黄河上游主要产流区气候变化及其对水资源的影响——以甘南高原为例

Climate Evolution and Its Impact on Water Resource Change in Main Runoff Generating Area of Upper Yellow River: A case study on Gannan Plateau

利用黄河上游主要产流区甘南高原地面气象观测资料和水资源定位观测资料,分析气候、水资源变化特征,及其二者的关系,建立水资源气候模式。分析表明:黄河上游主要产流区甘南高原大部分区域降水量年际变化呈下降趋势,降水量变化线性拟合倾向率在-22.6^-9.6mm/10a之间,降水量递减以秋季降水量递减为主,降水量减少突变点在1980—1990年之间,年际变化主要存在6~7a短周期振荡和15a的长周期振荡特征。气温年际变化趋势呈显著上升趋势,增温速度均大于全国增温速度,增温率以冬季最大,气温增高突变点在20世纪70年代。草地年干燥指数变化呈显著上升趋势,近50a来甘南高原气候趋于暖干化。水资源呈显著下降趋势,水资源存在2~3a、7~8a、20~23a的年际周期变化。水资源与降水量呈显著正相关,与干燥指数呈显著负相关,降水量减少,草地干燥指数上升,导致水资源减少。

Based on the surface meteorology and water resources observation data in the main runoff generating area of the upper Yellow River, the characters of climate evolution and water resources change and their relationship are analyzed; in addition the water resources climate model is also established. The results show that the inter-annual change of precipitation displayed descending trend, the tendency rate was -2.26-0.96 mm· a^-1, this reduction mainly happened in autumn and its sharp point was at 1980-1990. It is proved that the 6-7 a short period and 15 a long period are significant. The results also show that the interannual change of temperature displayed marked ascending trend, the rising rate of temperature is higher than that of whole nation and its sharp point was at 1970s, the aridity index of lawn also displayed prominent ascending trend, in recent 50 years the climate of Gannan Plateau showed warming and drying trend, It is also found that the water resources displayed remarkable descending trend, it existed 2-3 a, 7-8 a, 20- 23 a periods, water resource showed marked positive correlation with precipitation, while it showed marked negative correlation with aridity index, the water source will decrease if precipitation increase and dry index of grassland ascend.