_____________________________________________________________________________________________________ *Corresponding author: E-mail: paulfadthechemist@yahoo.com; Journal of Geography, Environment and Earth Science International 10(2): 1-11, 2017; Article no.JGEESI.32278 ISSN: 2454-7352 Assessment of Heavy Metal Enrichment and Level of Contamination of Floodplains Soil in Ondo State, Nigeria Fadojutimi Paul Olawale 1* , Aiyesanmi Festus Ademola 1 , Adelaja Oluwaseun Adekoya 1 and Oladele Soji George 2 1 Department of Chemistry, Federal University of Technology, P.M.B. 704, Akure, Nigeria. 2 Department of Geography, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria. Authors’ contributions This work was carried out in collaboration among all authors. Author FPO designed the study and wrote the protocol. Author FPO performed the statistical analysis, managed the literature search and wrote the first draft of the manuscript with assistance from authors AFA, AOA and OSG. All authors read and approved the final manuscript. Article Information DOI: 10.9734/JGEESI/2017/32278 Editor(s): (1) Masum A. Patwary, Geography and Environmental Science, Begum Rokeya University, Bangladesh. Reviewers: (1) Aliyu Adamu, National Institute for Pharmaceutical Research and Development (NIPRD), Abuja, Nigeria. (2) Reda Ragab Shahin, Cairo University, Egypt. Complete Peer review History: http://www.sciencedomain.org/review-history/19105 Received 18 th February 2017 Accepted 25 th April 2017 Published 17 th May 2017 ABSTRACT Flooding is one significant process that contributes to the movement of sediment and metals. With higher velocities of water, flooding can take contamination downstream. The soil samples were collected from three floodplains of Owena river, Ogbese river and Ala river in Ondo State were analyzed for their physico-chemical characteristics. The study also investigated the chemical speciation of Cd, Cu, Ni and Zn and total concentration in the soil samples. The concentration of the heavy metals in the selected floodplains were orderly as Zn > Cu > Ni > Cd. Investigating the speciation showed that contribution to the total metal content of the alluvial soil was from both geogenic and anthropogenic sources. Pollution/Contamination index evaluation showed that the alluvial soils had very slight metal contamination for all the metals except for Cd being found in the range of very severe contamination to slight contamination in Owena and Ala floodplains. Original Research Article