التفاصيل البيبلوغرافية
| العنوان: |
Proposal for a remote sensing trophic state index based upon Thematic Mapper/Landsat images |
| المؤلفون: |
Novo, Evlyn Márcia Leão de Moraes, Londe, Luciana de Resende, Barbosa, Claudio, Araujo, Carlos A. S. de, Rennó, Camilo Daleles |
| المصدر: |
Revista Ambiente & Água. December 2013 8(3) |
| بيانات النشر: |
Instituto de Pesquisas Ambientais em Bacias Hidrográficas, 2013. |
| سنة النشر: |
2013 |
| مصطلحات موضوعية: |
water quality, phytoplankton, monitoring |
| الوصف: |
This work proposes a trophic state index based on the remote sensing retrieval of chlorophyll-α concentration. For that, in situ Bidirectional Reflectance Factor (BRF) data acquired in the Ibitinga reservoir were resampled to match Landsat/TM spectral simulated bands (TM_sim bands) and used to run linear correlation with concurrent measurements of chlorophyll-α concentration. Monte Carlo simulation was then applied to select the most suitable model relating chlorophyll-α concentration and simulated TM/Landsat reflectance. TM4_sim/TM3_sim ratio provided the best model with a R² value of 0.78. The model was then inverted to create a look-up-table (LUT) relating TM4_sim/TM3_sim ratio intervals to chlorophyll-α concentration trophic state classes covering the entire range measured in the reservoir. Atmospheric corrected Landsat TM images converted to surface reflectance were then used to generate a TM4/TM3 ratio image. The ratio image frequency distribution encompassed the range of TM4_sim/TM3_sim ratio indicating agreement between in situ and satellite data and supporting the use of satellite data to map chlorophyll-α concentration trophic state distribution in the reservoir. Based on that, the LUT was applied to a Landsat/TM ratio image to map the spatial distribution of chlorophyll-α trophic state classes in Ibitinga reservoir. Despite the stochastic selection of TM4_sim/TM3_sim ratio as the best input variable for modeling the chlorophyll-α concentration, it has a physical basis: high concentration of phytoplankton increases the reflectance in the near-infrared (TM4) and decreases the reflectance in the red (TM3). The band ratio, therefore, enhances the relationship between chlorophyll-α concentration and remotely sensed reflectance. |
| نوع الوثيقة: |
article |
| وصف الملف: |
text/html |
| اللغة: |
English |
| تدمد: |
1980-993X |
| DOI: |
10.4136/ambi-agua.1229 |
| URL الوصول: |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1980-993X2013000300006 |
| Rights: |
info:eu-repo/semantics/openAccess |
| رقم الانضمام: |
edssci.S1980.993X2013000300006 |
| قاعدة البيانات: |
SciELO |
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