西藏那曲地区土壤温度变化特征及其与环境关系研究

Variation of Soil Temperature and Its Relationship with the Environment in Nagqu, Tibet

利用智墒(IST.HRGC-16S)监测了2017年6月-2019年9月西藏那曲市(31°33′49″N,116°00′37″E)不同土壤深度处(0、10、20、30、40、50、60cm)每小时的土壤温度;天圻气象站(WS00G10A)监测了2m高度处每小时的空气温度、空气相对湿度、大气压力、风速、风向、降雨量和累计太阳辐射量等指标,运用相关分析法分析了各层土壤温度与气象要素之间的关系。结果表明:(1)西藏那曲地区土壤温度在-15-17.5℃之间波动,土壤表层温度比深层随气温的变化明显;(2)0-30cm深度的土壤温度昼夜变化较为明显,呈现明显的波动周期,而30-60 cm深度的土壤温度变化不大。在一定范围内,土壤深度每增加10 cm,峰谷值滞后时间增加约1 h;昼夜温度波动性在代表月份中表现出冬季差值最大;(3)随土层深度增加土壤温度年平均值和地积温呈现先增高后降低的趋势,在土层深度30 cm处达到最大值,分别为4.27、1,557℃。(4)表层土壤温度对气象因子中空气温度、湿度、大气压、降雨量、累计太阳辐射强度的变化响应明显,相关系数分别为98%、91%、84%、75%、72%。研究结果揭示了那曲地区土壤温度变化规律及与环境关系,为探讨藏北高原生态脆弱区植物生长及其土壤和环境的关系提供研究基础。

Based on soil temperature data of 0-60 cm at 10 cm interval monitored by the IST(IST. Hrgc-16 s), the vertical variation characteristics of soil temperature were analyzed. and Then meteorological factors, including air temperature, humidity, atmosphere pressure, wind speed, rainfall, cumulative solar radiation and other indicators obtained by the Tianqi weather station(WS00G10A) from June 2017 to November 2019, were used to explore its relationship between soil temperature using the correlation method. The results showed that:(1) the soil temperature fluctuated between-15 ℃ and 17.5 ℃ in Nagqu region, Tibet, and the soil surface temperature changed significantly compared with the deep layer.(2) The diurnal variation of soil temperature in 0-30 cm was obvious, and had a distinct period of oscillation. However, the soil temperature in the 30-60 cm layer had little change, peak and valley value lagged behind by about 1 h with each 10-cm soil depth increased. The fluctuation of day and night temperature showed the greatest difference in special months, and the largest difference was in winter.(3) The annual average value of soil temperature and accumulated soil temperature showed an increasing trend firstly, then decreased with the increase of soil depth, and reached the maximum value of 4.27 ℃ and 1,557 ℃ at the soil depth of 30 cm.(4) Soil temperature(0 cm) had a significant response to the changes of air temperature, humidity, atmospheric pressure, rainfall and cumulative solar radiation intensity, with correlation coefficient of 98%, 91%, 84%, 75%, 72%, respectively. The experimental results revealed the law of soil temperature variation in Nagqu region, which laying a foundation for discussing plant growth and the relationship between soil and environment in the northern Tibetan plateau.