Lake eutrophication

Lake eutrophication

Created by Isabelle Alvarez – July 24, 2020, 6:36 p.m. – Last updated on nov. 9, 2021, 4:28 p.m.

Many lake have experienced sudden shift from oligotrophic to eutrophic state. This phenomenon is due to excess phosphorus in lake. The model describes the dynamics of phosphorus concentration and the phophorus inputs.The issue is to determine wether it is possible to maintain the lake in an oligotrophic state while preserving agricultural activities in its watershed.

Model
2-dimensional state space
\(L\) Phosphorus Inputs
\(P\) Phosphorus Concentration
1-dimensional control space
\(u\) Phosphorus Inputs Variation
Dynamics

\(L'=u\)
\(P'=-b*P+L+r*P^q/(m^q+P^q)\)

\(u>=umin\)
\(u<=umax\)

Parameters: \(b\), \(r\), \(q\), \(m\), \(umin\), \(umax\)

Constraints

\(L>=Lmin\)
\(L<=Lmax\)
\(P<=Pmax\)

\(P>=0\)

Parameters: \(Lmin\), \(Lmax\), \(Pmax\)

ViNOs

Title Date Published by Software Format Size File size
Parameters values: \(b=0.8, r=1.0, q=8.0, m=1.0, umin=-0.09, umax=0.09, Lmin=0.1, Lmax=1.0, Pmax=1.4\)
2D-lake-PSP-16384ppa July 24, 2020, 6:36 p.m. Sophie Martin Patrick Saint-Pierre Software bars 16385 bars 208.4 KB
2D-lake-PSP-65536ppa July 24, 2020, 6:36 p.m. Sophie Martin Patrick Saint-Pierre Software bars 65537 bars 887.0 KB
2D-lake-KdT-1024ppa July 24, 2020, 6:36 p.m. Isabelle Alvarez Viabilitree kdtree 6335 cells 633.2 KB
2D-lake-polygon May 9, 2022, 9:57 a.m. Vino Nouveau None polygon 721 points 13.5 KB
Parameters values: \(b=0.4, r=1.0, q=8.0, m=1.0, umin=-0.09, umax=0.09, Lmin=0.1, Lmax=1.0, Pmax=1.4\)
2D-lake-KdT-irrev-256ppa July 27, 2020, 6:24 p.m. Isabelle Alvarez Viabilitree kdtree 985 cells 89.9 KB
2D-lake-KdT-irrev-1024ppa July 27, 2020, 6:30 p.m. Isabelle Alvarez Viabilitree kdtree 3871 cells 377.9 KB
Loading...