近30年来甘肃气候变化趋势及其对干湿状况的影响

Climate changes and its influences on the aridity/humidity status in Gansu Province during the last three decades

以1971-2000年甘肃地区33个气象台站的观测数据为基础,应用1998年FAO推荐的Penman-Monteith模型,根据甘肃实际状况进行了辐射项校正,模拟了甘肃地区近30年的潜在蒸散,并且根据Vyshotskii模型计算了干湿指数。通过线性拟合分析了甘肃省近30年来气候变化趋势,采用Mann-Kendall方法进行了趋势检验。利用基于薄盘样条函数的Anusplin模型对地表干湿指数进行了空间栅格化。结果发现:甘肃地区近30年气候变化总体特征是气温呈上升趋势,降水呈减少趋势,潜在蒸散呈增加趋势,北部与南部站点有由干变湿的趋势,而中部的部分站点有由湿变干的趋势,气候变化及地表干湿状况的区域差异比较明显。

Gansu Province is one of the most sensitive and vulnerable areas of climate change in China. The study has great significance to the sustainable development in this area. Based on the climate data during the last three decades of 33 stations with a set of climatic factors such as precipitation, temperature, solar radiation, relative humidity and wind, potential evapotranspiration was calculated by applying Penman - Monteith model which was recommended by FAO in 1998 and humidity index by Vyshotskii model to indicate aridity or humidity status of the area. Then the changing trends of observed climatic factors （ temperature and precipitation） and calculated factors （potential evapotranspiration and humidity index） were analyzed, and the spatial distribution of aridity/ humidity status over Gansu Province during the period 1971 -2000 was calculated. Trends calculated by linear regression were tested through Mann - Kendall test. Results of the 33 meteorological stations in Gausu showed that the main trends of climate change are temperature rise and precipitation decrease ; potential evapotranspira- tion increase and half of the stations are ascending to more humid status and the other half stations are ascending to more arid status. The spatial pattern of the climate change trends and aridity/humidity status showed significant regional difference.