Analyzing dem characteristics for area affected by drought identified using vhi: A case study of Iaşi county

Abstract

In this paper was studied areas affected by drought using TCI, VCI and VHI. These indices are based on LST and NDVI. Drought is one of the most widespread and least understood natural phenomena. The droughts are the phenomena which affect large areas and remote sensing data covering large territory can be used to assess the droughts impact and their extent. In this study was used remote sensing images from the Landsat 8 Operational Land Imager (OLI), taken in April and May 2018. Study area, for this paper, geographically, is situated on latitude 47°32'N to 46°49'N and longitude 26°36'E to 28°05'E. This administrative unit is hit by heavy rains, floods, droughts and at larger periods of time by landslide events and earthquakes. NDVI values indicates that vegetation has been developed between 21st April and 7th May. LST values was about the same for images analyzed for study area. VHI is usually used to detect areas affected by severe drought. For these Landsat images analyzed was noticed that large areas were not affected by drought. Some zones were affected by moderate and mid drought – about the same for April and May. For these areas were made analysis to determine any connections between drought and altitude, gradient of slopes and exposure of slopes. Areas affected by moderate and mid drought have slope between 00 and 7.50 , mostly between 50 and 7.50 . Zones with slopes over 7.50 affected by drought is insignificant. Exposure of slopes for areas affected by drought is preponderant east and north-east.