Range Condition as Used in the Soil Conservation Service

Author(s):  
Donald T. Pendleton
2018 ◽  
Vol 8 (1) ◽  
pp. 31-40
Author(s):  
Amitai Silva Lima Junior ◽  
Rose Mary Gondim Mendonça ◽  
Paula Raquel Barreto Rodrigues ◽  
Domingos Bonfim Ribeiro dos Santos ◽  
Thaynan Gomes Andrade

O presente trabalho tem por objetivo caracterizar o solo de uma área susceptível a alagamento no município de Palmas/TO e analisar se o mesmo suporta as limitações para implantação da trincheira drenante como sistema drenante alternativo de baixo custo.Os resultados dos ensaios geotécnicos do solo e a análise granulométrica demostraram que o solo é areno siltoso com pequena quantidade de pedregulho, e 55 % de finos, a classificação conforme o Soil Conservation Service o solo se enquadra como solos arenosos com baixo teor de argila total, a massa especifica grão foi de 2,65 g/cm3, devido à presença do mineral quartzo e caulinita. O índice de plasticidade foi de 17,2% valor que estabelece a plasticidade do solo como altamente plástica.  Conforme a Carta de Plasticidade de Casagrande, a amostra de solo pode ser classificada comosolos argilosos de baixa compressibilidade. Os ensaios de dispersão rápida com submersão em solução de 0.001 N de hidróxido de sódio, o solo é classificado como sendo não dispersivo. O ensaio de desagregação do solo a reação da amostra à inundação foi a de faturamento. Os valores de condutividade hidráulica vertical encontrados para o anel metálico, foi de 49,284 mm/h, determinando que o solo e correlacionável a franco arenoso. Conclui –se que solo tem a capacidade de suporte da trincheira possuindo condutibilidade hidráulicae possui caráter não dispersivo, enquanto que o de desagregação indica um índice de colapsibilidade baixo.


2014 ◽  
Vol 16 (1) ◽  
pp. 188-203 ◽  

<div> <h1 style="text-align: justify;"><span style="font-size:11px;"><span style="font-family:arial,helvetica,sans-serif;">In this paper, the application of a continuous rainfall-runoff model to the basin of Kosynthos River (district of Xanthi, Thrace, northeastern Greece), as well as the comparison of the computational runoff results with field discharge measurements are presented. The rainfall losses are estimated by the widely known Soil Conservation Service-Curve Number model, while the transformation of rainfall excess into direct runoff hydrograph is made by using the dimensionless unit hydrograph of Soil Conservation Service. The baseflow is computed by applying an exponential recession model. The routing of the total runoff hydrograph from the outlet of a sub-basin to the outlet of the whole basin is achieved by the Muskingum-Cunge model. The application of this complex hydrologic model was elaborated with the HEC-HMS 3.5 Hydrologic Modeling System of the U.S. Army Corps of Engineers. The results of the comparison between computed and measured discharge values are very satisfactory.</span></span></h1> </div> <p>&nbsp;</p>


2017 ◽  
Vol 10 (2) ◽  
pp. 233-241
Author(s):  
Franciane Mendonça Dos Santos ◽  
José Augusto Lollo

This study was developed at Caçula stream watershed of Ilha Solteira (Brazil) for potential infiltration estimation based on digital cartography. These methods aim at low-cost and quick analysis processes in order to support the territorial planning. The preliminary potential infiltration chart was produced using ArcHydro and pedological information of the study area. The curve-number method (Soil Conservation Service) was used to determine the potential infiltration combining information related to land-use and soil types in the watershed. We also used a methodology that assumes being possible to evaluate potential infiltration of a watershed combining average annual rainfall, land-use and watershed natural attributes (geomorphology, geology and pedology). Results show that ArcHydro is efficient for a preliminary characterization because it shows flow accumulation areas, allowing higher potential of degradation areas in terms of floods, mass movement and erosion. As land-use classes have significant weight in Soil Conservation Service method assessing potential infiltration, this method allow us to evaluate how land-use changes affect water dynamic in the watershed. The propose based on natural environment attributes enables to determine the homologous infiltration areas based on a higher number of natural characteristics of the area, and thereby obtain a result that is closer to the local conditions and, consequently for degradation surface processes identification.


Hydrology ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 21 ◽  
Author(s):  
Bitew G. Tassew ◽  
Mulugeta A. Belete ◽  
K. Miegel

Understanding the complex relationships between rainfall and runoff processes is necessary for the proper estimation of the quantity of runoff generated in a watershed. The surface runoff was simulated using the Hydrologic Modelling System (HEC-HMS) for the Gilgel Abay Catchment (1609 km2), Upper Blue Nile Basin, Ethiopia. The catchment was delineated and its properties were extracted from a 30 m × 30 m Digital Elevation Model (DEM) of the Lake Tana Basin. The meteorological model was developed within HEC-HMS from rainfall data and the control specifications defined the period and time step of the simulation run. To account for the loss, runoff estimation, and flow routing, Soil Conservation Service Curve Number (SCS-CN), Soil Conservation Service Unit Hydrograph (SCS-UH) and Muskingum methods were used respectively. The rainfall-runoff simulation was conducted using six extreme daily time series events. Initial results showed that there is a clear difference between the observed and simulated peak flows and the total volume. Thereafter, a model calibration with an optimization method and sensitivity analysis was carried out. The result of the sensitivity analysis showed that the curve number is the sensitive parameter. In addition, the model validation results showed a reasonable difference in peak flow (Relative Error in peak, REP = 1.49%) and total volume (Relative Error in volume, REV = 2.38%). The comparison of the observed and simulated hydrographs and the model performance (NSE = 0.884) and their correlation (R2 = 0.925) showed that the model is appropriate for hydrological simulations in the Gilgel Abay Catchment.


2020 ◽  
Vol 25 (4) ◽  
pp. 204-213
Author(s):  
Sangjun Im ◽  
Jeman Lee ◽  
Koichiro Kuraji ◽  
Yen-Jen Lai ◽  
Venus Tuankrua ◽  
...  

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