Journal of Arid Meteorology

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Influences of Different Grades Precipitation on the Drought Release in Alpine Grassland

LI Hongmei1, LI Lin2, XIAO Hongbin3, ZHANG Tiaofeng1   

  1. 1. Qinghai  Climate  Center, Xining 810001, China; 2. Weather Modification Office of Qinghai Province,
     Xining 810001, China; 3. Qinghai Institute of Meteorological Science, Xining 810001, China
  • Online:2019-02-28 Published:2019-02-28

高寒草原不同量级降水对干旱解除的影响#br# 干旱解除的影响

李红梅1李林2肖宏斌3张调风1   

  1. 1.青海省气候中心,青海西宁810001;2.青海省人工影响天气办公室,
    青海西宁810001;3.青海省气象科学研究所,青海西宁810001

Abstract:

Based on the data of precipitation and soil volumetric water content per 10 minutes from March 1 to October 31, 2017, the effects of different precipitation levels on soil volumetric water content under different treatments were analyzed. The results are as follows: (1) Under light rain condition, the soil moisture at the 0-10 cm depth increased, and it was obviously weakened when the shielding rate exceeded 30%. The surface vegetation cover could improve the utilization rate of precipitation in a certain degree under light rain. (2) Moderate rain could improve the soil moisture at the 0-10 cm depth in the contrast area and under the treatments with shielding rate of 20% and 30% and the condition of poor soil moisture. The moderate rain could supplement effectively the soil moisture at the 0-30 cm depth in the contrast area and under the treatments with shielding rate of 20%, 30% and 40% under the condition of good soil moisture.  (3) Under heavy rain condition, the soil volumetric water at the 0-20 cm depth increased significantly in the contrast area and under the treatments with shielding rate of 20%, 30%, 40% and 60%, and that at the 20-30 cm depth also increased obviously in the contrast area and under the treatments with  shielding rate of 20%, 30% and 40%. (4) Flash heavy precipitation had very limited effect on improving soil moisture. Rainstorm was very effective in increasing the soil water at the 0-20 cm depth, but it was not as good as heavy rain in increasing soil moisture at the 20-30 cm depth. (5) The effective precipitation  thresholds value were 2.5, 7.0 and 10.0 mm at the 0-10 cm, 10-20 cm and 20-30 cm depths in the contrast zone, respectively. (6) Under the conditions of extreme drought, heavy drought, moderate drought and light drought, the minimum precipitation required for the drought relief were 21.5, 11.7, 5.0, 1.4 mm at the 0-10 cm depth, respectively, and it was 32.9, 18.6, 8.6, 2.7 mm  at the 10-20 cm depth, respectively.

Key words: alpine grassland, drought release, effective precipitation, precipitation threshold

摘要:

基于2017年3月1日至10月31日逐日每10 min降水量和土壤体积含水率试验数据,分析不同降水量级不同处理对土壤体积含水率的影响,结果表明:(1)小雨仅能提高0~10 cm土壤墒情,且在遮挡率超过30%时,效果明显减弱,同时地表植被覆盖能在一定程度上提高降水利用率。(2)在土壤底墒较差条件下,中雨能改善对照区、遮挡率20%和30%处理下0~10 cm土壤体积含水率;在土壤底墒较好条件下,中雨能有效补充对照区、遮挡率20%、30%和40%处理下0~30 cm土壤水分。(3)大雨条件下,在对照区、遮挡率20%、30%、40%和60%处理下,0~20 cm土壤体积含水率均有明显增加,在20~30 cm土壤层对照区、遮挡率20%、30%、40%处理下增加亦比较明显,大雨能完全解除0~30 cm土壤干旱。(4)短时强降水对土壤水分的补偿十分有限。暴雨对提高0~20 cm土壤体积含水率非常明显,但对提高20~30 cm土壤水分含量不及大雨效果明显。(5)在对照区,0~10 cm、10~20 cm和20~30 cm土层有效降水量阈值分别为2.5、7.0和10.0 mm。(6)特旱、重旱、中旱和轻旱条件下,0~10 cm土层干旱解除所需的最小降水量分别为21.5、11.7、5.0、1.4 mm,10~20 cm土层所需的最小降水量分别为32.9、18.6、8.6、2.7 mm。

关键词: 高寒草原, 干旱解除, 有效降水, 降水阈值

CLC Number: