祁连山及河西走廊地表干湿变化的时空分布

利用20个气象站1960-2006年的逐日气象资料, 采用FAO Penman-Monteith模型, 计算出祁连山及河西走廊各气象站的月潜在蒸发量, 在此基础上计算各气象站的月湿润指数, 然后进行季节、年地表湿润指数的统计, 进而对研究区地表干湿状况的时空变化进行分析.结果表明: 祁连山及河西走廊在20世纪80年代之前地表相对干旱, 之后相对湿润, 自60年代以来地表湿润指数有逐年增大的趋势; 年地表湿润指数的年际变化率为0.001 4 a-1, 相关系数为0.428 1, 通过了0.01的置信度检验, 表明地表湿润状况有明显改善, 其中春季和冬季增加趋势明显, 夏季增加趋势和秋季减小趋势不太明显.地表干湿变化趋势在空间上有差异, 东部表现为东西差异, 自东向西逐渐变湿, 乌鞘岭以东呈变干趋势, 其他大部分地区显著变湿, 中部大部分地区呈不明显的变干趋势, 而托来南山以北地区显著变干, 张掖绿洲显著变湿, 西部除敦煌以西呈不显著的变湿趋势, 其他大部分地区显著变湿. 

Temporal and Spatial Characteristics of Dry-Wet Conditions from 1960 to 2006 in Qilian Mountains and Hexi Corridor

Based on the climatic data of 20 weather stations from 1960 to 2006,the monthly potential evaporation was calculated using the Penman-Monteith model,and then the monthly humid index was reconstructed in Qilian Mountains and Hexi Corridor.In order to study the temporal and spatial characteristics of the dry-wet conditions in the study area,the seasonal and annual humid indices were analyzed.Statistical results indicate that the study area was drier before 1980s,and the humid index has been on the rise since ...