气候变化对陕南汉江流域植被净初级生产力的影响

摘要

根据陕南汉江流域及其周边34个气象站1959-2010年的逐日气温和降水资料,利用周广胜—张新时模型、Penman— Monteith公式、Mann—Kendall检验、相关分析和Spline插值等方法,分析了近52 a水热条件的变化及其对净初级生产力(NPP)的影响,并对NPP的未来变化进行预估.结果表明:1)汉江流域年均温为13.7℃,整体呈升高趋势(0.14℃·(10 a)-1)(p＜0.001),北部快于南部,东部快于西部.多年平均降水为747.3 mm,整体呈减少趋势,于1991年发生减少突变；2)NPP高值区位于大巴山区和米仓山部分地区,秦岭山地相对较小,表现出由南向北递减的空间格局.秦岭南麓部分地区NPP上升,汉江谷地除安康外均呈下降趋势,大巴山和米仓山一带除平利、镇坪外均呈现下降趋势.3)NPP与降水、相对湿度和湿润指数呈极显著的正相关关系(p＜0.001),与潜在蒸散、日照时数和气温负相关,温度对于NPP积累起到的作用有限,水分是主要制约因素；4)a情景下NPP增幅15％以上,b情景下增加9％左右,c情景下NPP整体下降.%Based on the temperature and precipitation data observed by 34 meteorological stations within and around Han River Basin between 1959 and 2010, NPP values were calculated by using Zhou Guang-sheng and Zhang Xin-shi Model. The spatio-temporal variations of temperature, precipitation, humid index, NPP and their relationships were analyzed by using correlation analysis, Mann-Kendall test, and Spline spatial interpolation method. The responses of NPP to the variations of temperature and precipitation in the future were discussed. The mam results were as follows. 1) Climate became warmer and drier, the trend rate of temperature was 0. 14℃/(10 a)-1 and the precipitation was -16. 3 mm/(10 a)-1. Abrupt change could be found in 1994 and 1991 respectively. In general,the climate warming rate was larger in northern part than southern part,precipitation decreasing rate distributed unevenly in the whole basin. 2)The NPP was large in Daba Mountain and Micang Mountain, NPP in Qinling Mountains was relatively small, decreased from south to north. NPP in the southern part of Qinling Mountains increased while some part of Hanjiang Valley,Daba Mountain and Micang Mountain decreased. 3) NPP correlated positively with humid index and precipitation,while correlated negatively with potential evaportranspiration,sunshine duration and temper-aturc. Temperature had limited impact on accumulation of NPP,water was the main factor. 4)The result of prediction demonstrated that under the scenario a and b.NPP would increase by about 15% and 9% respectively, while decrease under the scenario c.