全国干湿分布区动态变化研究

在全球气候变化的背景下,我国的干湿状况发生相应变化。本文主要研究过去60年全国干湿状况动态变化,以便于了解气候变化对我国干湿状况的影响。基于1951~2010年全国756个气象站点的气象数据,根据Penman-Monteith潜在蒸散量方法计算潜在蒸散发量,再结合降水量数据计算干燥度指数。利用干湿区划分阈值,划分1951~2010年不同干湿分区,主要有极端干旱区、干旱区、半干旱区、干性半湿润区、半湿润区、湿性半湿润区、湿润区分区,并研究1951~2010年10年年际动态变化。研究结果表明,全国在总体上趋向于干旱,尤其东北地区最为严重,而北疆地区趋向于湿润。不同年代呈现不同的干湿波动性规律,80年代为湿润时期,90年代为极端干旱时期,半干旱区范围明显增加并往东南移动。本研究对理解我国植被空间分布的变化和生态环境建设具有一定的指导意义。

Changes of Distribution of Arid and Humid Areas in China

Based on the background of global climate changes, distribution of arid and humid area has been changing in China. In order to understand the impacts of climate changes on China, this paper analyzed the dynamic changes of wet and dry areas of China during the past 60 years (1951-2010) based on climate data from 756 meteorological stations. Potential evaporation was calculated using Penman-Monteith method. Combined with precipitation data, aridity index for 1951 to 2010 was calculated. Based on the threshold of aridity index of wet and dry areas, six wet and day zones were divided, including hyper-arid, arid, semi-arid, dry sub-humid, sub-humid, wet sub-humid, and humid zones. The dynamic changes were analyzed per decade. Our results show that the majority area of China tends to be dry, particularly Northeastern China. Northern Xinjiang Autonomous Region tends to be wet. During the year of 1951 to 2010, the ten years'' changes had been different during different period. Wet period is 1980s. A period of extreme drought is 1990s. The range of semi-arid zone has increased. Our results are useful for understanding spatial distribution of vegetation and ecological environment construction.