CONCLUSIONS AND RECOMMENDATIONS - Integrating GIS, Remote Sensing, and Mathematical Modelling for Surface Water Quality Management - page 196

linked and what are their hydrodynamic characteristics under the different flow conditions, especially
when the main boundary in the upstream catchment is a control point or pumping stations are
controlling the flow within the main drainage system, and the downstream component is a shallow
lake which is controlled by the flow coming from the catchment and the tidal condition at the sea exit
channel. This model was viewed as important in order to understand the catchment-lake interactions.
10.1.4 Advanced 2D Shallow Lake Hydrodynamic Model
Since the shallow coastal lake at the downstream of the catchment is considered as a sink that receives
all the wastewater discharged from the watershed, it was important to develop a more detailed
modelling component for the lake system. The 2D hydrodynamic model was developed to facilitate a
more detailed study of the lake hydrodynamics, taking into account the effects of the main driving
forces on the flow which are wind and tides. The model was tested for different hydrodynamic
scenarios to determine the most sensitive parameters that affect the flow conditions within the lake.
The model showed that the main driving force that affects the flow velocities and currents in the lake
is the wind force. The wind is responsible for mixing and resuspension in the lake due to its shallow
depth, and this in turn is an important parameter to be considered during the water quality modelling
of the lake system.
10.1.5 Lake Water Quality and Eutrophication Screening Models
A reliable water quality model is based on a detailed and well structured hydrodynamic model that is
capable of describing the physical and hydrodynamic processes of the water system. Therefore the
water quality and eutrophication modelling tools for the shallow lake system in this research work are
coupled with the developed and calibrated hydrodynamic 2D model. The water quality modelling tools
are the main components of the WQMIS. They were divided into two main models: the basic
parameters model and the eutrophication screening model. The basic water quality modelling
component simulates the main water quality parameters including the oxygen compounds (BOD,
COD, DO), nutrients compounds (NH4, NO3, PO4), the temperature, salinity and the total suspended
sediments (TSM). This model was able to predict the basic water quality indicators of the lake system.
The second component is the eutrophication screening model for the lake. This is based on the
simulation of CHL-aorophyll-a concentration, which is considered as an indicator of phytoplankton
abundance and biomass in coastal and estuarine waters. Both models were applied on Edko shallow
lake at the fringes of the western Delta region of Egypt. The models tested the effect of the pollution
discharges from the catchment on the lake water quality. The basic parameters model showed high
concentrations of BOD, COD and nutrients (NO3 and PO4) that exceed the standard limits. The
eutrophication screening model showed high concentrations of TSM and CHL-a, which also exceeded
the standards limits to reveal a high eutrophication of Lake Edko. The eutrophication screening model
was also used to predict different management scenarios for the prevention of serious eutrophication
and deterioration of the lake.
10.1.6 Use of RS for calibrating and verifying mathematical models for lake water
quality parameters including TSM and CHL-a
Remote sensing is presented in this research study as an essential component in the WQMIS as it is
used in different applications within the research. The first basic use of remote sensing is for data
acquisition where ASTER and SPOT images were used to delineate the lake system components
including the water body, the vegetation buffer zone and the fisheries areas. The main use of remote
sensing data sets and the different associated analysis techniques was formulated in this research for
the calibration of shallow lake water quality models focusing on TSM and CHL-a as the main
parameters of concern. The combination of different types of remote sensing data (including
MODIS09 and SPOT 5 images) provided the optimal setup between spectral and spatial resolution