西藏阿里草地气候生产力对气候变化的响应

Response of Grassland Climatic Productivity to Climate Change in Ali Area of Tibet

利用1985~2013年的西藏阿里地区气象数据,依据Miami模型和Thornthwaite Memorial模型计算出阿里草地气候生产力的数值,分析了西藏阿里气候变化和草地气候生产力变化趋势和草地气候生产力与降水、气温变化的响应关系。研究表明,近29年来,阿里地区年平均气温增温的趋势明显,其倾向率为0.588℃/10a,年平均降水呈现减少的趋势,其倾向率为-2.926 mm/10a,草地气候生产力向减少趋势发展,其倾向率为-71.181kg/(hm^2·10a),年际变化188.04~2572.19kg/(hm^2·a)之间,当温度每升高1℃草地气候生产力下降15.526kg/(hm^2·a),降水每升高1mm草地气候生产力升高21.269kg/(hm^2·a)。在降水减少和气温升高的趋势下,气候向"暖干化"发展趋势明显,降水对草地生产力的影响将更加明显,草地生产力下降趋势给草地畜牧业发展带来了严重的影响。

In this study,climate data from the years between 1985 and 2013were used to analyze the trend of climatic change in Ali area of Tibet,and with the Miami and Thornthwaite Memorial model,the responses of grassland climatic productivity to precipitation and climate change were explored.The results show that the average temperature in Ali area presented an obvious rising trend with a tendency rate of0.588 ℃/10 ain recent 29 years,whereas mean precipitation considerably decreased with the tendency rate of-2.926 mm per decade.Besides,the tendency rate of climatic productivity was declining to-71.181kg/(hm^2·10a)and annual variation was in the range of 188.04~2572.19kg/(hm^2·a).As temperature raised 1 ℃ or precipitation added 1mm,grassland climatic productivity reduced 15.526kg/(hm2·a)or increased 21.269kg/(hm^2·a).Additionally,under the trend of decreasing precipitation and rising temperature,the impact of precipitation on grassland productivity will be more apparent with the climate developing into warmness and dryness,resulting in the decline of grassland productivity which will affect the agriculture and animal husbandry.