River Sediment Deposition Research Articles

"무인항공기를 활용한 금강 하도내의 퇴적지형 변화 특성 연구: 공주보 개방 전·후를 중심으로"

In this study is aerial photos and UAV(Unmanned Aerial Vehicle) images were used to analyzed the characteristics of depositional landform changes in the Geum river channels before and after the opening gate of Gongju weir. Based on the depositional landform classification result, the main stream and the bare land occupied most of the area in all periods, and also found that the main stream, mid-channel island, and sand bar occupied a greater degree of area increase or decrease compared to other landforms in the classification items. As a result of analyzing the characteristics of depositional landform changes before and after the opening gate of Gongju weir, it is judged that the depositional landforms have changed due to the decreased water level of the Geum river after the opening of the weir, the summer rainy season and typhoons, river stabilization after the effluence of Daecheong dam, supply and deposition of river sediments and fixation of vegetation. The results derived from this study can be used as basic data for the study of river depositional landforms and the establishment of management and conservation plans for the landforms in river channels.

An assessment of sedimentation in Terengganu River, Malaysia using satellite imagery

Abstract Sediment deposition causes the reduction of aquatic habitats and increase of water velocities within rivers, which negatively impacts the environment and the surrounding ecology. This makes the prediction of river sediment deposition a key factor for the protection of river environments. The prediction of sediment deposition in rivers through the integration of satellite imagery and unsupervised machine learning is beneficial and convenient, as it is less resource-intensive due to not requiring ground-truth data. The Terengganu River in Malaysia is used as a case study in this research. This study aims to discuss satellite imagery's key preparation processes, namely image correction and identification of determinant image bands through a correlation analysis. Satellite imagery of the Terengganu River between 1989 and 2019 is obtained from the United States Geological Survey (USGS). Image correction is successfully implemented on the available satellite imagery with the results shown in this study. Through the performed correlation analysis, the study finds that the determinant image bands for river sediment deposition prediction using unsupervised machine learning are the NST spectral bands, which consist of the NIR, SWIR, and TIR bands. This is due to the NST spectral bands exhibiting low correlations with respect to the RGB bands. It is found that correlation coefficients between the NIR band and red, green, and blue bands are generally the lowest, especially in 2009 with values of 0.1087, 0.2085, and 0.1252, respectively. This indicates that the NIR band is the most important determinant image band in predicting river sediment deposition. This study also identifies k-means, clustering large application (Clara), and hierarchical agglomerative clustering (HAC) as suitable unsupervised machine learning algorithms to be utilized in predicting river sediment deposition. Studies on the application of unsupervised machine learning algorithms on satellite imagery in the field of river sediment deposition prediction are currently scarce, possibly due to the gap of knowledge on the initial steps required for such application. Therefore, this study's novelty is the introduction and discussion on critical preliminary processes, specifically image correction and identification of determinant image bands, that are required for the successful implementation of unsupervised machine learning algorithms on satellite imagery for the prediction of river sediment deposition.

Hiệu quả sử dụng phân đạm sinh học đến sinh trưởng và năng suất lúa (Oryza sativa L.) trên nền đất phù sa bồi và phèn tiềm tàng ở khu vực Đồng bằng sông Cửu Long

The objectives of this study was to assess the efficacy of biological nitrogen fertilizer on growth and grain yield of rice cultivated in alluvial soil and potential acid sulfate soil in the Mekong Delta area. The field experiment was conducted in Summer-Autumn 2018 for alluvial soil with river sediment deposition and Summer-Autumn 2019 for potential acid sulfate soil. These experiments were laid out in split-plot design with three replicates. The sub-plots included two kinds of N fertilizer: (i) urea-Ca Mau nitrogen fertilizer, and (ii) Innovative biological nitrogen fertilizer and the main plots included three different application doses: 60% (48 kgN/ha), 80% (64 kg N/ha), and 100% (80 kgN/ha). The results showed that the height of rice plant, tillers, SPAD index, and rice yield of treatments with application doses of 60-80% N from innovative biological nitrogen fertilizer were not significantly different from the positive control treatment applying 100%N from Ca Mau nitrogen fertilizer. Thus, results of this study recommended to apply this innovative nitrogen fertilizer for paddy rice when cultivated in alluvial soil and potential acid sulfate soil in the Mekong Delta area.

Towards assessing the influence of sediment loading on Last Interglacial sea level

SUMMARY Locally, the elevation of last interglacial (LIG; ∼122 ka) sea level markers is modulated by processes of vertical displacement, such as tectonic uplift or glacial isostatic adjustment, and these processes must be accounted for in deriving estimates of global ice volumes from geological sea level records. The impact of sediment loading on LIG sea level markers is generally not accounted for in these corrections, as it is assumed that the impact is negligible except in extremely high depositional settings, such as the world's largest river deltas. Here we perform a generalized test to assess the extent to which sediment loading may impact global variability in the present-day elevation of LIG sea level markers. We numerically simulate river sediment deposition using a diffusive model that incorporates a migrating shoreline to construct a global history of sedimentation over the last glacial cycle. We then calculate sea level changes due to this sediment loading using a gravitationally self-consistent model of glacial isostatic adjustment, and compare these predictions to a global compilation of LIG sea level data. We perform a statistical analysis, which accounts for spatial autocorrelation, across a global compilation of 1287 LIG sea level markers. Though limited by uncertainties in the LIG sea level database and the precise history of river deposition, this analysis suggests there is not a statistically significant global signal of sediment loading in LIG sea level markers. Nevertheless, at sites where LIG sea level markers have been measured, local sea level predicted using our simulated sediment loading history is perturbed up to 16 m. More generally, these predictions establish the relative sensitivity of different regions to sediment loading. Finally, we consider the implications of our results for estimates of tectonic uplift rates derived from LIG marine terraces; we predict that sediment loading causes 5–10 m of subsidence over the last glacial cycle at specific locations along active margin regions such as California and Barbados, where deriving long-term tectonic uplift rates from LIG shorelines is a common practice.

Forecasting river sediment deposition through satellite image driven unsupervised machine learning techniques

The hydrologic and riverine systems of the Earth's surface, subject to ever increasing instability, requires forecasting techniques now more than ever. Existing mathematical and machine learning models for forecasting river sediment deposition are driven by non-remotely sensed data and/or require ground truth data. The study aims to demonstrate that remote sensing and unsupervised machine learning techniques coupled with appropriate validation metric can be employed to quickly forecast regions that are subject to future river sediment deposition. The results indicate that the NIR and other bands outside the visible range are determinant features for forecasting depositional areas, a multi-algorithm approach is both successful and necessary in indicating such regions and appropriate learning algorithm selection is more dependent on image cluster interpretability rather than cluster validation indices. However, the Silhouette Width validation index consistently picks the algorithm providing the result with most interpretability. Regions to be subjected to river sediment deposition were confirmed when validated against satellite images of the same region captured in the future. Such techniques can be employed in policymaking, disaster management, labeling for supervised learning etc.

Iron\u2019s fingerprint of deposits\u2014iron speciation as a geochemical marker

The article describes the studies of the iron speciation (the occurrence of Fe(II), Fe(III), and complexed iron) in acid leachable fraction of deposits. The speciation of iron was diverse for deposits of different origins and was the specific “fingerprint”—marker of deposition processes. The higher occurrence of Fe(II) may be connected with decantation which has been observed for lake sediments, the majority of Fe(III) with upper flow regime erosion-deposition processes, observed for river sediment deposition during flood episodes. As verification for this hypothesis, the explanation for the iron speciation in the different river sediment samples has been used.

Landslide hazards around Uttarkashi township, Garhwal Himalaya, after the tragic flash flood in June 2013

Garhwal Himalaya has witnessed extreme climatic conditions in the form of incessant rainfall during June 15–17, 2013, generating numerous primary as well as secondary landslide hazards due to flooding event in the Bhagirathi River. This was probably the second highest flood after the 1978 flood in the area. The paper documents the spatial distribution of landslides and its consequences in the lower reaches of the Bhagirathi Valley between Bhatwari and Uttarkashi. It has been observed that within a stretch of 28 km in the study area, the river gradient is highly variable ranging from 3.6 to 66.6 m/km and is marked by three major knick points. These knick points are well correlated with the disposition of thrusts and a fault present in the area. An inventory of 23 active landslides has been prepared. Based on these knick points, the entire area has been divided into four zones. The area between Bhatwari and Ganeshpur is marked by the zone of transportation and between Ganeshpur and Uttarkashi, the zone of deposition of river sediments. It has been estimated that there is an average aggradation of about 0.5 m/year in the Bhagirathi River around Uttarkashi. Further, the huge volume of material deposited in the river around Uttarkashi township is posing serious threat to the slope stability on either banks of river. This calls for an urgent need for the formulation of policy for dredging the material from riverbed in order to maintain the continuous and uninterrupted flow of water during high discharge, in order to mitigate the problems of slope stability along the course of the river.

Large‐scale Modeling of Soil Erosion with RUSLE for Conservationist Planning of Degraded Cultivated Brazilian Pastures

AbstractPasture degradation is one of the major environmental and economic problems of Brazilian livestock production. Based on the estimates of soil loss in 140,297 km2 pasturelands of Goiás State and the Federal District, the effects of land use and management and conservation practices on soil erosion by water were evaluated. Soil loss was estimated with the empirical revised universal soil loss equation model under four scenarios of land use and management of pastures and the implementation of terraces. The effects of converting hilly areas into permanently preserved areas were also evaluated. Well‐managed pastures planted in terraces and highly sloped areas with native vegetation featured a reduction of 709% in the rate of soil erosion by water in comparison with poorly managed pastures without soil conservation practices. The environmental consequences of pasture degradation become particularly important when they are associated with land use in the Amazon and Cerrado biomes because farmers in these regions are forced to open new natural areas. In addition, the high indices of bare soil in degraded pastures contribute significantly to sediment deposition in rivers and dams. The modeling of soil loss is demonstrated to be an important tool for land use planning and supporting public policies focused on the sustainable use of natural resources. The results of these simulations demonstrate the importance of actions to recover degraded pastures, such as the Federal Government's program known as ABC (Low Carbon Agriculture). Copyright © 2015 John Wiley & Sons, Ltd.

Study of Land use/land Cover Dynamics through Classification Algorithms for Harangi Catchment Area, Karnataka State, INDIA

Industrialization and urbanization are mainly responsible for the conversion of significant amount of vegetation rich lands such as forests and wetlands into agricultural lands and human settlements. This land use and land cover change in turn has influence on various hydrological processes such as soil erosion rate, sediment deposition in rivers and dams and also stream flow pattern in a catchment. Qualitative and quantitative analysis of Land use and Land cover (LU/LC) changes is necessary to assess the impacts of change in the pattern of natural vegetation on the earth's environment. Satellite images can provide useful information regarding spatial and temporal variation of LU/LC in an area. The purpose of this paper is to analyse the dynamics of LU/LC changes using LISS-III data for the years 2007, 2010 and 2013 of Harangi catchment, Coorg District, Karnataka State, India. Also, study compares three classification techniques such as Parallelepiped Algorithm, Minimum Distance to Mean Algorithm and Maximum Likelihood Algorithm based on the value of overall accuracy and kappa coefficient to check the reliability of the methods in classifying images. The overall accuracy and kappa coefficient obtained by using Parellelepiped, Minimum distance to mean and Maximum likelihood algorithm for the year 2013 are 81.47% & 0.71, 78.67 & 0.68 and 89.36% & 0.81 respectively. Based on these results, it can be concluded that, among all the three techniques, the Maximum Likelihood Algorithm gave higher accuracy with high kappa coefficient and Minimum Distance to Mean Algorithm gave lower accuracy. The LU/LC change detection results between years 2007 and 2013 indicated a drastic change in forest area, plantation and waste land among all other classes. The forest area decreased dramatically from 183.12 sq. km to 131.02 sq. km. Also, fallow land and water body are decreased from 68.89 sq. km to 42.63 sq. km and 6.71 sq. km to 3.82 sq. km respectively. In contrast, the plantation and waterlogged area are observed to have an increasing trend of about 56.07 sq. km to 146.55 sq. km and 17.99 sq. km to 23.81 sq. km. The urban area has been increased from 13.06 sq. km to 13.72 sq. km. The urbanization and agricultural activities are the major reasons for increase in plantation and urban area in an expense of decrease in forest area.

Modelo del transporte y deposición de Fe y Mn en el curso alto del río Lerma

A metal transport and deposition model together with concentration measurements of Fe and Mn was developed in the Upper Course of the Lerma River, Mexico State. The hydraulic sections of 27.9km of the Lerma River were measured in the field in order to supply the numerical model. A general mass balance equation considering full mixing in selected reaches of the Lerma River was developed and solved using the finite-difference method. At the same time a sampling campaign of water and sediment allowed us to obtain Fe and Mn concentrations in each phase. Metal concentrations were obtained by Energy Dispersive X-Ray Fluorescence Method (EDXRF). Partition coefficients for water and suspended sediment and for water and deposited sediment were calculated. Well defined periods and areas of deposition of Fe and Mn were obtained by the transport model and the spatial variation of the partition coefficients agree with the pattern obtained in the simulation. It is concluded that the current practice of constant values of the partition coefficients could not be used in modelling transport and deposition of metals if we are dealing with hydrologic extreme events and river sediment deposition areas.

A Geostatistical Analysis of Soil Properties in the Davis Pond Mississippi Freshwater Diversion

Land loss has been a major concern in the Mississippi River Delta as the levees constructed along the river caused a severe drop in sediment and nutrient loads for the adjacent wetland areas. Several freshwater diversions along the lower reach of the Mississippi River were built to resolve this. This study represents the first spatial survey of one such diversion, Davis Pond, with the objective to understand the current nutrient status and to determine a baseline of key soil properties. We also expect that the processes driving wetland accretion are scale dependent, and present the scale dependency in the spatial relationships of those properties which are key to accretion. These soil properties are: soil moisture (MOIST), bulk density (BD), pH, organic matter content (OM), total phosphorus (TP), nitrogen (TN), and carbon (TC) sampled 142 stations (0–10 and 10–20‐cm depth). Maps of soil properties in the recently accreted 0‐ to 10‐cm interval were produced using kriging. From the spatial correlation analysis we observed that TN, TC, and OM, in the 0‐ to 10‐cm depth interval, had similar spatial properties and were closely related to BD. The spatial relationship between TP or pH with any other variable was weak. We also inferred that processes driving dynamics of TP in the Davis Pond act on a finer spatial scale than processes affecting TN, TC, and OM. We can identify where there are different deposition processes affecting the spatial patterns in this wetland, that is, C deposition by the plants vs. mineral river sediment deposition.

Quantitative assessment of the role of deltas in the processes of deposition of river sediments

Theoretical principles of the sediment budget at river mouths and the role of deltas in the deposition of river sediments are discussed. The results of the quantitative assessment of sediment budget components at river deltas are given. The article shows the impact of such natural factors as delta sizes, peculiarities of their topography and hydrographic system, as well as a series of anthropogenic factors, including diking, water intake structures, etc., on the role of deltas in sediment retention.

Lena River discharge events in sediments of Laptev Sea, Russian Arctic

To reconstruct the variability of freshwater discharge to the Arctic via the Lena River, 22 gravity cores were collected along two transects that extend from the delta floodplain onto the Laptev Sea shelf. High magnetic susceptibility (MS) signals appear to be good indicators for river sediment deposition. Sedimentation of this terrestrial material forms fluvial units distinguished by coarse grain size and high MS signal produced by the magnetic properties from the river-derived material. The criteria to distinguish marine units are low magnetic susceptibility signals when compared with fluvial units, lithological descriptions and granulometric analyses. Sedigraph granulometric analyses in combination with wet sieving analyses (grain size > 4 Φ) reveal changes in grain-size distributions along the cores that are well correlated with magnetic susceptibility data. Fluvial and marine units were found to alternate sequentially along the cores. Data from cores comprising two transects in the Laptev Sea revealed 17 total fluvial events during the last 2000 years. The Lena River-derived sediment bedload could be traced 34.5–47.5 km far from the delta edge of Bykovskaya branch showing direct impact of Lena River discharge to the Laptev Sea.

Evidence for hydrochory and the deposition of viable seeds within winter flow‐deposited sediments: the River Dove, Derbyshire, UK

AbstractPrevious studies of the influence of hydrochory on plant dispersal have focused on relationships with existing vegetation patterns or litter deposits. River sediment deposition studies have assessed sediment accretion rates, particle size and quality. The link between seed and sediment transport and deposition has been overlooked and never quantified.This paper presents observations of over‐winter viable seed and sediment deposition on three river margin sites along the River Dove, England. At these sites, 105 paired artificial turf mats were installed on the river bank top, face and toe from October 1999 to March 2000 to collect river‐deposited material. From each pair, one mat was used to determine the dry weight; median particle size; percentage sand, silt, clay and organic content of deposited sediment. The other was used in germination trials to determine the number and species of deposited viable seeds. Topographic surveys and water level measurements supported the estimation of the hydrological characteristics of each mat location.Few seeds and little sediment were found on mats not inundated by river water. For these inundated, sediment characteristics varied primarily with elevation (relative to local mean river water level during the study period), with less marked between‐site contrasts. The species composition of viable seeds also varied with elevation. Detrended correspondence analysis (DCA) revealed associations between river/wetland‐related seed species and the bank toe samples. Regression analysis revealed significant relationships between seed number, sediment properties and mat elevation. Redundancy analysis (RDA) revealed associations between the species and abundance of viable seeds and elevation, sediment weight and organic matter content. These analyses suggest that sediment and seed deposition by rivers are closely related processes.The implications of these results for seed remobilization and dispersal and hydrochory within riparian zones are discussed, as are the implications of changes in sediment/seed delivery mechanisms, river flow regimes, and the hydraulic properties of river margins for seeds, sediments and riparian vegetation patterns. Copyright © 2003 John Wiley & Sons, Ltd.

Influence of crustal movements on landforms, erosion and sediment deposition in the Irangi Hills, central Tanzania

Abstract The influence of crustal movements on landforms, erosion and sediment deposition has been analysed in the severely eroded Irangi Hills in Kondoa District, central Tanzania. Field observations, in combination with satellite imagery, aerial photographs, and topographical and geological maps have been used. The Irangi Hills, which are uplifted relative to the vast Maasai Plain, consist of several tectonic blocks, with each block being tilted to the west. Frequent earthquakes indicate that relative uplift, faulting and tilting of the Irangi Hills are still taking place. The drainage pattern of the area and the deposition of river sediments are directly influenced by the morphotectonics. Where fault scarps occur, large rivers have cut into the bedrock across the fault scarps and follow antecedent stream courses, while small streams have been dammed, forming swamps or lakes. The denudation rate for a small catchment (33.4km 2 ) has been calculated to 2.7mm a −1 for the years 1836–1992 by using a dated sediment record. This is considered to be an accelerated denudation rate. The soil erosion of the Irangi Hills is a long-term natural stripping of regolith, accelerated by anthropogenic causes, probably in combination with crustal uplift and the tilting of tectonic blocks.

Dispersal and deposition of river sediments in coastal seas: Models from Asia and the tropics

The diverse mechanisms by which river-borne sediments are dispersed into coastal oceans and the associated patterns of deposition are considered for some tropical and Asian river mouth dispersal systems: the Huanghe (Yellow River), which enters the Bohai Gulf (China), the Purari River which enters the Gulf of Papua (Papua New Guinea) and the Jaba River, which enters Empress Augusta Bay (Bougainville, Papua New Guinea). These models contrast sharply with ‘conventional’ models such as that of the Mississippi, although in different respects. Extremely high suspended sediment concentrations off the Huanghe mouth cause sinking, gravity-driven plumes which produce rapid deposition very near the mouth; extremely rapid seaward growth of the subaqueous delta results. Although the average water discharge of the Purari exceeds that of the Huanghe, the average sediment discharge from the Purari is an order of magnitude less than that of the Huanghe. Suspended sediments transported via buoyant plumes from the Purari mouth are trapped inshore by the southeasterly trades and have their ultimate sink in the tidal estuaries to the west of the mouths rather than offshore. The Jaba is a small river with a very steep gradient and an extremely high bed load relative to water discharge. It has constructed a protruding and rapidly evolving delta. Literature on the Indonesian rivers Solo and Porong dispersal systems suggests that those systems may, at different times, be subject to processes similar to those which operate off the mouths of the Huanghe, Purari and Jaba although no single, direct analogies can be made.

An Effective Model of Sediment Deposition in Rivers

A two dimensional model of the dynamic of sediment deposition in rivers is described and evaluated in the paper. It is based on the hypotheses that sediment concentration is proportional to concentration at the equilibrium and settling velocity tends asymptotically to a maximum value as wash load increases. The model requires the estimation of only two parameters, which may easily be calibrated from turbidity data. It has been applied to determine the sediment deposition over a 35 kilometers long stretch of the Po river, in Northern Italy, in different flow, load and temperature conditions and its performances turned out to be surprisingly high, given the complexity of this kind of phenomenon.

A Resume of River Delta Types: ABSTRACT

Deltas and deltaic sediments are produced by the rapid deposition of stream-borne materials in relatively still-standing bodies of water. Notwithstanding the effects of subsidence and water level movements, most deltaic sediments are deposited off the delta shoreline in the proximity of the river's mouth. As these materials build upward to the level of the still-standing body of water, the remainder of deltaic sediments are deposited on shore, within the delta's flood plains, lakes, bays, and channels. Nearly 2,500 years ago, Herodotus, using the Nile as an example, stated that the land area reclaimed from the sea by deposition of river sediments is generally deltoid in shape. The build-up and progradation of deltaic sediments produces a distinct change in stream gradient from the fluvial or alluvial plain to the deltaic plain. Near the point of gradient change the major courses of rivers generally begin to transport much finer materials, to bifurcate into major distributaries, and to form subaerial deltaic plains. The boundaries of the subaerial plain of an individual delta are the lateral-most distributaries, including their related sediments, and the coast line. Successively smaller distributaries form subdeltas of progressively smaller magnitudes. Deltas may be classified on the basis of the nature of their associated water bodies, such as lake, bay, inland End_Page 334------------------------------ sea, and marine deltas. Other classifications may be based on the depth of the water bodies into which they prograde, or on basin structure. Many delta types have been described previously. Most of these have been related to the vicissitudes of sedimentary processes by which they form. Names were derived largely from the shapes of the delta shorelines. The configuration of the delta shores and many other depositional forms expressed by different sedimentary facies appear to be directly proportional to the relative relationship of the amount or rate of river sediment influx with the nature and energy of the coastal processes. The more common and better understood types, listed in order of decreasing sediment influx and increasing energy of coastal processes (waves, currents, and tides), are: birdfoot, lobate, cuspate, arcuate, and estuarine. The subdeltas of the Colorado River in Texas illustrate this relationship. During t e first part of this century, the river, transporting approximately the same yearly load, built a birdfoot-lobate type delta in Matagorda Bay, a low-energy water body, and began to form a cuspate delta in the Gulf of Mexico, a comparatively high-energy water body. Many deltas are compounded; their subdeltas may be representative of two or more types of deltas, such as birdfoot, lobate, and arcuate. Less-known deltas, such as the Irrawaddy, Ganges, and Mekong, are probably mature estuarine types. Others, located very near major scarps, are referred to the Gilbert type, which is similar to an alluvial fan. End_of_Article - Last_Page 335------------