基于GIS技术的南黄海辐射沙脊群海域水质分布特征与评价

Distribution Characteristics and Assessment of Water Quality of Radial Tidal Sand Ridge in South Yellow Sea by GIS

摘要: 使用Arcgis软件对南黄海辐射沙脊群附近海域2007年春秋两季表层水样的水质进行了分析，包括砷(As)、汞(Hg)、铜(Cu)、锌(Zn)、镉(Cd)、铅(Pb)、铬(Cr)七种重金属的含量分布变化。用Hakanson潜在生态危害指数法(HPERI)对该海域7种重金属进行生态风险评价，旨在为江苏沿海辐射沙脊区水质健康和海域生态环境保护提供科学依据，并为江苏沿海的开发利用提出合理化建议。研究结果发现，春秋两季As、Cd、Cr、Cu 4种重金属含量均低于国家海水水质I类标准；Pb和Zn在部分区域符合II类标准，其余各处符合I类标准；Hg在沙脊沉积区含量较高，春季为IV类海水，秋季为超IV类海水，在潮流通道含量较低，春季为I类海水，秋季为II、III类海水。秋季重金属较春季普遍含量更高，且整体分布呈现南移趋势。Hakanson潜在生态危害指数法评价结果表明，春秋两季该海域均以Zn的潜在生态危害最大，除秋季Zn存在强生态危害以外，其余重金属在春秋两季均为轻微生态危害；综合潜在生态风险以沿岸河口、港口附近和沙脊沉积区处为最高，表明人类活动是影响该海域重金属分布的主要因素；春季潜在生态风险属轻微，秋季高值区属中等风险。

Abstract: We used Kriging modelling in Arcgis 10.1 to find out the distribution characteristics of water qual-ity in Radial Tidal Ridge in South Yellow Sea during spring and autumn in 2007, focusing on 7 heavy metals as As, Hg, Cu, Zn, Cd, Pb, Cr. Hakanson Potential Ecological Risk Index (HPERI) was used to assess extents of heavy metals in this area to propose better suggestions for Jiangsu coastal development. According to our study, contents of heavy metals were higher and more enriched in south in autumn than in spring. Monsoon had a significant impact on distribution of those heavy metals in surface water in study area. Zn was found to contribute the most to the pollution status while other heavy metals were found to cause only slight ecological risk based on HPERI method. RI was high in costal Estuary and port area, where human impacts were significant, or sedimentary area of sand ridges, where tidal dynamics were weaker, which suggested that there was a tendency that pollution caused by human activities had turned into the most important impacting factor of the water quality in the Radial Tidal Sand Ridge in South Yellow Sea. And RI showed that the potential ecological risk was low in spring while high in autumn.