Ma Yali, Niu Zuirong, Sun Dongyuan, Wang Xingfan
College of Water Conservancy and Hydropower Engineering, Gansu Agricultural University, Lanzhou, 730070, China.
Sci Rep. 2024 Sep 12;14(1):21343. doi: 10.1038/s41598-024-72183-8.
The frequent occurrence of extreme climate events disrupts the regional water budget balance and leads to changes in the dry and wet conditions of the surface, making the water surplus and deficit more complex and variable. To explore the quantitative relationship between the spatiotemporal evolution of dry and wet conditions and meteorological factors in the Hexi Corridor under changing environmental conditions, the relative moisture index (MI) and FAO Penman-Monteith (FAO P-M) model were combined to construct a partial differential quantitative attribution model for dry and wet variations affected by climate factors in the Hexi Corridor. The results show that: (1) MI in the Hexi Corridor increased significantly (Z = 2.341) during 1960-2019, showing a wet-trend change, and the degree of drought increased from southeast to northwest in the Hexi Corridor. (2) The order of drought degree in four seasons is as follows: winter (- 0.95), spring (- 0.93), autumn (- 0.89) and summer (- 0.83). (3) The frequency of extreme drought, severe drought, moderate drought, and mild drought within 60 years of 21 meteorological stations accounted for 28.38%, 50.48%, 8.85%, and 7.38%, respectively, and the frequency above severe drought was the highest. (4) The sensitivity of meteorological factors gradually increased from northwest to southeast, and MI was the most sensitive to the change of precipitation (P), followed by net radiation (R), wind speed (u), mean temperature (T), relative humidity (RH) and maximum temperature (T). MI was the least sensitive to the change of minimum temperature (T). P is the most important meteorological variable that contributes to the increase of MI, followed by u, T and T. R, T and RH have the least influence, and the total contribution of the seven meteorological factors is 85.59%. Compared with the reference evapotranspiration, P is the main factor affecting the dry and wet variations in Hexi Corridor.
极端气候事件的频繁发生破坏了区域水平衡，导致地表干湿状况发生变化，使得水分盈亏更加复杂多变。为探究变化环境条件下河西走廊干湿状况时空演变与气象因子的定量关系，将相对湿度指数（MI）与联合国粮食及农业组织彭曼-蒙特斯（FAO P-M）模型相结合，构建了河西走廊气候因子影响干湿变化的偏微分定量归因模型。结果表明：（1）1960—2019年河西走廊MI显著增加（Z = 2.341），呈变湿趋势，且干旱程度自东南向西北递增。（2）四季干旱程度排序为：冬季（-0.95）、春季（-0.93）、秋季（-0.89）、夏季（-0.83）。（3）21个气象站60年间极端干旱、重度干旱、中度干旱、轻度干旱发生频率分别为28.38%、50.48%、8.85%、7.38%，重度以上干旱频率最高。（4）气象因子敏感性自西北向东南逐渐增大，MI对降水量（P）变化最为敏感，其次是净辐射（R）、风速（u）、平均气温（T）、相对湿度（RH）和最高气温（T），对最低气温（T）变化最不敏感。P是导致MI增加的最重要气象变量，其次是u、T和T。R、T和RH影响最小，7个气象因子总贡献率为85.59%。与参考蒸散量相比，P是影响河西走廊干湿变化的主要因素。
