Assessment of soil and water characteristics and land cover changes along the Tigris River in Baghdad

Abstract

Land cover changes impact the soil and water quality which are critical for environmental and human health. The goal of this study is to evaluate whether the land cover change along the Tigris River, one of the largest rivers in the Middle East, is causing any heavy metal contamination. The objectives of this study were: (1) To analyze the metal concentrations in the water and soil samples along the Tigris River and (2) identify and map the land cover changes of the Baghdad district. A total of nine water and soil samples were collected from three different Tigris River (TR) sampling locations, namely Gherai´at (TR1), Bab Al Moatham Bridge (TR2), and Karada-Masbah (TR3). Surface soil and water samples were collected, and analyzed for various metal concentrations. Landsat satellite imagery from 1984 and 2018 were analyzed and compared for land cover changes. Our water sample analysis revealed that As, Cd, Cr, Cu, Pb and Zn remained low and are within the permissible limit of WHO standards. Soil samples showed that Cu, and Pb concentrations in TR1 and TR2, respectively were higher compared to other locations. The metal concentrations in both water and soil samples at the sampled locations were at safe levels. Remote sensing analysis revealed that the water surface in the study area increased by about 5.3% while the vegetative surface decreased by 10.3% during the period of 1984 to 2018. Water and vegetative cover increased further in the south of Baghdad, along the Tigris River, compared to the north. The impact of land cover changes and increase in soil metal concentrations are higher on TR2 and TR3 locations. Environmental chemical analysis coupled with geospatial data helps to monitor the impact of land cover changes on water and soil quality by identifying areas vulnerable to change. Key words: Water quality, landsat, soil quality, heavy metal, land cover change.