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The study's aim was to affirm the micro morphological diversity of sand grains and to uncover the relationship between morphological features of sand grains and sampling sites from various transportation environments, like wind (Aeolian), River, Lake, and beach sand samples, their surface micromorphology and geochemical analysis has been investigated using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Analysis (EDS/EDAX). Exoscopy of sand particles are very useful for knowing the dominant type and rate of sediment transportation. Four different environmental sand samples were collected in the Andhra Pradesh (AP) and Karnataka (KA) states in South India. Aeolian, River, and Beach sand samples were collected in the Anantapur, Nellore, and Vishakhapatnam districts of AP. Lake samples were collected in the Udupi district of KA. The importance of the study is to identify the rate of transportation of the sample in different environmental condition like water, and wind. The present study data can be utilized for special relevance to environmental scientists, research scholars, and planning agencies for monitoring geomorphological agents for the sustainable development of ecosystems in a well-organized way. Micro textures on sand grain surfaces show details about the past environment. Environmental processes such as wind and water produce distinctive micro textures on sand grain surfaces, which can be seen using a scanning electron microscope at high magnification. The analysis of quartz sand grains from various sedimentary environments using a scanning electron microscope (SEM) showed that some sedimentary processes impose distinct surface textures on the grains.

The development of river-delta systems possesses some stochastic characteristics even under slow-varying external conditions. In this study, two sets of repeated physical modeling experiments were conducted to explore the deterministic and non-deterministic effects of the upstream river-inflow on sedimentary configurations in lacustrine shallow-water delta. The statistical analysis of the fluctuation characteristics of sedimentations indicated a commonness of the tendency of a quasi-deterministic mature state under the same sediment supply, and also deterministically, the average value, average amplitude, and average frequency of the geometrical characteristics of sedimentations were negative, positive, and positive correlated with discharge within the Runs-Averaged works respectively; non-deterministically, some outliers of average frequencies of the sedimental indicators revealed the variation of disturbance properties around the highly-active deltaic sections, and, the exceptional average amplitudes of both the indicator of sedimental height near the inlet and the indicator of sedimental width far from the inlet demonstrated the different modes of energy transformation during the process of systematic evolution. Furtherly within the Runs-Repeated works, in low-discharge cases, the unbalanced sediment transportation along the quasi-equiprobable anticlockwise-clockwise diverging directions from the polar perspective resulted in the remarkably negative relationships of both the average amplitude of the indicator of sedimental center and average frequency of the indicator of sedimental height versus the corresponding average values; in high-discharge cases, the uncertainties of the indicator of sedimental width always become prominent accompanied by the weakening of flow instability. This study innovatively interprets a new probabilistic way of understanding the deltaic sedimentations.

The processes of rill erosion and overland flow are significantly affected by freeze-thaw cycles. Meltwater concentrated flow laboratory experiments were carried out to assess the soil erosion of different frozen conditions based on the runoff energy consumption process which own to runoff energy against the sediment transportation and terrain evolution. The experiments were performed over frozen, shallow-thawed, and unfrozen soil-filled flumes under 1, 2, and 4 L/min flow rates with the temperature around 5 °C. The results imply that soil erosion became more severe with increasing flow rate. Variation rate of the soil erosion rate of frozen slope was highest under 1 and 2 L/min flow rates due to lower infiltration of water into soil. Variation in runoff energy consumption variation with flow time presented significant differences under unfrozen, shallow-thawed, and frozen slopes at equal runoff rate (p

Suspended particulate matter concentration (SPM) in coastal waters is of great importance for studying sediment resuspension and sediment transportation, especially for the profile distribution in bodies of water. The traditional SPM profile-obtaining method that uses a turbidity meter introduces large uncertainty for pigment particle-dominated waters. This research used a large amount of profile data on optical properties and hydrological measurements parameters (conductivity-temperature-depth (CTD), chlorophyll and turbidity), which were measured synchronously in the Bohai Sea and Yellow Sea; the data were used to analyze the relationships between the vertical distribution of the particulate backscattering ratio and the vertical distribution of pycnocline, chlorophyll and turbidity and to distinguish pigment particles and sediment particles in the vertical distribution. After considering the particle types, we also developed a novel method that exclusively depended on conventional hydrological measurements. The results show that the new method is simplified and effective and could significantly improve the accuracy of SPM estimations in coastal waters.

The assessment of the eco-environmental benefits of rivers has important guiding significance for improving water resource management, establishing water resource protection mechanisms, and maintaining river health. In view of the current imprecise quantitative methods of determining the eco-environmental benefits of rivers and based on the viewpoint of ecology, the significance and composition of river eco-environmental benefits were discussed. An emergy theory was introduced to quantify both the solar transformity of subtypes of water bodies and the sediment transportation benefit, which improved the indicator system of eco-environmental benefits. Applying the indicator system to the management practice of the Yellow River Basin, the eco-environmental benefits in 2015 were calculated by dividing the Yellow River into 66 sections. A Geographic Information System (GIS) atlas was then used to describe their spatial distribution. Eight typical cities were selected for the key analysis. Among these eight cities, the eco-environmental benefit inside the river in Xi’an section is the largest with a total emergy benefit of 1.08 × 1021 solar equivalent joules (sej) and a corresponding monetary benefit of 28.03 Chinese Yuan (¥)/m3. The eco-environmental benefit outside the river in Jinan section is the largest with a total emergy benefit of 1.37 × 1020 sej and a corresponding monetary benefit of 12.39 ¥/m3. This study proposed that rivers have great eco-environmental benefits, and the harmonious development of economy, society, and environment should be pursued in water resources management.

Most research conducted on the concentration distribution of sediment in the sedimentation tank does not consider the role of the suction dredge. To analyze concentration distribution more accurately, a suspended sediment transportation model was constructed and the velocity field in the sedimentation tank was determined based on the influence of the suction dredge. An application model was then used to analyze the concentration distribution in the sedimentation tank when the suction dredge was fixed, with results showing that distribution was in accordance with theoretical analysis. The simulated value of the outlet concentration was similar to the experimental value, and the trends of the isoconcentration distribution curves, as well as the vertical distribution curves of the five monitoring sections acquired through simulations, were almost the same as curves acquired through experimentation. The differences between the simulated values and the experimental values were significant.

Reef-islands on the rims of atolls are deposits of unconsolidated reef sediment that have accumulated as a result of sediment transportation processes. Reef-islands appear especially vulnerable to changing environmental conditions particularly regarding the impact of sea-level rise. The morphodynamic processes involved in the development of these landforms, however, are poorly understood and difficult to observe over long time periods. Several conceptual models of reef-island development have been proposed that offer insights into reef-island behaviour, particularly where these models can be implemented in a computational framework. This paper presents an aggregated-scale behaviour-oriented model that simulates sediment accumulation on an atoll rim. A requirement of the behaviour-based modeling approach is that the model parameters need to be determined for each application of the model. An inversion algorithm is used to estimate values for model parameters, including the maximum volume of the island and the sediment production rate. The model provides a framework for experimentation with modes of island development, links sediment production to the observed morphology of the reef-island, and quantifies the limits to reef-island development.

Persian Abstract: سدها همواره در طول چندین قرن گذشته بنا به دلایل مختلف از جمله کمبود و کاهش تدریجی منابع آب شیرین مورد توجه قرار گرفته اند. بسیاری از سدها در نزدیکی شهرها و به منظور تامین آب شرب و صنعت ساخته شده اند. لذا بررسی این دسته از سدها چه از لحاظ ضریب ایمنی و چه از لحاظ ظرفیت های گنجایش سیلاب بسیار حائز اهمیت میباشد. شکست سد می بایستی از جهات مختلف مورد بررسی قرار گیرد. افزایش ناگهانی آب پشت سد ناشی از سیلابهای بزرگ، تراوش در بدنه سدخاکی، سرریز آب از تاج سد به دلیل عملکرد نامناسب سرریزها و... ممکن است باعث تخریب سدها شود. هدف اصلی در این پایان نامه مدلسازی شکست سد، روندیابی سیلاب و تعیین پهنه سیلاب حاصل از شکست سد با استفاده از نرم افزارهای HEC-RAS, HECGEO-RAS ,ARC GIS می باشد. در انتها و از نتایج خروجی نرم افزار در مرحله مدلسازی نیز برنامه اقدامات اضطراری (EAP) سد مربوطه تهیه و ارائه خواهدشد. طبق مطالعات صورت گرفته و تجربیات مهندسین در زمینه شکست سد مجموعه اقدامات قسمت دوم (بعد از تخریب سد) مورد توجه بیشتر قرار گرفته و سعی شده است با پهنه بندی سیل ناشی از شکست سد(به کمک مدلسازی)، مناطقی از شهر را که در معرض خطر سیل گرفتگی قرار دارند شناسایی شوند. برای این منظور یکی از سدهای خاکی کشور که در نزدیکی شهرها ساخته شده است را مورد بررسی قرار خواهیم داد. سد مورد مطالعه سد شهر چای در استان آذربایجان غربی است که در بالا دست شهر ارومیه بنا شده است. کلمات کلیدی: 1- پهنه بندی سیلاب 2- شکست سد خاکی 3- سد شهرچای ارومیه 4- HECRAS English Abstract: Dams had always been prominent during past centuries due to several reasons, such as water deficiency and the gradual reduction in water resources. Many dams are built close to cities to provide water for drinking and industries; thus, it’s vital to consider them in the aspects of safety factor and capacity to contain the overflow. Failure of the dames should include different features, for instance, a sudden increase in stored water behind the dam as a result of massive floods, leakage in the body of soil dams, overflow in the dam crest due to insufficient functionality of spillway, etc. The primary purpose of this thesis is to model dam failure, flood forecasting, and determination of the flooded regions using ArcGIS, HEC-GeoRAS, and HEC-RAS. The case study was a large dam, Shahrchai Dam, which is built on the upstream of Urmia City, a city on the NorthWest of Iran with more than one million population. The results from modeling were used to provide an emergency action plan (EAP) for Urmia City.

An algorithm to extract exposure and inundation data from up to 1 year of published tide table data has been developed and implemented on a microcomputer. The timing of individual exposure-inundation events is calculated, along with the duration of each episode for a range of levels above tidal datum. This provides a forecast of beach accessibility. Subsidiary programs derive exposure-inundation statistics such as the total, mean, and maximum duration of each episode. These factors influence the vertical zonation of beach environments. The vertical velocity of the tide also is estimated for each level on the beach. This can be converted to over-beach velocity providing beach gradient is known. Another program calculates the duration of “still-water level” within selected vertical ranges, providing an index of waveenergy distribution, ice grounding phenomena, and probability of oil pollution. The approach has been tested at Frobisher Bay, Northwest Territories, Canada where maximum tides of as much as 10 m range cover extensive tidal flats. Maximum exposure and inundation times increase steadily up to minimum high and low tide respectively, beyond which they increase rapidly, but irregularly. Tide velocities exceed sediment transportation thresholds, especially in the mid-tidal range. Still-water duration peaks at both the mid-high and low-tide levels for simple semidiurnal tides. The programs provide an inexpensive way of categorizing tidal effects on the beach environment.

The paper presents quantitative aspects of sediment transportation typical for some Rumanian natural watercourses expressed as empirical, semi-empirical and theoretical relation-ships which have been established on the basis of the analysis and processing of field measurement data collected during several years on these rivers. All these analytical relationships, correlated with river hydraulic resistance aspects, have been generalized on the basis of similar measurements data collected on three American rivers.