Integrated modeling of agricultural scenarios (IMAS) to support pesticide action plans: the case of the Coulonge drinking water catchment area (SW France)

Abstract

Non-point source pollution is a cause of major concern within the European Union. This is reflected in increasing public and political focus on a more sustainable use of pesticides, as well as a reduction in diffuse pollution. Climate change will likely to lead to an even more intensive use of pesticides in the future, affecting agriculture in many ways. At the same time, the Water Framework Directive (WFD) and associated EU policies called for a "good" ecological and chemical status to be achieved for water bodies by the end of 2015, currently delayed to 2021-2027 due to a lack of efficiency in policies and timescale of resilience for hydrosystems, especially groundwater systems. Water managers need appropriate and user-friendly tools to design agro-environmental policies. These tools should help them to evaluate the potential impacts of mitigation measures on water resources, more clearly define protected areas, and more efficiently distribute financial incentives to farmers who agree to implement alternative practices. At present, a number of reports point out that water managers do not use appropriate information from monitoring or models to make decisions and set environmental action plans. In this paper, we propose an integrated and collaborative approach to analyzing changes in land use, farming systems, and practices and to assess their effects on agricultural pressure and pesticide transfers to waters. The integrated modeling of agricultural scenario (IMAS) framework draws on a range of data and expert knowledge available within areas where a pesticide action plan can be defined to restore the water quality, French "Grenelle law" catchment areas, French Water Development and Management Plan areas, etc. A so-called "reference scenario" represents the actual soil occupation and pesticide-spraying practices used in both conventional and organic farming. A number of alternative scenarios are then defined in cooperation with stakeholders, including socio-economic conditions for developing alternative agricultural systems or targeting mitigation measures. Our integrated assessment of these scenarios combines the calculation of spatialized environmental indicators with integrated bio-economic modeling. The latter is achieved by a combined use of Soil and Water Assessment Tool (SWAT) modeling with our own purpose-built land use generator module (Generator of Land Use version 2 (GenLU2)) and an economic model developed using General Algebraic Modeling System (GAMS) for cost-effectiveness assessment. This integrated approach is applied to two embedded catchment areas (total area of 360,000 ha) within the Charente river basin (SW France). Our results show that it is possible to differentiate scenarios based on their effectiveness, represented by either evolution of pressure (agro-environmental indicators) or transport into waters (pesticide concentrations). By analyzing the implementation costs borne by farmers, it is possible to identify the most cost-effective scenarios at sub-basin and other aggregated levels (W...

How to Enhance the Role of Science in European Union Policy Making and Implementation: The Case of Agricultural Impacts on Drinking Water Quality

“…Agriculture and Water Quality in the EU Agriculture accounts for almost half of the total EU land area and is a primary source of diffuse pollution of nutrients and pesticides significantly affecting most of the EU river basins [12,13]. Rapid changes in farming systems in the post-war decades allowed an increase in agricultural productivity and caused considerable impacts (physical and chemical) on freshwater resources [1,[13][14][15]. The focus on groundwater mainly concerns its use as drinking water as about 75% of EU inhabitants depend on groundwater for their water supply [16].…”

“…On the other hand, while national or EU funding can enhance the role of science and research projects in relation to policy, they rarely contribute to actual capacity building in the legislative sector and have limited influence on problem-solving or key stakeholders. In addition to strong professional organizations inhibiting structural changes in local areas, legislators rarely provide additional money to implement measures from River Basin Management Plans (RBMPs) as they rely on money from agricultural funds to tackle pollution from agricultural sources [12,14,16,22].…”

“…The WFD has been a significant force in raising awareness of the need to restore Europe's rivers, but its application during the first management cycle was limited [68,69]. The deadline for all rivers to be in a good ecological state passed due to a lack of effective policies and an inappropriate timescale for the resilience of water systems, especially groundwater systems [14,17]. To tackle this problem, the WFD now requires member states to design and implement cost-effective programs or measures to achieve the "good status" objective by 2027 at the latest [14,21].…”

Is there a way to rate insecticides that is less detrimental to human and environmental health?

“…Since the late 1970s, a wealth of scientific research from different disciplines shed light on the off-farm human health and the environmental risks of pesticide use (Vernier et al, 2017), concluding that an indiscriminate use of chemical inputs in the agricultural production system cannot be environmentally or socially sustainable in the long term (Travisi et al, 2004). Such improper use of pesticides reduces soil biodiversity, destabilizes soil structure and increases the greenhouse effect (Bertrand et al, 2015;Datta et al, 2016;Khalil and Osborne, 2018;Marín-Benito et al, 2017;Meersmans et al, 2009;Pelosi et al, 2014;Prashar and Shah, 2013;.…”

Simulating land use changes, sediment yields, and pesticide use in the Upper Paraguay River Basin: Implications for conservation of the Pantanal wetland

“…Scenario modeling is an important tool for predicting how changes in land use influence different pathways of future human development and policy choices (Rosa et al, 2017). This is particularly true for land use scenarios which may be used to: (1) help evaluate the potential impacts of environmental resource mitigation measures, (2) more clearly delineate protected areas, and (3) more efficiently distribute financial incentives to farmers who implement alternative practices (Vernier et al, 2017).…”