气象要素对华北地区夏季植被覆盖度的影响

植被覆盖对气候变化极其敏感,华北区地处我国半干旱—半湿润过渡地区,气象因子对该地区植被覆盖有重要的影响,但缺少有效的数理模型定量刻画气象要素对植被的影响。因此,本文基于华北区2000～2018年中分辨率成像光谱仪的植被覆盖数据和主要气象要素数据,开展了多气象要素影响植被覆盖度的研究,初步建立了华北夏季植被覆盖度与气象要素的关系。研究表明:(1)华北存在向暖干转变的趋势,且夏季植被覆盖度与降水、相对湿度呈正相关,与气温、日照时数和地温呈负相关。(2)影响华北地区植被覆盖度最重要的气象要素是相对湿度,体现了温度和降水的共同作用。(3)基于多元回归法和最小二乘法可以定量描述气象要素变化对植被覆盖度的可能影响。其中,五变量影响模型对植被覆盖度模拟的相关系数略偏高,因此,基于五变量气象要素可以更好的模拟植被覆盖度的变化。研究结果有利于了解气象要素如何影响植被生态系统,进而为国家生态文明建设提供理论参考依据。

Influence of Meteorological Elements on Summer Vegetation Coverage in North China

Vegetation coverage is extremely sensitive to climate change. North China is located in the semiarid and subhumid transitional region of China. Meteorological factors have an important impact on the vegetation coverage in this area. However, effective mathematical models to quantitatively describe the influences of meteorological elements on vegetation are lacking. Therefore, based on the vegetation coverage data of the Moderate Resolution Imaging Spectroradiometer and main meteorological element data in North China from 2000 to 2018, the authors analyzed the influence of multiple meteorological elements on vegetation coverage and initially established the relationship between the summer vegetation coverage and meteorological elements in North China. The main study conclusions are summarized as follows: (1) A trend toward warm and dry climate conditions in North China is observed, and summer vegetation coverage is positively correlated with precipitation and relative humidity and negatively correlated with temperature, sunshine hours, and ground temperature. (2) The most important meteorological element affecting the vegetation coverage in North China is relative humidity, which reflects the combined effect of temperature and precipitation. (3) The multiple regression and least squares methods can quantitatively describe the possible impact of the changes in meteorological elements on vegetation coverage. Therefore, the five-variable combination of meteorological elements can better simulate the change in vegetation coverage. Results elucidate how meteorological elements affect vegetation ecosystem and provide a theoretical reference for constructing national ecological civilization.