Abstract:

The environmental circumstances of periurban river in the transition zone between urban and country can reflect the effect of urbanization on rivers. This study revealed space characteristics of nutrients and geochemical forms of phosphorus in the sediment from the periurban riverNew Qinhuai River in Nanjing.The statistics data showed discrepanttrophic levels in different sections of the river due to various sewage discharge and sedimentary process. TOC, TN and TP ranged from 307 to 3497 g/kg, 830 to 2 370 mg/kg and 447 to 3 517 mg/kg respectively. The content sequence of phosphorus fractions was FeP or CaP> OrgP>>AlP>DP, in which FeP and CaP accounted more than 70% of TP, and both showed signals of nutritional status. The characteristics of nutrients and phosphorus fractions in Xishanqiaoqiao core and the estuarine core followed a mode marked threestage of "settlementdegradationstacked" changes in contents. FeP was the dominant form and accounting for 431% ～505% of TP in the Xishanqiao core. CaP was the dominant form and accounting for 463%～603% of TP in the estuarine core. The trophic level of New Qinhuai River is between rural river and urban river. The dominant phosphrous fractions are distributed in variant sites. In a way, the urbanization in the Yangtze River Delta does’t affect overall environment of the periurban river