Search results for "IMPACTS"
showing 10 items of 116 documents
Sociālās un ekonomiskās ietekmes ezeru attīrīšanā un labiekārtošanā.
2015
Bakalaura darba „Sociālās un ekonomiskās ietekmes ezeru attīrīšanā un labiekārtošanā” mērķis ir izprast ezeru un to ekosistēmu nozīmīgumu, regulējošās un atbalsta funkcijas, izanalizēt sociālos un ekonomiskos ieguvumus veicot ieguldījumus ezera infrastruktūras un tur mītošo zivju sugu pavairošanas projektos. Bakalaura darba uzdevumos ietilpst ekosistēmu darbības principu apskate, šā brīža makšķerēšanas nozares un ezeru stāvokļa un to problēmu apzināšanās, kā arī ārzemēs veikto pētniecisko darbu analīze un aptaujas rezultātu analizēšana. Lai spētu sniegt ieteikumus Smiltenes ezeru attīrīšanas un labiekārtošanas plāna projekta realizēšanai, tiek izpētīts Katvaru ezera apsaimniekošanas modelis…
Climats tropicaux d'aujourd'hui à demain : variabilité et changements
2008
Present and future tropical climates : their climate variability and their climate changes The oriffttality of tropical climates is re-examined under the light of climate variability and climate change, both present and future . The interannual variability of rainfall is on average larger in the tropics than in the extra-tropics, but it is also spatially more contrasted. Human communities have often responded to this constraint through efficient coping strategies. The regions showing the most variable climate do not necessarily have lower population densities, an indication that in the long run variability is not decisive. However, the recent demographic growth of these regions is often low…
Impacts sur le climat régional induits par l'immersion d'une zone aride : cas de Chott Jérid (sud de la Tunisie).
2017
This work aims to show the possible impacts on the regional climate that could be caused by the partial immersion ofChott Jérid located in the south of Tunisia. Climate simulations have been carried out using the Weather Research andForecasting (WRF) model to compare the present climate of the Chott area simulated over the period 1991-2011 under realconditions of land use to the climate simulated in the fictional presence of a vast artificial waterbody (or lake). Comparisonsshowed that the lake would have a particularly moderating effect on average air temperatures. The sensible heat flux wouldincrease substantially during the winter and decrease during the summer, while latent heat and moi…
Très longs épisodes secs hivernaux dans le bassin méditerranéen : variabilité spatio-temporelle et impact sur la production céréalière en Espagne.
2018
This study concerns the long winter sequences without rain at the whole Mediterraneanbasin scale. Objectives are (i) to define theses extreme events as geographical and climatological objectscharacterized by a location, a spatial extension and a temporal length and (ii) measured impacts of these eventson the cereal production in Spain. 76 events of very long dry spells (eVLDS) are detected over the 1957-2013period. These eVLDS are grouped into 4 typical recurrent configurations at the Mediterranean basin scale: North-East, West, Scattered & Localised and South-East. The eVLDS have a greater impact on barley, wheat and oatyields (winter crops grown through rainfed agriculture) than rainfall …
Cropping system dynamics, climate variability, and seed losses among East African smallholder farmers: a retrospective survey.
2014
Abstract Climate variability directly affects traditional low input and rain-fed farming systems, but few studies have paid attention retrospectively to the cropping system’s ability to mitigate climate risk. This study analyzes the impacts of rainfall variability on farmers’ seed variety losses over time, considering changes in smallholder farming systems. The cropping system dynamics, in favoring maize at the expense of sorghum and pearl millet, have induced an increasing risk of seed loss during drought. Combining ecological anthropology and climatology, a retrospective survey asking farmers about the period 1961–2006 was carried out at three altitudinal levels (750, 950, and 1100 m) on …
French collective expertise on herbicide-tolerant varieties
2013
The primary objective in creating herbicide-tolerant varieties is to offer the farmers with an efficient tool to ensure weed control and solve weed problems, but their use could eventually have expected or unexpected consequences according to conditions of implementation. A few of those varieties, obtained either through classical breeding or through induced mutagenesis are now on the European market (especially oilseed rape and sunflower) while a majority, which was obtained through genetic engineering, is not allowed for cultivation in this area. The report describes how CNRS and INRA experts dealt with the scientific literature, extracts key elements, points out necessary watchfulness on…
Study of acoustic properties and impact behavior of porous materials homogeneous type metal foams and inhomogeneous
2015
This work is concerned with the theoretical and experimental study of the acoustical properties of macroscopically homogenous and inhomogeneous porous media as well as their mechanical response to impacts. The model of Johnson - Champoux - Allard appeared adapted for the acoustical modeling. This model, associated with a recently developed approach involving the concept of parallel transfer matrices has lead to a new approach of macroscopically inhomogeneous porous materials based on “mixtures of materials”. Furthermore, a parametric study of the absorption coefficient as a function of porosity and frequency has been proposed. The maximums of absorption as well as the envelop of the absorpt…
Legumes in 21st century Europe: present and future importance in agri-food systems? New challenges for reseach.
2013
Intensification of agriculture since 1950 has globally led to the decline of grain legume crops, which currently represent less than 3 % of arable crops in France and Europe. Nevertheless, legumes have several major assets (i) as plant proteins for animal feed and human food and (ii) as plants fixing atmospheric N2 and thereby saving nitrogen inputs in cropping systems, and (iii) as diversification crops. The analysis of forage and grain legume producing systems in France showed that the dominant system results in a lock-in of the different factors limiting legume insertion into the current systems. But legumes could have a major role to play in the agroecological transition towards more su…
Practitioners’ Perceptions of Co-Product Allocation Methods in Biorefinery Development—A Case Study of the Austrian Pulp and Paper Indust…
2022
The utilization of coproducts is a strategy that can be applied to increase the economic and environmental performance of industrial processes and thus reach an objective targeted in several environmental policies. In multi-output production processes, allocation needs to be performed to assess the products’ environmental and economic performance. It is crucial to choose an adequate allocation method, because this choice has been shown to strongly influence overall outcomes. Consequently, rash choices can lead to poor decision-making. Various ways to apply and combine allocation methods can be found in the academic literature, but it is often difficult to find sufficient guidance on how to …
Plasticity in the trophic niche of an invasive ant explains establishment success and long‐term coexistence
2021
Invasive species are one of the main threats to biodiversity worldwide and the processes enabling their establishment and persistence remain poorly understood. In generalist consumers, plasticity in diet and trophic niche may play a crucial role in invasion success. There is growing evidence that invasive ants, in particular, occupy lower trophic levels in their introduced range compared to the native one, but evidences remain fragmented. We conducted stable isotope analysis at five locations distributed on two continents to infer the trophic position of the invasive ant Formica paralugubris in the native and introduced part of the range. This species forms large colonies and can be a vorac…