1961—2018年呼伦贝尔市潜在蒸散时空变化特征及其气象因子的响应

Spatial and Temporal Variation Characteristics and Attribution Analysis of Potential Evapotranspiration in Hulunbuir 1961-2018

本文旨在研究呼伦贝尔市1961—2018年潜在蒸散的时空变化,以期为当地气象生态研究提供基础的理论依据。基于呼伦贝尔1961—2018年16个气象站观测数据,采用趋势分析、M-K突变检验及偏相关系数等方法,从年、季节和年代际尺度分析了呼伦贝尔58年潜在蒸散量的时空变化特征及其原因。结果表明:(1)1961—2018年,呼伦贝尔年平均潜在蒸散量变化在320~771 mm,整体上呈现条带状自东北向西南、东南两个方向递增;夏季潜在蒸散量平均值最高,其次为春季和秋季,冬季最低;(2)年均潜在蒸散以2.3 mm/a的速率增加,并在1998年发生突变,之后增加趋势更加明显;(3)西南部呼伦贝尔草原区和岭东农业区增加趋势明显高于中部大兴安岭林区;(4)呼伦贝尔潜在蒸散的变化主要与风速、水汽压和相对湿度呈现负相关,和平均气温、气压呈现正相关;影响年潜在蒸散的主要因子为相对湿度和平均气温。结合潜在蒸散变化趋势,有针对性的合理规划水资源,对该地区生态环境评估及环境变化有重要的意义。

The purpose of this article is to study the spatiotemporal variation of potential evapotranspiration over the past 58 years, and provide a basis for the research on meteorological ecology in Hulunbuir. Based on the observation data of 16 meteorological stations in Hulunbuir from 1961 to 2018, the spatial and temporal variation characteristics and causes of potential evapotranspiration in the 58 years were analyzed from seasonal and decadal scales by means of trend analysis, M-K mutation test and partial correlation coefficient. The results showed that:(1) from 1961 to 2018, the annual average potential evapotranspiration changes in Hulunbuir ranged from 320 to 771 mm, and the overall trend was increasing from northeast to southwest and southeast;the average potential evapotranspiration was the highest in summer, followed by that in spring and autumn, and the lowest was in winter;(2) the annual average potential evapotranspiration increased at a rate of2.3 mm/a, and it had a mutation in 1998, after which the increase trend became more obvious;(3) the increase trend in grassland areas in the southwest and agricultural areas in the east was significantly higher than that in the Great Khingan Mountains forest zone;(4) the variation of potential evapotranspiration in Hulunbuir was negatively correlated with wind speed, vapor pressure and relative humidity, and positively correlated with average air temperature and air pressure;the main factors affecting annual potential evapotranspiration were relative humidity and average temperature. Combining with the potential trend of evapotranspiration, the rational planning of water resources is of great significance to the ecological environment assessment and environmental change in this area.