浅谈海水溶解氧污染指数计算中的有关问题

Discussion on problems in the calculation of dissolved oxygen pollution index in seawater

分别采用《环境影响评价技术导则地面水环境》(HJ/T 2.3—1993)和《海洋调查规范》(GB 12763.4—2007)中两种不同的公式计算海水饱和溶解氧,探讨了海水溶解氧污染指数计算中存在的问题。结果表明,饱和溶解氧随盐度的增加而逐渐增大,在正常海水盐度范围(25～35)内,两种公式计算所得的饱和溶解氧的相对偏差平均值为10.1%,而由此引起的溶解氧污染指数相对偏差的平均值则高达49.2%。因此,饱和溶解氧的求算公式对溶解氧污染指数的计算结果具有显著影响,海水饱和溶解氧的计算应采用GB 12763.4—2007中的公式,而不能简单套用HJ/T 2.3—1993中的公式。

The content of saturated dissolved oxygen in seawater was calculated by two formulas which referenced from technical guidelines for environmental impact assessment （HJ/T 2.3-1993） and specification of oceano- graphic investigation （GB 12763.4-2007） respectively. The existing problems in the calculation of dissolved oxygen pollution index were discussed and analyzed. It was found that the saturated dissolved oxygen content increased with salinity increments. When seawater was in the normal range of salinity （25-35）,the average relative deviation of dissolved oxygen content measured by two methods was approximately 10.1% ; however, the average relative deviation of dissolved oxygen pollution index reached 49.2%. It suggested that the calculation method of the saturated dissolved oxygen content had a significant effect on the result of dissolved oxygen pollution index. In view of this, the calculation of dissolved oxygen pollution index should employ the formula from GB 12763.4-2007 rather than simply use formula from HJ/T 2.3-1993.