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Geochemical Data Used to Trace Variations of Organic Carbon Sourcing Along a Trans-Himalayan River, Central Nepal

This data publication contains the data sets of a study aiming to trace variations in organic carbon sourcing along the Kali Gandaki River in Central Nepal. The data are on samples from different materials in the landscape (litter, soil, bedrock) and river sediments. On these samples we measured total organic carbon content, stable carbon and nitrogen isotopes, radiocarbon content and surface area. The data was generated between 2015-05 and 2017-12. The tabular data are provided as csv and Excel verisons.

FT-ICR-MS Data Used to Trace Variations of Organic Carbon Sourcing Along a Trans-Himalayan River, Central Nepal

This data publication contains a high resolution molecular dataset of a study aiming to trace variations in organic carbon sourcing along the Kali Gandaki River in Central Nepal. The data are on samples from different materials in the landscape (litter, soil, bedrock) and river sediments. On these samples we measured the extractable lipid fraction by measured by negative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). The data was generated between 2015-05 and 2017-12. Please consult the associated data description and Menges et al. (2020) for more details.

Flood characteristics of the 2016-02-22 event on the Eshtemoa River, Israel

Bedload transport is a key process in fluvial morphodynamics and hydraulic engineering, but is notoriously difficult to measure. The recent advent of stream-side seismic monitoring techniques provides an alternative to in-stream monitoring techniques, which are often costly, staff-intensive, and cannot be deployed during large floods. The Nahal (river) Eshtemoa is a gravel-bed river draining 119 km² of the Southern Hebron Mountains and the Northern Negev, northeast of Beer Sheva, Israel. The climate in the catchment is semi-arid, with a mean annual precipitation of 286 mm. Rainfall mainly occurs between October and May. The river is ephemeral with flash floods occurring on average five times per year (Alexandrov et al., 2009). The recurrence interval of the bankful discharge of 26 m3 s-1 has been estimated to be 1.25 years (Powell et al., 2012). Bedload fluxes are high by worldwide standards with sediment transport as much as 400 times more efficient than in a typical perennial humid river (Laronne and Reid, 1993; Reid and Laronne, 1995). The river is equipped with a monitoring station in a straight channel section with a trapezoidal cross section. The banks are nearly vertical, 1.2 m high, and comprise aeolian fines and interbedded gravel. The mean channel slope is 0.0075, which is generally mirrored by the water surface slope, with exception during the arrival of a flashflood bore (Meirovich et al., 1998). The data presented here are for the flood of the 22nd February 2016.They show a high bedload flux with peaks exceeding 1 kg/sm and water level between 0.5 and 0.8 m. The event has been previously described by Dietze et al. (2019). The data were used to assess the quality of a physical model (Tsai et al. 2012) predicting the seismic spectrum generated by the impact of bedload particles moving along the channel bed. The model requires knowledge on stream and sediment characteristics to constrain the source terms, e.g., the channel geometry and grain size distribution, as well as ground properties affecting the wave propagation, i.e., frequency-dependent wave velocity or attenuation characteristics. The complementary controlled source and passive seismological data are published in a separate data publication (Lagarde et al., 2020).

Raw data (pictures, DEMs, .mat files) about analogue landscapes evolution

This dataset includes raw data used in the paper by Reitano et al. (2022), focused on the effect of imposed boundary conditions (regional slope and rainfall rate) on the morphological evolution of analogue landscapes; the paper also focuses on applicability of stream power laws on analogue models, defining if and how the parametrization used in natural landscapes works in analogue ones. The experiments have been carried out at Laboratory of Experimental Tectonics (LET), University “Roma Tre” (Rome). Detailed descriptions of the experimental apparatus and experimental procedures implemented can be found in the paper to which this dataset refers. Here we present: • Pictures recording the evolution of the models. • GIFs showing time-lapses of models. • Raw DEMs of the models, used for extracting data later discusses in the paper. • Raw channels data (.mat files).

Laboratory and field data used to determine the controls of drainage density differences in two granitoid plutons in semi-arid Central Chile

Here we provide in situ 10Be data, meteoric 10Be data, X-Ray fluorescence data, infiltration rate field date, chemical extraction data, a summary of grain size data, all grain size data (Table S7), mineral point counting data, XRD data, soil grain size data, and data from laboratory measurements of hydrological parameters. Field work in Santa Gracia was conducted in February of the years 2019 and 2020 and laboratory work was conducted between 2019 and 2023. This data publication accompanies our study (Lodes et al., 2024), in which we investigate whether lithology controls drainage density in Santa Gracia, a semi-arid field site in Central Chile. In the study, we compare the density of drainages in two distinct, neighbouring landscapes underlain by a monzogranite and two diorite plutons (which we refer to as the “inner diorite” and the “outer diorite”). We collected multiple datasets to understand the underlying mechanisms behind the drainage density differences. The data was collected as part of the German Science Foundation (DFG) priority research program SPP-1803 “EarthShape: Earth Surface Shaping by Biota” (grant SCHE 1676/4-1 and -2 to D. S.; funding of P. G. through grant BE 1780/53-1 and -2).

PebbleCounts: a Python grain-sizing algorithm for gravel-bed river imagery

Grain-size distributions and their associated percentiles are a key geomorphic metric of gravel-bed rivers. Traditional measurement methods include manual counting or photo sieving, but these are typically achievable only at the patch (1 square meter) scale. With the advent of unmanned aerial vehicle systems and increasingly high-resolution cameras, we can now generate orthoimagery over large areas at resolutions of <1 cm. These scales, along with the complexity of many natural environments in high-mountain rivers, necessitate different approaches for photo sieving. Here, a new open-source algorithm is presented: PebbleCounts. As opposed to other image segmentation methods that use a watershed approach and automatically segment entire images, PebbleCounts relies on k-means clustering in the spatial and spectral (color) domain and rapid manual selection of well-outlined grains. This results in improved estimates for complex river-bed imagery without the need for post-processing.

River terrace height and width analysis

Climatically formed alluvial river-terrace sequences offer an exceptional opportunity to study valley-width evolution under similar discharge and lithologic conditions. To investigate additional parameters controlling valley width, we globally compiled alluvial-terrace sequences that have been associated with late Quaternary climate changes. All terrace cross-sections that are accepted to our compilation (1) include both valley sides, (2) show absolute values of distance and height, as well as profile location, and, (3) display a minimum of three terrace levels out of which at least one is preserved as a paired terrace. The terrace width and height measurements are summarized in this dataset. The data are presented as Excel and ASCII tables.

Beryllium-10 erosion rate data for hillslope erosion in the Coastal Cordillera, Chile

This data publication is supplementary to a study on the effect of large boulders and bedrock fracture patterns on hillslope denudation rates in the Chilean Coastal Cordillera, by Lodes et al. (submitted). Hillslope denudation rates are primarily determined by tectonic uplift rates, but landscape morphology is also controlled by climate and lithological properties such as bedrock fractures. Fracture patterns can influence the locations of ridges and valleys in landscapes through lowering surface grain sizes in fractured areas, and therefore the residence time of fractured hillslope material, dictating differential denudation rates. In this project, we used 10Be cosmogenic nuclide analysis to quantify the denudation rates of fractured bedrock, boulders, and soil on hillslopes, and compared the orientations of surrounding streams and faults, to understand the effects of fracturing and faulting on denudation rates, fluvial incision, and grain size in three field sites along a climate gradient in the Chilean Coastal Cordillera. In the humid and semi-arid climate zones, we found that denudation rates for unfractured bedrock and large hillslope boulders (10 to 15 m Myr-1) are lower than for soil (15 to 20 m Myr-1), indicating that exposed bedrock and boulders retard hillslope denudation rates. In the mediterranean climate zone, hillslope denudation rates are higher (40-140 m Myr-1) and show a less consistent pattern, likely due to steeper slopes. LiDAR-derived stream orientations support a fracture-control on landscape denudation in the three field sites, which we link with fracture density. Together, our results thus provide new insights into how fracture patterns can dictate topographic highs and valleys through grain size reduction. The main objective of this data publication is to provide our 10Be dataset which we used to calculate denudation rates for bedrock, boulders, and soils.

Erodibility proxy measurements in laboratory and field

A quantification of bedrock erodibility under fluvial impact erosion is required for various tasks in geomorphology, landscape evolution, and hydraulic engineering. However, it is challenging to measure in the field. Various proxy methods for easy measurement have been suggested and applied, but none of these has been benchmarked against high-quality data from the laboratory or field. We have collected field and laboratory data on erodibility using erosion mills as well as proxy data from the Schmidt hammer, Mohs' hardness, and the Annandale and Selby methods for 18 different lithological units.

Parallel Data of Rock geotechnical Properties and Erodibility Using Erosion Mills

To investigate geotechnical controls on erodibility of rocks in fluvial impact erosion, we raised a par-allel dataset of i) rock erodibility, using purpose designed erosion mills (Turowski et al., 2023a) including grain size distributions for the eroded material, and ii) rock properties such as compressive strength, indirect tensile strength, Young’s modulus, and Poisson’s ratio. In addition, we measured proxies for geotechnical parameters, including the Schmidt hammer rebound value, Mohs’ hardness, bulk density, and ultrasonic pulse velocities. Samples were obtained with a water-cooled, 200 mm diamond core bit in Switzerland and southern Germany, either from in-situ bedrock or boulders. In total, 18 lithological units were sampled. For some units, we obtained several cores either to increase the usable length or the quality, or to sample local variations in lithological properties (e.g., the dominant grain size) or geometry (e.g., the core orientation with respect to bedding planes). Back in the workshop, cores were cut into discs of either ~5.5 cm or ~12 cm length, for erosion and geotechnical experiments, respectively, and further prepared depending on the needs for the specific measurement.

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