Search results for "0208 environmental biotechnology"

Statistical check of USLE-M and USLE-MM to predict bare plot soil loss in two Italian environments

2018

The USLE-M and the USLE-MM estimate event plot soil loss. In both models, the erosivity term is given by the runoff coefficient, QR, times the single-storm erosion index, EI30. In the USLE-MM, QREI30is raised to an exponent b1> 1 whereas b1= 1 is assumed in the USLE-M. Simple linear regression analysis can be applied to parameterize both models, but logarithmically transformed data have to be used for USLE-MM. Parameterizing the USLE-MM with nonlinear regression of untransformed data could be a more appropriate procedure. A statistical check of the two suggested models (USLE-M and USLE-MM), considering two alternative parameterization procedures for the USLE-MM, was carried out for the Mass…

Uncertainty Analysis in the Evaluation of the DDF Curves Parameters in Climate Change Scenarios

2016

Abstract On the global scale, there is a robust observational evidence that, over the last decades, the frequency and intensity of extreme events significantly changed, even if regional and local studies have highlighted complex and non-uniform spatial patterns. Climate change can cause increased rainfall intensities which leads to an additional impact on drainage systems, due to the alteration of magnitude and frequency of peak flows over their service life. For this reason, the design criteria of urban drainage infrastructures need to be revised and updated, in order to take into account the possible variations of extreme rainfall. In particular, the Depth-Duration-Frequency (DDF) curves,…

The FLO Diffusive 1D-2D Model for Simulation of River Flooding

2016

An integrated 1D-2D model for the solution of the diffusive approximation of the shallow water equations, named FLO, is proposed in the present paper. Governing equations are solved using the MArching in Space and Time (MAST) approach. The 2D floodplain domain is discretized using a triangular mesh, and standard river sections are used for modeling 1D flow inside the section width occurring with low or standard discharges. 1D elements, inside the 1D domain, are quadrilaterals bounded by the trace of two consecutive sections and by the sides connecting their extreme points. The water level is assumed to vary linearly inside each quadrilateral along the flow direction, but to remain constant …

Real-time optimization of the key filtration parameters in an AnMBR: Urban wastewater mono-digestion vs. co-digestion with domestic food waste

2018

[EN] This study describes a model-based method for real-time optimization of the key filtration parameters in a submerged anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) and UWW mixed with domestic food waste (FW). The method consists of an initial screening to find out adequate filtration conditions and a real-time optimizer applied to a periodically calibrated filtration model for minimizing the operating costs. The initial screening consists of two statistical analyses: (1) Morris screening method to identify the key filtration parameters; (2) Monte Carlo method to establish suitable initial control inputs values. The operating filtration cost after implementing the…

Assessing dye-tracer technique for rill flow velocity measurements

2018

Abstract Rill erosion is considered one of the most important processes affecting soil because of the large amount of soil loss. The rill network acts as sediment source and is able to transport both rill flow-detached particles and those delivered from the interrill areas. Small flow depth in a rill and steep slope values of its bed affect significantly flow hydraulics. When rill flow velocity is measured using a dye-tracing method, the mean velocity is calculated by multiplying the measured surface velocity of the leading edge of the tracer plume by a correction factor. The main uncertainty of the dye-tracing technique stands in the relationship between mean and surface flow velocity. In …

Using LIDAR topography data for determination of morphology and terrace levels of the River Ogre Valley in Middle Latvia Lowland [abstract].

2016

A Soil Water Assessment Tool (SWAT) Modeling Approach to Prioritize Soil Conservation Management in River Basin Critical Areas Coupled With Future Cl…

2021

About 44% of the Indian landmass experiences the adverse impact of land degradation. This loss of sediments caused by soil erosion reduces the water quality of local water bodies and decreases agricultural land productivity. Therefore, decision-makers must formulate policies and management practices for sustainable management of basins that are cost-effective and environment friendly. Application of the best management practices (BMPs) to properly manage river basins is difficult and time-consuming. Its implication under various climate change scenarios makes it more complicated but necessary to achieve sustainable development. In this study, the soil and water assessment tool (SWAT) model…

Experiments for testing soil texture effects on flow resistance in mobile bed rills

2018

Abstract In this paper a recently theoretically deduced rill flow resistance equation, based on a power-velocity profile, was tested experimentally on plots of varying slopes and soil texture in which mobile bed rills are incised. Measurements of flow velocity, water depth, cross section area, wetted perimeter and bed slope conducted in rill reaches incised on experimental plots, having different slope values (9, 14, 22, 24 and 26%) and soil texture (clay fraction ranging from 42 to 73%), and literature data were used to calibrate the flow resistance equation. In particular, the relationship between the velocity profile parameter Γ, the channel slope, the flow Froude number and texture frac…

The use of constructed wetlands for the treatment of agro-industrial wastewater – A case study in a dairy-cattle farm in Sicily (Italy)

2017

Wastewaters generated by agro-industrial operations often represent an unsustainable cost for farms due to high wastewater-treatment management costs. The wastewater produced by dairies, wineries or oil mills may vary in quantity and in quality depending on the time of the year, making the use of a conventional treatment system less efficient and more costly. Constructed wetland systems (CWs) provide low-cost technology and an efficient solution in the treatment of a number of wastewaters from agriculture. They are simple to build, have low maintenance costs and are sustainable compared to conventional treatment methods. This paper shows a case study that was carried out on a dairy-cattle f…

2017

Abstract. The aim of this study is to present a framework that provides new ways to characterize the spatio-temporal variability of lateral exchanges for water flow and solute transport in a karst conduit network during flood events, treating both the diffusive wave equation and the advection–diffusion equation with the same mathematical approach, assuming uniform lateral flow and solute transport. A solution to the inverse problem for the advection–diffusion equations is then applied to data from two successive gauging stations to simulate flows and solute exchange dynamics after recharge. The study site is the karst conduit network of the Fourbanne aquifer in the French Jura Mountains, wh…