How adaptation strategies of crops could counteract climate change effects? The case of four catchments in Wallonia, Belgium.

in Geophysical Research Abstracts (2013), 15

A sharp increase in extreme heat and drought stress is projected in Belgium by the end of the 21st century, with the potential to significantly reduce crops’ yields under current agricultural practices ... [more ▼]

A sharp increase in extreme heat and drought stress is projected in Belgium by the end of the 21st century, with the potential to significantly reduce crops’ yields under current agricultural practices. This contribution uses an agro-hydrological model in order to assess the potential effects of climate evolution on crop development, yield, and water balance for the main agricultural productions in the Meuse catchment. Erosion risk is also evaluated. We show that grasslands and maize yield decrease and yield variability increases under climate change scenarios. The leaf area index study permits to put in emphasis the earlier start of the vegetation due to warmer climate. It appears that all the sensitive stages occur earlier in the season and that crops are negatively affected by summer drought stress. The better understanding of crops development under evolving climate allows us to propose some changes in agricultural practices and to assess their effectiveness. We evaluate different strategies of adaptation in agricultural practices in order to reduce the potential negative effects of climate change on grasslands and maize production. Adaptation strategies proposed are advanced sowing and harvesting date, introduction of a cover crop for maize and advance in the cutting dates for grasslands. In the particular case of the Vesdre catchment, shifting the growth period of maize permits to avoid the water-deficit period and allow increased yield. This shift makes it possible to introduce a cover crop that will drastically reduce winter soil erosion. For grassland, the adjustment of the cutting dates favored the first cut and the earlier start of the vegetation. The second cut is less profitable due to summer drought stress. The vulnerability assessments focused on the main rotation encountered in the cultivated areas and in the difference in the cover type of these crops. [less ▲]

Which agriculture can face climate change? Focus on varietal adaptation

Poster (2013)

Quelles pratiques agricoles pour protéger la qualité des eaux de surface et souterraines ? L’apport de la modélisation hydrologique

Conference (2012, October 10)

Modelling of agricultural diffuse pollution and mitigation measures effectiveness inWallonia (Belgium)

in Geophysical Research Abstracts (2012), 14(EGU2012), 9672

Implementation of European directives in the environmental field and, specially, in the water management field, generates a request from policy-makers for news tools able to evaluate impact of management ... [more ▼]

Implementation of European directives in the environmental field and, specially, in the water management field, generates a request from policy-makers for news tools able to evaluate impact of management measures aiming at reducing pressures on ecosystems. In Wallonia (Southern Region of Belgium), the Nitrate Directive (EEC/676/91) was transposed into the “Walloon action plan for nitrogen sustainable management in agriculture” (PGDA1) in 2002. In 2007, a second plan was launched to reinforce some topics (PGDA2). Furthermore, the goal of “good quality” of surface waters and groundwater imposed by the Water Framework Directive poses new challenges in water management. In this context, a “soil and vadose” hydrological model is used in order to evaluate diffuse pollutions and efficiency of mitigation measures. This model, called EPICgrid, has been developed at catchment scale with an original modular concept on the basis of the field scale “water-soil-plant” EPIC model (Williams J.R., Jones C.A., Dyke P.T. (1984). A modelling approach to determining the relationship between erosion and soil productivity. Transactions of the ASAE. 27, 129-144). The model estimates, for each HRU identified into a 1km2 grid, water and nutrients flows into the plant-soil-vadose zone system (Sohier C., Degré A., Dautrebande S. (2009). From root zone modelling to regional forecasting of nitrate concentration in recharge flows – The case of the Walloon Region (Belgium). Journal of Hydrology, Volume 369, Issues 3-4, 15 May 2009, Pages 350-359). The model is used to make prospective simulations in order to evaluate the impact of measures currently performed to reduce the effect of diffuse pollution on water surface quality and groundwater quality, at regional scale. Response of the soil-vadose zone to agricultural practices modification is analyzed for the deadlines of the Water Framework Directive: 2015, 2021 and 2027, taking into account two climatic scenarios. Simulations results showed that actual measures are not sufficient in some areas and that new actions are necessary. The EPICgrid model was also used to evaluate effectiveness of further measures that could be implemented in order to reduce agricultural diffuse pollution. The increasing of catch crops in vulnerable zones has shown a limited impact in theWalloon context. The modifications of agricultural practices such as crop rotations or mineral fertilizing amounts have shown a more significant impact on water quality. Furthermore, the farmers’ practices are evaluated each year by a measuring campaign of the soil nitrogen residue after harvest. These data allow us to improve the representativeness of the EPICgrid model in areas in which agricultural practices largely differs from regional statistics. [less ▲]

How could Mosan agriculture be impacted by climate change and future droughts?

in Geophysical Research Abstracts (2012), 14

Despite the great uncertainties regarding the future climatic context, lots of studies have focused on hydrological effects of climate change on the Meuse catchment. It appears that both winter high flows ... [more ▼]

Despite the great uncertainties regarding the future climatic context, lots of studies have focused on hydrological effects of climate change on the Meuse catchment. It appears that both winter high flows and summer low flows could be exacerbated. Climate change and its impacts on hydrology will thus affect various socio-economic sectors. High flows have been widely studied compared to low-flows. This poster will put the emphasis on a methodology developed in order to study impacts of droughts on agriculture. Agriculture is among the most impacted sectors due to climate change. The consequences could be both positive as negative in accordance with the range of predicted changes and the adaptation capacity of agricultural systems. Most of the existing studies related to climate change on agriculture focused on specific territory. Within the AMICE Interreg IVB project, a transnational approach has been developed to assess droughts impacts on agriculture through the Meuse basin. The project’s previous works gave us a common scenario of climate trends and of the evolution of the hydrology in the Meuse basin. The methodology is based on the use of a physically-based model able to simulate the water-soil-plant continuum (derived from EPIC model). In order to be transferable from one country to another, the methodology proposed used data available at the basin scale. The UE soil data base was complemented with local information on agricultural practices and statistics. Three crops have been studied: maize, wheat and barley. The basic cultural calendar is supposed to be the same for the different countries. The methodology developed permits to study the evolution of yields, leaf area index, crops stress due to excess or lack of water through time under different scenarios build up in the frame of the project. It appears that corn is negatively affected by climate change, and thus despite the CO2 fertilization effect. Wheat and barley have similar behavior and are positively affected by climate change and CO2 fertilization. Leaf Area Index study reveals that the different crops start earlier and reach earlier maturity. These first results will be completed with other economic sectors’analysis like drinkable water production, electricity production and navigation. Therefore, the project will progress towards a better understanding of economic effects of future droughts and low-flows. [less ▲]

Monitoring networks and modelling systems for assessing effectiveness of the EU Nitrates Directive Action Programmes: Approach by the Walloon Region (Belgium)

in Fraters, Dico; Kovar, Karel (Eds.) Developments in monitoring the effectiveness of the EU Nitrates Directive Action Programmes. Results of th second International Workshop, 10-11 june 2009 (2011, June)

Wallonia (Southern Region of Belgium) has implemented the Nitrates Directive by designating four vulnerable zones (now 42% of the territory) and introducing a first Action programme at the start of ... [more ▼]

Wallonia (Southern Region of Belgium) has implemented the Nitrates Directive by designating four vulnerable zones (now 42% of the territory) and introducing a first Action programme at the start of November 2002 and a second one in 2007. The Action programmes entail various means of reducing the risks of the pollution of water by nitrate: (a) struggle against nitrate losses in fields using a range of good agricultural practices, including certain restrictions on the use of fertilisers (quantities, spreading periods, soil conditions, etc.), (b) keeping a balance on each farm between the organic nitrogen produced and spreading capacities on agricultural land, (c) adapting storehouses for livestock effluent to a capacity of 6 months and (d) promoting transfers of livestock effluent between farms in excess balance and farms which still have a way of using it on their land. The paper presents the principle of “soil nitrate residue” measurements (APL in French) that permits a yearly monitoring of the farming practices and constitutes a self-evaluation tool for the farmers. The paper also introduces the reference model EPICgrid dedicated to nitrogen transfer modelling in the context of the Walloon region. Following the first comparison exercise, these tools are consistent and complementary approaches to help farmers and authorities in nitrogen management. In the context of the Walloon region, dealing with deep groundwater bodies, fast indicators of potentially leachable nitrogen and nutrient fate modelling are the most practical way of assessing effectiveness of the EU nitrate directive action programmes. [less ▲]

Modélisation pré-normative de pratiques agricoles et agro-environnementales en vue des plans de gestion des eaux de surface et souterraines en Région wallonne à l’aide du modèle EPICgrid-Qualvados

Report (2011)

Le présent Rapport synthétise et conclut les travaux réalisés dans le cadre de la Convention Qualvados 2 (Convention SPGE - ULg GxABT) : « Modélisation pré-normative de pratiques agricoles et agro ... [more ▼]

Le présent Rapport synthétise et conclut les travaux réalisés dans le cadre de la Convention Qualvados 2 (Convention SPGE - ULg GxABT) : « Modélisation pré-normative de pratiques agricoles et agro-environnementales en vue des plans de gestion des eaux de surface et souterraines en Région wallonne à l’aide du modèle EPICgrid-Qualvados ». [less ▲]

Hydrological response to climate change in the Lesse and the Vesdre catchments: contribution of a physically based model (Wallonia, Belgium)

in Hydrology & Earth System Sciences (2011), 15

The Meuse is an important rain-fed river in North-Western Europe. Nine million people live in its catchment, split over five countries. Projected changes in precipitation and temperature characteristics ... [more ▼]

The Meuse is an important rain-fed river in North-Western Europe. Nine million people live in its catchment, split over five countries. Projected changes in precipitation and temperature characteristics due to climate change would have a significant impact on the Meuse River and its tributaries. In this study, we focused on the impacts of climate change on the hydrology of two sub-catchments of the Meuse in Belgium, the Lesse and the Vesdre, placing the emphasis on the water-soil-plant continuum in order to highlight the effects of climate change on plant growth, and water uptake on the hydrology of two sub-catchments. These effects were studied using two climate scenarios and a physically based distributed model, which reflects the water-soil-plant continuum. Our results show that the vegetation will evapotranspirate between 10 and 17% less at the end of the century because of water scarcity in summer, even if the root development is better under climate change conditions. In the low scenario, the mean minimal 7 days discharge value could decrease between 19 and 24% for a two year return period, and between 20 and 35% for a fifty year return period. It will lead to rare but severe drought in rivers, with potentially huge consequences on water quality. [less ▲]

L’hydrologie, une partenaire de la géomorphopédologie pour une gestion transéchelle des grands enjeux environnementaux

Conference (2010, November 24)

La zone insaturée du sol et du sous-sol est souvent qualifiée de zone critique, étant donné son rôle d’interfaçage entre les compartiments aérien et souterrain de notre environnement. Dans les thématiques ... [more ▼]

La zone insaturée du sol et du sous-sol est souvent qualifiée de zone critique, étant donné son rôle d’interfaçage entre les compartiments aérien et souterrain de notre environnement. Dans les thématiques du transfert des solutés ou de la conservation des eaux et des sols, les recherches d’hydrologie et d’hydraulique agricole s’appuient sur les informations pédologiques et ce depuis une échelle extrêmement locale jusqu’à la vision régionale de la gestion environnementale. Le rôle des descriptions pédologiques dans la gestion et la protection des ressources naturelles est donc majeur. La dérivation des paramètres hydrodynamiques depuis les descriptions pédologiques des sols permet à l’hydrologue de quantifier et de représenter spatialement la dynamique des échanges eau-sol-végétation-atmosphère, les déplacements de l’eau dans le sol et la vadose ainsi que les déplacements et les transformations des solutés. L’hydrologue en retire des indicateurs de pression sur les ressources hydriques de surface et souterraine. Il calcule des flux d’eau, de nutriments et de sédiments à un pas de temps très fin et durant de longues périodes (plus de 30 années). Les recherches présentées ici couvrent la modélisation hydrologique physiquement basée à l’échelle régionale qui vise l’analyse prospective (au-delà de 2020) des mesures envisagées pour limiter les pollutions diffuses d’origine agricole, tout comme des modélisations physiques détaillées en sites expérimentaux. L’érosion hydrique des sols est un autre un enjeu majeur de gestion environnementale. Le sol étant une ressource peu renouvelable, les techniques de conservation des sols et l’aménagement hydraulique des bassins versants ruraux nécessitent la plus grande considération. Elles sont un outil supplémentaire de limitation des apports au cours d’eau (tant en termes de sédiments qu’en termes de nutriments). Là encore, les descriptions pédologiques permettent de cibler les sols les plus sensibles. De plus, les cartes des sols qui incluent une interprétation géomorphologique permettent de confronter les modèles d’arrachement, de transport et de dépôt de sédiments aux observations des pédologues faites lors des premiers levés et actuellement en cours. Ces observations de terrain, réalisées à plusieurs dizaines d’années d’intervalle, constituent un gisement de données précieux et quasiment unique pour la validation des modèles hydrologiques de perte en sol et de dépôt et en vue de l’étude morphodynamique des bassins versants. Il reste actuellement des besoins en termes de description pédologique. Ils ont trait à la caractérisation plus fine de certains sigles, où l’introduction d’éléments relatifs à la dynamique des flux pourrait s’avérer pertinente. Toutefois, on peut constater que dans le contexte actuel et crucial de préservation des ressources eau et sol, l’hydrologie et la science du sol sont réaffirmées comme des partenaires forts de gestion des grands enjeux environnementaux. [less ▲]

Utilisation de la CNOSW en tant que carte d'occupation du sol dans le modèle EPICgrid

Poster (2010, October 20)

Le modèle EPICgrid est un modèle hydrologique distribué de résolution 1km² couvrant toute la Wallonie. Il a été développé par Gx-ABT afin d’évaluer les flux d’eau, de nutriments et de sédiments vers les ... [more ▼]

Le modèle EPICgrid est un modèle hydrologique distribué de résolution 1km² couvrant toute la Wallonie. Il a été développé par Gx-ABT afin d’évaluer les flux d’eau, de nutriments et de sédiments vers les eaux de surface et vers les eaux souterraines. Il permet, entre autres, de tester l’impact de scénarios de gestion des nutriments sur la qualité des eaux en Région wallonne ainsi que des rapportages à différentes échelles dont les masses d’eau de surface. Le modèle requiert parmi ses données d’entrée une cartographie de l’occupation du sol. Dans un premier temps, la carte d'occupation des sols utilisée était issue du projet CARHY (Laime et Dautrebande, 1995) et reposait sur l'analyse d'images satellitaires Landsat pour refléter l’occupation du sol des années '90. En 2009, la CNOSW a été implémentée dans le modèle pour affiner spatialement et mettre à jour cette donnée en vue de simulations hydrologiques prospectives. Pour ce faire, les différentes classes de la CNOSW (niveau 5) ont été complétées au niveau des zones non cadastrées afin d’obtenir une couverture continue, hydrologiquement valide, de toute la Wallonie. Les classes ont ensuite été regroupées en classes hydrologiques d’occupation du sol (7 classes). La comparaison des cartes d’occupation du sol CARHY et issue de la CNOSW montre une répartition en classes similaire au niveau régional. Néanmoins, au niveau local, les différences marquées peuvent être constatées. Les zones urbaines sont également mieux représentées par la CNOSW. L’introduction de la CNOSW dans le modèle EPICgrid en apportant une spatialisation plus précise des occupations du sol a permis d’affiner les résultats du modèle et d’ouvrir de nouvelles pistes de développement telles que la représentation dans le modèle hydrologique du fonctionnement des bandes enherbées riveraines et inter-parcellaires. [less ▲]