广西多站点参考作物蒸散量时空变化分析

基于广西20个气象观测站点1957—2001年的逐月气象资料,采用Penman-Monteith公式计算各站点逐月、逐年参考作物蒸散量(ET0),采用变差系数和年际极值比分析ET0的年际变化特征,应用累积滤波器法、Ken-dall秩次相关法、R/S分析法分析ET0的变化趋势。研究结果表明,桂中ET0年际变化最剧烈,桂南ET0年际变化最小。岩溶发育地区的ET0的年际变化比非岩溶发育略显剧烈,但相差不大。20个站点中,5%站点的ET0呈显著上升趋势,95%站点的ET0呈下降趋势(下降趋势显著的站点占63.1%)。与1957—2001年相比,ET0呈上升趋势的站点由5%增加到未来的35%,且非岩溶地区ET0呈上升趋势的站点数大于岩溶地区。

Temporal and Spatial Variability of Reference Crop Evaporation in Guangxi Province

Based on the measured data during 1957—2001 at 20 metrological observation stations in Guangxi Province,monthly reference crop evaporation(ET0) was calculated by Penman-Monteith formula.The inter-annual change characteristics of ET0 were analyzed using the coefficient of variation and extremum ratio.Also cumulative filter method,Kendall test method and R/S test method were used to investigate the change of ET0.The results showed that the annual ET0 was subject to dramatic change in Central Guangxi,and the minimal change existed in Southern Guangxi.The annual change of ET0 in the karst area was a little drastic than that in no-karst area.5 percent ET0 of 20 metrological observation stations showed an increase trend,and 95 percent of that showed a decrease trend;furthermore,63.1 percent ET0 displayed an obvious increase trend.Compared with the change trend in period of 1957—2001,the sites of ET0 increase trend raised from 5 percent up to 35 percent in the next period,and in the karst area there were more sites in which ET0 increased than in on-karst area.