Fourth Study Conference on BALTEX Scala Cinema Gudhjem

More documents

Recommendations

Info

- 138 - Investigations of Variations in Water Level Times-Series at the German Baltic Sea Coastline Jürgen Jensen and Christoph Mudersbach Research Centre for Water and Environmental Engineering (fwu) at University of Siegen, Paul-Bonatz-Str. 9-11, 57076 Siegen, Germany, phone +49-271-7402627, e-Mail: jensen@fb10.uni-siegen.de 1. Introduction Changes in the global sea level have far reaching consequences for both humans and the natural environment. The whole German North Sea and Baltic Sea coastlines are protected against storm surges by dykes in order to protect the partially lower lying hinterland. Particularly in highly industrialized countries, as, for example, Germany, space requirements for population and industry are increasing. The existing space is used intensively and, in the case of flooding, high significant monetary and ecological damage will result. As a result of strongly increasing shipping traffic, shipping routes have been enlarged and are maintained. This has a direct influence on the storm surges coming into the estuaries, so that the inland can be affected more strongly by the consequences of such a storm surge (e.g. Hamburg 1962). The population and the economy must be protected against flooding. To achieve this, knowledge of the long, medium and short-term trends of the water levels is important. The tidal range is about 3m at the North Sea coastline. At the Baltic Sea no tidal range has to be considered. 2. Database Data pre-processing is a very important and time-consuming task. Data pre-processing is important because the original data can contain discrepancies and mistakes. One must check, therefore, whether there are obvious mistakes in the time series, or in cases where the gauge datum has changed. To make the data pre-processing and storage of data effective, the development of a relational database system is to be recommended. In this database, the data can be managed in an easy way and simple analysis can be carried out. For the present investigation, a database system in MS Access was developed (Fig. 1). This software was chosen because it is universally available and special demands are not made on the workstation. 3. Analysis and Results In the present investigation, a statistical analysis of the time series was carried out. Basic statistical parameters, such as, for example, mean values and standard deviations, were calculated for all time series. Four gauging stations at the German Baltic Sea coastline were combined to so called synthetic gauges to be able to make more general statements about the variances in the Baltic Sea. Further analysis, such as trends or adaptation functions, were carried out only for the synthetic time series. Figure 1. Initial form of the time series data base. The statistical analyses of the time series were carried out using the software package MATLAB (Version 6.5). With the aid of different adaptation functions, statements about the trends of the mean water levels at the German North Sea and Baltic Sea coastline can be made up to the year 2020. First, to all time series linear trends for different spans of time were calculated. For a more detailed description of the time series the influence of the nodal tide was considered. From this basis, further non-linear adaptation functions were examined which can describe better the given time series. The advantage of the nonlinear adaptation functions lies in their ability to describe the available time series more exactly. The disadvantage lies in the fact that they cannot be used so well for extrapolation. Therefore, particular care must be taken during the use of nonlinear adaptation functions at the point when they are ”running away”. Some results are shown in figure 2, where the time series of the Mean Sea Level (MSL) of the synthetic Baltic Sea gauging station is fitted by several non-linear adaptation functions. In the further analysis, the question is interesting of how the MSL of the North Sea and the Baltic Sea are related to each other. Due to the small tidal range in the Baltic Sea, the Baltic Sea can be considered as a damped gauge of the North Sea. A correlation between the Baltic Sea ∆MMSL and the ∆MMSL of the synthetic island-gauge North Sea shows these relationships (Fig. 3).
Figure 2. Time series of Mean Sea Level (MSL) of Baltic Sea The island-gauge was chosen for this comparison because there are no anthropogenic influences (e.g. dredging). The relationship can be described with a linear regression line by the form: f(x) = 0.60x + 1.73 Along with the regression line, the 95%-prediction bounds are represented. It can be seen well that almost all observed values lie within the indicated prediction bounds. The ∆MMSL of the Baltic Sea is in comparison to the ∆MMSL North Sea damped by 40%. Gauge) Sea ic (Balt SL M M d 15 10 5 0 -5 -10 linear 95% prediction bounds ostsyn (MSL) vs. inselsyn (MSL) -15 -20 -15 -10 -5 0 5 10 15 dMMSL (Island Gauge North Sea) Figure 3. Correlation of North- and Baltic Sea Mean Sea Level (MSL) 4. Conclusions The results of the present investigation basically confirm the investigations of the IPCC 2001. For practical questions, the knowledge of the specific trends of the water levels at the different gauging sites is of special importance. With the aid of this investigation, such questions can be answered better. As well as the MSL, the MHW, MLW and MTR were examined in the same way. These results show for the most part that the high water levels have been increasing in the last 40 years more strongly, than the low water levels. All results lead to the assumption that the tidal dynamics in the North Sea, and thus also the water levels in the Baltic Sea, have changed or are still changing. - 139 - It seems to be possible that, for example, the amphedromic points in the North Sea are displaced (JENSEN AND MUDERSBACH 2002b). The effects of such system changes must be considered with some concern, since the consequences are not predictable in detail. The trends of the water levels have to be observed and analysed exactly in future. Further investigations are needed. References IPCC: Climate Change, The IPCC Scientific Assessment, Report Prepared for IPCC by Working Group 1, WMO, UNEP, University Press of Cambridge, 2001 Jensen, J. and Mudersbach, C.: “Long-Term Changes of the Water Levels along the German North Sea Coastline”, in: Littoral 2002, 6th International Symposium in Porto, 22-26 September 2002, Bd. 2, Eurocoast, Porto, 2002a Jensen, J. and Mudersbach, C.: „Analysis of tidal water levels along the German North Sea coastlines“, in: Low-lying Coastal Areas – Hydrology and Integrated Coastal Zone Management, International Symposium, IHP/OHP-Berichte, Sonderheft 13, BfG IHP/OHP- Sekretariat, Koblenz, 2002b Jensen, J. and Mudersbach, Ch.: “Statistical analysis of water levels at the German Baltic Sea Coastline”, Proceedings of the 6. International MEDCOAST 2003-<strong>Conference</strong>, Ravenna, Italy, 2003 Jensen, J.: Änderungen der mittleren Tidewasserstände an der Nordseeküste, Mitteilungen LWI, TU Braunschweig, Heft 86, 1984 Jensen, J., Bender, F. and Blasi, Chr.: Analysis of the Water Levels along the German North Sea Coastline. Proceedings of the fifth conference MEDCOAST 01, Volume 3, Tunesia, 2001 Jensen, J. and Schönfeld, W.: Pegelzeitreihen der deutschen Nordseeküste - Ergebnisse einer statistischen Analyse. HANSA, 127. Jahrgang, Heft 17/18, 1990 Stigge, H.-J.: Nullpunktkorrektur für alle DDR- Küstenpegel (Mitteilung der Wasserwirtschaftsdirektion Küste), Beitr. Meereskd., 60(1989) Berlin, 1989
Page 1 and 2:
Fourth Stu
Page 3:
Preface The 4 th Study</str
Page 7 and 8:
- I - Table of Abstracts Title Auth
Page 9 and 10:
- III - Sensitivity in Calculation
Page 11 and 12:
- V - Parameter Estimation of the S
Page 13 and 14:
- VII - The Realism of the ECHAM5.2
Page 15 and 16:
Adam, W. K. .......................
Page 17 and 18:
- 1 - Activities of the GEWEX Hydro
Page 19 and 20:
eference site archive (Cabauw, Neth
Page 21 and 22:
- 5 - Remote Sensing of Atmospheric
Page 23 and 24:
minute averages around the satellit
Page 25 and 26:
- 9 - Precipitation Type Statistics
Page 27 and 28:
- 11 - Assimilation of New Land Sur
Page 29 and 30:
Multichannel Microwave Radiometer f
Page 31 and 32:
output has been processed in an equ
Page 33 and 34:
height dependence of the Z-R-relati
Page 35 and 36:
- 19 - CERES and Surface Radiation
Page 37 and 38:
- 21 - Coastal Wind Mapping from Sa
Page 39 and 40:
- 23 - Clouds and Water Vapor over
Page 41 and 42:
- 25 - Broadband Cloud Albedo from
Page 43 and 44:
- 27 - Observation of Clouds and Wa
Page 45 and 46:
shows a ground-track of the vessel
Page 47 and 48:
- 31 - Determination and Comparison
Page 49 and 50:
- 33 - Spatial Variability of Snow
Page 51 and 52:
- 35 - EVA-GRIPS: Regional Evaporat
Page 53 and 54:
- 37 - LITFASS-2003 - A Land Surfac
Page 55 and 56:
-39- Calibrated Surface Temperature
Page 57 and 58:
- 41 - The Marine Boundary Layer -
Page 59 and 60:
- 43 - Characteristics of the Atmos
Page 61 and 62:
Figure 2. Surface stress from two d
Page 63 and 64:
During the experiment the water was
Page 65 and 66:
While the number of smallest drops
Page 67 and 68:
SCANDIA will not be supported any l
Page 69 and 70:
- 53 - Relationships Between Precip
Page 71 and 72:
- 55 - Analysis of the Role of Atmo
Page 73 and 74:
- 57 - Meteorological Peculiarities
Page 75 and 76:
Baltic Sea Inflow Events Jan Piechu
Page 77 and 78:
- 61 - The Different Baltic Inflows
Page 79 and 80:
- 63 - Observations of Turbulent Ki
Page 81 and 82:
- 65 - The Influence of Synoptic Si
Page 83 and 84:
-67- Improved Method for the Determ
Page 85 and 86:
-69- The Helicopter-Borne Turbulenc
Page 87 and 88:
- 71 - CEOP Reference Site Data fro
Page 89 and 90:
- 73 - The BALTEX Hydrological Data
Page 91 and 92:
- 75 - Hydrological and Hydrochemic
Page 93 and 94:
-77- Sea-level Monitoring at MARNET
Page 95 and 96:
1 0.8 0.6 0.4 0.2 GO(CLD-M) ERA40 S
Page 97 and 98:
Figure 2. Monhly mean values of lat
Page 99 and 100:
In the case of an ideal fit, the co
Page 101 and 102:
- 85 - Influence of Atmospheric For
Page 103 and 104: The largest inter-annual variabilit
Page 105 and 106: References Andrejev, O, Sokolov, A.
Page 107 and 108: On the other hand, if the stratific
Page 109 and 110: Cyberska 1989, Cyberska and Krzymin
Page 111 and 112: - 95 - Continental-Scale Water-Bala
Page 113 and 114: - 97 - ICTS (Inter-CSE Transferabil
Page 115 and 116: The subsurface flow calculation is
Page 117 and 118: functions only data with higher qua
Page 119 and 120: - 103 - Modelling the Impact of Ine
Page 121 and 122: - 105 - Objective Calibration of th
Page 123 and 124: - 107 - Validation of Boundary Laye
Page 125 and 126: - 109 - Simulated Dynamical Process
Page 127 and 128: spreads along isobaths (fig.2). As
Page 129 and 130: than the precipitation pattern of J
Page 131 and 132: Figure 2. Long-term variability in
Page 133 and 134: obvious from temperature charts. Ho
Page 135 and 136: shortening of the winter seasons by
Page 137 and 138: Maximum 5 day precipitation (mm) Nu
Page 139 and 140: scale parameters the correlation be
Page 141 and 142: similar: the locations of main mini
Page 143 and 144: - 127 - Storminess on the Western C
Page 145 and 146: - 129 - Trends in Wind Speed over t
Page 147 and 148: - 131 - Wind Energy Prognoses for t
Page 149 and 150: - 133 - Detection of Climate Change
Page 151 and 152: Figure 3. Cross section of salinity
Page 153: of 35 m/s up to 3 hours. Data on wi
Page 157 and 158: - 141 - Calculation and Forecast of
Page 159 and 160: - 143 - An Overview of Long-Term Ti
Page 161 and 162: - 145 - Baltic Sea Saltwater Inflow
Page 163 and 164: - 147 - Significance of Feedback in
Page 165 and 166: Lindström, G., Johansson, B., Pers
Page 167 and 168: - 151 - Air-Sea Fluxes Including Mo
Page 169 and 170: - 153 - The Realism of the ECHAM5.2
Page 171 and 172: - 155 - Figure 3. Accumulated total
Page 173 and 174: Figure 2. Example for Fourier decom
Page 175 and 176: Figure1. Modeled percent volume cha
Page 177 and 178: conditions even more challenging th
Page 179 and 180: surface heat fluxes close to zero.
Page 181 and 182: - 165 - Figure 1. Modeled seasonal
Page 183 and 184: - 167 - Present-Day and Future Prec
Page 185 and 186: - 169 - Extreme Precipitation on a
Page 187 and 188: at the stations Pärnu (Estonia) an
Page 189 and 190: 6. Results There are many possible
Page 191 and 192: and vegetation, and to derive the h
Page 193 and 194: The structure of water bodies cadas
Page 195 and 196: Figure 1. The area of Gdańsk subje
Page 197 and 198: - 181 - Climate and Water Resources
Page 199 and 200: - 183 - Generating Synthetic Daily
Page 201 and 202: The evapotranspiration is affected
Page 203 and 204: Model parameters and coefficients:
Page 205:
3. Hydrodynamic model of nutrient l
Page 208 and 209:
No. 15: Minutes of 8 th Meeting of
show all

Fourth Study Conference on BALTEX Scala Cinema Gudhjem

Create successful ePaper yourself

Delete template?

Save as template?