利用NDVI资料估算中国北方草原区牧草产量

该文利用NOAA/AVHRR归一化植被指数（NDVI）资料和牧草地面观测资料，分5种草地类型建立了牧草产量遥感模型，所有模型的相关系数均大于0.7，说明这些模型可以较好地估算中国北方草原区牧草产量。由于牧草产量地面观测资料来自于北方主要草原省，数据具有较好的代表性，利用牧草产量遥感估算模型能够将过去小区域牧草产量估算扩展到整个北方草原。通过对模型结果的空间分析表明，中国北方高产草原位于内蒙古东部、甘肃祁连山区、新疆天山和阿尔泰山地区、青藏高原东部，同时也表明遥感模型对草地资源清查也是一种很好的手段。通过对模型结果的时间分析表明，牧草产量遥感模型可以表现出牧草产量随气象条件变化的波动性，这个性质表明牧草产量遥感模型可以用于气象灾害造成的损失评估。

Estimation of forage yield in Northern China based on NDVI data

Five kinds of remote sensing models were established for estimating the forage yield of the meadow in Northern China based on NOAA/AVHRR NDVI data, and the forage yield from the ground observation. The correlation coefficients of the five models were more than 0.7, which showed that the models were effective. Because the data of the forage yield were measured in the provinces such as Inner Mongolia, Gansu, Ningxia, Xinjiang, Qinghai and Tibet where the meadow was the main vegetation type, they were representative for the whole grassland in Northern China. So the models could extend the study area accordingly. The spatial analysis of the model results showed that the fertile meadows in Northern China lied in the eastern Inner Mongolia, Qilian Mountain in Guansu, Tianshan Mountain and Altai Mountain in Xinjiang, and the eastern Qinghai-Tibet Plateau. In this sense, the models could be applied in the survey of the resource of grassland. The time analysis of the model results revealed that the forage yield was mutative with the climate. So, the models could be applied to estimate the loss because of the climate disaster.