Accompanying The adaptation of irrigated agriculture to climate CHAnge – ATCHA

In the context of agriculture increasingly relying on groundwater irrigation, it is crucial to develop reliable and applicable methods for assessing the sustainability of agricultural systems under climate change. A wide variety of models have been developed for ex-ante evaluation of management policies or assessment of the impacts of land-use changes. They are commonly used to support decision making by stakeholders through participatory approaches. However, due to the difficulty in implementing truly trans-disciplinary projects, the models rarely represent both the complex biophysical processes at stake in agricultural watersheds and the farmer adaptation strategies to changes. Consequently, these models are not able to adequately account for the spatial and temporal interactions and feed-backs between these two components. The Indian context is an extreme case where the integration of these components is both essential and challenging: the “groundwater revolution” which started three decades ago and induced a well identified “groundwater crisis” with tremendous impacts on water resources and ecosystems, is being carried out by millions of very small farmers owning individual borewells, with a large diversity of practices and strategies.

The ATCHA project aims to accompany the adaptation of farming systems to climate change by combining an integrated biophysical model with a participatory approach in a network of experimental watersheds in the Karnataka state.

Through a truly trans-disciplinary approach, involving hydrologists, geochemists, soil scientists, agronomists, geographers, economists and sociologists and with a strong participation of Indian partners including scientists, extension service agents and stakeholders, we aim at demonstrating the ability of integrated models to share knowledge between researchers and stakeholders and to co-build and assess scenarios of sustainable development of agriculture. The ATCHA project is based on (1) the strong partnership initiated with the International Joint Laboratory IFCWS (Indo-French Cell for Water Sciences, involving the Indian Institute of Science, Bangalore) which allowed to build an extensive database in the Berambadi experimental watershed (Critical Zone Observatory, ORE BVET) and (2) a specific Indo-French project (CEFIPRA AICHA, 2013-2016) in which an integrated model combining hydrology (AMBHAS), agronomy (STICS), economy (MoGire) and farmer decision (Namaste) models was developed. The ATCHA project will complement the Sujala III project (2014-2019), led by the Karnataka Watershed Department and in which IFCWS takes part in the coordination of the monitoring carried out in 14 experimental watersheds across the Karnataka state.

The ATCHA project is composed of 3 work packages (in addition to the coordination WP): i) development of novel methodologies to gather spatialized information on soils and land use, using both ground and multi-satellite data at high spatial and temporal resolution ii) improvement of the model realism by calibrating a large number of tropical crops and bridging knowledge gaps for modelling nutrient cycles in tropical irrigated agro-systems and iii) development of a participatory approach to build and assess scenarios of adaptation to climate change and its critical assessment.
We expect the ATCHA project to produce not only significant scientific advances on the functioning of agro-hydrosystems under high anthropogenic pressure but also to have a strong socio-economic impact, in terms of capacity building for the Indian partners (in particular for crop and agro-system modelling), improving the relevance of advice given to farmers by extension services and the efficiency of public policies.