1980—2008年莱州湾主要污染物的时空变化

Spatio-Temporal Variability of Principal Pollutants in Laizhou Bay from 1980 to 2008

莱州湾水质受河流入海、生活排污和养殖业等多方面影响,污染问题日益突出而备受关注。论文以1980—2008年间相关文献和监测数据为基础,研究了莱州湾主要污染物———无机氮、无机磷、COD浓度的变化趋势,并用网格化方法还原文献数据讨论污染物的区域分布特征。结果表明:莱州湾无机氮丰水期与枯水期浓度比1.26,无机磷1.07,COD 1.06,污染物主要是由陆源向海输运产生。无机氮是莱州湾的主要污染物,1990年代无机氮的年均浓度是1980年代的3.2倍,2001—2008年又增加了38%,2004年以来超出三类水质标准。NH4-N在1990年代之后占DIN比例由70%～85%下降到20%左右。无机磷、COD浓度近15a来保持在一类水质,但无机磷有潜在上升趋势。从区域分布看,第1区块受黄河口、小清河口影响是无机氮、无机磷的高值区。第2、3区块水质较好,而第4区块的无机氮、无机磷浓度自2004年之后已远远超过第1区块,莱州湾的主要污染源有黄河口向湾底诸河口转移的趋势,应引起重视。第4区块始终是COD的相对高值区。

The water quality in Laizhou Bay affected by the rivers flow, the domestic sewerage and the aquaculture, the problems have become increasingly extrusive and cause for concern. The paper studied the variation trend of the mean pollutants-inorganic nitrogen, inorganic phosphorus and chemical oxygen demand in Laizhou Bay , and discussed their areal distribution using Gridding Method, based on the pa- pers and data from 1980 to 2008. The results showed that the proportion between high-water period and low-water period of the three pollutants were 1.26,1.07 and 1.06, considered that they were produced by rivers flow. DIN was the principal pollutant in Laizhou Bay, whose concentration is 3. 2 times in 1990s compared with 1980s, and added 38% in 2001--2008, and then beyond the class III of sea-water quality standards after 2004. The proportion of NH^-N in DIN declined form 70%-85% to 20o% after 1990s. While the concentration of DIP and COD up to the class I, but DIP still had the rising trend. Shown from regional distribution, Block 1 was a high value area of DIN and DIP influencing by the estuary of yellow River and Xiaoqing River. The water of Block 2 and 3 was better, but concentrations of DIN and DIP in Block 4 had been far more than Block 1 after 2004. It should be noticed that the primary pollution source of Laizhou Bay translated from Yellow River Estuary to the southern rivers, where was always the rela- tive high value area of COD.