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    气候变化对秦岭南北植被净初级生产力的影响(Ⅰ)——近52 年秦岭南北气候时空变化特征分析

    Effects of climate change on net primary productivity of vegetation in the northern and southern regions of the Qinling Mountains(玉): Temporal and spatial characteristics of climate change in recent 52 a

    • 摘要: 根据秦岭南北54 个气象站1960—2011 年逐日数据,利用FAO Penman-Monteith 公式计算各站的潜在蒸散量和湿润指数;采用样条曲线插值法(Spline)、气候倾向率、相关分析等方法对该区气温、降水、潜在蒸散和湿润指数的时空变化特征以及影响其变化的气象要素进行分析。结果表明:1)秦岭南北多年平均气温由北向南逐步上升,1993 年是气温变化的转折点,1993 年以前秦岭以南地区降温更明显,1994 年起绝大部分站点气温显著(P<0.01)上升,秦岭南北无明显差异;2)多年平均降水量由南向北递减,1995 年以前各区降水量均表现出下降趋势,秦岭以北地区降水量下降更明显,1995 年以后70%以上站点降水量增多,秦岭以北地区有变干趋势,秦岭南坡微弱变湿,其余地区整体升降趋势不明显;3)潜在蒸散量呈东高西低的分布格局,各子区蒸散量呈现较为一致的下降趋势(P<0.05),但无明显转折点,秦岭以南的广大地区相对于秦岭以北蒸散量下降更明显;4)湿润指数由南向北递减,秦岭以北地区以暖干化为主,而秦岭以南以暖湿化为主,季节尺度上,4 个子区表现出的变化规律较为一致,春季和秋季绝大部分站点的湿润指数呈下降趋势,而夏季和冬季则以上升趋势为主;5)湿润指数与日照时数、最高气温、平均气温和蒸散量呈显著水平(P<0.01)的负相关关系,与最低气温和风速相关关系不显著,降水量和空气湿度的增加会对湿润状况的改善起到正向作用。

       

      Abstract: Based on the daily data from 54 meteorological stations in Northern and Southern Regions of the Qinling Mountains between 1960 and 2011, with the help of FAO Penman-Monteith formula, the potential evapotranspiration and humid index were calculated. By using the Spline interpolation method, climate trend rate, correlation analysis and other methods, we analyzed the distribution of temporal and spatial variation characteristics of temperature, precipitation, potential evapotranspiration and humid index as well as the meteorological elements which influenced evapotranspiration and humid index. The results are given as follows: 1) The average annual temperature of the northern and southern regions increased gradually from north to south, 1993 was the turning point of temperature, and cooling trend in southern area before 1993 was more obvious. Since 1994, the temperature of most stations increased significantly (P <0.01), and there was no significant difference among four regions. 2) The annual precipitation decreased from south to north. Precipitation showed a downward trend before 1995, and the northern region was more obvious. While precipitation increased since 1995, including more than 70% stations. The northern part was becoming dry while the southern slope was becoming wet, and there was no significant change in other parts. 3)The potential evapotranspiration decreased from eastern part to western part. All the sub regions showed consistent downward trend (P<0.05). Southern slope was more obvious than northern slope, but there was no significant turning point. 4)The humid index decreased from south to north. The northern region was becoming warmer and drier, while southern region was becoming cooler and wetter. At the seasonal scale, four sub regions showed the same tendency, that humid index of most stations in spring and autumn showed a decreasing trend while in summer and winter showed an increasing trend. 5) Sunshine hours, average temperature, maximum temperature and evapotranspiration correlated negatively with humid index significantly ( P < 0.01). But minimum temperature and wind speed had no significant relationship with humid index. The increase of precipitation and relative humid can improve humid index.

       

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