| Title |
Analysis of a Spatial Distribution and Nutritional Status of Chlorophyll-a Concentration in the Jinyang Lake Using Landsat 8 Satellite Image |
| Authors |
장민원 ( Min Won Jang ) ; 조현경 ( Hyun Kyung Cho ) ; 김상민 ( Sang Min Kim ) |
| DOI |
https://doi.org/10.15681/KSWE.2019.35.1.1 |
| Keywords |
Aizaki trophic; Chlorophyll a; Eutrophication; Landsat 8; Nutritional status index |
| Abstract |
The purpose of this study is to evaluate the nutritional status of Lake Jinyang using Landsat 8 satellite image band correlated with chlorophyll-a, which is also related to algae proliferation. We selected 20 Landsat 8 images dating from 2013 to 2017, taken close to water quality measurement date when the cloud cover was less than 20 %. Based on the results of the previous studies, analyzing the correlation between chlorophyll-a, and Landsat 8 satellite image band, we selected near infrared wavelength, band 5 which is closely related to the population of algae. The nutritional status was classified using the Aizaki trophic state index (TSIm). The results of the regression equation between band 5 and the observed chlorophyll-a data was used to calculate chlorophyll-a for the image data from 2013 to 2017. The concentration of chlorophyll-a ranged from 3 to 16.1 mg/m3. To illustrate the spatial distribution of chlorophyll-a within the lake, the chlorophyll-a concentration was divided into five grades. The images on October 14, 2014 and April 10, 2016 showed relatively high value of chlorophyll-a, while January 18, 2015 and December 6, 2016 chlorophyll-a value were below 5. The images on October 14, 2014 and April 10, 2016 were rated as eutrophic status in most areas. The results of simulating water quality for the day when the water quality was not measured resulted to an approximate value for the Panmun station while the Naedong station needed some corrections. |