Using Indexes to Detect the Environmental Changes of Hor Al-Dalmaj and Surrounding Areas in Central Sector of Mesopotamia Plain

Abstract

The study area has large desertification areas which covered by salty soils and sand dunes and sand sheet. It lies in Wassit, Al-Qadissiya and Karbala Governorates in central sector of the Mesopotamia plain.

The study area depends on Thematic Mapper (TM) data of Landsat 5 for two scenes acquisition in 1990, Enhancement Thematic Mapper (ETM) data of Landsat7 for two scenes Acquisition in 2002, these data are mosaic and subset it by using area of interest (AOI) file and made use of a nearest neighbor polynomial correction within the ERDAS 9.2 software.The images carried out with WGS84 datum and UTM N38 projection using nearest neighbor resampling.

Different types of indexes were adopted as practical tools for monitoring of Hor Al-Dalmaj and surrounding areas such as Normalized Differential Vegetation Index (NDVI), Water Index (WI), Eolian Mapping Index (EMI) and Salinity Index (SI) to study environmental changes from 1990to 2002, by using ERDAS 9.2 Imagine and Arc GIS 9.3 programs.

The vegetation distribution determined by Normalized Differential Vegetation Index (NDVI), Water determined by using Water Index (WI), Eolian sediments determined by using Eolian Mapping Index (EMI) and to detect the salinity soil used Salinity Index (SI).

The obtained result showed that the desertification lands have increased during the period from 1990 to 2002.

Keywords: Environmental Changes, Normalized Difference Vegetation Index (NDVI), Water Index (WI), Eolian Mapping Index (EMI), Salinity Index (SI).