Ali Erturk

Application of Watershed Modeling System (WMS) for Integrated Management of a Watershed in Turkey

Watershed models, that enable the quantification of current and future pollution loading impacts, are essential tools to address the functions and conflicts faced in watershed planning and management. In this study, the Watershed Modeling System (WMS) version 7.1 was used for the delineation of boundaries of Koycegiz Lake-Dalyan Lagoon watershed located in the southwest of Turkey at the Mediterranean Sea coast. A Digital Elevation Model (DEM) was created for one of the major streams of the watershed, namely, Kargicak Creek by using WMS, and DEM data were further used to extract stream networks and delineate the watershed boundaries. Typical properties like drainage areas, characteristic length and slope of sub-drainage areas have also been determined to be used as model inputs in hydrological and diffuse pollution modeling. Besides, run-off hydrographs for the sub-drainages have been calculated using the Rational Method, which produces valuable data for calculating the time variable inflow and input pollution loads to be further utilized in the future water quality models of the Creek. Application of WMS in the study has shown that, it is capable to visualize the results in establishing watershed management strategies.

2D finite element ecological model for the Curonian lagoon

The results of application of 2D finite element model SHYFEM to the Curonian lagoon (Baltic Sea) are considered. SHYFEM consist of a physical processes module and an eutrophication module EUTRO adapted for the SHYFEM code from well known modelling system WASP. The SHYFEM/EUTRO model calibration results were compared with the performance of various biogeochemical models analysed in other studies (153 studies published from 1990 to 2002). The performance of all corresponding state variables—dissolved oxygen, NO3, NH4, PO4, phyto- and zooplankton—was slightly lower than median model performance which could be considered satisfactory given the initial state of model formulation and calibration. Model underestimates phytoplankton autumn blooms, especially for the southern part of the lagoon, where fine sediments dominate and water residence time is high. It can be concluded that, in order to increase model performance, the eutrophication module should be improved to account for the dominance of different phytoplankton groups as well as for the exchanges between the sediments and the water column. The amount and quality of the data available for the model setup and calibration are unsatisfactory and should be improved for the development of the next enhanced model version.

Application of Water Quality Modelling as a Decision Support System Tool for Planned Buyuk Melen Reservoir and Its Watershed

Istanbul, the largest metropolis of Turkey and one of the most crowded metropolises in the world, is facing the risk of water scarcity. Analyses indicated that one of the alternative solutions coping with this problem is water transfer from a watershed that is located outside the administrative boundaries of Istanbul. Due to its water potential and relatively less degraded water quality, Buyuk Melen Watershed was considered to be the most feasible option. As the result of analyses, State Hydraulic Works (DSI) has planned construction of a reservoir in the Buyuk Melen Watershed to supply the required amount of water for Istanbul also in low flow seasons. Since the reservoir will be located at the downstream region of the watershed, its water quality will be affected by human-induced activities, thus measures need to be taken to prevent pollution prior to reservoir construction. Quantifying the response of the planned reservoir to external pollution loads is an important step in the planning and management of the watershed. Mathematical modelling is a useful tool for estimating the future water quality and understanding the possible responses of the reservoir to various pollution loads. In this study, a water quality model capable of simulating hydrodynamics, transport and water quality in reservoirs is used for preliminary estimation of possible impacts of several management options in the watershed. Model results indicated that, all of the point sources in the watershed must be controlled by advanced wastewater treatment and should be diverted from the streams and the planned reservoir. Model results also indicated that reduction of agricultural diffuse loads by 30–40% is expected to have a perceptible improvement of reservoir water quality.

CASE STUDY: DIELDRIN ATTACK IN DALYAN LAGOON

During the first two weeks of December of 2005, NATO sponsored an Advanced Study Institute (ASI) In Istanbul, Turkey. Part of this ASI involved a case study of a terrorist attack, where a chemical was assumed to be dumped into Sulunger Lake in Turkey. This chapter documents the response developed by the ASI participants to this scenario, in terms of hydrodynamic transport, ecosystem effects, and decision making.

Assessment of the effects of variation in external nutrient loads on the Curonian lagoon ecosystem

Curonian lagoon, the largest coastal lagoon in Europe is characterized by the strong seasonal and interannual variation in nutrient loads and water quality parameters is characterized by the dominance of the Nemunas rivers discharges. Coupled hydrodynamic and NPZD model was applied to assess the impacts of the foreseen reduction of nutrient loads prescribed in the State Plan to Improve the Quality in the Curonian lagoon, which was approved in 2006. The simulation of 1999-2000 was used as the background scenario. The NPZD model applied takes into the account the recently evaluated atmospheric nitrogen fixation by the cyanobacteria during the summer ldquobloomsrdquo and combined effects of temperature and wind climate.

An overview of integrated and interdisciplinary studies on conservation of a coastal lagoon system in Turkey

This paper presents part of the results of ongoing integrated and interdisciplinary studies conducted at a vulnerable coastal lagoon system with the aim of protecting it from further anthropogenic pollution. The target area is in southwestern Turkey, consisting of a lake that joins the Mediterranean Sea via a lagoon channel system. Land resources in the watershed are identified, including all the elements of the physical environment that influence potential land‐use, and are illustrated by the application of geographical information systems through mapping and visualization of various thematic layers of land. This study will enlighten those working on lagoon watersheds aiming at conservation of natural resources since it states the results of the studies conducted so far through various disciplines, and presents how data are utilized by the groups in an integrated manner. Based on the available data, pre‐modelling studies on hydrodynamic modelling and on water quality modelling are also referred. Identification of a watershed depends on gathering satisfactory data, which will further be used to establish sustainable development and management plans, apart from utilizing the obtained data for watershed and hydrodynamic modelling approaches and to better understand such complex systems.

Decision Support Systems and Tools

RAMIRO NEVES1, ALI ERTURK2, IRINA CHUBARENKO3, ARIANNA AZZELLINO4, BOJAN SRDJEVIC5, BORIS CHUBARENKO3, ERCAN ZENGIN6, ERIC MASSON7, GEORG UMGIESSER8, KARIM HILMI9, PEDRO GALVAO10 AND STEFANIA GOTTARDO11 1Instituto Superior Tecnico, Lisboa, Portugal 2Istanbul Technical University, Department of Environmental Engineering, Istanbul, Turkey 3Atlantic Branch of P.P. Shirshov Institute of Oceanology of Russian Academy of Sciences, Russian Federation 4POLITECNICO DI MILANO (University of Technology), Italy 5Department of Water Mangement, Faculty of Agriculture, University of Novi Sad, Serbia 6Ankara Water and Sewage Administration, ASKI, Ankara, Turkey 7USTL, UFR Geographie et Amenagement, Villeneuve-d’Ascq Cedex, France 8ISMAR-CNR (Marine Science Institute), Venice (Italy) 9Institut National de Recherche Halieutique, Casablanca, Morocco 10Hidromod Modelacao em Engenharia, Lda. Lisboa, Portugal 11CVR, Venice Research Consortium, Italy