中国草原产草量遥感监测

Remote sensing monitoring upon the grass production in China

根据MODIS遥感数据和同期地面调查数据,对我国2005年草原产草量进行了系统估算。用MODIS数据计算全国草原的归一化植被指数NDVI,针对6个不同类型草原区建立了NDVI和地面样方的产草量之间的关系模型,用这些模型推算全国草原产草量分布。结论如下:(1)2005年我国草原有3个牧草高产中心,分别位于东北呼伦贝尔草原、锡林浩特草原和大兴安岭西麓;青海东部、四川西北部和甘肃中南部以及新疆西北部;(2)2005年全国草原干草总产量达到29421.39万t,平均单产达到829.67kg/hm2干草;(3)2005年干草产量位列前7位的省区依次是内蒙古、青海、新疆、四川、西藏、黑龙江和甘肃;例如,内蒙古因草原面积大而成为我国第一大草原牧草生产省,2005年有6037.08万t干草;(4)总产草量位于前5位的草地类型依次为高寒草甸类、温性草原类、低地草甸类、温性草甸草原类与山地草甸类;(5)2005年8月份全国草原产草量与2004年同期相比总体持平;各草原大省的变化情况分别为:青海、甘肃2省区的草产量略有增加,青海增加了9.02%、甘肃增加了3.63%;内蒙古减少约3%;西藏、新疆和四川3省区基本与2004年同期持平。研究结果对我国草原监理、草原畜牧业发展和草地生态系统研究具有较大的参考价值。

Using MODIS remote sensing data and ground productivity of grasslands in China for the year 2005. The truth data, we conducted a thorough investigation to the Normalized Difference Vegetation Index （NDVI） was first computed from the MODIS data. Then the data from the NDVI images were used to correlate to the grass yield data from the ground sampling campaigns. Six regional models were accordingly established from the correlation for estimation of grass production in the six main types of steppes in China. The main results from the estimation could be summarized as follows： （ 1 ） High grass productivity in 2005 was obtained in the following 3 regions ： the grassland covering Hulunbuir, Xilinhaote, and the western Daxing ＂anling Gansu, and the northwestern , the region including the eastern Qinghai, the northwestern Sichuan and the mid-southern Xinjiang region. （2） Total hay output of the grasslands in China amounted to 294213.9 thousand tons in 2005, with an average yield of 829.67 kg/hm2. （3） The following seven provinces were the largest grass producers in China： Inner Mongolia, Qinghai, Xinjiang, Sichuan, Tibet, l-Ieilongjiang and Gansu. For example, Inner Mongolia produced 60370.82 thousand tons of hay in 2005, hence became the no. 1 grass producer of China. （4） Among the steppes types, the following five had the largest grass production： Alpine meadow, Temperate steppe, Low-land meadow, Temperate meadow steppe and Montane meadow, with total production accounting for 62.2% of China. （5） Grass production of the entire China in August 2005 remained at the same level as that in August 2004. However, the situations of major grassland provinces were different： grass production in both Qinghai and Gansu in 2005 increased 9.02% and 3.63% respectively when compared with that in 2004. The grass production in Inner Mongolia decreased 3%, while the production in Tibet, Xinjiang and Sichuan remains unchanged when compared to that in 2004. These results were very important for grassland administration, pasture grazing and grassland ecosystem studies in China.