关键词: 呼伦贝尔, 降水集中度, 降水集中期, 干旱

Abstract:

Based on the pentad precipitation data of 16 meteorological stations in Hulunbeir from 1961 to 2016, this paper analyzed the characteristics of spatial and temporal distributions and variations of the precipitation concentration degree (PCD) and precipitation concentration period（PCP）in growing seasons, and the relationship between precipitation concentration and the occurrence of drought was revealed. The results are as follows: (1) The spatial distribution characteristics of PCD and PCP were obvious in Hulunbeir, PCD increased from northeast to southwest, and the PCP decreased from northwest to southeast. (2) Since 1961, the PCD and PCP both showed a downward variation trend, which meant that the precipitation tended to be uniform, and the maximum precipitation appeared earlier. (3) Mann-kendall test and moving t-test showed that the PCD in Hulunbeir was no obvious mutation in recent 55 years, and the PCP mutation occurred in 1978. (4) The coincidence rate of precipitation concentration and drought disaster in different ecological regions showed that the pastoral region was the highest, next was the forest region, and the agricultural region was the lowest, and coincidence rate in pastoral region was more than 80%, which indicated that the occurrence of drought was most closely related to the concentration degree of precipitation in pastoral region.

Key words: Hulunbeir, PCD, PCP, drought