利用EOS/MODIS、NOAA/AVHRR卫星遥感监测的植被指数(NDVI)、地面定点监测的实际地上牧草产量资料,依据卫星遥感监测原理,在点和面上研究、建立了植被指数与牧草产量之间的关系模式,给出了草地资源卫星遥感监测和评价方法。监测和评价结果显示:2004年青海省草地资源从东南部向西北部逐渐递减,产量最高区处于黄南州南部和果洛州东南部,最低区处于西北部的柴达木盆地,近20年来天然草地资源的分布规律没有发生变化,但草地生产力在逐步下降,草地资源在逐年减少,仅果洛州全州平均牧草产量比1986年下降了4.04%,牧草总量减少85.10×104t,理论载畜量减少了63.11×104只绵羊单位;暖干旱化的气候变化趋势是造成青海省天然草地生产力下降、呈现退化趋势的主要原因。

Using the vegetation index (NDVI) monitored by EOS/MODIS,NOAA/AVHRR satellites, and the grass yield and vegetation coverage determined on the ground,and according to the principle of remote sensing monitoring,combining rearch work on key spots with that in other areas,the relational patterns between vegetation index and grazing yield,vegetation index and vegetation coverage were established.And the method of the grassland resources monitored by remote sensing and their appraisal was produced.The results showed that in 2004 the grassland resources of Qinghai Province decreased gradually from the southeast to the northwest,the area with the highest yield was in the south of Huangnan Prefecture and the southeast of Golog Prefecture,and the area with the lowest yield was in the northwest of Qaidam Basin.The distributing status of natural grassland resources for the last 20 years didn’t change,but the productivity of the grassland was dropping gradually,and the grassland resources were reducing year by year,and in Golog alone the average grass yield dropped by 4.04% compared with that of 1986,with a total grass yield reduction of 851000t and the reduction of theoretical number of animals carried 631100 sheep.The warming and drying climatic changing trend was the main reason for the descending and degenerating of the natural grassland productivity in Qinghai Province.