scholarly journals Testing the Prediction Ability of LEM-Derived Sedimentary Budget in an Upland Catchment of the Southern Apennines, Italy: A Source to Sink Approach

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 911 ◽  
Author(s):  
Gioia ◽  
Lazzari
Keyword(s):  
Sediment Flux ◽  
Southern Apennines ◽  
Short Term ◽  
Prediction Ability ◽  
Small Catchment ◽  
Bathymetric Survey ◽  
Landscape Modification ◽  
Source To Sink ◽  
Natural Landscapes ◽  
Sedimentary Budget

Landscape evolution models (LEMs) represent one of the most promising approaches to evaluate sedimentary budget, although factors such as the high number of parameters or the difficulty evaluating the robustness of the results can represent a limitation in their application in natural landscapes. In this paper, the Caesar–Lisflood LEM has been applied in a small catchment (i.e., about 9 km2) of southern Italy draining an artificial reservoir in order to test its ability to predict sediment flux and erosion rate. Short-term (i.e., about 20 years) estimation of the sediment volumes accumulated in the reservoir has been reconstructed by a bathymetric survey and compared to the results coming from the coeval LEM simulations. Results indicate a good accordance between LEM-based erosion volume estimations and direct sedimentation assessment, thus testifying to the high potential of such models to solve issues of sedimentary budget and short-term landscape modification.

scholarly journals Long- to short-term denudation rates in the southern Apennines: geomorphological markers and chronological constraints

2011 ◽  
Vol 62 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Dario Gioia ◽  
Claudio Martino ◽  
Marcello Schiattarella
Keyword(s):  
Sediment Accumulation ◽  
Radiometric Dating ◽  
Sedimentation Rates ◽  
Southern Apennines ◽  
Short Term ◽  
Small Catchment ◽  
Fluvial Terraces ◽  
Denudation Rates ◽  
Land Surfaces

Long- to short-term denudation rates in the southern Apennines: geomorphological markers and chronological constraints Age constraints of geomorphological markers and consequent estimates of long- to short-term denudation rates from southern Italy are given here. Geomorphic analysis of the valley of the Tanagro River combined with apatite fission track data and radiometric dating provided useful information on the ages and evolution of some significant morphotectonic markers such as regional planated landscapes, erosional land surfaces and fluvial terraces. Reconstruction of paleotopography and estimation of the eroded volumes were perfomed starting from the plano-altimetric distribution of several orders of erosional land surfaces surveyed in the study area. Additional data about denudation rates related to the recent and/or active geomorphological system have been obtained by estimating the amount of suspended sediment yield at the outlet of some catchments using empirical relationships based on the hierarchical arrangement of the drainage network. Denudation rates obtained through these methods have been compared with the sedimentation rates calculated for two adjacent basins (the Pantano di San Gregorio and the Vallo di Diano), on the basis of published tephrochronological constraints. These rates have also been compared with those calculated for the historical sediment accumulation in a small catchment located to the north of the study area, with long-term exhumation data from thermochronometry, and with uplift rates from the study area. Long- and short-term denudation rates are included between 0.1 and 0.2 mm/yr, in good agreement with regional data and long-term sedimentation rates from the Vallo di Diano and the Pantano di San Gregorio Magno basins. On the other hand, higher values of exhumation rates from thermochronometry suggest the existence of past erosional processes faster than the recent and present-day exogenic dismantling. Finally, the comparison between uplift and denudation rates indicates that the fluvial erosion did not match the tectonic uplift during the Quaternary in this sector of the chain. The axial zone of the southern Apennines should therefore be regarded as a landscape in conditions of geomorphological disequilibrium.

scholarly journals Modeling Short-Term Landscape Modification and Sedimentary Budget Induced by Dam Removal: Insights from LEM Application

2020 ◽  
Vol 10 (21) ◽  
pp. 7697
Author(s):  
Dario Gioia ◽  
Marcello Schiattarella
Keyword(s):  
Landscape Evolution ◽  
Dam Removal ◽  
Sediment Flux ◽  
Short Term ◽  
Open Problems ◽  
Landscape Modification ◽  
Natural Processes ◽  
Base Level ◽  
Geomorphic Response ◽  
Fluvial Incision

Simulation scenarios of sediment flux variation and topographic changes due to dam removal have been investigated in a reservoir catchment of the axial zone of southern Italy through the application of a landscape evolution model (i.e.,: the Caesar–Lisflood landscape evolution models, LEM). LEM simulation highlights that the abrupt change in base level due to dam removal induces a significant increase in erosion ability of main channels and a strong incision of the reservoir infill. Analysis of the sediment dynamics resulting from the dam removal highlights a significant increase of the total eroded volumes in the post dam scenario of a factor higher than 4. Model results also predict a strong modification of the longitudinal profile of main channels, which promoted fluvial incision upstream and downstream of the former reservoir area. Such a geomorphic response is in agreement with previous analysis of the fluvial system short-term response induced by base-level lowering, thus demonstrating the reliability of LEM-based analysis for solving open problems in applied geomorphology such as perturbations and short-term landscape modification natural processes or human impact.

scholarly journals Did the last sea level lowstand always lead to cross-shelf valley formation and source-to-sink sediment flux?

2006 ◽  
Vol 111 (F4) ◽  
Author(s):  
Torbjörn E. Törnqvist ◽  
Santina R. Wortman ◽  
Zenon Richard P. Mateo ◽  
Glenn A. Milne ◽  
John B. Swenson
Keyword(s):  
Sea Level ◽  
Sediment Flux ◽  
Source To Sink

scholarly journals Multi-zone prediction analysis of city-scale travel order demand

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248064
Author(s):  
Pengshun Li ◽  
Jiarui Chang ◽  
Yi Zhang ◽  
Yi Zhang
Keyword(s):  
Prediction Model ◽  
Clustering Algorithm ◽  
Intelligent Transportation System ◽  
Spatial Clustering ◽  
Support Vector ◽  
Nearest Neighbour ◽  
Short Term ◽  
Prediction Ability ◽  
Demand Prediction ◽  
Zone Division

Taxi order demand prediction is of tremendous importance for continuous upgrading of an intelligent transportation system to realise city-scale and personalised services. An accurate short-term taxi demand prediction model in both spatial and temporal relations can assist a city pre-allocate its resources and facilitate city-scale taxi operation management in a megacity. To address problems similar to the above, in this study, we proposed a multi-zone order demand prediction model to predict short-term taxi order demand in different zones at city-scale. A two-step methodology was developed, including order zone division and multi-zone order prediction. For the zone division step, the K-means++ spatial clustering algorithm was used, and its parameter k was estimated by the between–within proportion index. For the prediction step, six methods (backpropagation neural network, support vector regression, random forest, average fusion-based method, weighted fusion-based method, and k-nearest neighbour fusion-based method) were used for comparison. To demonstrate the performance, three multi-zone weighted accuracy indictors were proposed to evaluate the order prediction ability at city-scale. These models were implemented and validated on real-world taxi order demand data from a three-month consecutive collection in Shenzhen, China. Experiment on the city-scale taxi demand data demonstrated the superior prediction performance of the multi-zone order demand prediction model with the k-nearest neighbour fusion-based method based on the proposed accuracy indicator.

scholarly journals Short-term sediment yields from small catchment of Sungai Anak Bangi Selangor

2009 ◽  
Vol 55 ◽  
pp. 55-59 ◽  
Author(s):  
Mohd Ekhwan Toriman ◽  
◽  
Mazlin Mokhtar ◽  
Othman Karim ◽  
M. Barzani Gasim ◽  
...  
Keyword(s):  
Short Term ◽  
Small Catchment ◽  
Sediment Yields

Geomorphic variability and sediment dynamics in small catchments of dryland environments: Application into sand mining

2021 ◽  
Author(s):  
Abhishek kumar Singh ◽  
Nishith Bhatt
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Mining Activity ◽  
Series Data ◽  
Western India ◽  
Natural Sand ◽  
Small Catchment ◽  
Sediment Routing ◽  
Source To Sink ◽  
Small Catchments

<p>The understanding of the sediment routing system and source-to-sink dynamics in a catchment is vital as it helps to assess areas undergoing erosion and deposition. This is significant in catchments which undergo active mining activities especially natural sand materials. The role of climate and natural erosional processes is vital in this as mining of sand is also affected by natural replenishment. In present study, we take a case study of a small catchment of 30km length ~ Chharri, situated in arid landscape of Kachchh of western India. Using geomorphic assemblage mapped using remote sensing and field investigation, we identified natural sub-sinks (depocenters) in the Chharri river valley. The investigation was validated by studying sediment profiles of the depocentral landforms in seasonal time series (pre-monsoon and post monsoon sessions). The changes in morphology, sediments accumulations were integrated to assess the natural sand replenishment in areas which had been undergoing mining activity. Based on time series data it was deduced that the small catchments in dry-land environments, the sand production and dynamics is modulated by type of vegetation, pattern in precipitation and human intervention. The results of such source-to-sink study have long-term implications on sand replenishment, mining activity and landscape evolution of such river basins.</p>

scholarly journals Theoretical Interpretation of the Exceptional Sediment Transport of Fine-grained Dispersal Systems Associated with Bedform Categories

2018 ◽  
Author(s):  
Tian Zhao ◽  
Qian Yu ◽  
Yunwei Wang ◽  
Shu Gao
Keyword(s):  
Sediment Transport ◽  
Regime Shift ◽  
Sedimentary Environment ◽  
Sediment Flux ◽  
Theoretical Interpretation ◽  
Fine Grained ◽  
Transport Regime ◽  
Source To Sink ◽  
Bed Roughness ◽  
Set Up

Abstract. Being a widespread source-to-sink sedimentary environment, the fine-grained dispersal system (FGDS) features remarkably high sediment flux, interacting closely with local morphology and ecosystem. Such exceptional transport is believed to be associated with changes in bedform geometry, which further demands theoretical interpretation. Using van Rijn (2007a) bed roughness predictor, we set up a simple numerical model to calculate sediment transport, classify sediment transport behaviors into dune and (mega-)ripple dominant regimes, and discuss the causes of the sediment transport regime shift linked with bedform categories. Both regimes show internally consistent transport behaviors, and the latter, associated with FGDSs, exhibits considerably higher sediment transport rate than the previous. Between lies the coexistence zone, the sediment transport regime shift accompanied by degeneration of dune roughness, which can considerably reinforce sediment transport and is further highlighted under greater water depth. This study can be applied to modeling of sediment transport and morphodynamics.

scholarly journals The rate and extent of wind-gap migration regulated by tributary confluences and avulsions

2021 ◽  
Vol 9 (4) ◽  
pp. 687-700
Author(s):  
Eitan Shelef ◽  
Liran Goren
Keyword(s):  
Migration Rate ◽  
Erosion Rate ◽  
Critical Role ◽  
Climatic Changes ◽  
Climatic Conditions ◽  
Sediment Flux ◽  
Drainage Area ◽  
Valley Wind ◽  
Area Distribution ◽  
Natural Landscapes

Abstract. The location of drainage divides sets the distribution of discharge, erosion, and sediment flux between neighboring basins and may shift through time in response to changing tectonic and climatic conditions. Major divides commonly coincide with ridgelines, where the drainage area is small and increases gradually downstream. In such settings, divide migration is attributed to slope imbalance across the divide that induces erosion rate gradients. However, in some tectonically affected regions, low-relief divides, which are also called wind gaps, abound in elongated valleys whose drainage area distribution is set by the topology of large, potentially avulsing side tributaries. In this geometry, distinct dynamics and rates of along-valley wind-gap migration are expected, but this process remains largely unexplored. Inspired by field observations, we investigate along-valley wind-gap migration by simulating the evolution of synthetic and natural landscapes, and we show that confluences with large side tributaries influence migration rate and extent. Such confluences facilitate stable wind-gap locations that deviate from intuitive expectations based on symmetry considerations. Avulsions of side tributaries can perturb stable wind-gap positions, and avulsion frequency governs the velocity of wind-gap migration. Overall, our results suggest that tributaries and their avulsions may play a critical role in setting the rate and extent of wind-gap migration along valleys and thus the timescale of landscape adjustment to tectonic and climatic changes across some of the tectonically most affected regions of Earth, where wind gaps are common.

scholarly journals Landscape responses to dynamic topography and climate change on the South African source-to-sink system since the Oligocene

2021 ◽  
Author(s):  
Claire A. Mallard ◽  
Tristan Salles
Keyword(s):  
South African ◽  
Large Scale ◽  
Sedimentary Basin ◽  
Drainage System ◽  
Sediment Flux ◽  
Mantle Flow ◽  
Dynamic Topography ◽  
The South ◽  
Source To Sink ◽  
Underlying Mechanisms

Abstract. The South African landscape displays important lithological and topographical heterogeneities between the eastern, western margins and the plateau. Yet the underlying mechanisms and timings responsible for this peculiar layout remain unclear. While studies have proposed a post-Gondwana uplift driver, others have related these heterogeneities to a more recent evolution induced by deep mantle flow dynamics during the last 30 million years. This theory seems supported by the rapid increase of sediment flux in the Orange basin since the Oligocene. However, the triggers and responses of the South African landscape to dynamic topography are still debated. Here we use a series of numerical simulations forced with Earth data to evaluate the contribution of dynamic topography and precipitation on the Orange river source-to-sink system since the Oligocene. We show that, if the tested uplift histories influence deposits distribution and thicknesses in the Orange sedimentary basin, they poorly affect the large-scale drainage system organisation and only strongly impact the erosion across the catchment for two of the four tested dynamic topography cases. Conversely, it appears that paleo-rainfall regimes are the major forcing mechanism that drives the recent increase of sediment flux in the Orange basin. From our simulations, we find that climate strongly smoothed the dynamic topography signal in the South African landscape and that none of the currently proposed dynamic topography scenarios produce an uplift high enough to drive the pulse of erosion and associated sedimentation observed during the Palaeocene. These findings support the hypothesis of a pre-Oligocene uplift. Our results are crucial to improve our understanding of the recent evolution of the South African landscape.

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