Monitoring regional drought using the Vegetation Condition Index
Monitoring regional drought using the Vegetation Condition Index
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DOI：
10.1080/01431169608949106
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发表时间：
1996-09-20
影响因子：
3.4
通讯作者：
Kogan, FN
中科院分区：
文献类型：
--
作者：
Liu, WT;Kogan, FN
最近利用NOAA AVHRR GVI数据生成的归一化植被指数图像监测大规模干旱模式及其对植被的气候影响。本研究的目的是使用植被状况指数（VCI），以进一步分离区域的NDVI变化的地理贡献，以评估区域干旱的影响。1985年7月至1992年6月期间的每周NDVI数据被用来制作南美洲大陆的NDVI和VCI图像。用中值滤波技术对每年的NDVI数据进行平滑处理。利用NDVI和VCI的阈值划分干旱区。干旱模式划定的归一化植被指数和VCI同意相当不错，从巴西的降雨量图观察到的降雨量异常。NDVI值较好地反映了不同的地理条件。VCI划定的干旱地区的季节和年际比较为分析区域干旱的时空演变以及定性估计作物产量提供了有用的工具。建议在建立大尺度作物产量预测模型时，除NDVI外，还可利用VCI数据。
NDVI (Normalized Difference Vegetation Index) images generated from NOAA AVHRR GVI data were recently used to monitor large scale drought patterns and their climatic impact on vegetation. The purpose of this study is to use the Vegetation Condition Index (VCI) to further separate regional NDVI variation from geographical contributions in order to assess regional drought impacts. Weekly NDVI data for the period of July 1985 to June 1992 were used to produce NDVI and VCI images for the South American continent. NDVI data were smoothed with a median filtering technique for each year. Drought areas were delineated with certain threshold values of the NDVI and VCI. Drought patterns delineated by the NDVI and VCI agreed quite well with rainfall anomalies observed from rainfall maps of Brazil. NDVI values reflected the different geographical conditions quite well. Seasonal and interannual comparisons of drought areas delineated by the VCI provided a useful tool to analyse temporal and spatial evolution of regional drought as well as to estimate crop production qualitatively. It is suggested that VCI data besides NDVI may be used to construct a large scale crop yield prediction model.