• CN 62-1175/P
• ISSN 1006-7639

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

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

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.

CLC Number: