The pollution of river water and sediments by heavy metals has assumed serious problems due to their toxicity and accumulative behaviour globally and locally. This research paper aim at mapping heavy metal contamination in urban rivers in Ibadan metropolis, Nigeria namely; Ona and Omin using GIS techniques. Systematic method of sampling stream sediments along the drainage channels was adopted. In all, fifty-eight (58) samples were collected and analyzed for heavy metals such as As, Cd, Cu, Pb, Zn etc using inductively coupled plasma- optical emission spectrometry (ICP-OES) at ACME in Canada. The concentration of the heavy metals was compared with water quality standard prescribed by WHO, BIS, ICMR, FAO, SQG-TEC and PEC. Geochemical maps of heavy metal distributions were produced using Arc GIS 10. However, general assessment shows that Ona and Omin rivers are polluted. It is therefore recommended that urgent management steps be taken to arrest future deleterious effects and sustainability of these water bodies for human consumption.
Key Words: Urban River, Heavy metal, Pollution, GIS, Ibadan