ICG2022-17

ICG2022
Applied Geomorphology 

Although there is naturally an overlap between Applied Geomorphology and many of the more specific thematic sessions of the Conference, in this one we intend to discuss general aspects of Applied Geomorphology with particular emphasis on the application of geomorphological techniques and analyses to the solution of planning, territorial and environmental management or engineering problems, what involves tasks of cartography, terrain analysis and monitoring of geomorphological dynamics relevant to decision-making processes. Thus, the presentation and discussion of works on the following topics, among others, is encouraged:
i. Cartography for geomorphological application;
ii. Ecosystem based disaster risk reduction;
iii. River and floodplain restoration;
iv. Seismic geomorphology for hydrocarbon exploration;
v. Morphostructures and environmental sensitivity;
vi. Building mining river diversions;
vii. Flood management and planning.

Conveners: Olav Slaymaker, Sumiko Kubo, Antonio Guerra, Virgínia Teles
Orals
| Tue, 13 Sep, 09:00–10:30|Room Sala Aeminium-C1A (b)
Poster
| Attendance Tue, 13 Sep, 10:45–11:00 | Display Mon, 12 Sep, 09:00–Tue, 13 Sep, 19:00|Poster area

Orals: Tue, 13 Sep | Room Sala Aeminium-C1A (b)

Chairpersons: Olav Slaymaker, Sumiko Kubo, Virgínia Teles
09:00–09:15
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ICG2022-532
Archana Raje

Water is essential for life on earth. It is unequally distributed over the earth surface. Water scarcity occurrs due to both natural as well as anthropogenic causes. One of the major regions behind water scarcity is that its demand has increased twice than earlier as the population growing exponentially. Some of the major causes of water  scarcity are over use of water, pollution of water, drought, ground water pollution. Some problems arise because of water scarcity like lack of access to drinking water, diseases, sanitation issues, distruction of habitats. This paper is an attempt to investigate the causes and consequnces of water crisis. The data for present analysis have been obtained form secondary sources and various agencies. The main objective of the present paper is to attempt evaluation of the water resources. Study reveals that water is rapidly becoming scarce resource in India because the demand of water is increasing due to pressure of population and changing consumption pattern. For instance, in some parts of the study area, there is evidence of progressive declined in the water table due to over pumping by the tubewells. The situation is getting alrming year after year. These problems can be solved conjunctive use of surface and ground water. There is urgent need for the development of surface water irrigation where ground water utilization is high.

How to cite: Raje, A.: Water Crisis in India : An Overview, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-532, https://doi.org/10.5194/icg2022-532, 2022.

09:15–09:30
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ICG2022-181
Ian D. Rutherfurd, Thom Gower, James Grove, Christine Arrowsmith, Geoff Vietz, Ben Dyer, and Alex Sims

The River Murray is Australia’s largest and most important river.  It carries water for irrigation and city supply from the mountains in the east, semi-arid west.  The river crosses a series of low-angle alluvial fans (distributive fluvial systems) in its 1500 km path.  The Barmah Choke is a narrow section of the River Murray’s channel, formed by a Holocene river avulsion, that restricts flow capacity from the upper to lower Murray River.  The flow capacity of the Choke has declined nearly 20% since the 1980s, which imposes a constraint on regulated flows supplied down-valley, and is constraining economic development downstream.  Whilst there could be multiple geomorphic factors explaining the decline, we demonstrate that the most likely cause is a sheet of coarse sand shallowing the river, much of which originated from historical gold mining and catchment erosion in late 1800s.  The sheet of sand is reducing depth diversity, filling pools up to 5m deep, and degrading the ecological and cultural values of the river.  The whole length of the river through the Barmah Forest has shallowed over the last 30 years, aggrading by 1.9 m at the upstream end and 0.70 m in the most downstream section of the Choke (about 10% decrease in area).  The total volume of sand stored between Yarrawonga and Barmah is over 20 million m3, and the average total annual sand load transported into the 82km long Choke ranges between 130,000 m3 in a normal flow year to 500,000 m3 in a flood year (which translates into 2 – 9 cm of aggradation per year).  Surprisingly, overall, long-duration regulated irrigation flows have decreased the rate of sand transport through the Choke.  Decreasing downstream flow capacity across the Barmah Fan is a natural characteristic of this type of distributive fluvial system, but the sand sheet is accelerating the rate of decline.  Without intervention, conveyance through the Choke will inevitably continue to decline until the river avulses into a new channel.  A range of solutions are explored, but all are extremely expensive. 

How to cite: Rutherfurd, I. D., Gower, T., Grove, J., Arrowsmith, C., Vietz, G., Dyer, B., and Sims, A.: How human impacts on geomorphology echo through the centuries: explaining the declining flow capacity in Australia's most important river, the Murray.    , 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-181, https://doi.org/10.5194/icg2022-181, 2022.

09:30–09:45
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ICG2022-252
Marisa Matos Fierz

 

The present work aims to deepen and discuss the weaknesses of coastal soils in the face of contamination by dumps. Although the dumps were suspended, important areas remained that were contaminated. However, as it is an area that was much explored in more remote times, it is being recovered and with possibilities of urban uses, or even for recovery for use in leisure. Bearing in mind that coastal areas are very important for the economy of the cities located in areas them, mainly because they involve transition areas from coastal to marine environments and many of them may have a geomorphological configuration favorable to ports of flow of national production or receipt of products imported - via ocean. In order to know how the areas contaminated by dumps are being recovered in an environment even more fragile by the genetic characteristics of its soils, waters, relief and landscape, as well as by the dynamic processes arising from the continent, the sea and the atmosphere by the climate. With a case study, we seek to analyze the possibilities of better use in the management of these areas that were once contaminated by dumps and analyze the geomorphological compartmentalization and resilience of this fragile environment. And also describe the methods and techniques applied in these areas for their revitalization.

How to cite: Fierz, M. M.: The Environmental Fragility of The Coastal Area of ​​São Paulo In The Face of Contamination By Landfill: Contribution to the Possibilities of (Management) Decontamination and Reuse., 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-252, https://doi.org/10.5194/icg2022-252, 2022.

09:45–10:00
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ICG2022-613
Mukta Raje

Evaluation of Changes in landuse due to anthropogenic activities in highly urbanized flood plain of Prayagraj city, Uttar Pradesh, India

                                                                                                                  Dr Mukta Raje – Associate Professor , SPG college Mihrawan,  Jaunpur, Uttar Pradesh , India

 

 

Urban settlement along the river Ganga with in Prayagraj city is prevalent since ancient time. Present scenario,both natural landscape as well as cultural settlement are the consequence of centuries long anthropogenic activities. Present study aims to understand the trend in landuse changes from 2000 to 2020 in this highly urbanized flood plain and its relation to geomorphology and anthropogenic activities. The  study adopts a relatively new approach to identify site specific condition for characterizing the landuse changes over a certain region of Ganga Yamuna Doab. The study indicates the best possible landuse conditions for better management and reduction in geo hydrological risk by suggested preventive measures. The research also indicates many landuse variations caused by socio-economic changes.

 

How to cite: Raje, M.: Evaluating Landuse Changes due to Anthropogenic Activities in Highly Urbanized Flood Plain of Prayagraj city, Uttar Pradesh India, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-613, https://doi.org/10.5194/icg2022-613, 2022.

10:00–10:15
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ICG2022-646
Isabel Paiva, Pedro Pinto dos Santos, João Pardal, Lucio Cunha, and Alexandre Tavares

The geomorphological and geological characteristics of karst regions are very specific and complex, affecting the hydrological processes significantly. Due to the enormous heterogeneity and non-linearity of karst terrains, the hydrodynamic functioning of karst watersheds considerably differs from non-karst watersheds. Quantifying and understanding the influence of these watershed characteristics in the hydrodynamics of karst and non-karst areas is crucial for managing water resources and extreme hydrological episodes, particularly in the present scenario of hydroclimatic variability and uncertainty.

The present study establishes a comparison between two watersheds: (i) a karst basin (Anços) composed of Middle Jurassic karstified limestones, dominated by a rough plateau that promotes the infiltration, and (i) a non-karst basin (Arunca) characterized by Upper Jurassic and Cretaceous marly limestones, and Cenozoic thick mudstones deposits (low permeability promoting surface runoff). The rivers' water level was logged every 20 minutes by a gauge station from 2010 to 2020, and the rainfall was also registered for the same period.

The objectives of this study are (i) to examine, from a quantitative perspective, the influence of geomorphological and geological characteristics on the runoff coefficient using statistical analysis; (ii) to quantify the rainfall-runoff lag time and the recession coefficients from the analysis of storm hydrographs simultaneously in both watersheds; (iii) to deepen the knowledge about the behavior of each watershed in flood episodes through hydrological simulation.

The results showed that geomorphological and geological watershed characteristics play an essential role in the hydrodynamic functioning of the Anços and Arunca watersheds. Furthermore, the outcomes of this study revealed a pronounced contrast between the two watersheds in the reaction to rainfall and mainly in the first stage of the recession limb. It should be highlighted that the non-karst watershed presents a faster and more extreme hydrological behavior expressed in a peak hydrograph. On the reverse, the karst watershed demonstrated a higher storage capacity, revealed by the shape of the recession curve.

How to cite: Paiva, I., Pinto dos Santos, P., Pardal, J., Cunha, L., and Tavares, A.: Geomorphology and lithology as factors influencing hydrological dynamics. Comparative analysis of karst vs. non-karst watersheds in the central-western region of Portugal, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-646, https://doi.org/10.5194/icg2022-646, 2022.

10:15–10:30
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ICG2022-728
Rajib Kumar Saha

Khagrachari and Mohalchari Upazilas (sub-district) of the Khagrachari hill district are located and characterized by a series of parallel hills that tend to be NNW-SSE, situated in the central part of the eastern fold belt of Bangladesh. The central part of the hills features a series of medium high mountains, including the mysterious Alutila cave of Matiranga area of Khagrachari A cave formed in an around 1000 m high hill named as Alutila (potato hill) or Arbari hill. A vast network of streams and valleys flows down the slopes of the hills and represents a well-developed drainage system in the study area. The drainage system in the study area possess dendritic pattern. The Chengi River of the study area is running almost E-W trend cutting across the hill ranges of Khagracahri. There are also a large number of streams (chara or chari in local term) and large lake named ‘Mataipukhiri (Debota Pukur)’ which was naturally formed above 491 msl. The surficial deposit in the study area has been divided into: Dihing Formation, Undivided Dihing and Dupitila Formation, Dupitila Formation, Girujan Clay Formation, Tipam Sandstone Formation, Bokabil Formation and Bhuban Formation. According to laboratory analysis, Dihing sandstone is composed of very fine to medium-sized sand and is poorly sorted. Dupitila sandstone is composed of medium to fine sand and is moderately sorted. Tipam sandstone layer consisting of fine sand. Bokabil sandstones range from fine sands to very fine sand. Various types of sedimentary structures have been observed for example, cross-stratification, cross-lamination, wavy stratification, clay gall, calculus and nodular structure. The concentration of heavy minerals in the sedimentary rocks of the Khagrachari and Mohalchari areas are not significant. However, the heavy mineral concentration gradually increases from the Ding Formation (1.74 to 2.14)%, the Dupitila Formation (1.81 to 2.67)%, the Tipam Formation (1.55 to 3.92)%, and the Bokabil Formation (3.58 to 4.01)%. The identified minerals are quartz, muscovite, biotite, augite, hornblende, garnet, epidote, rutile, tourmaline, actinolite, tremolite, zircon, monazite, kyanite, sillimanite, apatite and other opaque minerals. The analyzed samples have very high abundance of augite, hornblende, and kyanite. The presence of white clay and glass sand has been investigated at Manikchari area in the Kagrachari hill area. The results of the chemical analysis show the percentages of SiO2 (63.4-82.0)%, Al2O3(5.78-18.51)%, Fe2O3(0.45-17.93)%, Na2O (0.160.80)%, K2O (0.403.24)%, MnO is (0.162)%, CaO is (0.03-0.93)%, and ignition loss is (1.60-7.58)%. The existence of quartz sand (silica enriched) and white clay had also been confirmed adjacent to the surveyed area. Investigations of lithology, minor sedimentary structures and grain size parameters infers that the overall paleoenvironment was a transition from shallow waters condition prevailed during the early sedimentation phase of the area.

How to cite: Saha, R. K.: Geomorphic and Sedimentological Evolution of Khagrachari-Mahalchari hills of Bangladesh, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-728, https://doi.org/10.5194/icg2022-728, 2022.

Display time: Mon, 12 Sep 09:00–Tue, 13 Sep 19:00

Poster: Tue, 13 Sep, 10:45–11:00 | Poster area

Chairpersons: Olav Slaymaker, Sumiko Kubo, Virgínia Teles
P83
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ICG2022-14
Ulises Rodrigo Magdalena, Juan Pablo Zbrun Luoni, Guillermo Ribeiro, and Raul Reis Amorim

Advances in the access and processing of morphometric data from Remote Sensing and associated with the computational progress in terms of data storage and optimization through computational algorithms allow us to determine the boundaries of the geomorphological units demarcated by conventional procedures, enabling the exploration of hypotheses on landscape dynamics. Thus, this manuscript aims to delimit the geomorphological units of the Northwest of the San Luis Province - Argentina, through the Geological Chart 3366-II Villa de Merlo, of the National Program of Geological Charts of the Argentine Republic of the Servicio Geológico Minero Argentino (SEGEMAR). We used the random forest algorithm in this manuscript. We concluded that the results sometimes generalize the geomorphological units bounded by conventional methods. Still, in other cases, these boundaries get refined and allow us to explore the hypothesis of the subdivision of the “Piedemonte Occidental” Unit into “Piedemonte Superior” and “Piedemonte Inferior”. Furthermore, the results point out the shortcomings of the random forest presented as a black-box and eventually overestimate some geomorphological units in incorrect regions. However, this algorithm is still an important support tool for interpreting landscape dynamics.

KEYWORDS: geomorphology, random forest, landscape, spatial planning, digital cartography, remote sensing.

How to cite: Magdalena, U. R., Luoni, J. P. Z., Ribeiro, G., and Amorim, R. R.: Machine learning-based identification of the geomorphological units of the Northeastern sector of the San Luis Province - Argentina, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-14, https://doi.org/10.5194/icg2022-14, 2022.

P84
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ICG2022-38
Helen Cristina Dias, Daniel Hölbling, and Carlos Henrique Grohmann

Shallow landslide recognition and mapping are essential for susceptibility, vulnerability, and risk assessment. Efficient mapping approaches can be used to identify source, transport, and deposition areas and enable the creation of geomorphological, seasonal, and event-based inventories. In Brazil, landslides are a frequent natural hazard that occurs every year, mostly in the summer season (Dec-Mar). Despite their frequency, no guidelines or common procedures for landslide mapping exist. The application of new methods for recognition and mapping may improve the creation of standards for landslide inventory mapping and the enhancement of consistent landslide databases in Brazil. Manual, semi-automated, and automated methods are commonly used to identify hazards worldwide, with remote sensing and geomorphological information being the primary data for landslide mapping. Object-based image analysis (OBIA) is a well-established method for mapping natural hazards and geomorphological features. Although several studies have demonstrated the applicability of OBIA for landslide mapping in various environments, its application for landslide mapping in tropical environments in Brazil is still incipient. In 2014, the city of Itaóca (São Paulo state, Brazil) was affected by a high-magnitude mass movement event responsible for infrastructure damages and deaths. The aim of this study is to identify rainfall-induced shallow landslides using the OBIA method in the Gurutuba watershed (area of 4,5 km²), Itaóca. The recognition and mapping were performed using a RapidEye satellite image (5 m), dated 2014/01/30, in eCognition 10.0 (Trimble) software. The OBIA classification process considers spectral, spatial, contextual, and hierarchical information. Preliminary analysis indicated promising results and good applicability of the OBIA method. Many shallow landslide scars were identified, whereby large scars were more easily recognized by the method than small ones. The mapping accuracy was assessed by comparison to a reference dataset, which was created by visual interpretation of the RapidEye image. However, more research is needed to increase the transferability of the approach to allow the analysis of a more complex and larger area.

 

How to cite: Dias, H. C., Hölbling, D., and Grohmann, C. H.: Recognition of shallow landslides using object-based image analysis: preliminary results in the Gurutuba watershed, Brazil, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-38, https://doi.org/10.5194/icg2022-38, 2022.

P85
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ICG2022-45
Reverse Landscaping – A proposal for reconstructing the disappearing landscapes through a multi-disciplinary approach
(withdrawn)
Mk Rafeeque, Mk Sreeraj, Tr Anoop, and Sheela Nair
P86
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ICG2022-235
Elena Fernandez-Iglesias, Rosana Menendez-Duarte, and Gil Gonzalez-Rodriguez

Erosion and deposition processes produce morphological forms over the channel and floodplains. Those forms depend on flow characteristics such as high velocity and deep water. By taking into account geomorphological criteria, the floodplain area presenting erosive and sedimentary morphologies is called Preferential Flow Area (ZFP). The ZFP was defined in the modification of the Hydraulic Public Domain Regulation (Royal Decree 9/2008, 11 January) and it is one of the units identified in the Spanish Flooding Zone Mapping System (SNCZI). The relationship between flood deposits and water flood deep is usually simulated by using physical models and hydraulic modelling. Nevertheless, there is little knowledge about the true relation by using field survey data. In order to improve the knowledge about the relations between geomorphological criteria based of flood forms and the ZFP, several field works were developed after floods in the lower part of the Sella River in Asturias (NW Spain). The present study considers the flood on 7 March 2009 with 5 year return period. 98 water flood data observed on field with 11 flood sand deposits thickness measured over floodplains was considered. The average value of sand deposits thickness was 0.14 m, with maximum data of 0.40 m, with an average value of water deep over these flood deposits of 1.54 m. An important correlation between these values was found and the linear and exponential model exhibit a good fitting explaining 81% and 86% of the deep-water variability respectively. By taking to account these results, flood sand deposits over 10 cm thickness could be used to identify representative areas of high flood hazard and the Preferential Flow Area.

How to cite: Fernandez-Iglesias, E., Menendez-Duarte, R., and Gonzalez-Rodriguez, G.: Relationship between field observations of flood sand deposits and water depth applied to the identification of flood hazard areas (Sella River, NW Spain), 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-235, https://doi.org/10.5194/icg2022-235, 2022.

P87
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ICG2022-623
Christiane Brazão, Renato Villela, Nelson Ferreira Fernandes, and Leonardo Cassara

In the last few decades, many studies have focused on the hydrologic effects and sediment regulation by LULC changes. Besides, land degradation by soil erosion is a major problem in many tropical developing countries, particularly when natural vegetation is converted to farmland. In Brazil, the MATOPIBA Region located in the Cerrado biome, has been considered the greatest national agricultural frontier, responsible for a large part of the Brazilian production of grains and fibers. The flat topography, the deep soils and the favorable climate for the cultivation of the main crops of grains favored the accelerated agricultural expansion in the last 30 years. In order to analyze and measure erosion and sediment regulation in the Rio Grande watershed were performed using two models: InVEST and ARIES. The aim of the InVEST model is to map and quantify the sediment delivery and retention services. It is a spatially-explicit model working with calculations at the pixel scale. The ARIES program works through ecosystem services modeling and calculations that, depending on the used module, considers both supply and demand. The mean sediment retention, in InVEST model, which is the difference in the amount of sediment delivered by the current watershed and a hypothetical watershed where all land use types have been converted to bare ground, was 42.76 ton/year/ha. These results should be taken as a good first estimate of the current scenario for the sediment retention service. This is due to some limitations of the SDR model. It uses the revised universal soil loss equation (RUSLE), which is limited in scope with regards to sediment source. ARIES model, for the Sediment Regulation analysis, used RUSLE to calculate soil loss and soil retention by vegetation in tons of sediments per hectare per year. The data of rain erosivity comes from the Global Rainfall Erosivity database (factor R) and the soil erodibility data (factor K) from Soil Grids. The sediment retention calculation is done through the application of RUSLE twice, first with the current land use and land cover and then with bare soil (Martínez-López et al., 2019). Then a subtraction is made between the two outputs, which determines the collaboration that current use and coverage has on sediment retention. The basin presents a mean value of 905.37, standard deviation of 1854.58 and maximum and minimum value of 39982.67 and 0, respectively. A limitation of the InVEST sediment model compared and ARIES is the temporal and spatial scale of its outputs. It is able to provide only average annual impacts under steady state conditions, limiting the model’s usability for ecosystem services in need of assessment via timescales shorter than one year.

How to cite: Brazão, C., Villela, R., Ferreira Fernandes, N., and Cassara, L.: Analysis of sediment production through InVEst and Aries modeling in the Brazilian Cerrado, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-623, https://doi.org/10.5194/icg2022-623, 2022.

P88
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ICG2022-285
Priyank Pravin Patel and Sayoni Mondal

The role of vegetation as a bioengineering tool for mitigating riverbank erosion has long been acknowledged but is comparatively less researched. Grasses, in particular, are effective in combating erosion by providing dual support. While their aboveground biomass reduces flow velocities, the underground root network binds detachable soil particles, thereby consolidating bank slopes. The effectiveness of installing Vetiver grass (Vetiveria zizanioides) hedges/buffers for this purpose has been investigated in plot level studies along the River Ketia, a spill-channel of the River Silabati in Paschim Medinipur district of West Bengal, which is part of the Gangetic delta lowlands of India. The impact of this grass' root network on the local soil physicochemical properties was studied along with its contribution towards slope stabilisation. The mechanical reinforcement properties of the Vetiver grass roots were examined from root tensile strength and root morphological parameters. While the uppermost (0-10 cm) soil layer showed an increase in the soil organic carbon content, the saturated hydraulic conductivity, decreased bulk density and increasing size of surface macro-aggregates (>0.25mm), all attested to the increasing stability of soil aggregates brought about by root reinforcement. With an increased root tensile strength in the surface layers, the root area ratio was also discerned as being satisfactorily high and Vetiver grass roots were observed to enhance soil cohesion. A channel cross-section survey across the Ketia in the pre- and post-monsoon seasons of 2019–2020 showed changes in channel dimensions, with the Vetiver-protected right bank getting slightly aggraded while the left flank (bereft of such protection) suffered erosion. Flood modelling in HEC-RAS was done to examine the extent to which flow velocities could be reduced by such grass buffers, using roughness coefficients garnered from similar simulation exercises elsewhere. The overall results attest that Vetiver grass can be a sustainable riparian erosion conservation tool along lowland rivers.

How to cite: Patel, P. P. and Mondal, S.: Examining the root-soil interactions within live Vetiver grass buffers towards their deployment for riverbank stabilisation in the Gangetic delta lowlands of India, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-285, https://doi.org/10.5194/icg2022-285, 2022.