Abstract
Monitoring seawater quality using remotely sensed data is a cost-effective and
comprehensive means for detecting short and long-term changes in coastal and marine
ecosystems. Our study aims to assess water quality and the health of aquatic ecosystems in
Algiers Coast by the quantification of Secchi disk depth (SDD), phytoplankton (diatoms and
dinoflagellates species) and suspended particles matters (MES), using in-situ measurements and
Landsat images. We developed empirical models to assess these parameters by comparing insitu measurements with various spectral bands and band ratioing products derived from Landsat8 OLI images of Algiers bay. The results of phytoplankton modeling in Algiers bay, showed a
wide variation between coastal and offshore stations. The number of diatoms was less than that
of dinoflagellates, these two algae communities illustrated different spectral behavior. In
addition, we learned that the Southeastern area of the bay can be influenced by harmful algae
blooms developed on offshore because of hydrodynamic forces that push these blooms toward
this area.
We applied the same methodology to studying suspended particulate matter and seawater
transparency. The results demonstrated that the ratio of the coastal aerosol band and the green
band (i.e., band 1 / band 3) shows a significant relationship to asses water transparency, while
the ratio (i.e., band 2 / band 3) is significantly correlated to asses suspended matter. The study
also showed that Algiers Bay can be divided geographically according to water movement and
the spatial distribution of physico-chemical parameters into two main parts (North-West and
South-East).
We tested the applicability of the obtained models (transparency and suspended matter) on
the Kuwait Bay, considering that it presents different hydro-biological and optical characteristics
from those of the Algerian coast, in order to know the possibility of transferring and applying
our models at different spatiotemporal scales. The results showed that only the models extracted
from Zone I gave a significant relationship for predicting transparency and suspended matter.
In Bou-Ismail Bay, we focused on modelling sea surface temperature over a 32-year period
(1984 to 2016), using the thermal bands of Landsat satellite series. The results showed that two
models can predict seasonal and annual variations in water temperature in order to monitor sea
surface temperature in the future.
Moreover, we have developed a new computer software: "MariseSoft" which can manage in a
semi-automatic process the database of field measurements and analysis of marine
Monitoring seawater quality using remotely sensed data is a cost-effective and
comprehensive means for detecting short and long-term changes in coastal and marine
ecosystems. Our study aims to assess water quality and the health of aquatic ecosystems in
Algiers Coast by the quantification of Secchi disk depth (SDD), phytoplankton (diatoms and
dinoflagellates species) and suspended particles matters (MES), using in-situ measurements and
Landsat images. We developed empirical models to assess these parameters by comparing insitu measurements with various spectral bands and band ratioing products derived from Landsat8 OLI images of Algiers bay. The results of phytoplankton modeling in Algiers bay, showed a
wide variation between coastal and offshore stations. The number of diatoms was less than that
of dinoflagellates, these two algae communities illustrated different spectral behavior. In
addition, we learned that the Southeastern area of the bay can be influenced by harmful algae
blooms developed on offshore because of hydrodynamic forces that push these blooms toward
this area.
We applied the same methodology to studying suspended particulate matter and seawater
transparency. The results demonstrated that the ratio of the coastal aerosol band and the green
band (i.e., band 1 / band 3) shows a significant relationship to asses water transparency, while
the ratio (i.e., band 2 / band 3) is significantly correlated to asses suspended matter. The study
also showed that Algiers Bay can be divided geographically according to water movement and
the spatial distribution of physico-chemical parameters into two main parts (North-West and
South-East).
We tested the applicability of the obtained models (transparency and suspended matter) on
the Kuwait Bay, considering that it presents different hydro-biological and optical characteristics
from those of the Algerian coast, in order to know the possibility of transferring and applying
our models at different spatiotemporal scales. The results showed that only the models extracted
from Zone I gave a significant relationship for predicting transparency and suspended matter.
In Bou-Ismail Bay, we focused on modelling sea surface temperature over a 32-year period
(1984 to 2016), using the thermal bands of Landsat satellite series. The results showed that two
models can predict seasonal and annual variations in water temperature in order to monitor sea
surface temperature in the future.
Moreover, we have developed a new computer software: "MariseSoft" which can manage in a
semi-automatic process the database of field measurements and analysis of marine