农牧交错带植被演变对区域气候影响的模拟

A Numerical Simulation of the Impact of Vegetation Evolution on the Regional Climate in the Ecotone of Agriculture and Animal Husbandry over China

利用中尺度模式WRF和1981年、1990年卫星遥感地表分类数据,模拟分析了典型年份农牧交错带内地表植被变化对2001-2010年中国区域气候的影响。结果表明:(1)相对于1981年,1990年交错带内38°N以北(南)植被覆盖增加(减小),地表粗糙度增加(减小)。(2)当植被覆盖度增加(减小)、地表粗糙度增加(减小)时,交错带相应地区及附近地区温度升高(降低)。(3)交错带植被演变导致我国降水量差值场存在自东向西的"正-负-正"分布,地表粗糙度增加(减小)对应降水量差值增加(减少),且降水量越大,水循环越充足,植被演变对降水量的影响表现越突出。(4)交错带的植被演变主要影响中高层风场,且存在明显的季节性差异。500 h Pa气旋状(反气旋状)偏差风场环流中心对应着降水量差值场的正值(负值)。

As one of the three human factors that affect climate change, real vegetation cover over the ecotone of agriculture and animal husbandry can affect regional and global climate by changing surface radiative forcing, en- ergy and water circulation, greenhouse gas and aerosol emissions. The ecotone of agriculture and animal hus- bandry in China is a key area in China＇s land surface change. The regional climate effect caused by its evolution has important research significance. The impact of real vegetation cover over the ecotone of agriculture and ani- mal husbandry changing in typical years on the regional climate over China during 2001 --2010 was studied by u- sing WRF （Weather Research and Forecasting） model and the surface classification data of satellite remote sens- ing in the years 1981 and 1990. There are some conclusions after analyzing the change of temperature, precipita- tion and wind. The main conclusions are as follows： （1） In 1990, compared with 1981, vegetation cover over the ecotone of agriculture and animal husbandry increases （decreases） in the north of 38°N, and the surface roughness increases （decreases）. （2） When the vegetation cover over the ecotone of agriculture and animal hus- bandry increases （decreases） and the surface roughness increases （ decreases）, the temperature of the agriculture and animal husbandry and the nearby areas increases （decreases）. （ 3 ） The evolution of vegetation cover over the ecotone of agriculture and animal husbandry leads to the ＂positive-negative-positive＂ of the precipitation differ- ence over China from the east to the west. The surface roughness increases （decreases） causes the precipitation increases （decreases）. When there are more precipitation, there will be more water cycle. The evolution of vege- tation cover over the ecotone of agriculture and animal husbandry are more sensitive to places where precipitation is high. The more precipitation with more water circulation causes the more prominent the effect of vegetation evolution on precipitation. （4） The vegetation evolution of the intersected zone mainly affects the middle and high-level circulation fields, the cyclonic （anti-cyclonic） circulation at 500 hPa corresponds well with the in- crease （decrease） of the precipitation difference field.