# Near-surface geophysical and sedimentological analyses for the lower havel inner delta - a dataset of the floodplain lithostratigraphy

## TL;DR

This paper presents a detailed geophysical and sedimentological dataset from the Lower Havel River Inner Delta to study floodplain sediment layers and support environmental restoration.

## Contribution

The novel contribution is a high-resolution, multi-method dataset combining geophysical and sedimentological data for floodplain lithostratigraphy analysis.

## Key findings

- The dataset characterizes near-subsurface sedimentary architecture and composition across multiple spatial scales.
- Geophysical and core drilling data reveal the vertical and lateral extent of peat, clayey, sandy alluvial units, and glaciofluvial sediments.
- The data support palaeochannel reconstruction and floodplain modeling for environmental and geomorphological studies.

## Abstract

Floodplains are dynamic and sensitive landscapes, shaped by natural hydromorphological processes and centuries of human intervention. Understanding floodplain lithostratigraphy is essential for reconstructing environmental change and supporting floodplain restoration and management. Here, we present a multi-method, high-resolution dataset from the Lower Havel River Inner Delta in Brandenburg (Northeast Germany), combining electromagnetic induction (EMI), electrical resistivity tomography (ERT), and driving core drilling data to characterise near-subsurface sedimentary architecture and sediment composition across multiple spatial scales.

EMI measurements (n ≈ 230,000) were conducted across two areas of 120,000 m² and 77,800 m² using a portable three-coil system (CMD-Mini Explorer, GF Instruments) with vertical dipole configuration and coil spacings of 32 cm, 71 cm, and 118 cm. These provided depth-resolved apparent electrical conductivity (ECa) values. Complementary ERT transects (total length: 928 m) were acquired using a multi-electrode DC resistivity system (Resecs, GeoServe) in wenner alpha and dipole-dipole configurations, generating high-resolution resistivity models. EMI and ERT were applied in combination to enable the extrapolation of transect-based geophysical data into spatially continuous models.

To ground-truth the geophysical results, 21 sediment driving core drillings were extracted with a percussion corer (Cobra Pro, Atlas Copco), described in the field (including Munsell colour, grain size, redox features, carbonate and humus content), and analysed in the lab for content of total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN) and total sulfur (TS) and grain size using sieving and X-ray granulometry. The data provide insight into the vertical and lateral extent of peat, clayey and sandy alluvial units, and glaciofluvial basal sediments. All geophysical and lithological data are georeferenced and made available as raw and processed formats.

This comprehensive dataset supports palaeochannel reconstruction, floodplain stratigraphic modelling, and landscape-scale sediment analysis. It is of high relevance to researchers in geomorphology, wetland ecology, soil science, and environmental reconstruction. Moreover, it provides a valuable baseline for long-term monitoring and restoration planning in Central European lowland river systems.