Sediment dynamics and channel adjustments following a torrential flood in a small catchment: Gemenea, Eastern Carpathians

Detection of soil pipe network by electromagnetic induction (EMI) in relation to the high resolution UAV data

10.5194/egusphere-egu21-3399 ◽

2021 ◽

Author(s):

Anita Bernatek-Jakiel ◽

Marta Kondracka ◽

Maciej Liro

Keyword(s):

Electrical Conductivity ◽

High Resolution ◽

Electromagnetic Induction ◽

Geophysical Methods ◽

Ground Surface ◽

Degradation Process ◽

Receiver Coil ◽

Small Catchment ◽

Eastern Carpathians ◽

Soil Piping

Subsurface erosion by soil piping is a widespread land degradation process that occurs in different soil types around the world. Recent studies have shown that piping erosion may lead to the significant soil loss and disturbances of ground surface. This process accelerates also gully erosion. However, it is still omitted in hydrological models of a catchment, as well as in soil and water erosion models. It seems that the main problem in soil piping studies lies on the basic issue, i.e., the detection of subsurface tunnels (soil pipes). As geophysical methods enable the exploration below the ground surface, they are promising in soil piping studies.&#160;This study aims to evaluate the suitability of the electromagnetic induction (EMI) to detect subsurface network of soil pipes. The detailed study was conducted in the small catchment (Cisowiec) in the Bieszczady Mts. (the Eastern Carpathians, SE Poland), where pipes develop in Cambisols. The measurements were carried out using a conductivity meter EM38-MK2 (Geonics) in both vertical and horizontal measuring dipole orientations. The EM38-MK2 provided simultaneous measurements of apparent electrical conductivity with two transmitter receiver coil separation (0.5 m and 1 m). In order to compare subsurface data with the surface response (i.e., depressions and collapses), the high resolution DEM and orthophotos have been produced. These data have been prepared using Structure from Motion (SfM) technique based on the images taken from the low altitude by an Unmanned Aerial Vehicle (UAV; DJI Phantom-4 equipped with a 1' camera). The UAV-derived products (orthophotos and DEM) have the resolution of 0.014 x 0.014 m and point density of 9240 per 1 m2.&#160;The EMI results are presented on the maps that gathered data at three depths (0.4 m, 0.75 m, 1.5 m). The results revealed the soil pipes as areas characterized by higher electrical conductivity than the surroundings. The spatial distribution of subsurface tunnels corresponds with the ground depressions and collapses detected in the field and seen on the high resolution DEM and orthophoto. The use of EMI in piping research has been evaluated.&#160;The study is supported by the National Science Centre, Poland within the first author&#8217;s project SONATINA 1 (2017/24/C/ST10/00114).

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Sediment Dynamics and Channel Adjustments Following Torrential Floods in an Upper Alpine Valley (Guil River, Southern French Alps)

Engineering Geology for Society and Territory - Volume 3 ◽

10.1007/978-3-319-09054-2_65 ◽

2014 ◽

pp. 313-317 ◽

Cited By ~ 1

Author(s):

Monique Fort ◽

Gilles Arnaud-Fassetta ◽

Bétard François ◽

Etienne Cossart ◽

Malika Madelin ◽

...

Keyword(s):

Sediment Dynamics ◽

Alpine Valley ◽

French Alps ◽

Channel Adjustments

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Implementation of runoff attenuation features into a landscape evolution model for the assessment of the impact on catchment sediment dynamics

10.5194/egusphere-egu2020-5008 ◽

2020 ◽

Author(s):

Eleanor Pearson ◽

Jonathan Carrivick ◽

Rob Lamb

Keyword(s):

Landscape Evolution ◽

Water Storage ◽

Flood Management ◽

Sediment Dynamics ◽

Evolution Model ◽

Small Catchment ◽

Management Schemes ◽

The Impact ◽

Grazing Livestock ◽

Over Time

Runoff attenuation features such as bunds and leaky barriers&#160;are increasingly incorporated into catchment flood management schemes. However, with any structure resulting in a barrier to flow, sediment dynamics are also affected, which will in turn affect the feature&#8217;s hydraulic effectiveness over time. The geomorphological impact of these features is often overlooked. This work looks at using the CAESAR-Lisflood landscape evolution model to assess how to implement runoff attenuation features into a catchment and evaluate their corresponding impact on sediment dynamics and subsequent change to water storage efficacy. The simulations were based on a small catchment, situated south of the Yorkshire Dales, UK, where the land is primarily used for grazing livestock. Features were implemented through the editing of the underlying topography&#160;allowing features to be fully erodible and scenarios were created based on feature shape, size and quantity. Of the features implemented, there was no unified response to the flood event simulated. Generally, many of the features themselves were affected by erosion, reducing their ability to hold water over time. Fewer features experienced deposition upstream compared to those experiencing erosion, which may suggest scour as opposed to sedimentation as a management issue that would need to be monitored. Nonetheless, the model scenarios run permitted an optimal design and layout of runoff attenuation features within the catchment to be established.

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