Estimation of Chlorophyll-a Concentration in Gulf of Kutch, India Using AQUA MODIS Sensor Data

Abstract

Introduction: In the recent few years, researchers have used remote sensing technology to study various water quality parameters. One of such parameters is chlorophyll- concentration in the water bodies. Chlorophyll-a is indicative of algal Bloom in water bodies. Algal blooms can decrease the dissolved oxygen concentration in water bodies. Low dissolved oxygen concentration is dangerous for aquatic plants and animals. Aim: Using remote sensing, near-surface concentration of the photosynthetic pigment chlorophyll-a can be estimated. Using the spatial distribution of chlorophyll-a concentration, concentration of phytoplankton and zooplankton can be correlated. In the present study, the coastal region around the Gulf of Kutch has been selected as the study area. The Gulf of Kutch is in India, and is spread along the coastal regions up to an approximate length of 150 km. Methodology: In the present study, AQUA-MODIS sensor has been used to estimate Chlorophyll-a content in the Gulf of Kutch. Level-2 data from the period 2015 to 2022 has been acquired and processing of data has been done using SeaWiFS Data Analysis System (SeaDAS) software, developed by NASA. SeaDAS has been used for processing and analyzing ocean color data. Results: The results revealed that chlorophyll-a concentration varied from 3 mg/m3 to 18 mg/m3 for the study area. Also, as one moves from Gulf of Kutch towards Arabian sea, the concentration kept on decreasing and reached at 0.4 mg/m3. Conclusion: The results also suggested that regions where chlorophyll concentration was high, the phytoplankton concentration might also be high in those regions. Thus, near to coastal regions, phytoplankton concentration also dominates.