Siltation

About: Siltation is a research topic. Over the lifetime, 1420 publications have been published within this topic receiving 20983 citations.

National Markets and the Impacts of State Land Use and Environmental Programs

Abstract: Environmental and resource quality recently have become special public concerns. A few states have already enacted legislation posing land use-environmental restrictions. Vermont, Hawaii, Colorado, Maine, Massachusetts and New York, passed land use laws. Illinois formed a Pollution Control Board to quantify nutrients and sediment polluting streams and suggest action. In 1971, the Iowa Legislature passed the “Conservancy District Act,” creating soil conservancy districts “to preserve and protect public interest in soil and water resources for future generations.” Legislation centers on soil erosion and sedimentation. Erosion is declared a nuisance if it results in siltation damage. The law sets allowable soil loss limits on land at one to five tons per acre per year, depending on soil type.

Rain pipe silt collecting device for river channel silt prevention

Abstract: The utility model relates to a water conservancy facility, in particular to a rain pipe silt collecting device for river channel silt prevention. The rain pipe silt collecting device for river channel silt prevention is characterized in that a collecting well is arranged in the position, close to the river bank, of a rain pipe, so that rainwater firstly flows into the collecting well in the pipeline, precipitates, flows into the pipeline again and is discharged into the river channel. A well lid can be arranged on the collecting well, silts precipitating in the collecting well can be cleaned periodically, and the siltation volume of the river channel can be reduced.

Aspects of optimization of soil erosion control systems.

Abstract: In recent decades we are witnessing a rapidly expanding areas affected by soil erosion (both hydric and wind erosion) and the disastrous consequences of this natural phenomenon in all continents. Soil degradation is an ancient process that cannot be stopped completely, only controlled, appeared with agriculture, but its extent and impact on the environment are currently more alarming. The negative effects of this process are: reducing the production capacity of ecosystems, global climate change and the environment in general, deterioration of human food resources, undermining economic development. The consequences of erosion on national economies are multiple: direct (agricultural production losses, floods, silting etc.), and indirect: degradation of pastures, that pushing grazing in forests, so their degradation; chaotic modification of runoff drainage regime on slopes which removes required water from vegetation; appearance of rapid floods, producing significant damages; increased river discharges; floods; entrainment, destruction and transportation of particles that form fertile soil horizon. Soil erosion control system include all activities and works which providing the administration of public domain of land, with local / national interest, and their sustainable management. Soil erosion control arrangements, consisting in general from a set of hydrotechnical structures and non-structural measures, produce both a favorable and unfavorable influences on environment. Their different constructive and exploitation solutions exercise a significantly impact on the environment. Therefore the advantages and disadvantages of each solution must be weighed and determined to materialize one or other of them seriously argued. The optimization of soil erosion control systems is needed to meet current and future requirements in the field of rational land management in the context of integrated management. Optimization process of soil erosion control systems includes several components related to environmental protection, technical side and the business side. This paper summarizes the main aspects and possibilities of optimization of existing soil erosion control systems and those that are to be achieved.

Reservoir sedimentation and estimating dam storage capacity using bathymetry survey: a case study of Abrajit Dam, Upper Blue Nile basin, Ethiopia

Abstract: This specific study was conducted on the Abrajit reservoir in east Gojjam, Amhara region, Ethiopia. The general objective of the study was to investigate reservoir siltation and determination of the remaining valuable life span of the reservoir using ArcGIS 10.5 version and Golden surfer 16 latest version. A bathymetric survey using echo-sounding equipment (Garmin GPSMAP421s) was conducted and a topo map of reservoir data was used for assessment of the sediment volume. The accumulated sediment volume was estimated by subtracting the triangular interconnected network (TIN) map of the initial bed level from the currently measured bed level. The result of the research revealed that to date, 343,700.1 m3 bulk of sediment was accumulated in the reservoir that reduces 20% of the total reservoir capacity. In the results from the bathymetric investigation and software analysis, annually 28,641.675 m3 year−1 amount of sediment is coming from the catchments to the reservoir that contributed 1.66% of annual reservoir volume reduction. The measured recent storing capacity for the Abrajit Dam was 1,388,870 m3. From a comparison of remaining reservoir storage and annual sediment load, the reservoir will not serve more than 12 years. The estimated specific sediment yield (SSy) was found to be 4733.387 ton km−2 year−1. Therefore, to improve the estimated life span of the reservoir, watershed management is very important and further study is required to identify the area where watershed conservation will focus in the future. Upon the findings, the reservoir volume is running to reduce and it cannot serve all the demand what it designed for during the dry season. As a result, operation curves should be mandatory to give water service for the critical water needs, and regular monitoring of sediment accumulation in the reservoir is recommended.