北京山区植被盖度季节变化规律模拟研究

CHANGE PATTERN OF VEGETATION COVERAGE IN THE MOUNTAINOUS AREA OF BEIJING

通过摄影与数字图像处理相结合的方法分析了 1999年北京山区典型植被覆盖度的季节动态变化规律 .研究结果表明 ,北京山区典型植被的覆盖度随季节都呈非线性变化 ,成熟期之前各种植被覆盖度增加较快 ,然后保持平稳 ,成熟期之后略呈减小趋势 ;不同植被类型的植被覆盖度随季节的变化规律又有所差异 ,其中农地 ,尤其是灌溉玉米其覆盖度随季节变化最为显著 ;不同的植被类型的植被覆盖度达到鼎盛期的日期也存在很大差异 ,果树最早 ,出现在 6月初 ,非灌溉玉米最晚 ,出现在 7月下旬 ;另外 ,北京山区典型植被受干旱影响的程度也各不相同 .该结果可为北京山区土壤侵蚀模型预报、水土保持规划和环境治理提供一定的理论依据 .

How the typical vegetation coverage changed with time in the mountainous area of Beijing in 1999 is studied after processing the photos taken in field. The results show that in the mountainous area of Beijing in 1999 the typical vegetation coverage changs nonlinearly, that is, the vegetation coverage increases rapidly at first, tends to keep stable then, and decreases gradually finally. It is evident that all of the typical vegetation coverage changes greatly with time with the farmland most prominently. The dates when the maximum coverage is reached varies with different vegetation with the gaps being 1 to 2 months. And to which extent the vegetation coverage is influenced by drought depends on the vegetation type. These results may serve as one of the guides for parameter selection in soil loss models, soil conservation plan, and environment control.