柘林湾海水养殖污染负荷估算与空间特征分析
Estimation on pollution load and analysis on spatial characteristics of mariculture in Zhelin Bay
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摘要: 针对典型海湾不同海水养殖类型的污染负荷量进行估算方法探讨和空间分布特征分析,以广东省柘林湾为例,利用面向对象影像分析及光谱特征值法在Landsat8 遥感影像上提取养殖类型的面积,结合率定的污染系数,进行了不同养殖类型的污染负荷量估算,并利用GIS 技术得到养殖区环境氮磷负荷空间分布特征。结果表明:2013 年柘林湾海水养殖主要污染总负荷量为13 641.62 t,其中氮总量为3 475.65 t、磷总量为927.95 t、化学需氧量总量为9 238.02 t;网箱养殖主要污染负荷贡献率最大,池塘养殖次之,高位池养殖最小;养殖区产生氮磷污染最为严重的区域是柘林湾的网箱养殖区和黄冈镇的池塘养殖区。通过典型海湾海水养殖污染负荷评估方法研究,实现了海湾海水养殖面源污染的监测与估算,为沿海海水养殖的污染监测和生产调控提供了科学依据。Abstract: This paper discussed the method for estimating the pollution load of different mariculture types, and analyzes the spatial distribution characteristics in typical bay. In the case of Zhelin Bay in Guangdong province, the area of mariculture types were extracted by using the object image analysis and spectral eigenvalue method in Landsat8 remote sensing image. The pollution load of different breeding types was estimated with the coefficient of contamination. And the spatial distribution of nitrogen and phosphorus was obtained by using GIS technology in the area of aquaculture. The results showed that the total pollution load of mariculture in Zhelin Bay in 2013 was 13 641.62 t,of which the total nitrogen,phosphorus and chemical oxygen demand were 3 475.65 t,927.95 t and 9 238.02 t,respectively. The main pollution load of cage-culture was the largest,the pond culture was second,and the high pond culture was the smallest. The areas where the nitrogen and phosphorus pollution was most severe in the breeding area were cage-culture area in Zhelin Bay and pond culture area in Huanggang Town. Through typical bay mariculture pollution load evaluation method study,the paper implements the gulf mariculture of non-point source pollution monitoring and estimation,for coastal aquacultural pollution monitoring and regulation to provide scientific basis for production.