Coastal Lagoons - Chapter 9 docx

Case Studies I. Ethem Gönenç, Vladimir G. Koutitonsky, Angel Pérez-Ruzafa, Concepción Marcos Diego, Javier Gilabert, Eugeniusz Andrulewicz, Boris Chubarenko, Irina Chubarenko, Melike Gürel, Aysegül Tanik , Ali Ertürk, Ertugrul Dogan, Erdogan Okus, Dursun Z. Seker, Alpaslan Ekdal, Aylin Bederli Tümay, KiziItan Yüceil, Nusret Karakaya, and Bilsen Beler Baykal CONTENTS 9.1 Introduction I. Ethem Gönenç 9.1.1 Grande-Entrée Lagoon 9.1.2 Mar Menor Lagoon 9.1.3 The Baltic Sea Lagoons 9.1.4 Koycegiz–Dalyan Lagoon 9.2 Three-Dimensional Structure of Wind-Driven Currents in Coastal Lagoons Vladimir G. Koutitonsky 9.2.1 Introduction 9.2.2 Grande-Entrée Lagoon 9.2.3 Wind-Driven Currents: Observations 9.2.4 Wind-Driven Currents: Numerical Modeling 9.2.5 Conclusion Appendix 9.2.A: The MIKE3-HD Numerical Model 9.2.A.1 Governing Equations 9.2.A.2 Wind Stress 9.2.A.3 Eddy Viscosity 9.2.A.4 Bottom Stress Acknowledgments References 9.3 The Ecology of the Mar Menor Coastal Lagoon: A Fast-Changing Ecosystem under Human Pressure Angel Pérez-Ruzafa, Concepción Marcos Diego, and Javier Gilabert 9 L1686_C09.fm Page 371 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press 9.3.1 Functional Typology 9.3.1.1 Location, Origin, Climate, and Hydrography 9.3.1.2 Hydrodynamics 9.3.1.3 Sediment 9.3.1.4 Biological Assemblages 9.3.2 Recent History of Changes in the Lagoon Resulting from Human Activities 9.3.3 Main Changes Affecting the Lagoon’s Ecology 9.3.3.1 Changes Induced by Water Renewal Rates 9.3.3.2 Changes Related to Nutrient Inputs 9.3.4 Suggestions for Monitoring and Modeling Programs References 9.4 Vistula Lagoon (Poland/Russia): A Transboundary Management Problem and an Example of Modeling for Decision Making Eugeniusz Andrulewicz, Boris Chubarenko, and Irina Chubarenko 9.4.1 Transboundary Management Problems of the Vistula Lagoon 9.4.1.1 The Vistula Lagoon and Its Catchment Area 9.4.1.2 Anthropogenic Pressure and Its Environmental Effects 9.4.1.3 Economic Problems in the Catchment Area 9.4.1.4 Issues Affecting Transboundary Management 9.4.1.5 Efforts toward Transboundary Management of the Vistula Lagoon 9.4.2 Ecological Modeling as a Tool for Transboundary Management 9.4.2.1 Numerical Model of the Vistula Lagoon 9.4.2.2 Data Collection for Model Implementation 9.4.2.3 Hydrodynamic Modeling (MIKE21 HD) 9.4.2.4 Advection-Dispersion Modeling (MIKE21 AD) 9.4.2.5 Eutrophication Model (MIKE21 EU) 9.4.2.6 Scenario Assessment 9.4.2.7 Summary and Management Recommendations Acknowledgments References 9.5 Koycegiz–Dalyan Lagoon: A Case Study for Sustainable Use and Development Melike Gürel, Aysegül Tanik, Ali Ertürk, Ertugrul Dogan, Erdogan Okus, Dursun Z. Seker, Alpaslan Ekdal, K izi ltan Yüceil, Aylin Bederli Tümay, Nusret Karakaya, and Bilsen Beler Baykal, and I. Ethem Gönenç 9.5.1 Decision Support System (DSS) Development 9.5.1.1 Identification of Environmental, Social, and Economical Characteristics of Koycegiz–Dalyan Lagoon System 9.5.1.1.1 Environmental Characteristics 9.5.1.1.1.1 Geography 9.5.1.1.1.2 Climate L1686_C09.fm Page 372 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press 9.5.1.1.1.3 Meteorology 9.5.1.1.1.4 Air Quality 9.5.1.1.1.5 Geology and Hydrogeology 9.5.1.1.1.6 Soil Characteristics 9.5.1.1.1.7 Vegetation Cover 9.5.1.1.1.8 Hydrological Characteristics 9.5.1.1.1.9 Hydrodynamic Characteristics 9.5.1.1.1.10 Water Quality 9.5.1.1.1.11 Ecological Characteristics 9.5.1.1.2 Socio-Economic Characteristics 9.5.1.1.2.1 Demographical Characteristics 9.5.1.1.2.2 Land Use 9.5.1.1.2.3 Transportation, Energy, and Communication Facilities 9.5.1.1.2.4 Infrastructure Facilities 9.5.1.1.2.5 Social Facilities 9.5.1.1.2.6 Sectors and Their Characteristics 9.5.1.1.2.7 Income and Manpower Distribution 9.5.1.1.3 Pollution Sources and Waste Loads 9.5.1.1.3.1 Point Sources of Pollutants 9.5.1.1.3.2 Nonpoint Sources of Pollutants 9.5.1.1.3.3 Estimated Pollution Loads 9.5.1.1.4 Administrative and Legal Structure 9.5.1.2 Decision Support System Tools 9.5.1.2.1 GIS 9.5.1.2.2 Models 9.5.1.2.2.1 Rivers and Rural Area Run-Off Modeling 9.5.1.2.2.2 Hydrodynamic and Water Quality Modeling of the Lagoon System 9.5.1.2.3 Monitoring 9.5.1.2.3.1 Monitoring System Design 9.5.1.2.3.2 Using Monitoring Results as a Tool 9.5.1.2.4 Indicators/Indexes 9.5.1.2.5 Economic Evaluations and Cost-Benefit Analysis 9.5.1.2.6 Public Involvement 9.5.1.2.7 Social Impact Assessment (SIA) 9.5.1.2.8 Discussions on Evaluation of Tools 9.5.2 Basis of Sustainable Management Plan Acknowledgments References L1686_C09.fm Page 373 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press 9.1 INTRODUCTION I. Ethem Gönenç This chapter presents selected case studies from different areas of the world. These studies provide detailed information on how to apply the methodologies and practical approaches discussed in the other chapters of this book. These case studies are examples of how to integrate modeling into the decision-making process for sus- tainable management of lagoons. The brief summaries that follow outline the aim and scope of these case studies. 9.1.1 G RANDE -E NTRÉE L AGOON The first case study area is the Grande-Entrée Lagoon in the Gulf of St. Lawrence, Québec, Canada. The aquaculture industries are focused on determining the carrying capacity of the lagoon for shellfish to maximize production. As defined in previous chapters, lagoons are shallow marine systems where tides and local and nonlocal winds play a major role in the dynamics of water motion. The management of shoreline ponds and/or caged/fenced areas for aquaculture depend on an understand- ing of water movement. Normally, when local winds blow along a lagoon axis, downwind drift currents (see Chapter 3 for details) develop in the shallow areas near both shores. Water pile-up at the lagoon end causes horizontal pressure gradients, which in turn force upwind gradient currents somewhere in the lagoon between the drift currents. The hypothesis put forth here is that gradient currents occur near the bottom in the deeper parts, away from the surface wind stress. This hypothesis was tested in Grande-Entrée Lagoon, using current observations recorded at 1 m above the bottom. A three-dimensional (3D) numerical model and empirical orthogonal function (EOF) analysis of currents and winds show that bottom currents are negatively correlated with the wind directions. The numerical model is first used to simulate the horizontally induced two-dimensional (2D) wind-induced current fields. Results show that currents are quickly set up near both shores, and that a weak and sluggish return flow occurs in between those shores. The model is then used to simulate the 3D current structure under the same wind conditions. The hypothesis is verified: gradient upwind currents occur in the deep layers of the lagoon basin, while currents near the surface are oriented downwind. Such a 3D current structure can have significant effects on water renewal in the bottom layers and on the general lagoon ecosystem dynamics. It suggests that a 3D model should be considered when developing lagoon ecosystem numerical models and when selecting optimal sites for aquaculture development. 9.1.2 M AR M ENOR L AGOON The second case study area is the Mar Menor, a coastal lagoon in the Mediterranean Sea, Spain. As do many lagoons throughout the world, this area supports a wide range of beneficial uses and socio-economic interests. It is recognized as an emblem- atic environment of the Región de Murcia, on the southwestern Mediterranean coast L1686_C09.fm Page 374 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press of Spain. The area is a vital part of the regional development plans to provide high- quality tourist and recreational services. The lagoon and surrounding coastal area maintain important fisheries, such as eel, grey mullet, gill-head bream, sea bass, striped bream, and crustaceans, partic- ularly shrimp. The lagoon is, however, an object of social concern because of its rapid rate of development in the last decade and the detrimental impact of this development on the ecosystem, such as point and nonpoint pollution, shoreline and habitat destruction that result in degradation of the aquatic environment, and decreased fishery production. Some of these changes result from coastal work on tourism facilities, such as land reclamation; the opening, deepening, and extending of channels; urban development and associated waste; construction of harbors for sport; and creation of artificial beaches. Other factors include changes in agricultural practices in the watershed, such as the change from extensive dry crop farming to intensively irrigated crop farming and the increase in agricultural waste and nutrient input into the lagoon and coastal aquatic environment. These circumstances make the Mar Menor a useful example for analyzing the biological patterns and processes affected by changes in hydrogeographic conditions, nutrient inputs, and lagoon characteristics (see Chapter 5). 9.1.3 T HE B ALTIC S EA L AGOONS The third case study area is the Baltic Sea lagoons. The Curonian, Odra, and Vistula lagoons are of great importance for the quality of coastal waters and open sea areas. These lagoons are natural filters for agricultural, industrial, and munic- ipal waste loads. These anthropogenic pressures are particularly intense in the southern and southeastern parts of the Baltic catchment area. This region is densely populated. Industrial activity is intense, and a large proportion of land is used for agriculture. The Vistula Lagoon experiences higher anthropogenic loading than the Odra or Curonian lagoons because of its relatively small water volume and very poor treat- ment facilities in its catchment area. The Vistula Lagoon was one of the first areas in the Baltic region where genuine strides in transboundary management have been attempted, including the implementation of modeling as a decision-making tool by both scientific institutions and national environmental authorities. 9.1.4 K OYCEGIZ –D ALYAN L AGOON The fourth case study area is Koycegiz–Dalyan Lagoon in the Mediterranean Sea in Turkey. This lagoon is widely regarded as a stellar example of ecosystem modeling for sustainable management in the context of the NATO-CCMS pilot study. A decision support system has been established, and monitoring and modeling are used to support decision making in the lagoon and watershed. These four case studies are models that offer valuable insight into the decision- making process for ensuring thoughtful sustainable management of lagoons world- wide. L1686_C09.fm Page 375 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press 9.2 THREE-DIMENSIONAL STRUCTURE OF WIND-DRIVEN CURRENTS IN COASTAL LAGOONS Vladimir G. Koutitonsky 9.2.1 INTRODUCTION A coastal lagoon is a shallow water body separated from the ocean by a barrier, usually parallel to the shore, and connected, at least intermittently, to the ocean by one or more inlets. 1 A lagoon can be choked, restricted, or leaky depending on the inlet configuration. 2 These geomorphologic features affect hydrodynamic processes inside the lagoon, namely the flushing time, the circulation, and the mixing of waters. 3, 4 Depths of most lagoons seldom exceed a few meters so they respond quickly to forces acting at the air–sea interface and at the lagoon open boundaries. Forces acting at the lagoon lateral boundaries are tides, nonlocal forcing at the ocean boundary, and freshwater run-off, when present, at the upstream boundary. Forces acting at the air–sea interface include heat and water fluxes resulting from changes in air temperatures, precipitation and evaporation, and wind stress. These forces accelerate the motion and establish barotropic and baroclinic pressure gradients in the lagoon and across its inlets. They also modulate the turbulent mixing as well as the vertical and horizontal density gradients in the lagoon. 5 Bottom friction decel- erates the motion and plays a significant role in the momentum balance. 6 This study focuses on the combined effects of wind stress, horizontal barotropic pressure gra- dients, and bottom friction in coastal lagoons. Normally, winds blowing along the major axis of a lagoon set up downwind coastal currents in the shallower regions near both shores. The resulting water pile- up at the downwind end of the lagoon sets up horizontal (barotropic) pressure gra- dients that can induce upwind gradient currents elsewhere in the lagoon, between the coastal currents. This study suggests that wind-driven currents in lagoons are three- dimensional (3D) in space and that 2D models may not be adequate to describe them. Such a 3D structure may influence primary production, 7 nutrient fluxes, 8 and the transport of dissolved and particulate matter in the lagoon. 9,10 Modeling the response of ecosystems to the above physical processes is discussed in Hearn et al. 6 and in earlier chapters. The objective of this study is to demonstrate that wind-induced currents can have a 3D structure in some coastal lagoons even when their depths are relatively shallow (~5 m). The hypothesis put forth is that return gradient currents occur in the deeper layers of the lagoon, away from the surface where motion is still respond- ing to wind stress. This may have implications for water renewal in the bottom layer, for the transport of dissolved or particulate matter in the lagoon, and for biogeochem- ical fluxes at the sediment interface. The hypothesis is tested in Grande-Entrée Lagoon (Section 9.2.2) where predominant winds are oriented along the lagoon axis. 11 Low frequency current, sea levels, and wind time series obtained during a 1989 field experiment are analyzed in Section 9.2.3. Section 9.2.4 compares the results of 2D and 3D model simulations of these wind-driven currents. The numerical model used in this study is the MIKE3-HD model, 12,13 briefly described in Appendix 9.2.A. Conclusions are given in Section 9.2.5. L1686_C09.fm Page 376 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press 9.2.2 G RANDE -E NTRÉE L AGOON The Magdalen Islands are located in the middle of the Gulf of St. Lawrence in eastern Canada (Figure 9.2.1). They include several lagoons that have traditionally sustained aquaculture activities. Two of these lagoons, Grande-Entrée Lagoon (GEL) and Havre aux Maisons Lagoon (HML), are connected by a 60-m wide and 7-m deep pass under a bridge. The geometry of their entrance passes makes them leaky and restricted lagoons, respectively, and a tidal phase difference between these entrances generates significant tidal currents in some parts of the lagoons. 11 The focus of this study is GEL (Figure 9.2.1). Its bathymetry features a 7.5-m-deep navigation channel leading from its entrance to a harbor in its northern part. This channel separates a deeper basin (5–6 m) to the east from a shallower region (2–3 m) to the west leading to HML. The eastern deep basin sustains considerable mussel aquaculture activities. Tides in GEL are mixed and mainly diurnal with an average tidal range at the entrance of 0.58 m, reaching 0.95 m during spring tides. 11 The lagoon surface area is about 68 km 2 such that the tidal prism for normal tides is about 74.4 × 10 6 m 3 . Assuming that a fraction β of this volume remains inside the lagoon during each tidal cycle and is completely mixed with ambient waters, 14 a lower limit for the GEL flushing time of 6 days during strong wind conditions ( β = 1) and 23 days during calm wind conditions ( β = 0.25) is estimated. GEL has no freshwater river run-off and evaporation is negligible. FIGURE 9.2.1 Grande-Entrée Lagoon bathymetry in the Magdalen Islands (upper left inset), in the Gulf of St. Lawrence, Canada (lower right inset). 0 05 km 47°35′ 47°30′ 61°30′ 47°30′ 47°20′ Grande-Entrée Lagoon U.S.A. 0 Bridge QUEBEC GULF OF ST. LAWRENCE Atlantic Ocean 200 km 15 km Harve aux Maisons Lagoon 62°00′ 61°40′ 61°40′ 10 m 5 m 2 m 20 m N L1686_C09.fm Page 377 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press As a result, waters in the lagoon show little vertical density stratification except perhaps during the ice-melting period (April). Finally, winds are predominant from the southwest-northeast axis, that is, along the major axis of the lagoon. 11 9.2.3 W IND -D RIVEN C URRENTS : O BSERVATIONS A large-scale multidisciplinary field experiment was carried out in GEL during the summers of 1988 and 1989. 15,16 The objective was to study the impact of increasing mussel aquaculture on the biological production of the lagoon. Aanderaa current meters and tide gauges were moored exactly 1 m above the bottom from May 5 to May 20, 1989 at several stations in the lagoon, including C1, C6, C10, C12, and C11 in the deep basin (Figure 9.2.2). Mooring C1 outside the inlet was fitted with a second current meter near the surface that was left in the water for a longer period of time. Divers performed daily inspections of all moorings in order to remove possible rotor contam- ination by drifting algae. Conductivity and temperature profiles were obtained at several locations in the lagoon over neap and spring tidal cycles. Finally, winds and atmospheric pressure were measured at Grindstone (Figure 9.2.2). Analysis of the complete current and sea-level data set has been reported elsewhere. 11,16 It was shown that tidal currents reach speeds above 0.5 m/s at the lagoon entrance and in the shallow regions to the west, while in the deeper basin, to the right of the navigation channel, FIGURE 9.2.2 Positions of sea level (L1) and current (Cx) recording stations during 1989 in Grande-Entrée Lagoon in the Magdalen Islands, Gulf of St. Lawrence. C11 C12 C10 L2 L1 L1 C1 0 0 N 62°00′ 61°40′ 47°30′ 47°20′ 61°40′ 61°30′ 47°30′ 47°35′ 15 km Grindstone Current meter Tide gauge Meteorological station 5 km L9 C6 L1686_C09.fm Page 378 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press they are almost nonexistent (ellipse major axis speeds ~ 0.01 m/s). The water renewal time in the deep basin was estimated to vary between 12 and 20 days. Since tidal currents are almost nonexistent, water exchange in this basin must be due solely to a combination of local winds and nonlocal forcing at the mouth. For completeness, local winds and the forcing functions at the mouth (station C1, L1) are presented in Figure 9.2.3 from May 5 to 20, 1989, a period during which current meter records are FIGURE 9.2.3 Wind vectors and sea levels at stations L1 and L2 (low frequency, dotted line), salinity and temperatures at the surface (solid line) and at the bottom (dotted line) at station C1 from May 5 to 20, 1989. 6 7 8 9 10111213141516171819 21 m m m/s WINDS SEA LEVEL L2 SEA LEVEL L1 SALINITY C1 TEMPERATURE C1 MAY 1989 2220 + + + + ++++++++++ ++++++ +++++++++++++++ +++++++++++++++ +++++++++++++++ ++++++++++++++++ 15.0 10.0 5.0 −5.0 0.0 5.4 5.2 5.0 4.8 4.6 4.4 4.2 8.4 8.2 8.0 7.8 7.6 7.4 7.2 31.0 30.5 30.0 29.5 29.0 6.0 5.0 4.0 3.0 2.0 psu °C L1686_C09.fm Page 379 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press available inside the lagoon. Water salinity and temperature at the surface (solid line) and near the bottom (dotted line) do not show considerable differences. Hence, waters entering the lagoon are vertically mixed. Inside the lagoon, waters normally also remain well mixed 16 under the influence of omnipresent winds. Winds during the May 5–20 period were oriented along the lagoon axis only occasionally (arrows on top, Figure 9.2.3). This study focuses on the May 12–14 reversing wind event because current measurements inside the lagoon were available then. Winds on May 12 were southwesterly, along the lagoon axis, and they reversed on May 13 to become north- easterly. Low-frequency sea levels (dotted lines superimposed on sea levels in Figure 9.2.3) indicate that sea levels at the mouth (L1) and inside the lagoon (L2) were almost identical, as expected in a “leaky” lagoon. 11 Northeasterly (southwesterly) winds led sea-level rises (falls) at L1 and L2. It is not clear if this response was a local set-up or a gulf-wide response to large-scale winds. The application of a 3D hydrodynamic model to the Gulf of St. Lawrence 17 showed that, under prevailing southwesterly winds, sea levels rise in the northern gulf and decrease in the southern gulf and in the Magdalen Islands region. So it is possible that sea levels at the mouth (L1) and inside the lagoon (L2) respond to such nonlocal forcing as well as to local winds. Winds, sea levels at L2, and wind-driven currents in the deep basin at C6, C10, C11, and C12 (see Figure 9.2.2) were then examined during the reversing wind event of May 12–14 to detect upwind return flows in the lower layers of the deep basin. The hourly time series were first low-pass filtered (cut-off frequency set at 34 h) in order to remove tidal oscillations and high-frequency noise. 18 These series are shown in Figure 9.2.4. The numerical simulations (Section 9.2.4) will focus on the same wind event. Several points are worth noting about the wind-driven current observations. Measured at 1 m above the bottom, the currents shown are located in the deeper layers of the basin. Their principal axes of variability (Table 9.2.1) indicate that they are oriented along axes that differ slightly (between 8 and 27°) from the lagoon longitudinal axis (40°). They also exhibit an out-of-phase relation with the wind direction. This out-of-phase relation can be objectively established from empirical orthogonal function (EOF) analysis 19 of the wind component resolved along the lagoon axis and the current vectors resolved along their principal axis of variability (Table 9.2.1). The correlation matrix for the resulting series at C6, C10, C12, and C11 and the longitudinal wind series is presented in Table 9.2.2a. Results from the EOF analysis of this matrix are presented in Table 9.2.2b in terms of the percentage of the total variance in the series explained by each empirical mode and the percentage of the variance in each series explained by each mode. Results suggest that all near-bottom currents resolved along their principal axis are negatively correlated with the longitudinal wind and that 75% of the total variance is explained by the first empirical mode. This mode explains 96% of the wind variance and the largest portion of the variance in each current series, except for the variance in currents at C6, which is partly explained by mode 2. In summary, these observations tend to support the hypothesis that the wind-driven circulation in a lagoon can be three-dimensional in space and that the return flow can occur at depth in an upwind direction. Simple analytical reasoning provides insight into these findings. 20 Consider the steady-state motion in a lagoon of variable depth H(x, y) resulting from horizontal pressure gradients and vertical shear friction, in the absence of Coriolis accelerations L1686_C09.fm Page 380 Tuesday, November 2, 2004 2:42 PM © 2005 by CRC Press [...]... 193 7 and 197 6 the built-up lagoon perimeter increased from 12 to 54%, and to 56% in 198 6 and 64% in 199 4 (Figure 9. 3 .9) There © 2005 by CRC Press L1686_C 09. fm Page 404 Tuesday, November 2, 2004 2:42 PM 200 Surface (km 2) 1.6 180 1.4 160 1.2 140 Shore development (Pshore ) 120 1 100 0.8 80 Perimeter (km) 60 0.6 0.4 40 20 0 25 B.C 0.2 Urban shoreline (km) 1868–1875 192 6– 193 5 193 7– 194 7 196 9 – 198 1 0 199 4... mean, June 198 7) 37°C (August 198 6) 0 mm (usually in March and from June to August) 50 mm (December 198 7) 110 h of sun (December 198 7) 195 cal/cm2 * day (monthly mean, January 198 5) −3.4°C (January 198 5) 497 .9 mm ( 198 7) 1442 .9 mm ( 198 1) 2344 h of sun ( 198 5) 113.5 mm ( 198 3) 115.2 mm ( 198 8) 2053.8 h of sun ( 198 2) Atmospheric temperature (absolute values) Rainfall Evaporation Solar radiation Source: Data... Modern Society (CCMS) devoted to ecosystem modeling of coastal lagoons for sustainable management It is funded by NATO-CCMS fellowship award © 2005 by CRC Press L1686_C 09. fm Page 390 Tuesday, November 2, 2004 2:42 PM SA. 8-3 -0 1B (97 1261) Nestor Navarro contributed to the analysis of the 198 9 data set as part of his M.Sc thesis The 198 8– 198 9 Grande-Entrée lagoon project was funded partly by Fisheries... Rev., 91 , 91 , 196 3 24 Rodi, W., Examples of calculation methods for flow and mixing in stratified fluids, J Geophys Res., 92 (C5), 5305, 198 7 © 2005 by CRC Press L1686_C 09. fm Page 392 Tuesday, November 2, 2004 2:42 PM 9. 3 THE ECOLOGY OF THE MAR MENOR COASTAL LAGOON: A FAST-CHANGING ECOSYSTEM UNDER HUMAN PRESSURE Angel Pérez-Ruzafa, Concepción Marcos Diego, and Javier Gilabert 9. 3.1 FUNCTIONAL TYPOLOGY 9. 3.1.1... York, 199 4, 69 4 Spaulding, M., Modeling of circulation and dispersion in coastal lagoons, in Coastal Lagoon Processes, Kjerfve, B., Ed., Elsevier Oceanographic Series 60, Elsevier, New York, 199 4, 103 5 Nunez Vaz, R.A., Periodic stratification in coastal waters, in Modeling Marine Systems, Vol II, Davies, A., Ed., CRC Press, Boca Raton, FL, 199 0, 69 6 Hearn, C.J., Lukatelich, R., and McComb, A., Coastal. .. New York, 199 4, 133 9 Lacerada, L.D., Biogeochemistry of heavy metals in coastal lagoons, in Coastal Lagoon Processes, Kjerfve, B., Ed., Elsevier Oceanographic Series 60, Elsevier, New York, 199 4, 221 10 Nichols, M.M and Boon, J.D., III, Sediment transport processes in coastal lagoons, in Coastal Lagoon Processes, Kjerfve, B., Ed., Elsevier Oceanographic Series 60, Elsevier, New York, 199 4, 157 11... Therriault J.-C., Ed., Can Sp Pub Fish Aquat Sci., 113, 57, 199 1 18 Walters, R.A and Heston, C., Removing tidal-period variations from time series data using low-pass digital filters, J Phys Oceanogr., 12, 112, 198 2 19 Emery, W.J and Thompson, R., Data Analysis Methods in Physical Oceanography, Pergamon Press, London, 199 7 20 Mathieu, P.-P., Deleersnijder, E., Cushman-Roisin, B., Beckers, J.-M., and Bolding,... the same: the low-pass sea level fluctuations recorded at L1, outside GEL (Figure 9. 2.2) Bathymetry data from the Canadian Hydrographic Service charts 495 1, 495 2, 495 4, and 495 5 were used to construct a rectangular grid with 360 cells along the x-axis (east) and 298 cells along the y-axis (north), each cell measuring 90 m × 90 m in size The simulations in both © 2005 by CRC Press L1686_C 09. fm Page 384... November 2, 2004 2:42 PM 400 Rainfall/Evaporation (mm) Rainfall Evaporation 300 deficit of the net annual hydric balance > 600,000 m3/km2 200 100 0 J- 198 1 J-82 J-83 J-84 J-85 years J-86 J-87 J-88 FIGURE 9. 3.3 Hydric balance in the Mar Menor area over a 10-year period Rainfall is scarce and usually concentrated in brief, torrential downpours during the year (Data from the San Javier meteorological station.)... over © 2005 by CRC Press L1686_C 09. fm Page 397 Tuesday, November 2, 2004 2:42 PM TABLE 9. 3.1 Minimum and Maximum Value of Climatic Variables in the Mar Menor Area ( 198 1– 198 8) Maximum Annual Rainfall 300 mm (November 198 7) Evaporation Solar radiation Monthly Minimum 165.5 mm (May 198 1) 280 .9 h of sun (July 198 1) 623 cal/cm2 * day (monthly mean, June 198 7) 37°C (August 198 6) 0 mm (usually in March and . Baykal CONTENTS 9. 1 Introduction I. Ethem Gönenç 9. 1.1 Grande-Entrée Lagoon 9. 1.2 Mar Menor Lagoon 9. 1.3 The Baltic Sea Lagoons 9. 1.4 Koycegiz–Dalyan Lagoon 9. 2 Three-Dimensional Structure of Wind-Driven. Currents in Coastal Lagoons Vladimir G. Koutitonsky 9. 2.1 Introduction 9. 2.2 Grande-Entrée Lagoon 9. 2.3 Wind-Driven Currents: Observations 9. 2.4 Wind-Driven Currents: Numerical Modeling 9. 2.5 Conclusion Appendix. Conclusion Appendix 9. 2.A: The MIKE3-HD Numerical Model 9. 2.A.1 Governing Equations 9. 2.A.2 Wind Stress 9. 2.A.3 Eddy Viscosity 9. 2.A.4 Bottom Stress Acknowledgments References 9. 3 The Ecology of the Mar Menor Coastal