Impact of Watershed and Climate Changes on River Bed Morphology and Biota

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Modeling erosion and sedimentation coupled with hydrological and overland flow processes at the watershed scale

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100271/1/wrcr20373-sup-0001-suppinfo1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/100271/2/wrcr20373-sup-0002-suppinfo2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/100271/3/wrcr20373.pd

Hydrodynamics of surface irrigation: vertical structure of the surge front

A model for surface irrigation is developed that allows the determination of the vertical structure of the velocity profile in the vicinity of the wave front. The pressure is not assumed to be hydrostatically distributed and no assumptions are made regarding the shape of the freesurface profile. The turbulent kinetic energy and rate of dissipation are computed by a two-equation model and accurate determination of the bottom shear makes possible the analysis of particle suspension. The model is based on a two-dimensional finite element model in the vertical plane and uses the kinematic condition for determining the position of the free surface. It also incorporates a numerical technique for describing surface penetration and wave breaking by combining a Lagrangian approach that allows the computational nodes to move individually and then automatically reshapes the element grid. The potential value of the model lies in its ability to provide information on vertical mixing, settling and suspension of contaminated solids commonly found in irrigation applications.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46911/1/271_2004_Article_BF00187196.pd

Soil governance in Greece : a snapshot

For thousands of years, soil resources in Greece have been a critical underpinning of local socio-economies. However, soil threats are increasing rapidly, primarily due to human activity and the impacts of climate change. Greek and other European state governments have established legal frameworks to protect soil, but there is a great need for centralization and harmonization with European Law. This chapter highlights the importance of integrated soil governance frameworks that could be applied at the regional or international level while also supporting public engagement and local focus. It also considers the urgent need to address erosion - a major threat to soil resources in Greece that affects local well-being, environmental sustainability and heritage sites

A kinematic model for surface irrigation: An extension

An edited version of this paper was published by AGU. Copyright 1982 American Geophysical Union.The kinematic model for surface irrigation, reported previously by Sherman and Singh (1978), is extended. Depending upon the duration of irrigation and time variability of infiltration, three cases are distinguished. Explicit solutions are obtained when infiltration is constant. When infiltration is varying in time, a numerical procedure is developed which is stable and has fast convergence. A rigorous theoretical justification is developed for computation of the depth of water at and the time history of the front wall of water advancing down an infiltrating plane or channel. A derivation is given of the continuity and momentum equations when there is lateral inflow and infiltration into the channel bed.This study was supported in part by funds provided by the National Science Foundation under the project Free Boundary Problems in Water Resource Engineering, NSF-ENG-79- 23345

Hydraulic resistance to overland flow on surfaces with partially submerged vegetation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96239/1/wrcr13661.pd

Space discontinuous Galerkin method for shallow water flows - kinetic and HLLC flux, and potential vorticity generation

In this paper, a second order space discontinuous Galerkin (DG) method is presented for the numerical solution of inviscid shallow water flows over varying bottom topography. Novel in the implementation is the use of HLLC and kinetic numerical fluxes in combination with a dissipation operator, applied only locally around discontinuities to limit spurious numerical oscillations. Numerical solutions over (non-)uniform meshes are verified against exact solutions; the numerical error in the $L_2$-norm and the convergence of the solution are computed. Bore-vortex interactions are studied analytically and numerically to validate the model; these include bores as "breaking waves'' in a channel and a bore traveling over a conical and Gaussian hump. In these complex numerical test cases, we correctly predict the generation of potential vorticity by non-uniform bores. Finally, we successfully validate the numerical model against measurements of steady oblique hydraulic jumps in a channel with a contraction. In the latter case, the kinetic flux is shown to be more robust