Study And Analysis On The Space Distribution And Aquaculture Area Based On Landsat-8 Data

Both of the coastal nuclear power position and aquaculture areas of sea surface are located in offshore sea. There were two problems caused the attention of people. First,Whether there were any intersection between the aquaculture and the scope of nuclear power plant cooling water;Second, whether there were bad influence the cooling water for the farmed fish. The aim of this paper is to explore the relationship of spatial position and distribution between the scope of heated water and aquaculture areas of sea surface through remote sensing technology,which is of great significance.Lianyungang in Jiangsu province, with a long coastline, not only possesses nuclear plant with units of millions watt, but also possesses millions of square kilometers of aquaculture. This paper choose Tianwan waters of Lianyungang as study area, explored the effect scope of heated water of nuclear power plant through the inversion of sea surface temperature using Landsat-8 images; and explored the distribution of cultivation areas of sea surface through optimal threshold segmentation method. The method applied to estimate surface temperature of waters in experimental plot is single channel algorithm based on thermal infrared using HJ-1B images, including radiative transfer model method、mono-window algorithm by Qinzhihao and single-channel algorithm by Jiménez-Mu?oz&Sobrino. The result showed that the precision of radiative transfer model method was highest among the three mentioned kinds of method through the comparison between inversion value and measurement value obtained by sea surface buoy. We verified the inverted temperature of study area through radiative transfer model method using the MODIS sea surface temperature, and found that the average error of inversion was around 0.5K. The extraction of aquaculture areas of sea surface was based on the spectral characteristic of visible and near-infrared radiometer in Landsat-8.In order to extract the aquaculture areas of sea surface, the processed images were carried out texture analysis through GLCM(gray level co-occurrence matrix) and the optimal threshold of segmentation was calculated by taking the gray average as quantitative index; Using the image of anvanges verify the accuracy of extraction. There were good consistency between the aquaculture areas of the optimal threshold extraction and the classification result obtained by eCognition software object-oriented. The precision of inversion that can meet the need of practical requirements.The study area in the research is representative. It can not only realize the exploration of scope of heated water of nuclear power plant and also realize the extraction of cultivation areas of sea surface. In the paper, the sea surface temperature went through verification twice. Firstly, the results of the three kinds of temperature inversion were compared with measurement values; Secondly, the precision of radiative transfer model method was verified. The extraction of aquaculture areas of sea surface made full use of the spectral characteristic of Landsat-8, combined with the texture analysis and threshold segmentation method, the result of the extraction showed that the method was of considerable precision and accuracy. The relationship between the space distribution of cooling water and the aquaculture area was analyzed.