A Study of Sediment Yield in the Deji Reservoir Watershed Using Risk Analysis

2020 ◽  
Author(s):  
Wen Wei Chang ◽  
Chao Yuan Lin
Keyword(s):  
Risk Analysis ◽  
Sediment Yield ◽  
Risk Model ◽  
Delivery Ratio ◽  
Sediment Delivery Ratio ◽  
Topographic Wetness Index ◽  
Sediment Delivery ◽  
Good Relationship ◽  
Reservoir Watershed ◽  
Scs Cn

<p>Deji Reservoir Watershed was used as a sample site to understand the sediment yield using risk analysis. The historic typhoon and/or torrential storm events were collected to estimate the excessive runoff for each event. The distribution of SCS-CN is obtained by combining the maps of land use and soil texture, and the excess rainfall (Pe) and the maximum water storage (S) for each event were then calculated according to SCS-CN. Regression analysis shows that there is a good relationship between estimated runoff (x) and measured runoff (y); y=0.9561x+3*10<sup>6</sup>, R<sup>2</sup>= 0.9414. Topographic wetness index (TWI) and sediment delivery ratio (SDR) were derived from DEM. The risk model developed to assess the sediment yield is calculated from the multiplication of hazard (Pe), vulnerability (TWI), and exposure (SDR). The total siltation amount of Deji Reservoir from 2009 to 2017 was taken as the measured value, and the estimated amount of sediment yield was calculated from the aforementioned formula  to obtain the potential index of sediment yield. The results show that there is also a good relationship between estimated sediment yield (x') and measured sediment yield (y') annually; y'=10<sup>-11</sup>x'<sup>2</sup>-0.0223x'+9*10<sup>6</sup> , R<sup>2</sup>= 0.74.</p><p>Keywords: Risk Analysis, Curve Number, Sediment Delivery Ratio</p>

KAJIAN EROSI LAHAN DI KAWASAN AIR STRIP RUNWAY 2600 BANDARA DEPATI AMIR (PGK) BERDASARKAN TATA GUNA LAHAN MASTERPLAN ULTIMATE

2019 ◽  
Vol 7 (2) ◽  
pp. 100-111
Author(s):  
Miskar Maini ◽  
Junita Eka Susanti
Keyword(s):  
Sediment Yield ◽  
Soil Loss ◽  
Universal Soil Loss Equation ◽  
Delivery Ratio ◽  
Sediment Delivery Ratio ◽  
Sediment Delivery ◽  
Soil Loss Equation

Standar permintaan engineering pesawat agar desain bangunan infrastruktur di area Air Strip Runway 2600 yang ada dapat mempunyai fungsi lain. Sedangkan kondisi lain sangat menentukan keselamatan karena lahan di sekitar Air Strip Runway 2600 Bandara Depati Amir (PGK) jika tidak ditutupi vegetasi seperti rumput, kondisi lain lahan yang belum ditutupi vegetasi di sekitar Air Strip Runway 2600 berpotensi akan mengalami erosi lahan, kemudian hasil erosi lahan ini akan terbawa oleh aliran air sehingga akan masuk ke saluran drainase yang akan menyebabkan sedimentasi pada saluran drainase tersebut, akhirnya akan berkurang efektifitas kinerja saluran drainase tersebut. Metode yang digunakan untuk memprediksi laju rata-rata erosi di area Air Strip Runway 2600 dengan memperhitungkan faktor erosivitas hujan, erodibilitas tanah, kemiringan lereng atau panjang lereng, pengelolaan tanaman dan konservasi tanah, yang masing masing tata guna lahan tersebut mengacu pada Masterplan Ultimate Bandara Depati Amir (PGK). Perhitungan dilakukan menggunakan persamaan USLE (Universal Soil Loss Equation) yang dikembangkan oleh Wischmeier dan Smith (1965, 1978), kemudian Sediment Delivery Ratio (SDR) dan Sediment Yield.Hasil penelitian ini, prediksi laju erosi permukaan pada area Air Strip Runway 2600 Bandara Depati Amir (PGK) tahun pertama yang mencapai 5,60 mm/tahun atau 100,76 Ton/Ha/tahun, laju erosi tahun kedua mencapai 3,38 mm/tahun atau 60,84 Ton/Ha/tahun dapat diklasifikasikan ke dalam kelas bahaya erosi sedang (kelas III) dan nilai SDR adalah sebesar 56,3%, nilai sediment yield (SR) pada tahun pertama sebesar 5.887,59 Ton/Tahun, pada tahun kedua ketika rumput pada area Air Strip telah tumbuh dengan sempurna terjadi penurunan hasil sediment yield yaitu nilai SR sebesar 3.554,85 Ton/Tahun.

Soil Sediment Loading and Related Environmental Impacts from Farms

2017 ◽  
Author(s):  
Vito Ferro
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Erosion ◽  
Sediment Yield ◽  
Water Storage ◽  
Sediment Deposition ◽  
Delivery Ratio ◽  
Sediment Delivery Ratio ◽  
Sediment Delivery ◽  
Soil Particles

Beyond damage to rainfed agricultural and forestry ecosystems, soil erosion due to water affects surrounding environments. Large amounts of eroded soil are deposited in streams, lakes, and other ecosystems. The most costly off-site damages occur when eroded particles, transported along the hillslopes of a basin, arrive at the river network or are deposited in lakes. The negative effects of soil erosion include water pollution and siltation, organic matter loss, nutrient loss, and reduction in water storage capacity. Sediment deposition raises the bottom of waterways, making them more prone to overflowing and flooding. Sediments contaminate water ecosystems with soil particles and the fertilizer and pesticide chemicals they contain. Siltation of reservoirs and dams reduces water storage, increases the maintenance cost of dams, and shortens the lifetime of reservoirs. Sediment yield is the quantity of transported sediments, in a given time interval, from eroding sources through the hillslopes and river network to a basin outlet. Chemicals can also be transported together with the eroded sediments. Sediment deposition inside a reservoir reduces the water storage of a dam. The prediction of sediment yield can be carried out by coupling an erosion model with a mathematical operator which expresses the sediment transport efficiency of the hillslopes and the channel network. The sediment lag between sediment yield and erosion can be simply represented by the sediment delivery ratio, which can be calculated at the outlet of the considered basin, or by using a distributed approach. The former procedure couples the evaluation of basin soil loss with an estimate of the sediment delivery ratio SDRW for the whole watershed. The latter procedure requires that the watershed be discretized into morphological units, areas having a constant steepness and a clearly defined length, for which the corresponding sediment delivery ratio is calculated. When rainfall reaches the surface horizon of the soil, some pollutants are desorbed and go into solution while others remain adsorbed and move with soil particles. The spatial distribution of the loading of nitrogen, phosphorous, and total organic carbon can be deduced using the spatial distribution of sediment yield and the pollutant content measured on soil samples. The enrichment concept is applied to clay, organic matter, and all pollutants adsorbed by soil particles, such as nitrogen and phosphorous. Knowledge of both the rate and pattern of sediment deposition in a reservoir is required to establish the remedial strategies which may be practicable. Repeated reservoir capacity surveys are used to determine the total volume occupied by sediment, the sedimentation pattern, and the shift in the stage-area and stage-storage curves. By converting the sedimentation volume to sediment mass, on the basis of estimated or measured bulk density, and correcting for trap efficiency, the sediment yield from the basin can be computed.

scholarly journals Estimating sediment delivery ratio by stream slope and relief ratio

2018 ◽  
Vol 192 ◽  
pp. 02040 ◽  
Author(s):  
Kieu Anh Nguyen ◽  
Walter Chen
Keyword(s):  
Soil Erosion ◽  
Storage Capacity ◽  
Length Ratio ◽  
Delivery Ratio ◽  
Sediment Delivery Ratio ◽  
Sediment Delivery ◽  
Transportation Process ◽  
Shihmen Reservoir ◽  
Reservoir Watershed ◽  
Steep Terrain

Nowadays, the storage capacity of a reservoir reduced by sediment deposition is a concern of many countries in the world. Therefore, understanding the soil erosion and transportation process is a significant matter, which helps to manage and prevent sediments entering the reservoir. The main objective of this study is to examine the sediments reaching the outlet of a basin by empirical sediment delivery ratio (SDR) equations and the gross soil erosion. The Shihmen reservoir watershed is used as the study area. Because steep terrain is a characteristic feature of the study area, two SDR models that depend on the slope of the mainstream channel and the relief-length ratio of the watershed are chosen. It is found that the Maner (1958) model, which uses the relief-length ratio, is the better model of the two. We believe that this empirical research improves our understanding of the sediment delivery process occurring in the study area.

scholarly journals MODELLING RESERVOIR SEDIMENTATION AT BIN EL OUIDANE DAM, MOROCCO

AGROFOR ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
El Mouatassime SABRI ◽  
Ahmed BOUKDIR ◽  
Rachid El MASLOUHI ◽  
Mustapha MABROUKI ◽  
Abdellah EL MAHBOUL ◽  
...  
Keyword(s):  
Information System ◽  
Soil Erosion ◽  
Sediment Yield ◽  
Delivery Ratio ◽  
Reservoir Sedimentation ◽  
Mountainous Areas ◽  
Sediment Delivery Ratio ◽  
Sediment Delivery ◽  
Sparse Vegetation ◽  
Bin El Ouidane

This study was conducted in the Oued El Abid watershed upstream of the Bin ElOuidane dam, in Tadla-Azilal province (Morocco) to quantify the dam siltationrates. To assess the annual soil erosion and the sediment yield the universal soilloss equation (USLE) was used. A geographic information system (GIS) was usedto generate and integrate maps of the USLE factors. A spatial distribution of soilerosion in the Oued El Abid watershed was obtained. The soil erosion wasdetermined for each rural commune in order to identify the soil erosion hotspot andestimate the amount of soil that has been transported downstream (Bin El OuidaneDam). Soil erosion ranged from very limited values for flat and well covered areasto over 2100 t /ha/y in mountainous areas with sparse vegetation. The total annualsoil loss within the watershed is estimated at 19. 6 million tons per year. Anequation of sediment delivery ratio (SDR) based on river gradient was calculated.It was found that the value of SDR at the outlet of the watershed Oued El Abid was0. 65 with a sediment yield of 12. 74 million tons per year which affect thedurability of the dam.

scholarly journals Evaluation of the SEdiment Delivery Distributed (SEDD) Model in the Shihmen Reservoir Watershed

2020 ◽  
Vol 12 (15) ◽  
pp. 6221
Author(s):  
Kent Thomas ◽  
Walter Chen ◽  
Bor-Shiun Lin ◽  
Uma Seeboonruang
Keyword(s):  
Sediment Yield ◽  
Economic Cost ◽  
Future Research ◽  
Delivery Ratio ◽  
Sediment Delivery ◽  
Sediment Control ◽  
Watershed Prioritization ◽  
Aerial Photogrammetry ◽  
Shihmen Reservoir ◽  
Reservoir Watershed

The sediment delivery ratio (SDR) connects the weight of sediments eroded and transported from slopes of a watershed to the weight that eventually enters streams and rivers ending at the watershed outlet. For watershed management agencies, the estimation of annual sediment yield (SY) and the sediment delivery has been a top priority due to the influence that sedimentation has on the holding capacity of reservoirs and the annual economic cost of sediment-related disasters. This study establishes the SEdiment Delivery Distributed (SEDD) model for the Shihmen Reservoir watershed using watershed-wide SDRw and determines the geospatial distribution of individual SDRi and SY in its sub-watersheds. Furthermore, this research considers the statistical and geospatial distribution of SDRi across the two discretizations of sub-watersheds in the study area. It shows the probability density function (PDF) of the SDRi. The watershed-specific coefficient (β) of SDRi is 0.00515 for the Shihmen Reservoir watershed using the recursive method. The SY mean of the entire watershed was determined to be 42.08 t/ha/year. Moreover, maps of the mean SY by 25 and 93 sub-watersheds were proposed for watershed prioritization for future research and remedial works. The outcomes of this study can ameliorate future watershed remediation planning and sediment control by the implementation of geospatial SDRw/SDRi and the inclusion of the sub-watershed prioritization in decision-making. Finally, it is essential to note that the sediment yield modeling can be improved by increased on-site validation and the use of aerial photogrammetry to deliver more updated data to better understand the field situations.

scholarly journals PREDICTING SOIL EROSION AND SEDIMENT YIELD IN THE TAPACURÁ CATCHMENT, BRAZIL

2014 ◽  
pp. 75-82 ◽  
Author(s):  
Richarde Marques Da Silva ◽  
Celso A. G. Santos ◽  
Alexandro Medeiros Silva
Keyword(s):  
Sediment Yield ◽  
Quantitative Estimation ◽  
Delivery Ratio ◽  
Sediment Delivery Ratio ◽  
Sediment Delivery ◽  
Resources Management ◽  
Erosion Coefficient ◽  
Erodibility Coefficient ◽  
Empirical Coefficients ◽  
Annual Sediment

The EPM is a model for qualifying the erosion severity and estimating the total annual sediment yield. The EPM uses empirical coefficients (erodibility coefficient, protection coefficient and erosion coefficient) and a matrix of the basin physical characteristics. The EPM gives a quantitative estimation of erosion intensity as well as the estimation of sediment yield and transportation. To analyze the suitability of the Gavrilovic method for use with GIS techniques, we prepared cartographic data on geology, pedology, slope, temperature and land use in digital form. A raster-based Geographic Information System (GIS) was applied to generate the erosion-severity and sediment yield maps. In order to validate the EPM estimated erosion, data annual sediment yield were collected between 1999 and 2007. The results showed a mean sediment delivery ratio (SDR) of around 8% and a calculated mean sediment yield of 0.108 t/ha/year, which is close to the observed one, 0.169 t/ha/year. The obtained soil loss map could be considered as a useful tool for environmental monitoring and water resources management.

scholarly journals Different approaches to estimate the sediment yield in a tropical watershed

RBRH ◽  
2018 ◽  
Vol 23 (0) ◽  
Author(s):  
Carina Barbosa Colman ◽  
Karina Mendes Pinheiro Garcia ◽  
Rodrigo Bahia Pereira ◽  
Enio Arriero Shinma ◽  
Fernanda Ely Lima ◽  
...  
Keyword(s):  
Sediment Yield ◽  
Soil Loss ◽  
Delivery Ratio ◽  
Ungauged Basins ◽  
Sediment Delivery Ratio ◽  
Sediment Delivery ◽  
Yield Values ◽  
Sdr Model ◽  
Tropical Watershed ◽  
Soil Loss Equation

ABSTRACT Several Sediment Delivery Ratio (SDR) models have been used to estimate Sediment Yield (SY), mainly in data-scarce and ungauged basins, such as in many regions of Brazil. However, it is difficult to choose the most suitable SDR model, mainly because of the lack of investigations of this approach using observed data. Here, we investigated the performance of five widely used SDR models (SDREST) to estimate sediment yield values (SYEST ) based on observed data in a tropical watershed. We used observed sediment yield values (SY OBS) during September 2011 to July 2017 in three sub-basins of the Guariroba Basin, Midwestern Brazil. To estimate the average annual soil loss, we used the Revised Universal Soil Loss Equation. The SDROBS and SYOBS ranged from 5.56 to 10.54% and 940.76 to 5,400.32 t yr-1, respectively. The Williams and Berndt (1972) method presented the best performance, with a percent bias ranging from -2.34 to 3.30% in SRD estimation. Therefore, this model provided suitable SDR and SY estimates, and may be useful to estimate SY in other tropical data-scarce and ungauged basins.

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