiang. In particular, the mean annual precipitation is up 30% in the area of the Talimu River and the upper reach region of the Yili River.

     

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