Statistical analysis of water data from an online EXO2 monitoring sonde : Modelling Chlorophyll-a using an EXO2 sonde
Espinola, Benoit (2017)
Metropolia Ammattikorkeakoulu
2017
All rights reserved
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201705107417
https://urn.fi/URN:NBN:fi:amk-201705107417
Tiivistelmä
This thesis aims to make statistical analysis and chlorophyll-a modelling based on the evolution over time of different chemical parameters in Lake Gennarbyträsket.
The project, which was done in collaboration with Länsi Uudenmaan Vesi ja Ympäristö ry, is part of the European Union’s project Village Waters aiming to find and suggest better wastewater treatment solutions for villages and small settlements.
Chlorophyll-a is one of the indicators used to determine the trophic level of a lake. Under-standing the roles of the different chemical parameters with the chlorophyll-a production process will help to develop a model that can be used for water quality monitoring system for municipalities. An EXO 2 water monitoring sonde has been deployed on site to measure in half an hour intervals pH, temperature, turbidity, dissolved oxygen, conductivity, a-chlorophyll and cyanobacteria levels.
Parameters evolve following different natural cycles, such as day and night or seasons. To be able to have enough data and to have significant results, the monitoring program needs to last for at least two sampling seasons. Unfortunately, the data available for this thesis partially covers an open water sampling season for chlorophyll-a. This thesis is therefore a preparation work for a possible long term research.
During this thesis, a model building methodology has been established, but this methodology requires validation using new data. The model seems to be providing good estimates for long period averages of chlorophyll-a despite its lack of precision for real time modelling.
The results of this thesis leads to believe on the existence of interactions between the different parameters measured. Nevertheless, there is clear need to collect more data, including local weather data, to be able to establish a more robust model of the production of chlorophyll-a. Additionally, further investigation is required to formulate proper conclusions.
The project, which was done in collaboration with Länsi Uudenmaan Vesi ja Ympäristö ry, is part of the European Union’s project Village Waters aiming to find and suggest better wastewater treatment solutions for villages and small settlements.
Chlorophyll-a is one of the indicators used to determine the trophic level of a lake. Under-standing the roles of the different chemical parameters with the chlorophyll-a production process will help to develop a model that can be used for water quality monitoring system for municipalities. An EXO 2 water monitoring sonde has been deployed on site to measure in half an hour intervals pH, temperature, turbidity, dissolved oxygen, conductivity, a-chlorophyll and cyanobacteria levels.
Parameters evolve following different natural cycles, such as day and night or seasons. To be able to have enough data and to have significant results, the monitoring program needs to last for at least two sampling seasons. Unfortunately, the data available for this thesis partially covers an open water sampling season for chlorophyll-a. This thesis is therefore a preparation work for a possible long term research.
During this thesis, a model building methodology has been established, but this methodology requires validation using new data. The model seems to be providing good estimates for long period averages of chlorophyll-a despite its lack of precision for real time modelling.
The results of this thesis leads to believe on the existence of interactions between the different parameters measured. Nevertheless, there is clear need to collect more data, including local weather data, to be able to establish a more robust model of the production of chlorophyll-a. Additionally, further investigation is required to formulate proper conclusions.