Ecological risks assessments of heavy metal contaminations in the Yancheng red-crown crane national nature reserve by support of GIS technique

All 83 surface soil layer samples were gathered from the north to south in Yancheng coast to study the ecological risks from heavy metals. Ten heavy metals, Cr, Cu, Fe, Mn, Ni, Sr, Ti, V, Zn, Co, were analyzed. Taking the core region as a specific zone, we did the spatial zonal statistics to get the average value of each metal within the core region. Compared this zonal average value of each metal with the average value of the 83 soil samplings, we found that the former was higher, and some metals´ high peak value distributed in the core region, including Mn, Ni, Ti. Multivariate statistics of the 10 metals were also done to detect the possible inputting source of them. We found that human disturbances were the main induced sources, except the background value. Though the ecological risks from the heavy metals were now not serious, it was not robust enough that only the core region being severely managed, and an integrated management mode was proposed, based on the detailed hydrology process research.