Maqola

A five‐year analysis of MODIS NDVI and NDWI for grassland drought assessment over the central Great Plains of the United States

Yingxin GuScience Applications International Corporation US Geological Survey Center for Earth Resources Observation and Science Sioux Falls South Dakota USAJesslyn F. BrownScience Applications International Corporation US Geological Survey Center for Earth Resources Observation and Science Sioux Falls South Dakota USAJ. P. VerdinUS Geological Survey Center for Earth Resources Observation and Science Sioux Falls South Dakota USABrian WardlowNational Drought Mitigation Center University of Nebraska at Lincoln Nebraska USA

2007en

ABI

Annotatsiya

A five‐year (2001–2005) history of moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) data was analyzed for grassland drought assessment within the central United States, specifically for the Flint Hills of Kansas and Oklahoma. Initial results show strong relationships among NDVI, NDWI, and drought conditions. During the summer over the Tallgrass Prairie National Preserve, the average NDVI and NDWI were consistently lower (NDVI < 0.5 and NDWI < 0.3) under drought conditions than under non‐drought conditions (NDVI>0.6 and NDWI>0.4). NDWI values exhibited a quicker response to drought conditions than NDVI. Analysis revealed that combining information from visible, near infrared, and short wave infrared channels improved sensitivity to drought severity. The proposed normalized difference drought index (NDDI) had a stronger response to summer drought conditions than a simple difference between NDVI and NDWI, and is therefore a more sensitive indicator of drought in grasslands than NDVI alone.

Hali tarjima qilinmagan

Identifikatorlar

DOI: 10.1029/2006gl029127

Iqtiboslar va manbalar

3 ta iqtibos0 ta foydalanilgan manba

Koʻrsatkichlar — AkademScholar