Sapanca Gölü su kalitesi yönetimi için egölem modeli

Abstract

The average values of both quality and quantity of water sources in the catchment area reaching the lake collected from literatüre are taken as inputs to the lake. As sufficient data are present, no long lasting and detafled analyses are conducted. Recent studies conducted at different times show the general status of the lake. in chapter VE, for the starting conditions of the lake, data obtained firom a study conducted by TÜBiTAK in 1992 are used. in the calibration part of the model, the data of the above mentioned study are correlated with experimental data to come out with the coefficients symbolizing the lake. The processes and mechanisms controlling the model and hs coefficients are then checked with similar experimental data of TÜBÎTAK derived in the year of 1993. This checking procedure correlates with the study. in the final part (Chapter VIII) of the study, the calibrated model is applied to years of 1996-1997 and the outcomes of certain limits indicating the variations of water quality are shovvn in graphical forms. As a conclusion, this model can be used for a long term basis to observe the fiıture water quality variations of a lake. Thus, depending on the simulation resufts, management and control strategies of the lake can be developed. in the model, phytoplanktons are based in the heart of the ecological processes. The trophic relationship between phytoplanktons and nutrients control the mechanism gbverning the water qualfty criteria of the lake. For the achievement of mineralization, nitrification, biochemical oxidation and respiration processes, Oa through natura! aeration and dissolved Û2 present in the water as a result of photosynthesis is used. The end product of respiration is COa and is used by the algae. in the model, the lake is identified in terms of finhe elements in the vertical direction. These elements are characterized in the model in terms of their thickness, surface areas and by their volumes. For each element it is assumed that water body is of completely mbced type and that variations in only vertical direction are considered. Thus, the variations in horizontal directions and sideways are ignored. Input and output data can be supplied to each element in the model Ali the relationships mentioned above can be solved by finite elements procedure and the variation of the required parameter can be calculated in terms of depth and time. The EGÖLEM sofhvare prepared to serve for the purpose of this study contains öne main and 19 subroutine programs. The evaluation of data received by the application of the model are presented in Chapter VI. The data used in the sofhvare is listed under seven groups; meteorological data, boundary condftions, quality parameters of the model and others. Öne of the most important items listed above is the meteorological data. This data is used to calculate the thermal transfer of the water surface. in the model, öne of the two calculation procedures may be used. These are named as thermal budget method and equilibrium temperature method. in the equilibrium temperature method, if the water clearness and the composMon of element thickness is the main part of the radiation along the element surface errors may be seen during the estimation of surface temperature. it is recommended to use thermal budget method if the average Secchi dişe depth is greater man the element thickness. Two methods are also recommended to be used for determining the diffiısion process in the lake. These are stability method and \vind method. in the stability method, h is assumed that when the maximum density gradient ör maximum stability of the water column is reached, the mbcing is at a minimum state. The other method is recommended to be applied in cases of wind dominant lakes where turbulence diflusion is of high importance. in this study, the wind effects are quite significant and thus, it is an important parameter directing the diflusion process. For this reason, wind method is used. xvi The average values of both quality and quantity of water sources in the catchment area reaching the lake collected from literatüre are taken as inputs to the lake. As sufficient data are present, no long lasting and detafled analyses are conducted. Recent studies conducted at different times show the general status of the lake. in chapter VE, for the starting conditions of the lake, data obtained firom a study conducted by TÜBiTAK in 1992 are used. in the calibration part of the model, the data of the above mentioned study are correlated with experimental data to come out with the coefficients symbolizing the lake. The processes and mechanisms controlling the model and hs coefficients are then checked with similar experimental data of TÜBÎTAK derived in the year of 1993. This checking procedure correlates with the study. in the final part (Chapter VIII) of the study, the calibrated model is applied to years of 1996-1997 and the outcomes of certain limits indicating the variations of water quality are shovvn in graphical forms. As a conclusion, this model can be used for a long term basis to observe the fiıture water quality variations of a lake. Thus, depending on the simulation resufts, management and control strategies of the lake can be developed. in the model, phytoplanktons are based in the heart of the ecological processes. The trophic relationship between phytoplanktons and nutrients control the mechanism gbverning the water qualfty criteria of the lake. For the achievement of mineralization, nitrification, biochemical oxidation and respiration processes, Oa through natura! aeration and dissolved Û2 present in the water as a result of photosynthesis is used. The end product of respiration is COa and is used by the algae. in the model, the lake is identified in terms of finhe elements in the vertical direction. These elements are characterized in the model in terms of their thickness, surface areas and by their volumes. For each element it is assumed that water body is of completely mbced type and that variations in only vertical direction are considered. Thus, the variations in horizontal directions and sideways are ignored. Input and output data can be supplied to each element in the model Ali the relationships mentioned above can be solved by finite elements procedure and the variation of the required parameter can be calculated in terms of depth and time. The EGÖLEM sofhvare prepared to serve for the purpose of this study contains öne main and 19 subroutine programs. The evaluation of data received by the application of the model are presented in Chapter VI. The data used in the sofhvare is listed under seven groups; meteorological data, boundary condftions, quality parameters of the model and others. Öne of the most important items listed above is the meteorological data. This data is used to calculate the thermal transfer of the water surface. in the model, öne of the two calculation procedures may be used. These are named as thermal budget method and equilibrium temperature method. in the equilibrium temperature method, if the water clearness and the composMon of element thickness is the main part of the radiation along the element surface errors may be seen during the estimation of surface temperature. it is recommended to use thermal budget method if the average Secchi dişe depth is greater man the element thickness. Two methods are also recommended to be used for determining the diffiısion process in the lake. These are stability method and \vind method. in the stability method, h is assumed that when the maximum density gradient ör maximum stability of the water column is reached, the mbcing is at a minimum state. The other method is recommended to be applied in cases of wind dominant lakes where turbulence diflusion is of high importance. in this study, the wind effects are quite significant and thus, it is an important parameter directing the diflusion process. For this reason, wind method is used. xvi The average values of both quality and quantity of water sources in the catchment area reaching the lake collected from literatüre are taken as inputs to the lake. As sufficient data are present, no long lasting and detafled analyses are conducted. Recent studies conducted at different times show the general status of the lake. in chapter VE, for the starting conditions of the lake, data obtained firom a study conducted by TÜBiTAK in 1992 are used. in the calibration part of the model, the data of the above mentioned study are correlated with experimental data to come out with the coefficients symbolizing the lake. The processes and mechanisms controlling the model and hs coefficients are then checked with similar experimental data of TÜBÎTAK derived in the year of 1993. This checking procedure correlates with the study. in the final part (Chapter VIII) of the study, the calibrated model is applied to years of 1996-1997 and the outcomes of certain limits indicating the variations of water quality are shovvn in graphical forms. As a conclusion, this model can be used for a long term basis to observe the fiıture water quality variations of a lake. Thus, depending on the simulation resufts, management and control strategies of the lake can be developed.