Michez Adrien

Michez Adrien
University of Liège | ulg · Gembloux Agro-Bio Tech

PhD

About

54
Publications
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721
Citations

Publications

Publications (54)
Article
Full-text available
La surface de la pessière wallonne a diminué de 30 % entre 1980 et 2010. L’exploitation d’un grand nombre de peuplements arrivés à maturité ces deux dernières décennies et un faible taux de replantation expliquent cette tendance. La crise des scolytes que nous avons connue ces dernières années, si elle a accentué la pression sur la ressource en épi...
Article
Full-text available
Managers need to know how to mitigate rising stream water temperature (WT) due to climate change. This requires identifying the environmental drivers that influence thermal regime and determining the spatial area where interventions are most effective. We hypothesized that (i) extreme thermal events can be influenced by a set of environmental facto...
Article
Full-text available
Ecosystem complexity is among the important drivers of biodiversity and ecosystem functioning, and unmanned aerial systems (UASs) are becoming an important tool for characterizing vegetation patterns and processes. The variety of UASs applications is immense, and so are the procedures to process UASs data described in the literature. Optimizing the...
Article
The highlighting and study of extreme water temperatures, which endanger numerous species, is of particular interest for river managers planning for future thermal conditions. Extreme water temperatures, defined as temperatures outside the normal range, are predicted to occur more frequently. This range includes seasonality and other trends in temp...
Article
Full-text available
The connectivity of riparian forests can be used as a proxy for the capacity of riparian zones to provide ecological functions, goods and services. In this study, we aim to test the potential of the freely available Copernicus “Riparian Zones” dataset to characterize the connectivity of riparian forests located in two European bioclimatic regions—t...
Article
Full-text available
En application de nouvelles dispositions du Code de l’Eau entrées en vigueur fin 2018, les gestionnaires de cours d’eau publics wallons ont élaboré des programmes d’actions détaillés (PARIS) pour la période 2022-2027, à l’échelle d’unités de gestion physiquement homogènes appelées « secteurs ». Ces PARIS ont pour vocation de contribuer à une gestio...
Article
Full-text available
Riparian ecosystems are home to a remarkable biodiversity, but have been degraded in many regions of the world. Vegetation biomass is central to several key functions of riparian systems. It is influenced by multiple factors, such as soil waterlogging, sediment input, flood, and human disturbance. However, knowledge is lacking on how these factors...
Article
Full-text available
Wildlife monitoring is an important part of the conservation strategies for certain endangered species. Non-invasive methods are of significant interest because they preserve the studied animal. The study of signs, especially tracks, seems to be a valuable compromise between reliability, simplicity and feasibility. The main objective of this study...
Article
Full-text available
In the context of global biodiversity loss, wildlife population monitoring is a major chal-lenge. Some innovative techniques such as the use of drones—also called unmanned aerial vehi-cle/system (UAV/UAS)—offer promising opportunities. The potential of UAS-based wildlife censususing high-resolution imagery is now well established for terrestrial ma...
Article
Full-text available
L’eau, ressource à protéger, est de plus en plus soumise à diverses contraintes liées notamment à la demande croissante en eau et au réchauffement climatique. Dans ce contexte, la gestion durable des cours d’eau est plus que jamais une nécessité. Pour mettre fin à la détérioration de l’état des masses d’eau et les amener à un « bon état », la direc...
Article
Riparian vegetation is a central component of the hydrosystem. As such, it is often subject to management practices that aim to influence its ecological, hydraulic or hydrological functions. Remote sensing has the potential to improve knowledge and management of riparian vegetation by providing cost-effective and spatially continuous data over wide...
Article
Full-text available
Forest monitoring tools are needed to promote effective and data driven forest management and forest policies. Remote sensing techniques can increase the speed and the cost-efficiency of the forest monitoring as well as large scale mapping of forest attribute (wall-to-wall approach). Digital Aerial Photogrammetry (DAP) is a common cost-effective al...
Article
Full-text available
Applied to grazing management, unmanned aerial systems (UASs) allow for the monitoring of vegetation at the level of each individual on the pasture while covering a significant area (>10 ha per flight). Few studies have investigated the use of UASs to describe the forage quality in terms of nutritive value or chemical composition, while these param...
Article
Full-text available
The use of unmanned aerial systems (UASs) has rapidly grown in many civil applications since the early 2010s. Nowadays, a large variety of reliable low-cost UAS sensors and controllers are available. However, contrary to ultralight aircrafts (ULAs), UASs have a too small operational range to efficiently cover large areas. Flight regulations prevail...
Article
Full-text available
In the context of the climate and biodiversity crisis facing our planet, tropical forests playing a key role in global carbon flux and containing over half of Earth's species are important to preserve. They are today threatened by deforestation but also by forest degradation, which is more difficult to study. Here, we performed a systematic review...
Article
Full-text available
Nous avons utilisé le réseau wallon de surveillance du niveau d’eau des cours d’eau non navigables (réseau Aqualim) afin d’étudier leur régime thermique. Le réseau Aqualim enregistre, en plus de la hauteur d’eau, la température de l’eau toutes les 10 minutes afin de calibrer les données de hauteur d’eau. Nous nous sommes donc intéressés à ces donné...
Book
Full-text available
Ce guide concerne la gestion de toute végétation ligneuse présente sur les berges et les rives des cours d’eau, qui a une influence directe sur le cours d’eau ou qui est directement influencée par celui-ci. Il a été réalisé par la faculté de Gembloux- Agro-Bio Tech de l’Université de Liège à la demande de la Direction des Cours d’eau non navigables...
Article
Many studies focus on stream water temperature (WT) because it is considered a key ecological factor. However, few of them have investigated the use of WT data from water level monitoring networks, which often measure WT as ancillary data. Our study was conducted in southern Belgium at a high temporal resolution with continuous data recorded at int...
Article
Full-text available
Trees have important and diverse roles that make them essential outside of the forest. The use of remote sensing can substantially support traditional field inventories to evaluate and characterize this resource. Existing studies have already realized the automated detection of trees outside the forest (TOF) and classified the subsequently mapped T...
Article
Full-text available
The tools available to farmers to manage grazed pastures and adjust forage demand to grass growth are generally rather static. Unmanned aerial systems (UASs) are interesting versatile tools that can provide relevant 3D information, such as sward height (3D structure), or even describe the physical condition of pastures through the use of spectral i...
Article
Full-text available
In recent decades, remote sensing has increasingly been used to estimate the spatio-temporal evolution of crop biophysical parameters such as the above-ground biomass (AGB). On a local scale, the advent of unmanned aerial vehicles (UAVs) seems to be a promising trade-off between satellite/airborne and terrestrial remote sensing. This study aims to...
Poster
Full-text available
La température des cours d’eau est un facteur central pour la compréhension du fonctionnement des écosystèmes aquatiques. La Wallonie (Sud de la Belgique) dispose d’un réseau permanent de monitoring de hauteur d’eau d’environ 140 stations mesurant également la température de l’eau à intervalles de 10 minutes. L’objectif de cette communication est...
Article
Forested catchments are generally assumed to provide higher quality water in opposition to agricultural and urban catchments. However, this should be tested in various ecological contexts and through the study of multiple variables describing water quality. Indeed, interactions between ecological variables, multiple land use and land cover (LULC) t...
Conference Paper
Full-text available
Sous l'impulsion de son administration, la Wallonie a entamé un processus de révision des modalités de gestion de ses cours d'eau publics, notamment à travers le projet des Programmes d'actions sur les rivières par une approche intégrée et sectorisée (PARIS). Les PARIS ont pour but d'intégrer dans le temps et dans l'espace l'ensemble des mesures de...
Conference Paper
Full-text available
Le ministère en charge de l'environnement et l'Office national de l'eau et des milieux aquatiques (Onema, intégré à l'Agence française pour la biodiversité depuis le 1er janvier 2017) ont organisé le 10 juin 2016, à Paris, une journée d'échanges sur les avancées techniques et scientifiques et leurs applications opérationnelles offertes par la téléd...
Article
Full-text available
Description of the subject. Understanding the current situation and evolution of forests is essential for a sustainable management plan that maintains forests’ ecological and socio-economic functions. Remote sensing is a helpful tool in developing this knowledge. Objectives. This paper investigates the new opportunities offered by using Sentinel-2...
Conference Paper
Full-text available
Field measurements in the ICOS program are spatially limited whereas the monitored gas fluxes may have a large footprint. Aerial remote sensing has the advantage to monitor large areas. The main goal of our research was to test the potential of unmanned aerial vehicles (UAV) to upscale parameters monitored through the ICOS program. In this study, w...
Article
Full-text available
Forested catchments are generally assumed to provide higher quality water. However, this hypothesis must be validated in various contexts as interactions between multiple land use and land cover (LULC) types, ecological variables and water quality variables render this relationship highly complex. This paper applies a straightforward multivariate a...
Article
Full-text available
Riparian buffers are of major concern for land and water resource managers despite their relatively low spatial coverage. In Europe, this concern has been acknowledged by different environmental directives which recommend multi-scale monitoring (from local to regional scales). Remote sensing methods could be a cost-effective alternative to field-ba...
Thesis
Full-text available
Michez Adrien (2016) Caractérisation multi-échelle des bandes riveraines des cours d'eau wallons par télédétection active et passive. Thèse de doctorat. Université de Liège-Gembloux Agro-Bio Tech. 159 p. Résumé Les bandes riveraines des cours d'eau constituent des milieux d'une richesse exceptionnelle aux multiples facettes, comportant les habitats...
Article
Full-text available
Damage caused by ungulates to agricultural areas are difficult to evaluate because the real extent of the damage remains usually poorly described and potentially arising conflicts. Recent advances in unmanned aerial system (UAS) provide new versatile mapping and quantification possibilities in a wide range of applications. We used crop fields (Zea...
Chapter
Forest surfaces on a global scale represent one-third of the world land area. Human civilizations have always interacted closely with these ecosystems, notably through the broad range of environmental services that they provide: protection of water resources, soil protection, mitigation of the excesses of local climate, reduction of impacts of gas...
Article
Full-text available
Riparian forests are critically endangered many anthropogenic pressures and natural hazards. The importance of riparian zones has been acknowledged by European Directives, involving multi-scale monitoring. The use of this very-high-resolution and hyperspatial imagery in a multi-temporal approach is an emerging topic. The trend is reinforced by the...
Article
Full-text available
Riparian zones are key landscape features, representing the interface between terrestrial and aquatic ecosystems. Although they have been influenced by human activities for centuries, their degradation has increased during the 20th century. Concomitant with (or as consequences of) these disturbances, the invasion of exotic species has increased thr...
Article
Full-text available
In forestry, top height is a common parameter used as indicator of the stand development stage. It can be used to estimate the potential production of monospecific even-aged stands. However, accurate field estimation of top height is time-consuming and expensive. Since the last two decades, LiDAR has proven to be very useful in estimating forest he...
Article
Full-text available
Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at tree level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS) should be used in order to efficiently discriminate deciduous tree species. The goal of this research is to determine when is the best t...
Article
Full-text available
La hauteur dominante est une information souvent utilisée en gestion forestière. Il s'agit d'un bon indicateur du niveau de développement des peuplements, pouvant être employé pour estimer le niveau de productivité des peuplements purs équiennes. Cependant, son estimation à partir de mesures de terrain est relativement fastidieuse et coûteuse. Depu...
Article
Full-text available
The present study proposes an innovative approach to automatically extract riparian zone characteristics in order to assess its quality, from pre-determined river management reaches (1-3 km long) to regional scale (ca. 13,000 km for 1,000 management sectors). The aim of this remotely sensed monitoring is to improve river and riparian zone managemen...
Poster
Full-text available
Wild boar ability to cause important damages to agricultural lands is not anymore to be demonstrated. These damages often raise conflicts between farmers and hunters due to the associated economic losses. Objective and accurate method for real impact assessment of losses suffered by farmers is thus needed. Currently,in Wallonia damage assessment is...
Poster
Full-text available
D’une invention initialement militaire, les drones - et les applications qui dérivent de leurs utilisation - tendent à se banaliser au sein du domaine civil. En terme d’applications géographiques, les micro-drones (< 2 kg) occupent un segment nouveau dans les techniques d’acquisition d’informations, à mi-chemin entre deux segments plus classiques,...
Poster
Full-text available
Introduction : Despite their relatively low area coverage, riparian forests are central landscape features providing several ecosystem services. Nevertheless, they are critically endangered in European countries by human pressures (livestock grazing, land use conflicts, canalizations, waste water, ...) andalso by natural hazards such as the recent...
Article
Full-text available
Due to the paucity of suitable habitat, hippos are very rare in the Congo Bassin. Compared to East-African populations, Central African populations of hippos have been less studied. Information found in the literature regarding the animal’s basic ecology is limited. This study focuses on the description of the diet of an isolated hippo population i...

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Projects

Projects (5)
Project
To better manage our forest resources, high quality spatial and temporal information is required. Such information can be derived from remote sensed data acquired at different scales by satellites, aircrafts and UASs. However, this abundant and miscellaneous data has to be processed, analyzed and synthetized before being useful for forest managers (with concrete effects in the field). New tools and algorithms are thus being developed for mapping and monitoring forest characteristics (structures, compositions, etc.) and changes (cuttings, disturbances, etc.).
Project
This PhD thesis aimed at assessing land use and in particular, forest cover effects on water related ecosystem services.
Project
First, the research aims to improve our knowledge of the thermal regime in Wallonia, Belgium (> 12000km of watercourse) using data from a network of about 140 stations measuring continuous temperature data (frequency: 10 minutes) since 2012. Then, we want to highlight the main environmental factors influencing stream water temperature among hydromorphological, topographical, land cover and seasonal variables. This data will also be used to carry out a model of the riparian vegetation as well as the shadow on Walloon rivers. Thirdly, infrared thermal camera will be used to understand spatial variability.