Patterns of hydrochorous dispersal in agricultural channels

Author(s):  
Fabrice Vinatier ◽  
Gabrielle Rudi ◽  
Gilles Belaud ◽  
Jean-Stéphane Bailly

<p><span>rimary </span><span>soil</span><span>I</span><span>ditches</span><span> during short but intense storms. Furthermore, these man made ditches provide valuable habitat for fauna and flora, </span><span>but the spread of the weed could be limited by preserving existing hydraulic structures or maintaining areas where the density of terrestrial vegetation is sufficient to enhance seed retention downstream.</span></p>

2020 ◽  
pp. 109-116
Author(s):  
N.P. KARPENKO ◽  
◽  
M.A. SHIRYAEVA

The purpose of the work is to consider methods for calculating the forecast of groundwater backwater in the zone of influence of hydraulic structures. The analysis of analytical dependences of calculation of the forecast of groundwater backwater for various calculation schemes is carried out. For a homogeneous scheme of the geofiltration structure, a numerical model is proposed and a computational program for calculating the groundwater backwater is developed. It allows calculating the groundwater backwater from the channel at any time in the discrete mode. To simplify the solution of the problem of calculating the groundwater backwater, a computer program was created in the programming language Phyton Version 8.3 which quickly solves this hydrogeological problem. A possible range of geofiltration parameters is proposed for calculating the groundwater backwater near main channels. The adaptation and implementation of the software model was carried out for a specific object – the Bolshoy Stavropol channel-5, for which forecast calculations were made. The results of predictive calculations of groundwater backwater are the basis for the assessment of areas of possible flooding – the territory within which the level of ground water increases as a result of their backup by a hydraulic structure.


10.29007/2k64 ◽  
2018 ◽  
Author(s):  
Pat Prodanovic ◽  
Cedric Goeury ◽  
Fabrice Zaoui ◽  
Riadh Ata ◽  
Jacques Fontaine ◽  
...  

This paper presents a practical methodology developed for shape optimization studies of hydraulic structures using environmental numerical modelling codes. The methodology starts by defining the optimization problem and identifying relevant problem constraints. Design variables in shape optimization studies are configuration of structures (such as length or spacing of groins, orientation and layout of breakwaters, etc.) whose optimal orientation is not known a priori. The optimization problem is solved numerically by coupling an optimization algorithm to a numerical model. The coupled system is able to define, test and evaluate a multitude of new shapes, which are internally generated and then simulated using a numerical model. The developed methodology is tested using an example of an optimum design of a fish passage, where the design variables are the length and the position of slots. In this paper an objective function is defined where a target is specified and the numerical optimizer is asked to retrieve the target solution. Such a definition of the objective function is used to validate the developed tool chain. This work uses the numerical model TELEMAC- 2Dfrom the TELEMAC-MASCARET suite of numerical solvers for the solution of shallow water equations, coupled with various numerical optimization algorithms available in the literature.


2019 ◽  
pp. 68-72
Author(s):  
E. A. Volkova

A monograph “Vegetation and biotopes of the “Narochansky” National Park was published in Minsk, Belarus in 2017, edited by A. V. Pugachevsky (Grummo et al., 2017). It includes the Map of terrestrial vegetation (S. 1 : 60 000) and the Map of biotopes (S. 1 : 60 000). Some small-scale maps such as the Map of changes in forest cover of the “Narochansky” National Park for the period 1985–2016, the Map of forest loss in the “Narochansky” National Park for the period 1985–2016 and a series of inventory and analytical maps on the basin of the Naroch Lake are given. This monograph can be considered as a small regional Atlas with detailed explanatory texts to the maps. It presents the experience on vegetation mapping accumulated in the Laboratory of Geobotany and Vegetation mapping of the Institute of Experimental Botany of the National Academy of Sciences of Belarus. Despite some critical comments, mainly concerning the biotope map, this publication of Belarusian geobotanists deserves an approval. They received the full answers to the questions posed: “What do we protect?” and “What is a current state of the vegetation of the National Park and the main trends of its dynamics? Cartographic design is made at a high level; the maps have both scientific and practical importance in the planning of environmental and economic activities.


2018 ◽  
Vol 6 (3) ◽  
pp. 20-28
Author(s):  
Faisal Al Tabatabaie ◽  
Dhabia Sabeeh Al Waily

The use of cutoffs underneath the hydraulic structures is considered a safe solution to ensure the stability of hydraulic structure against uplift pressure and piping phenomenon in addition to the sliding and overturning forces of the water. These cutoffs are used at critical sections underneath the floor of hydraulic structure to substitute with their depths the horizontal lengths of the creep line of the hydraulic structure base. In this paper, the experimental method- by using electrical analogue model- was carried out to plot the flow net and study the efficiency of the front and rear faces of the cutoffs for dissipating the potential energy of the percolating water underneath the floor of hydraulic structure. An electrical analogue model which was used in this study consists of twenty five models with different depths of upstream and downstream cutoffs. After plotting the flow net for all models, it is concluded that the efficiency of the inner sides are less than that of the outer sides which were investigated before in this topic of this work that both faces reduction values in the uplift pressure are considered the same, where the efficiency of the outer face of upstream cutoff is (70.35) % and for the inner face is (29.64)%, while for the downstream cutoff the efficiency for the outer face is (76.21)% and for the inner face is (23.79)% .


2021 ◽  
Vol 1058 (1) ◽  
pp. 012059
Author(s):  
Mostafa H. Hamedi ◽  
Ali N. Hilo ◽  
Thaar S. Al-Ghasham ◽  
Nadheer S. Ayoob ◽  
Hamid Shirazi ◽  
...  

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