Chloride concentrations within the estuary are affected by many processes, which can be summarized in three main factors; the inflow of salt water due to tides; the inflow of fresh water due to river discharge and the mixing processes between these inflows. Previous research indicated that deepening of the New Waterway and Botlek may lead to increased chloride concentrations in the Rhine-Meusedelta. In this research daily averaged values were used. Due to the dependence of the inflow of salt water on the tidal water movement, however, this analysis is best performed at the time scale of the in- and outflow of the tidal wave. The inflow of fresh water in the Rhine-Meusedelta originates from the Waal, Meuse and Lek rivers, of which the discharge volumes are measured upstream of the estuary. These discharges take a certain amount of time to reach the measurement locations for chloride concentrations in the estuary. Similarly, the inflow of salt water with the tidal wave, measured as the water level at the mouth of the estuary, takes time to propagate into the estuary and reach the chloride concentration measurement locations. These time lags are determined, with the use of a cross-correlation analysis between the observed boundary conditions and the chloride concentrations, at four different locations in the estuary. Resulting time lags vary from 110 minutes to 280 minutes regarding the tide and 750 minutes to 1900 minutes regarding the discharges of the Waal, Meuse and Lek.
This paper represents an attempt to address the transition to farming through a long-term study of plant microwear traces on flint tools. We report on a series of archaeological research projects which show the presence of a specific type of siliceous plant-working flint tool in the Mesolithic and Early Neolithic of the Rhine/MeuseDelta region that disappears when the first evidence for crop growing appears in the archaeological record. A long-running programme of experimentation has shown that these plant traces are related to plant craftwork. The disappearance of tools displaying traces of this particular type of plant-working at the time agriculture starts to take hold in this region has led us to argue that this craft was related in some way to subsistence, probably a change in subsistence technology. We show that microwear studies of plant polish on tools offer a complimentary and often overlooked form of evidence to more traditional methods of studying the Neolithisation process.
The Biesbosch National Park is a 9000-hectare tidal fresh- water wetland in the lower Rhine–Meusedelta in the south- west of the Netherlands (see Fig. 1a and b). The area was reclaimed in medieval times, but it became completely inun- dated by the St. Elisabeth flood, which was a combination of two storm surges and two floods of the river Rhine be- tween 1421 and 1424 (Zonneveld, 1959). In the subsequent two centuries, an approximately six-meter thick deltaic splay developed (Kleinhans et al., 2010). The lower 4 m of this splay is sand, covered by 2 m of clay (De Bont et al., 2000). In AD 1861, the Nieuwe Merwede, an artificial branch of the river Rhine, was excavated through the area. As a conse- quence, water levels dropped and large parts of the wetland were embanked and reclaimed as polders for agriculture dur- ing the second half of the 19th century (De Bont et al., 2000; Rijsdorp et al., 2006). However, since 2008, several of these polder areas have been depoldered (i.e., reopened) for river water to increase the discharge capacity of the river Rhine. The study area of the Kleine Noordwaard was among the first polder areas that have been depoldered.
Five settlements are known on the Older Dunes with a noticeable concentration (of isolated finds also) between the mouth of the Meuse and the mouth of the Rhine. It is very likely that the conditions there were particularly favourable for settlement. The oldest system of coastal barriers, covered with low dunes, was situated there in the form of a broad, high sand ridge behind a very wide shore flat. Its vegetation consisted of a tall-growing forest, undoubtedly full of wild animals; there was a good supply of fresh water and no danger of being flooded. There are, however, so many factors affecting the distribution pattern that we cannot say that the other coastal barriers, existing at that time, were not inhabited. The belt of coastal barriers, which at the time of the VL Culture formed the actual coast or lay in its immediate vicinity, was in any case visited, as appears from a few isolated finds there (a flint axe and whet- stone in The Hague 59 ), and the find of a sperm-whale tooth and bones of the grey seal in the
Seldom do natural circumstances influence the settlement patterns and inhabitation sequence so thouroughly as in the sea-level-governed Holocene sedimentation area at the Rhine/Meuse estuary. In a general survey of the archaeological remains and data the influence of the transgres- sion-regression cyclicity on the occupation history is worked out. Finally the archaeological data are used to construct a new, detailed curve for the relative rise of the Mean High Water level in the Rhine mouth district.
The construction of dikes meant that the natural drainage system was enclosed and had to be largely replaced by an artificial system. This is the place to say something about the likely age of these peat streams, the Giessen, Laak, Lede and also the Alblas. The map shows that they all start in or near the important Schoonrewoerd stream ridge. It is clear that for a great part they are fed by seepage from this sand body. This will certainly have been the case after the Lek became the main outlet of the Rhine, for it cuts the Schoonrewoerd ridge near Culemborg. Although the laying out of their courses was perhaps older, and although they may even have already existed in Roman times, it seems to us that these streams in their present extent are very new and not in fact older than about A.D. 900. Support for such a late date is given by the archaeological finds. So far no reliable finds older than the 11th century have been made along these streams.
The second stage may be labelled «economic and ideological ». The economic aspect comprises the introduction of domestic animals and cereals, with as earliest document the presence of all four animal domesticates at De Bruin phase 3 : cattle, pig, goat and sheep. The phase is dated between 4800 and 4450 cal BC (2 sigma range) ; there are some arguments to date these bones rather late in this period. Domesticates are absent in the earlier phases and at other sites dating from the first half of the fifth millennium, implying the introduction in the delta environment around 4500. This is an intriguing fact, since it means an introduction well before the michelsberg culture / spiere group and their expansion all over the Belgian loess zone. Consequently the source must be looked for not in south-western but in south-eastern direction, the evolved Rössen communities of the Rhineland, which fits well with the contact lines as documented by the axes. This being the case we are the more aware of our restricted view on the neolithisation in the intervening sand area in between the loess zone and the Rhine/meusedelta, which is almost devoid of Rössen evidence.
In our approach, we assumed for the Netherlands that all areas (“dike rings”) will inundate during a flooding event, while they might only partly flood in reality. Therefore, both basin-wide potential damage, as well as expected annual damage, do not provide information on the damage of a single event. For the part of the Rhine basin upstream of the Netherlands, we used inundation maps from the Rhine Atlas (ICPR, 2001) that are to date the best available. The Rhine Atlas assumes flood prone areas to inundate completely. However, several 2-D hydrodynamic inundation simulations for the Lower Rhine by Lammersen (2004) showed that the flood-prone areas do not always entirely inundate, depending on breach locations and flood wave characteristics. We therefore recommend more inundation calculations upstream of the Netherlands which are currently only incidentally available, in order to aid further flood risk assessments.
In this master thesis my findings regarding the characteristics of Rhine flood waves simulated with GRADE are presented. This study is inter alia done to graduate from the master Water Engineering and Management at the University of Twente. I spent approximately 8 months on this study, which was generally a fun thing to do. I learned a lot about how to do scientific research in the hydrological field. Mainly the calculations and interpretation of the calculation results was interesting work in my opinion. First of all I would like to thank Jaap Kwadijk for giving me the opportunity to work on this interesting project. His feedback helped me to understand how scientific research should be done and to improve this thesis. Also Martijn Booij was of great support during the whole study for which I am grateful to him. I want to thank both Frederiek Sperna Weiland and Mark Hegnauer for all their help and good advice. My classmates and colleagues from the University of Twente and Deltares helped me with difficulties I experienced during the process. They also positively distracted me from the work sometimes, which I very much appreciated, because this made me come to other better ideas and thoughts in some cases. Finally I would like to thank my friends and family who supported me during the whole graduation process. Especially I would like to thank Gwen Kamphuis for being there for me to vent my ideas and frustrations and for giving me the support I needed.
Low flow events have occurred in the Rhine River in the past. Examples of this are the summers of 1969, 1976, 1985 and in 2003. Due to these events, the focus of attention with regards to the low flow phenomena has increased. Because of the damage which can be caused by a low flow. Low flows are important, so that adaptive measures may be taken when deemed necessary. An example of this is adapting management strategies towards low flows, reducing the amount of damage suffered. This could be implemented for shipping navigation or the cooling management of energy plants. If more low flows occurs the shipping occurs due to climate change, this is quite important to handle the problem.
Multiple trend matrices for the original non-homogenised an- nual maximum flow series at gauges Maxau, Worms, Mainz, Kaub, Andernach, Cologne, Rees and Lobith are summarised in Fig. 2 (A1–H1). They show for all gauges periods of sta- tistically significant flood increase starting from around 1955 till 2009, and at gauges downstream of Worms additionally from around 1970 till 2005, with relative changes up to 40 to 60 %. For all significant trends the linear model (KTRL) is suitable for describing the relative change in flood flows. For the longer terms starting at the beginning of the 1950s up until 2009, only a few positive flood trends with moderate relative changes from a few percentage up to about 30 % are detected. Generally, the study period is dominated by posi- tive trends for all gauges. Only the trends in the last decades starting from the late 1970s to late 2000s are negative, al- though this period includes two major Rhine floods in 1993 and 1995.
One of the most important part of this research is to isolate the influence of hydrological model structures on the discharge simulation. This was the main aspect that had to be kept in mind when preparing the hydrological models for the simulation of the Meuse basin. Thus, an experiment has been designed where only the hydrological model structure varies. First of all hydrological models have been selected with similar ideas and conceptualisations. This means that the same data can be used in all the hydrological models. Furthermore, it makes it easier to identify which model structure components influence the, in this case, annual maximum discharge simulations. Secondly the routing that connects the sub-basins for the discharge of the Meuse basin at Monsin is kept constant for all hydrological models. This means that the time that it takes for discharge to reach the next sub-basin does not change and cannot influence discharge simulation differences. Finally, the calibration of the hydrological models is performed with the use of an aggregated objective function, which takes multiple hydrograph aspects into account. This aggregated objective function is optimized by changing the model parameters with an optimization algorithm. The influence of human decision making on the calibration process is reduced and ensures that the hydrological models are calibrated in a similar fashion.
David Walt’s family story is deeply connected with the various modes of transportation that made the Delta accessible for settlers. His great-great-grandfather, Martin Walt, moved into the region with the steamboat business in the 1860s as the owner of a company based in Memphis and Higginsport, Kentucky, that ran mail boats to and from the White River, across the Mississippi from Rosedale. The family also has roots in Shaw, where David Walt’s great-grandfather, Rufus Putnam Walt, Sr., worked at the railroad depot until his promotion to stationmaster in Cleveland. The patriarchal lineage of the Walt family is shown in the far right photograph of the two men, Martin Walt and Rufus Putnam Walt, Sr., holding baby Rufus Putnam Walt, Jr., who was David Walt’s grandfather.
The discharge at Borgharen is affected by extraction of wa- ter which is diverted outside the basin. The observed time series were corrected for these canal extractions (Ashagrie et al., 2006). However, detailed information was available only after 1990. Prior to this date the water extraction has been estimated on an annual basis, and has been set at a fixed rate (Ashagrie et al., 2006). Moreover, the discharge of the Meuse river is influenced by the operation of weirs and reser- voirs, which particularly affect discharge during low flows. In fact, the Meuse river is navigable over a substantial part of its total length, connecting the Rotterdam-Amsterdam- Antwerp port areas to the industrial areas upstream. During low flow periods the weirs are operated to maintain a mini- mum stream level for shipping.
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Damages induced by a 100 yr flood of the river Meuse in the Walloon region (Belgium) were assessed at the level of individual land plots. Two time horizons were considered: present (2009) and 2100. To account for the evolution of exposure between 2009 and 2100, a new methodology has been developed to model future developments in the residential sector. Nine different spatial planning scenarios were considered, together with two climate scenarios (“dry” and “wet”). Results show that, between 2009 and 2100, flood damage could be multiplied by 1.01–1.4 in the dry scenario and by 5.4–6.3 in the wet one. In the dry scenario, urbanization is the only influencing factor because 100 yr flood discharge is assumed not to increase. In contrast, in the wet scenario, the effect of climate change is 3–8 times more influential than the effect of urbanization. These results must be considered in the light of the particularly wet hydrological scenario used as well as the assumption of no evolution of protection measures.
In this type of error, the used Q-h relation is outdated and will contain certain errors. The determination of the water level h is performed well, but the corresponding discharge Q is not realistic due to changes in the conditions of the river, such as changes in the river bed. To simulate this kind of errors a systematic error can be introduced. This systematic error starts to increase just after a revision of the Q-h relation. The errors increase to a certain maximum systematic error just before a new Q-h relation is set up. The systematic errors are assumed to be absolute deviations from the original values, because it is assumed that the expiration of the Q-h relation is caused by changes in the cross section. In that case, it is more logical to insert an absolute value for the systematic error than to insert a relative error. Other assumptions are that the systematic error is positive and that the Q-h relation is revised every 5 years. This assumption is an estimation of the period between two revisions and is based on the research of Jansen (2007) in which the period of five years has proved to be a current practice in the Meuse River.