We investigate how crop cultivation started in the Dutch lowlands. In their research, Huisman and Cohen make use of geological datasets, geophysical measurements, mechanical drilling and microscopic and palaeobotanical techniques. All these means will help them to investigate how and how quickly crop cultivation was introduced.

Project lead by Hans Huisman (PI, RUG) & Kim Cohen (co-PI, UU).

1 PhD at Utrecht (Familetto @ Dept. Ph.G.; supervised by Cohen, Huisman, Hoek, Stouthamer) - RM Delta buried levee landscapes. Central NL lagoon 'Swifterbant' inland tidal river levees, paleo-soil investigation, micromorphology, landscape suitability, offsite evidence of human land clearing and neolithic tillage 

1 PhD at Groningen (Smuk @ GIA; supervised by Huisman, Schepers, Raemaekers, ...) - archaeobotany, evidence for agricultural human presence in paleovegetation signals.

Further consortia partners: Barcelona Archeobotany (Madello), BIAX (Kubiak-Martens), RAAP (Willemse).

• prof. dr. Esther Stouthamer
• dr. Kim Cohen
• Elena Familetto MSc

• Hans Huisman (RUG); various others.

Detailed knowledge of past vegetation change is a valuable resource that contributes to addressing a variety of problems, including the planning of forest restoration projects, it assists in archaeological surveys and sheds light on past human-environment interactions. For the time before historical maps, information on past vegetation comes from pollen preserved in lake sediments and peats. While the Netherlands are particularly rich in pollen analytical investigations, data and interpretations are difficult to access and therefore often not considered. We aim to overcome this shortcoming by collecting and collating the existing Dutch pollen data into a national atlas of past vegetation and land cover change with direct applications to forest restoration, archaeology, and education. The map series will contain detailed reconstructions for the period from 15,000 years ago to the present in 1000 to 500-year timesteps. All original data will be placed into the public domain using the international Neotoma platform to ensure ease of access and long-term storage. 

In constructing the maps, we will use the constraints of the abiotic landscape on the vegetation such as soil substrate, water table depth or the location of river channels for the past and present. Based on existing algorithms (Multi Scenario and Downscaling approach) we will develop a software solution for pollen-based quantitative vegetation reconstruction using environmental constraints. The wealth of information on subsurface geology in the Netherlands is internationally unprecedented providing an ideal situation to develop this approach further. The mapping will facilitate the synthesis of the many pollen diagrams spanning only a few thousand years resulting in regionally differentiated Holocene vegetation histories for the Netherlands, hitherto not available. Prior to mapping, data compilations will be used to analyse dependencies of vegetation composition and the dynamics of change on abiotic and biotic controls such as soil substrate. Resulting quantitative vegetation reconstructions will be compared to constraints not used in the map making process such as distance to the sea and known archaeological finds. Emphasis will be on reconstructions of past vegetation openness and its dependency on substrate, coastal proximity, and peat growth. The stability and resilience of different forest types will be evaluated to assist in forest restoration projects in cooperation with Staatsbosbeheer. Relationships between past vegetation patterns and archaeological finds will be analysed with support from archaeological consultants (RCE, BIAX, ADC). TNO will support the digitization of legacy data and evaluation of age models. Staatsbosbeheer and RCA will help in the dissemination of the results.

• dr. Timme Donders
• dr. Thomas Giesecke
• dr. Kim Cohen
• dr. Oliver Schmitz

This research programme focuses on a period of severe pan-European economic and demographic change: the Late Roman Period (AD 300-500) and Early Middle Ages (AD 500- 1000). Physical-geographical and biogeological data point at marked climatic variability and changing landscapes during this time interval. In geomorphologically sensitive regions such as river deltas and coastal areas these changes must have had a noticeable impact on the location and lay-out of urban centres and rural settlements, land use and subsistence strategies, and connections of population centres to their economical ‘hinterland’. Recent developments in digital infrastructure in the Humanities and Geosciences in the Netherlands for the first time enable us to study these phenomena from an interregional and interdisciplinary perspective.

We study how settlement dynamics, land use, infrastructure, demography and trade between AD 300 and 1000 were related to changes of the landscape and climate, focusing on the Lowlands’ geomorphologically most sensitive regions. This reconstruction takes place within three complementary PhD-projects, in the realms of archaeology, physical geography and biogeology. Project A focuses on occupation patterns and land use in coastal, river and Pleistocene sandy regions, project B on natural geomorphologic landscape dynamics in these regions, and project C on vegetation changes and climate.

Results will be synthesized in an interdisciplinary reconstruction of the interactions between cultural and environmental dynamics in the Lowlands between AD 300 and 1000 in a broader northwest-European context. The study will greatly improve the archaeological understanding of dynamics in the Early Medieval Lowlands and strongly enhance the framework for future research of this key period.

• prof. dr. Hans Middelkoop
• drs. Marjolein Gouw-Bouman
• dr. Kim Cohen
• prof. dr. Esther Stouthamer

• Prof. dr. ir. Theo Spek - University of Groningen
• Dr. Bert Groenewoudt - Cultural Heritage Agency of the Netherlands
• Drs. Menne Kosian - Cultural Heritage Agency of the Netherlands

Severe floods caused extensive damage and life-loss throughout Europe over the last decades. The magnitude and the short recurrence interval between large events in several river systems, have raised questions about the actual safety standards for flood protection. In The Netherlands it was reason to raise the 1,250-yr design flood for river dikes in the Netherlands (Waterwet, 2009) from 15,000 to ~16,000 m3/s. A major problem in coupling magnitudes of observed floods to a statistical recurrence time interval, is the uncertainty in recurrence that originates from limited number of actually observed-and-measured large floods: a 110-year interval of discharge data can be presumed to poorly represent the distribution of extremes through time. Non-stationarity of the flooding regime further complicates the use of short discharge records for flood frequency analysis, as it is not expected that the distribution and magnitudes of floods is fixed in time. During the Holocene, climate variability and growing human influence have exerted perturbations to the fluvial system, which translates to gradual changes in flood probabilities.

In this research, we unlocked information on historic and prehistoric floods, by harvesting information from sedimentary records from oxbow lake fills of the Lower Rhine, through detailed continuous grainsize analysis on the irregularly lamintated deeper lake-fill facies (laboratory effort at Utrecht University and VU Amsterdam). With this data, we could extend the more commonly used observational records on Rhine floods (Lobith discharge measurements back to 1901, water level measurements back to 1772). We produced (PhD thesis dataset and peer-reviewed papers): quantitative discharge reconstructions back to 1772 (assessment of water level readings); sediment-based peak-discharge magnitude reconstructions back to 1550 (from the Bienener Alt-Rhein oxbow fill), and millenia-long continous sedimentary flood-event occurence and intensity records from a stack of oxbow fills (sampled in the Rhine upper delta/lower valley in the Netherlands/Germany), resolving each 1/25 year flood back to 500 AD and each 1/100 year flood back to 8200 years ago. Besides in Rhine river management (flood safety assesment, design of dikes and river bed), the results find application in archaeology (Postdoc add-on: event-registration in medieval river cities, taphonomy of Roman Limes sites), river process-geomorphology (stability of bifurcations, success and failure of avulsions) and Rhine floodplain geological mapping (event-stratigraphy, palaeomeander preservation 'half life').

The project Floods of the past - Design for tomorrow (Utrecht University and Twente University, funded by NWO-STW Water2015 call), the NWO-ALW Rubicon  personal grant to Dr. Willem Toonen (Oct 2014 - March 2017 at Aberystwyth University, Wales UK), and Sedimentary flood history research for the Lower Meuse valley at VU Amsterdam (Fei Peng MSc on a Chinese national grant, supervision Dr. M. Prins et al.) are follow ups to this project. The results are also used within our 'Dark Ages in an interdisciplinary light' project (Utrecht University).

• prof. dr. Hans Middelkoop
• dr. Kim Cohen
• dr. Ad van der Spek

• Dr. Maarten Prins - Grainsize lab Vrije Universiteit Amsterdam
• Dr. H.J.T. Weerts - RCE Cultural Heritage Agency of the Netherlands

Delta Evolution is the label we use since 2005, for the Utrecht University research line in Lowland Geomorphology and Quaternary Geology, carried out by the Department of Physical Geography, in cooperation with other institutes. Delta Evolution is also the label put on the strategic research cooperation (since 2008) of the group with departments in Deltares Research Institute and TNO Geological Survey of the Netherlands, that have their offices on the Utrecht science campus too. The Delta Evolution program also connects to the network of alumni of Physical Geographers and Quaternary Geologists active in commercial consultancy companies and governmental agencies in the field of water management, hydrology, civil engineering, nature conservation and archaeology in The Netherlands and to colleagues at other universities - with whom we collaborate in shared projects. Our research and networks extend to deltas internationally - see the pages of the Future Deltas focus area for example. 

The Netherlands and the Rhine-Meuse delta in it are strongholds for our research. Our scientific research treats this delta as the mega-case, to draw smaller cases from - and to compare with other delta systems (other mega-cases) to test and validate what part of our insights are delta-specific and what is generic. The lowlands that the program focuses on include: delta plains, coastal plains, larger river valleys, peat wetlands, lagoon and fenlands and so on. These areas connect to upstream catchments and coastal marine systems downstream. Besides holding sedimentary and geomorphic record of their dynamic formation (lowland genesis, natural and human impacts thereon), the lowlands are also archives that recorded change of the upstream catchment (size of floods and amounts of sediment received), the coastal system (transgression, tides, barrier coasts, storms), the climate system (storms, precipitation, temperature), the biological system (vegetation and fauna, aquatic, riparian, terrestrial), the deeper earth (neoteconics, glaciohydro-isostasy), and archeological history (finds, sites, use of landscape). This feeds interdisciplinary and multidisciplinary research. Also, the better the build-up, making-of and age of the lowlands is understood (data integration, synthesis), the better the archives and science based on becomes (duplication, cross-validation, stacking). This is a main reason to carry-over mapping and dating knowledge from individual projects to Delta Evolution's living datasets, that in turn feed into new projects.

Delta Evolution as an umbrella programma, bundles series of PhD/Postdoc projects and contract-research projects and includes long-term dataset management from and between these projects. Goals in Delta Evolution at present are:

1. Perform novel scientific research in Geomorphology and Quaternary Geology of lowland areas,

• by using and expanding the present datasets (already huge and of high quality) and knowledge (from several disciplines), 
• by exploring the limits of our process-understanding and innovate the techniques of modelling geomorphology to cover longer timescales (1000-100,000 years), 
• by pushing the resolution and accuracy of our mapping and dating, and innovate the techniques that combine these (GIS palaeogeography, 3D/4D geomodelling),
• by striving to time-slice the evolution of deltas and quantify rates of morphological, sedimentary and hydrological change as they were changing over time (thus documenting shifts in controls)
• by addressing research questions on the delta system at nested spatial, temporal and functional scales (whole delta, individual branches and swamps, fluvial vs. tidal affected reaches, human-impacted, semi-natural, natural parts of the system's suites of environments and processes; transgressive vs high-stand periods).
• by combining new-collected data from field- and lab work with existing data, statistical analysis and physical numerical modelling.

2.  Synchronize the academic delta research with applied research activities

• by valorizing new scientific insights early on in national mapping projects and geological/geotechnical/geohydrological advice.
• by making early use of data-collection opportunities arising from larger infrastructural projects in the Netherlands delta, in academic research.
• by topping up scientific research with contract-research and vice-versa: have exchange of input data, syncing the interpretation, and reviewing the data output.
• by releasing high-quality data-sets and update these from time to time: take-in, monitoring and review of applied and academic research results from 3rd parties.
• by taking up advisory roles, if possible in early stages, in projects that demand geological-geomorphological  information for plannig and decision making.
• by connecting the Delta Evolution research output to internationally actual themes such as: global change, sustainability, climate change, sea-level change and land subsidence, delta urbanisation, environmental pressure, groundwater demand, hydrocarbon demand, ecological demand, interdisciplinarity science demand. See the pages of the Future Deltas focus area for examples. 

• dr. Kim Cohen
• prof. dr. Esther Stouthamer
• prof. dr. Hans Middelkoop
• dr. Gilles Erkens
• dr. Tim Winkels
• prof. dr. Maarten Kleinhans
• drs. Marjolein Gouw-Bouman
• dr. Ad van der Spek
• dr. Marcel van der Perk
• dr. Teun van Woerkom MSc
• Bas Knaake MSc
• J.I.M. (Jelle) Moree MSc

• Deltares
• TNO Geologische Dienst Nederland
• Rijksdienst Cultureel Erfgoed
• VU Amsterdam