Журнал дистанционного зондирования и ГИС

Абстрактный

NDVI: Vegetation Performance Evaluation using RS and GIS

Khillare Anjali A, K. A. Patil

Vegetation is a crucial part of ecosystem and plays a key role for soothing global environment. Normalized Difference Vegetation Index (NDVI) is one such remote sensing technique which is used to compute vegetation cover change. Remote sensing and geographical information system methods are used often in examining natural resources, determination of land changes and related planning work. The methodology discussed in this study is based in association with remote sensed data about vegetation, in the form of Normalized Difference Vegetation Index (NDVI). The main application of this index is to monitor the vegetation cover. NDVI is the function of the spectral contrast between the reflected Near Infrared (NIR) and Visible (VIS) radiance from a surface. A further study is made on the calculated NDVI to evaluate the agricultural drought index in the form of Vegetation Health Index. This index is a combination of Vegetation Condition Index (VCI) and Land Surface Temperature (LST). VHI classifies vegetation health, which is suitable to indicate agricultural drought extent. A correlation is studied statistically between NDVI, VHI, precipitation and temperature. The present study is focussed on the Shirur and Khed talukas of Pune district for the years 2000,2003,2009,2012,2015 and 2018 for particular months. The use of data Landsat 7 ETM+ for year till 2012 and data Landsat 8 OLI for 2015 and 2018 was made. Data was obtained from U. S Geological Survey. The precipitation data was taken from maharain.gov.in. Thus, vegetative cover over the specified area was studied including the drought severity. A liner regression analysis is performed using the evaluated data which can be used to forecast the vegetation condition as an early warning system for agricultural drought.