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Southeast Asia has been actively undergoing land conversion into agricultural lands over past few decades. This creates the challenges to the nation in dealing with the non-point source pollutants in many fluvial systems, thus requiring an effective approach in sediment source apportionment for an appropriate target mitigation procedure. The trace element property from different source points was used for catchment classification of Galas River. Sediment sample collection was carried out at the sources and sink areas of the catchment system. Fine sediment was analysed using X-ray fluorescence to obtain elemental composition followed by the statistical test and numerical model. Out of 83 elements, 12 elements (Mn, Ca, Cr, Ga, Dy Hf, Y, V, Th, Pb, Zn and Sr) have been selected as best tracer signatures. The solver model has indicated Pergau River as the major sediment contributor to this large catchment system. The model output could directly be proportional with the land-use practice, indicating excessive terrestrial alteration has taken place within the sites for agricultural plantation purposes. Thus, this highly recommends for the decision-making use to the targeted areas to overcome the serious sedimentation issues caused by the tillage operation in affected stream points and to improve the watershed quality.

To study the impact of River Nestos (North Greece) dams construction on coastal morphology.

In order to study the evolution of the coastal morphology in the area, an “one‐line shoreline change model” was developed (PELNCON). The model's input comprises the field characteristics, the wave characteristics at the breaker line and a “source” term for the sediment supply rate by River Nestos. The model calculates the shoreline change over a given period of time. The annually transported sediment quantity by the river is estimated using filed measurements and other models' results for various sites along the Greek part of the hydrologic basin of Nestos (Nestos is a transboundary river extending along Greece and Bulgaria).

The “PELNCON” results demonstrate a serious erosion threat for the coastal area due to the sediment budget deficit of about 1.8 × 10⁶m³/year.

The developed model is subject to common structural weaknesses of computational modelling based on the one‐line shoreline change theory.

The developed model is user‐friendly and can be applied to any coastal area of known characteristics, providing realistic results.

This paper is an attempt to model the correlation between two large‐scale phenomena, namely coastal erosion and water/sediment management in river basins, setting at the same time the basis for further study on this particular scientific field.

Although there have been extensive studies on the hydrological and erosional impacts of logging, relatively little is known about the impacts of conversion into agricultural plantation (namely rubber and oil palm). Furthermore, studies on morphological impacts, sediment-bound chemistry and forensic attribution of deposited sediment to their respective sources are scarcer. This chapter introduces the potential for using the multi-proxy sediment fingerprinting technique in this context. Featuring pilot projects in two major flood-prone river systems in Malaysia, the studies explore application of geochemistry-based sediment source ascription. The geochemical signatures of sediment mixtures on floodplains were compared to sediments from upstream source tributaries. The tributaries were hypothesised to have different geochemical signatures in response to dominant land management. The first case study took place in the Segama River system (4,023 km²) of Sabah, Malaysian Borneo where a mixture of primary forest, logged-forests and oil palm plantations were predominant. The second case study was in the Kelantan River Basin (13,100 km²) with two major tributaries (Galas River and Lebir River) where logged-forests and rubber and oil palm plantations are dominant land-uses. Both case studies demonstrated the applicability of this method in ascribing floodplain deposited sediment to their respective upstream sources. Preliminary results showed that trace elements associated with fertilisers (e.g. copper and vanadium) contribute to agricultural catchment signatures. Alkaline and alkaline-earth elements were linked to recently established oil palm plantations due to soil turnover. Mixing model outputs showed that contributions from smaller, more severely disturbed catchment are higher than those from larger but milder disturbed catchments. This method capitalises on flood events to counter its adverse impacts by identifying high-priority sediment source areas for efficient and effective management.

Prediction of sediment yield for a particular river is essential to study the river morphology, agricultural land management and the lake/reservoir sedimentation investigation. The purpose of this research was to predict sediment yield by simulating and optimizing using model analysis from Bilate River.

Continuous daily sediment produced was estimated using sediment rating curve analysis. Sediment yield was simulated with soil and water assessment tool (SWAT) and the parameters were optimized by using Sequential Uncertainty Fitting algorithm. A total of 15 years of monthly flow and sediment yield data was calibrated and validated during the course of time.

Results evaluated through SWAT showed that the model performance was very good. From the model output prediction, the total measured and simulated sediment yield were 5.425 million ton/year and 5.538 million ton/year, respectively. The result indicates that there were high amount of soil loss resulting into sediment yield produced from the watershed per year which needs appropriate soil and water conservation techniques. Thus, the finding of this research work can provide an effective watershed/river basin management and environmental restoration.

This paper is an original research work and all the referred sources are cited properly wherever deemed fit.

To present a novel moving boundary problem related to the shoreline movement in a sedimentary basin and demonstrate that numerical techniques from heat transfer, in particular enthalpy methods, can be adapted to solve this problem.

The problem of interest involves tracking the movement (on a geological time scale) of the shoreline of a sedimentary ocean basin in response to sediment input, sediment transport (via diffusion), variable ocean base topography, and changing sea level. An analysis of this problem shows that it is a generalized Stefan melting problem; the distinctive feature, a latent heat term that can be a function of both space and time. In this light, the approach used in this work is to explore how previous analytical solutions and numerical tools developed for the classical Stefan melting problem (in particular fixed grid enthalpy methods) can be adapted to resolve the shoreline moving boundary problem.

For a particular one‐dimensional case, it is shown that the shoreline problem admits a similarity solution, similar to the well‐known Neumann solution of the Stefan problem. Through the definition of a compound variable (the sum of the fluvial sediment and ocean depths) a single domain‐governing equation, mimicking the enthalpy formulation of a one‐phase melting problem, is derived. This formulation is immediately suitable for numerical solution via an explicit time integration fixed grid enthalpy solution. This solution is verified by comparing with the analytical solution and a limiting geometric solution. Predictions for the shoreline movement in a constant depth ocean are compared with shoreline predictions from an ocean undergoing tectonic subsidence.

The immediate limitation in the work presented here is that “off‐shore” sediment transport is handled in by a “first order” approach. More sophisticated models that take a better accounting of “off shore” transport (e.g. erosion by wave motion) need to be developed.

There is a range of rich problems involving the evolution of the earth's surface. Many of the key transport processes are closely related to heat and mass transport. This paper illustrates that this similarity can be exploited to develop predictive models for earth surface processes. Such models are essential in understanding the formation of the earth's surface and could have a significant impact on natural resource (oil reserves) and land (river restoration) management.

For the most part the solution methods developed in this work are extensions of the standard numerical techniques used in heat transfer. The novelty of the work presented rests in the nature of the problems solved, not the method used. The particular novel feature is the time and space dependence of the latent heat function; a feature that leads to interesting analytical and numerical results.

Understanding the factors that contribute to the growth of sediment delta lobes in river systems has significant benefit towards protecting civil and social infrastructure from severe weather events. To develop this understanding, this paper aims to construct a three‐dimensional numerical model of a sediment delta depositing on to a two‐dimensional bedrock basement entering an ocean at a constant sea‐level.

The approach used adapts and applies techniques and schemes previously used in building numerical heat transfer models of melting systems. Particular emphasis is placed on modifying fixed grid enthalpy like schemes.

The resulting model provides important insight on the features that control the partition of sediment delta deposition between the land and ocean domains. The model also illustrates how tectonic subsidence may control the rate of delta growth.

This is the first numerical heat transfer inspired model of a three‐dimensional sediment delta deposit over both land and ocean domains. The problem has scientific merit in that it represents a melting‐like moving boundary problem with two distinct moving boundaries and a space/time dependent latent heat. Further, this work is a necessary first step towards building a comprehensive understanding of how to restore delta systems to protect civil and social infrastructure.

This study aims to provide a review for scour in complex rivers and streams with coarser bed material, steep longitudinal bed slopes and dynamic environments, in the interest of the safety and the economy of hydraulic structures. The knowledge of scour in such geographical complexities is very crucial for a comprehensive understanding of scour failures and for establishing definitive criteria to bridge this major research gap.

The existing available literature shows significant work done in case of silt, sand and small sized coarser bed material but any substantial work for bed material of gravel size or above is lacking, resulting in a wide gap. Though some researchers have attempted to explore possibilities of refining the existing models by adding pier size, shape, sediment non-uniformity and armouring effects, which otherwise have been given a miss by the various researchers, including the pioneer in the field Lacey–Inglis (1930). But still, a rational model for scour estimation in such complex conditions for global use is yet to come. This is because all the parameters governing the scour have not been studied properly till date as is evident from the globally available literature and is witnessed in the field too, in recurrent failure of hydraulic structures especially bridges.

The researchers presume that the finer materials move only as a result of erosion. However, in actual field conditions, it has been observed that the large-sized stones also roll down and cause huge erosion along the river bed and damage the hydraulic structures, especially in the steep river/stream beds along hilly slopes. This fact has been overlooked in the models available globally and has been highlighted only in the current work in an attempt to recognize this major research gap. A study carried out on a number of streams globally and in Jammu and Kashmir, India also, has shown that in steep river and stream beds with bed material consisting of gravel size or greater than gravel, large scour holes ranging from 1 m to 5 m were created by furious floods, and due to other unknown forces along the channel path and near foundations of hydraulic structures.

To the best of the authors’ knowledge, this work is purely original.

The purpose of this paper is to analyse the results of particle size profiles carried out in the dam Mãe d’água, located in the metropolitan region of Porto Alegre, Rio Grande do Sul, becoming a tool of support for geochemistry evaluation works of sediments in this basin.

The methodology comprised the particle size analysis of eight cores sampled using the extraction profile technique “Sampling Cores.” A total of 56 sub-samples were obtained at different depths, varying between 0 and 52 cm. The particle size analysis of the sub-samples was carried out with the protocol relating to Brazilian analysis standards NBR 7,181; for determination of the particle size distribution of thick sediments, the sieve method was used, and for fine sediments, the pipette method was used.

The results show that for the different depths, the sediment profiles show similarity in their sedimentary deposition layers. Cores T1, T6, T7 and T8 showed a classification with predominance of mud. Cores T2 and T5 showed variations throughout their sedimentary profile, varying of mud predominance to sand with gravel, and on cores T3 and T4, the predominant characteristic is sand with mud and sand with gravel, respectively.

It can be seen in this paper that energy of sedimentological flow reaches it in a different way, creating these three sectors (first, sand with gravel; second, sand with mud and third, mud) with different characteristics – morphodynamic and sedimentological. These characteristics are important for the study of the heavy metals on the soil and therefore for reducing the risk of contamination of water courses.

The purpose of this paper is to investigate the effectiveness of mitigation measures adopted in a scheme of EIA follow-up by examining their performance in reducing geo-environmental impacts in earthwork activities during the Rodoanel southern section construction in São Paulo, Brazil. This environment is fragile in terms of affected watersheds because the highway crosses two important reservoirs that supply most of the metropolitan water demand. Therefore, this research also aims at promoting water quality control.

This study combines complementary sources as evidences in the literature and field checks, tests and monitoring. The methodology was supported by criteria for evaluating the effectiveness of mitigation measures in the case study approach.

The EIA follow-up activities contributed to the maintenance of environmental conditions in the majority of the control points at the end of the construction phase. Water quality parameters were not statistically different before and during the construction of the highway. The choice and arrangement of mitigation measures were successful in ensuring water quality control by avoiding siltation.

A robust scheme for designing and evaluating mitigation measures contributes to the improvement of their effectiveness and is pivotal to the success of the EIA follow-up.

This case study serves as an example for extending EIA follow-up practice in special to the improvement of the design and evaluation of mitigation measures in similar contexts.