Siltation

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

Formation and Evolution of Chaohu

Abstract: On the lake around since the late Pleistocene sediments,pollen,14C age,ancient culture,such as a large number of archaeological data analysis,and TM satellite images using image processing,extraction of the vegetation and soil moisture conditions and other characteristics,combined with the layout of ancient ruins point distribution and the relationship between the ancient river of information complex,and information according to historical records,the fall of Chaohu Lake is due to faults formed lakesDetermine the lake from the scope of the original formation and evolution of the process to form the present lake,Chaohu Lake from the formation,the area gradually expanded,due to climatic,tectonic and sediment siltation and human in modern times a large number of reclaiming land from lakes and shrinking current shape

Loss of ignition as a proxy indicator for assessing the lithological composition of the recent sediments accumulated in some freshwater lakes from the Danube Delta, Romania

Abstract: The paper asserts the percent horizontal and vertical distribution of the main lithological components (the total organic matter, total carbonates and minerogenic clastic fraction) in the grab surface layer and core sediment samples of some fluvial - Danubian lakes. The study is corroborated on the analysis of 144 grab sampling stations and 6 Hydro-Bios sediment cores collected during 2010-2013. Evaluations of the above mentioned parameters considered in surface sediments, and in samples from distinct cores have been defined by Loss on Ignition (LOI) method. By using the total organic matter concentration results in the grab sediment, as a proxy, it was tried to be pursued the source of the organic matter input into the lakes during the recent period. Evaluating the mean areal distribution values of the total organic matter, the shallow water depth, and assuming the autochthonous input as a main contributing source, it was exhibited that the investigated lakes are over-supplied with organic material, passing through a continuous shallowing environments due to a strong siltation of the canals and streams. The assessment of the vertical distribution results reported a distinctive pattern with infrequent dominantly organic layers interposed with sequences of minerogenic clastic contents. These fluctuations indicate seasonal shifts that have repercussion on the depositional environment conditions on some moments in time. The results obtained by LOI method yields excellent, medium or small correlation between the variations in the investigated parameters.

Boukourdane (algeria): a reservoir dam with low siltation rate

Abstract: This article discusses hydraulic phenomenon’s that pose enormous problems for dam managers. This is the phenomenon of silting which decreases over time the useful volume of the dam and closes the discharge sluices. In Algeria, 20 dams are threatened by rapid silting of the reservoir. However, more than 30 dams have low rate of siltation. Our study focuses on the silting of the reservoir dam Boukourdane. On the bathymetric database and investigative missions to the dam site, it appears that the siltation rate for Boukourdane reservoir dam is 0.3 million m 3 /year, a filling speed equal to 0.28%/year. A value well below the threshold of 1%/year which ranks as the Boukourdane dam low rate of siltation dam. His life was estimated to be over 300 years.

Tracer elements revealed the soil organic carbon sources in a dam-controlled watershed

Abstract: The dynamics of the soil organic carbon (SOC) pool and the mechanisms that underpin those dynamics are at the frontier of terrestrial carbon (C) cycling research. Soil erosion seriously affects the migration and redistribution of SOC, driving a critical part of the C cycle. In this study, soil samples were collected from a 14.69 m sediment profile formed between 1960 and 2017, which was located in a small agricultural catchment on the Loess Plateau in northwest China. Nuclear tracer elements (137Cs, 210Pb) and stable C isotopes (δ13C) from organic matter were used to quantitatively identify the SOC sources in different siltation stages. The method used assumes that the contribution of a source is proportional to the elemental concentration in that source. SOC in soil samples from different erosion source areas (farmland, forest land, grassland, shrub land and ditch wall) were compared against the deposit in the check dam. The concentration of SOC in the sediments of the check dam was between 1.21 g kg−1 and 4.03 g kg−1. Nearly half of the SOC in the check dam sediments was traced back to the ditch wall. Farmland contributed 24.8 %, while shrub land contributed the least SOC at 0.4 %. SOC erosion attributed to farmland decreased gradually, while the relative contribution from the ditch wall increased. Within the agricultural catchment area, there was a net migration of SOC from the various land cover types (the source) to the sedimentary area behind the dam (the sink). These results indicate that a dynamic balance exists between redistribution and heterotopic storage of SOC during sedimentation. This study provides an opinion for sediment source identification and the soil C cycle in watersheds on the Loess Plateau.