Review of relationship between PNPI and NDVI indices (Case study: monitoring of drought in Azarbaijan - Iran 2000- 2005)

Droughts are natural hazards with varying patterns in space, time, and intensity. This phenomenon is a major natural disaster that has caused many problems in many countries. Awareness of drought status, with the prediction and area mapping of drought intensity can due to considerable decrease in risk of this phenomenon. Prediction of droughts with use of suitable index and providing of drought intensity maps with help of remote sensing technology with minimum time and cost is important step for managing this phenomenon. The purpose of this study was to investigate the possibility of drought monitoring using normalized difference vegetation index (NDVI) and remote sensing technology, with an area of 47,830 square kilometers of East Azarbaijan province. And also to identify the worst drought in years is studied. East Azarbaijan province is one of the Iran’s provinces that have been faced with severe drought in recent years. In this study, the drought index PNPI (percent of normal precipitation index) and NDVI index (normalized difference vegetation index) were reviewed in order to monitor drought in East Azarbaijan province. For this goal were calculated PNPI index for 12 meteorological major stations (2000 to 2005) in this province and then drought area map, according to that index, was provided. Then NDVI maps with use of images of 10-day maximum normalized vegetation were provided. The result show, that 2001 with minimum NDVI has most severe drought and also there is .8 correlation between average PNPI index and average NDVI index. There is therefore possibility of producing drought maps with the NDVI index.

کلیدواژه ها:

Drought ، Remote sensing ، PNPI ، NDVI