渤海湾港口生态风险评估

以天津港为例,利用相对风险模型(RRM)对渤海湾港口生态风险进行评价。根据RRM,将天津港划分为北疆、南疆、东疆和临港等4个风险小区。在每一风险小区中,选取2种生境类型(滩涂和近海水体)、2种风险源(船舶运输和港口码头)和3种生态终点(底栖动物、浮游植物、浮游动物),以此计算生态风险值,根据风险值高低分为高、较高、中等、低和弱5个等级。评价结果表明,在两种风险源中,船舶运输风险相对较大;在生境中,近海水体的风险值远大于滩涂;在生态终点中,风险高低为底栖动物浮游植物浮游动物。天津港生态风险可以划分为3个等级:北疆为高风险区、南疆为较高风险区、东疆和临港均为中等风险区。

Ecological risk evaluation of port in Bohai Bay

The rapid development of ports has brought great economic benefits to the region; however, it has also caused some ecological risk. Ecological risk assessment is the basic of the risk management. In order to enhance the risk management, ecological risk assessment is necessary, which is of fundamental importance to set controlling plans. In the present study, we take Tianjin Port as a case, and firstly use the relative risk model (RRM) to evaluate the ecological risk of the port. Tianjin Port is located in the Bohai Bay. This bay is a semi-enclosed bay, which is located in the western region of Bohai Sea in northern China. The Bohai Bay has been conditioned strongly, historically, by different anthropogenic pressures. In particular, during the recent three decades, with rapid industrialization and urbanization, the seashore area of Bohai Bay were reclaim for agriculture and aquiculture, and subsequent occupation of those areas for urban, industrial and port developments have provoked a dramatic reduction in size. Based on the RRM, we divide the Tianjin port into four risk units, including Beijiang Wharves, Nanjiang Wharves, Dongjiang Wharves, and Lingang Wharves. Two main habitat types (the coastal wetland and nearshore waters), two risk sources (Transportation and wharves), three kinds of ecological receptors (zoobenthos, phytoplankton, and zooplankton), were identified and to calculate the comprehensive ecological risk value. In the present study, the risk grades can be classed five grades. When the risk value rang from 0 to 2, is the weak risk. The value is from 2 to 4 is the low risk, 4 to 6 is the middle risk, 6 to 8 is the relatively high risk, and more than 8 is the high risk. The results showed that the risk of the transportation is higher than the wharves risk in the two risk source. The risk of the nearshore water is higher than the coastal wetland in four risk units. For the risk of the ecological receptors, we found that the zoobenthos was significantly more influenced than both the phytoplankton and zooplankton. There were three class risk grades in the present study. The first grade is the Beijiang Wharves, with the risk value of 10.77, belonging to the high risk area. Nanjiang Wharves is belonged to the relatively high risk area, with the risk value of 6.12. The risk value of Dongjiang Wharves, and Lingang Wharves was 4.76 and 4.92, respectively, suggesting that they were in the grade of the middle risk level.