1901—2014年黄土高原区域气候变化时空分布特征

气候变化对黄土高原地区环境与经济影响重大,研究其在小地理尺度上的时空变化趋势对该区应对全球气候变化制定适应性策略有重要意义。论文基于CRU 1901—2014年逐月气候数据集,利用Delta空间降尺度方法对该数据集在黄土高原地区进行降尺度处理并评价,最后采用距平、Mann-Kendall趋势检验和Sen’s斜率估计方法分析该区历史时期气候变化的时空分布特征。结果表明：1）使用Delta法将分辨率为0.5°×0.5°的月降水量和月均温数据降尺度到分辨率为1 km×1 km的网格上是可行的,其中线性插值法最适合该区降尺度过程。2）1901—2014年该区年降水量年际变化趋势不显著,但年均温以0.1 ℃/10 a的速率显著上升;与气候平均值相比,20世纪60年代为相对湿冷期,80年代以后为相对干暖期;年降水量在该区西部地区（面积占3.05%）以0.24 mm/10 a~3.52 mm/10 a的速率显著增加,年均温在西部以外地区（面积占91.30%）以0.02 ℃/10 a~0.17 ℃/10 a的速率由西南向东北显著上升。3）1981—2010年黄土高原西部地区（面积占92.02%）相比气候平均值变干变暖,西部以外地区（面积占7.98%）变湿变暖;年降水量只在民和及其以南极少数地区（面积占0.05%）以17.25 mm/10 a~27.93 mm/10 a的速率显著增加,年均温在西部以外地区（面积占87.61%）以0.23 ℃/10 a~0.71 ℃/10 a的速率显著上升。上述研究结果可为该区在制定应对全球气候变化策略时提供科学依据。

Spatiotemporal Distribution Characteristics of Climate Change in the Loess Plateau from 1901 to 2014

Climate change has a significant influence on the environment and economy in the Loess Plateau (LP) region. Studying the spatio-temporal trends of climate change at the fine scale would be conductive to develop flexible adaptation and mitigation strategies against the climate change issues in this region. This study downscaled CRU climate data from 1901 to 2014 to spatial resolution of 1 km using the Delta downscaling method and evaluated the monthly climate change in this region. The spatio-temporal characteristics of the climate in this region were analyzed with the anomalies method, Mann-Kendall trend test, and Sen’s slope estimation method. The results are as following: 1) The Delta downscaling method performs well in generating monthly precipitation and temperature data with 1 km spatial resolution. Among the four interpolation methods, the bilinear interpolation is the best method for the downscaling process. 2) During 1901-2014, the annual precipitation had no significant trend, while the annual average temperature presented a significant increasing trend with 0.1 ℃/10 a. Compared with the average level of the climate during 1961-1990, the climate in 1960s was cold and wet, while it was dry and warm after 1980. The annual precipitation in the west of the LP region (accounting for 3.05% of the area) showed a significant increasing trend during 1901-2014, ranging from 0.24 mm/10 a to 3.52 mm/10 a. The annual average temperature in region other than the west of the LP region (accounting for 91.30% of the area) showed a significantly increasing trend ranging from 0.02 ℃/10 a to 0.17 ℃/10 a during 1901-2014, and the magnitudes of the trend increased from southwest to northeast. 3) During 1981-2010, the climate in the west of the LP region (accounting for 92.02% of the area) was drier and warmer than it was during 1961-1990, while in the rest region (accounting for 7.98% of the area) it became wetter and warmer. The annual precipitation in Minhe and region south to Minhe (accounting for 0.05% area) presented a significantly increasing trend during 1981-2010, ranging from17.25 mm/10 a to 27.93 mm/10 a. The annual average temperature in region other than the west of the LP region (accounting for 87.61% of the area) had a significantly increasing trend during 1981-2010, ranging from 0.23 ℃/10 a to 0.71 ℃/10 a. These results could provide a scientific basis for developing strategies addressing global climate change issues in the LP region.