Soil erosion has been traditionally divided into surface (sheet, rill, and gully erosion) and subsurface erosion (soil piping). Rills and gullies concentrate overland flow, whereas soil pipes concentrate subsurface flow, leading to a significantly increased flow erosivity. These forms of concentrated flow erosion, both above and below ground, represent an important sediment source within watersheds and produce sizeable economic losses (e.g. reduced crop yields, reservoir sedimentation, mass failures including landslides and embankment failures). These processes occur in almost all climatic zones, soil types, and land use conditions suggesting a great variability of controlling factors. Moreover, soil pipes, rills and gullies are effective links for transferring water, sediment and pollutants. Despite their relevance, the physical mechanisms that constitute concentrated flow erosion remain poorly understood.
This session aims to address this research gap and will focus on recent studies aiming to better understand the process of rill, piping and gully erosion, with the ultimate aim of developing predictive tools and effective management strategies. As such we welcome contributions on: monitoring and measurement techniques; the factors and processes controlling rill, piping and gully erosion; modelling approaches; prevention, restoration and control measuress; and the role of soil pipes, rills and gullies in hydrological and sediment connectivity.

In many parts of the world, agriculture is threatened by climate change and land degradation in the form of soil erosion. Soil erosion involves the loss of fertile topsoil and reduction of soil productivity, as well as increased mobilization of sediment and delivery to rivers. Sedimentation of water bodies is especially problematic in arid regions where water scarcity is frequent. Furthermore, the dynamics of soil erosion and deposition processes substantially affects the redistribution of soil carbon in the landscapes. Despite being a significant risk to soil and water resources, soil erosion is an overlooked threat, especially in terms of climate change due to increased soil carbon emissions. Considerable discussion still exists about whether erosion results in enhanced emissions of carbon to the atmosphere (C source) or enhanced sequestration of carbon in the soil (C sink). More scientific information is essential to assess the role and impact of soil erosion on the terrestrial carbon budget, highlighting the effect of topography, soil type, land use/land cover and soil management. Another question of importance is the “intra-storage” of mobilized soil and carbon along the hillslopes and in different compartments within catchments. Driving factors of soil carbon distribution and the role of sediment connectivity across the landscape induced by erosion remain largely unknown. This session combines contributions on soil erosion and soil carbon at hillslope, small or large catchment scale in different agroecosystems, including both agricultural and forestry landscapes, using a diverse set of tools and data analyses such as field measurements, monitoring techniques, remotely sensed and GIS analyses, modelling, isotopic and non-isotopic erosion tracers, fingerprinting techniques, among others. Let’s come together and share findings, views and concepts to better understand soil erosion processes and its effect on the landscape-scale distribution of soil carbon.

Public information:
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PROGRAM online Chat

16:15
WELCOME to SSS2.5 online chat by conveners

16:17 (Chairperson: Leticia Gaspar)
D2148 | EGU2020-5833
Soil Organic Carbon Distribution and Isotope Composition Response to Erosion in Cropland under Soybean/Maize Production
Greg McCarty, Xia Li

16:27 (Chairperson: Leticia Gaspar)
D2149 | EGU2020-11147
Visual assessments and model estimations of soil erosion and relations to soil organic carbon
Hakan Djuma, Adriana Bruggeman, Marinos Eliades

16:37 (Chairperson: Jay Le Roux)
D2150 | EGU2020-3947
Soil erosion and sediment transport in South Africa: an overview
John Boardman, Ian Foster

16:47 (Chairperson: Jay Le Roux)
D2151 | EGU2020-8802
South Africa’s agricultural dust sources and events from the MSG SEVIRI record
Frank Eckardt, Johanna Von Holdt, Nickolaus Kuhn, Anthony Palmer, Jonathan Murray

16:57 (Chairperson: Jay Le Roux)
D2152 | EGU2020-3913
Determining Sub-Catchment Contributions to the Suspended Sediment load of the Tsitsa River,
Eastern Cape, South Africa
Laura Bannatyne, Ian Foster, Ian Meiklejohn, Bennie van der Waal

17:07 (Chairperson: Jay Le Roux)
D2153 | EGU2020-1186
Gully Initiation on the Quartzite Ridges of Ibadan, South West, Nigeria
Olutoyin Fashae, Rotimi Obateru, Adeyemi Olusola

17:17 (Chairperson: Lionel Mabit)
D2156 | EGU2020-494
Are human activities main drivers of soil organic carbon losses in mountain rainfed agroecosystems?
Ivan Lizaga, Leticia Gaspar, Laura Quijano, Maria Concepción Ramos, Ana Navas

17:27 (Chairperson: José Alfonso Gómez)
D2160 | EGU2020-17676
Lateral transport of SOC induced by water erosion in a Spanish agroecosystem
Leticia Gaspar, Lionel Mabit, Ivan Lizaga, Ana Navas

17:37 (Chairperson: Iván Lizaga)
D2163 | EGU2020-10027
Erosion and sediment enrichment ratio in volcanic soils
Ludmila La Manna, César Mario Rostagno, Manuela Tarabini, Federico Gomez, Ana Navas

17:47 (Chairperson: Jay Le Roux)
D2166 | EGU2020-2228
Quantitative assessment of gully erosion dynamics using a GIS implementation of Sidorchuks' DYNGUL model in Southern KwaZulu-Natal, South Africa
Adel omran, Dietrich Schroeder, Christian Sommer, Volker Hochschild, Aleksey Sidorchuk, Michael Maerker

17:57
GENERAL DISCUSSION

18:00
CLOSING SSS2.5 online chat by conveners

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The quantification and understanding of hydrological, erosive, and biogeochemical processes in catchments are essential to the sustainable management of water and soil resources. Soil-erosion studies and hydrological simulation models comprise a large range of scopes and objects of investigation with different levels of spatial and temporal scales and/or innovative approaches that are important tools to address environmental problems in a cost-effective way. Thus, for example, analyses may range from absence-presence inventories of erosion features in large areas, -such as badlands-, to detailed studies of rill and ephemeral gullies; or focus on the assessment of the overall expansion of permanent gullies and their evolution; characterization of headcut migration; or identification of downstream deposition areas after intense sheet/rill erosion; among others. Assessment of the environmental impact of economic activities in catchments should be based on the acquisition of experimental data to implement and/or to evaluate conservation practices at different scales. However, monitoring systems can be restricted by technological, economic and legal factors, spatial and temporal sampling strategies and availability, and are rarely conceived in the long term.
Remote sensing is increasingly being utilized to address a plethora of hydrological and soil erosion issues, providing highly valuable information both on surface reflection and surface heights. In fact, the continued improvement of remote sensing techniques has allowed the study of a large range of erosive processes at varying spatial and temporal scales. More sensitive and accurate sensors are available every day. In addition, the frequency of observations is rapidly increasing and new statistical analysis techniques are increasingly used.
Here, the authors are encouraged to present new environmental challenges related with the use of models, remote sensing techniques and new experiments to address hydrological and erosive issues. In addition to classical modeling procedures such as evaluation of models; new conceptualizations to address current environmental problems facing society, tools and techniques aimed to conserve water, soil and nutrients, and evaluate degradation processes of soil and water as well as analyses concerning the ways and potential of using remote-sensing techniques to assess soil erosion are also expected.

The latest reference document of the United Nations (UN) on the status of global soil resources (FAO & ITPS, The Status of the World’s Soil Resources 2015) stresses that "…the majority of the world’s soil resources are in only fair, poor or very poor condition" and soil erosion is a major threat to soil worldwide. Soil erosion is the detachment and transport of soil particles or aggregates by action of wind, water, and gravity and is responsible for land degradation processes that end in Desertification. High erosion rates results in non-sustainable agriculture production and the need to find expensive solutions via costly governmental policies.

This session will show the State-of-the-Art of the soil erosion processes in agriculture, forest and urban areas. Our main objective is to assess the process but also to find solutions that may help farmers, policy makers and to support the ongoing research activities of the Food and Agriculture Organization of the United Nations (FAO) and the Global Soil Partnership (GSP) on soil national erosion, i.e., the new bottom-up UN Global Soil Erosion Map (GSERmap).

Restoring degraded landscape, managing soil and water resources are important for human well-being. Hillslope management and bioengineering, reforestation, and torrent control work using transverse structures, such as check dams and more recently open check dams, are becoming more common to mitigate soil erosion and torrential hazards. Such techniques are particularly important as they control the flux of water, sediments, nutrients, and other solutes from headwaters to downstream in any watershed management. The design and criteria of the check dams are also facing challenges due to complex hydrological, geological, and biological processes that affect water and sediment transport over a wide range of spatial and temporal scales. However, there are still lack of long term monitoring and sufficient understanding on the effects of soil and water conservation techniques on soil erosion processes, vegetation restoration, and torrential hazards control. Integrated watershed management also becomes increasingly crucial to mitigate the unprecedented impacts of environmental changes (e.g. climate, land-use changes). In this fourth consecutive year of organizing the session during EGU, we welcome studies that focus on soil conservation techniques from hillslopes to watershed scale. Any contributions to the understanding of soil erosion control and sediment transport management based on detailed field monitoring, high-quality laboratory works, mathematic models and effectiveness assessment methods are welcomed. In particular, we propose an approach to join and share scientific and technical studies from all around the world related to the legacy effects of check-dams and the potential of open check dams, highlighting the role of complex interactions between ecological elements, geomorphic processes and engineering activities.

Public information:
Online Chat Schedule

08:30 (14:30 Beijing Time)
WELCOME to SSS2.9 online chat by convener team

08:32 (14:32) (Chairperson: Yang Yu)
D2135 | EGU2020-1236
Influence of Check Dams on Flood and Erosion Dynamic Processes of a Small Watershed in the Loss Plateau
Shuilong Yuan, Guoce Xu, Peng Shi, and Kexin Lu

08:40 (14:40) (Chairperson: Yang Yu and Peng Li)
D2136 | EGU2020-1361
Understorey vegetation drives surface runoff and soil loss in teak plantation-based system of Northern Laos
Layheang Song, Laurie Boithias, Oloth Sengtaheuanghoung, Chantha Oeurng, Christian Valentin, Phabvilay Sounyafong, Anneke de Rouw, Bounsamai Soulileuth, Norbert Silvera, Alain Pierret, and Olivier Ribolzi

08:48 (14:48) (Chairperson: Manuel Esteban Lucas Borja and Peng Li)
D2137 | EGU2020-1690
The Topography Meter: a measurement system applicable for gravity-erosion experiments using a novel 3D surface measuring technique
Xiangzhou Xu, Feilong Xu Xu, Wenzhao Guo, and Chao Zhao

08:56 (14:56) (Chairperson: Manuel Esteban Lucas Borja)
D2138 | EGU2020-2066
Distribution of soil organic carbon impacted by land-use change and check dam on the Loess Plateau of China
Peng Shi, Yan Zhang, Kexin Lu, Zhaohong Feng, and Yang Yu

09:04 (15:04) (Chairperson: Guillaume Piton)
D2140 | EGU2020-4738
Alternative approach for works controlling stony debris flows
Carlo Gregoretti, Matteo Barbini, Martino Bernard, and Mauro Boreggio

09:12 (15:12) (Chairperson: Manuel Esteban Lucas Borja and Peng Li)
D2143 | EGU2020-7441
Soil water flow behavior of abandoned farmland restored with different vegetation communities in the Loess Plateau of China
Rui Wang, Zhengchao Zhou, Ning Wang, Zhijing Xue, and Liguo Cao

09:20 (15:20) (Chairperson: Manuel Esteban Lucas Borja)
D2144 | EGU2020-1388
Plant root exerted a stronger positive effect on aggregate stability than soil during plant secondary succession on the Loess Plateau, China
Lie Xiao and Peng Li

09:28 (15:28) (Chairperson: Demetrio Antonio Zema)
D2145 | EGU2020-737
The magnitude of soil erosion of small catchments with different land use patterns under an extreme rainstorm on the Northern Loess Plateau, China
Nan Wang and Juying Jiao

09:36 (15:36) (Chairperson: Demetrio Antonio Zema)
D2146 | EGU2020-1232
Quantitative assessment of check dam system impacts on catchment hydrological response - a case in the Loess Plateau, China
Tian Wang, Zhanbin Li, Jingming Hou, Shengdong Cheng, Lie Xiao, and Kexin Lu

09:44 (15:44) (Chairperson: Demetrio Antonio Zema)
D2147 | EGU2020-1234
Effects of ecological construction on the transformation of different water types on Loess Plateau, China
Binhua Zhao and Zhanbin Li

09:52 (15:52) (Chairperson: Guillaume Piton and Peng Li)
D2150 | EGU2020-4779
Adaptation of the MMF (Morgan-Morgan-Finney) model to Mediterranean forests subject to wildfire and post-fire rehabilitation measures
Demetrio Antonio Zema, Joao Pedro Nunes, and Manuel Esteban Lucas-Borja

10:00 (16:00) (Chairperson: Guillaume Piton)
D2162 | EGU2020-9921
Check dams effects on plant and soil interface immediately after wildfire
Bruno Timóteo Rodrigues, Manuel Esteban Lucas-Borja, Demetrio Antonio Zema, and Yang Yu

10:08 (16:08) (Chairperson: Guillaume Piton)
D2164 | EGU2020-10009
Are site characteristics and channel hydro-morphology related with check dam functioning? A case study in México
Manuel Esteban Lucas-Borja, Bruno Gianmarco Carrà, Demetrio Antonio Zema, and Yang Yu

10:20 (16:20) A brief conclusion and closing SSS2.9 online chat by conveners
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The chat SSS2.9 will be available on 05 May, 08:30–10:15 (14:30-16:15, Beijing Time)

Land cover plays a key role for geomorphic processes in steep-land environments. It exhibits both beneficial and adverse effects on hillslope denudation and substantially influences landscape evolution. Land cover information becomes of fundamental importance in many applications for assessing soil erosion loss and landslide activity at difference scales, from local to global analysis. Apparent land cover of a landscape affects the accuracy of most investigations that aim to detect, observe, analyse, model or predict geomorphic and landform-shaping processes. In contrast, denudational processes have a strong impact on both natural ecosystems and cultivated land, leading from increasing environmental diversity to economic damages.
This session is designed to cluster the most recent scientific researches on the analyses, modelling and prediction of soil erosion and landslide processes that are directly linked to land cover dynamics. Such variations can alter the soil properties as soil reinforcement and soil aggregation, and make the modelling and prediction of higher complexity.
Studies that pay heed on the impact of land cover changes on shallow or deep-seated and transient or long-term slope instabilities as well as surface water flow and related soil erosion processes are welcome. Research abstracts are invited to address:
1. observation and detection of different land cover types, land use changes and occurrences of erosion or landslides using a wide spectrum of technologies, from field measurements to remote sensing techniques;
2. analyses on the relationship between land cover and geomorphic processes from local to regional scale;
3. prediction of impacts on surface water flow, erosion and slope stability due to land cover changes;
4. innovative modelling approaches for assessing soil instabilities (statistical, physically-based, numerical) that focus on model implementation, parameterisation, uncertainties and simulation of land cover evolution;
5. development of guidelines and regulations for practitioners, technicians, policy and decision makers.
We highly welcome pioneering research from all fields, especially from geomorphology, agricultural science, soil science, geotechnics and environmental engineering. In particular, young career scientists are encouraged to contribute to the session with original and advanced studies.

Climate change (CC) is expected affecting weather forcing regulating the triggering, reactivation, and severity of slope failures and soil erosion. In this view, the influence of CC can be different according to the area, the time horizon of interest and to the specific trends of weather variables. Similarly, land use/cover change can play a pivotal role in exacerbating or reducing such hazards.
Thus, the overall impacts depend on the region, spatial scale, time frame and socio-economic context addressed. However, even the simple identification of the weather patterns regulating the occurrence of such phenomena represents a not trivial issue, also assuming steady conditions, due to the crucial role played by geomorphological details. To support hazards’ monitoring, predictions and projections, last-generation and updated datasets with high spatio-temporal resolution and quality - like those from the Copernicus Services’ Portals - are useful to feed models, big-data analytics and indicators’ frameworks enabling timely, robust and efficient decision making.
The Session aims at presenting studies concerning ongoing to future landslide dynamics and soil erosion hazards across different geographical contexts and scales (from slope to regional, to global scale) including analyses of historical records and related climate variables, or modeling approaches driven by future climate exploiting downscaled output of climate projections. Studies assessing variations in severity, frequency and/or timing of events and consequent risks are valuable. Finally, tested or designed adaptation strategies can be discussed.