An IRIT contribution to COP26

Can computer science save the planet? In any case, computer models can contribute to a better understanding of the effects of different policies that could be put in place to fight against the threats that threaten it. This is what is shown by Benoît Gaudou, Associate Professor at the University of Toulouse Capitole and member of SMAC Team – IRIT, and a group of Franco-Vietnamese researchers, through their contribution to the research project GEMMES. It is a cooperation between the Vietnamese government, the AFD (French Development Agency) and the IRD (Institute of Research for Development), with the aim of conducting a study to assess “the various socio-economic impacts of climate change and possible adaptation strategies implemented in Vietnam.” The report “Climate change in Viet Nam Impacts and adaptation” was presented at the COP26 in Glasgow and handed over to the Vietnamese authorities.

The Mekong Delta, a very sensitive area

Vietnam is a country particularly vulnerable to the consequences of climate change. It has more than 3200 km of coastline. According to the scenario of a rise in water level of one meter, 5% of the country’s land surface could disappear. This situation concerns in particular the Mekong delta, and this threatens the economic and food security of the country. The rise in temperature, which has led to an increase in typhoons, droughts and river and coastal erosion, is also a major concern.

According to the AFD (French Development Agency), “adaptation to climate change necessarily involves adapting this population and its agricultural practices, particularly land use.”

This need to adapt is the subject of cooperation between the Vietnamese government, AFD and IRD, which have decided to conduct an integrated study up to 2050. The research focuses on the different socio-economic impacts of climate change and on the adaptation strategies that can be implemented in Vietnam. The responses to global temperature increase scenarios of 1.5°C, 2°C or 3°C correspond to different global climate change scenarios. These scenarios integrate different databases that need to be intelligible and analyzed in an optimized way.

Thus, computer models and technologies can appear as real tools for climate change adaptation strategies. They constitute a real support for collecting and analyzing data, and simulating complex scenarios to understand what are the most optimal solutions to the urgent environmental situation.

IT for the environment

Benoit Gaudou, within the framework of his hosting by the IRD in Vietnam, participated in the elaboration of chapter 10 (page 441) of the report presented at the COP26. The objective of this paper is to present how the use of computer models can be used to represent and understand the interactions between adaptation strategies at different spatial and social scales, under several climate scenarios. It highlights the contribution of agent modeling to the evaluation of adaptation strategies.

These computer models are variations of a basic model called LUCAS (Land Use Change for Adaptation Strategies). LUCAS simulates the interactions between individual and collective strategies and their effects on land use. LUCAS provides a projection of land use in the Mekong Delta for 2030, with a projection to 2050, which allows for the design of long-term projections. Input data for model verification and calibration is collected from the 2015 land use map and interpreted from Sentinel 2 imagery for 2020.

This approach has the advantage of taking into account different parameters that are inseparable when implementing climate change adaptation strategies. LUCAS shows that it is possible to consider in a model, simultaneously, adaptation efforts at the individual level and proposed strategies at the regional level, with the aim of accurately assessing the effectiveness of the latter. This approach also facilitates the subsequent integration of more specialized models applied to rice yields, salt and sediment transport, demographics, and others. LUCAS-based virtual experiments have the potential to change the way adaptation planning is conducted in the future.

The computer models can therefore be used to calculate the land use areas at risk from the effects of climate change. They allow the simulation of land use changes in the Mekong Delta, year by year, under the influence of adaptation strategies at different levels. Key climate change indicators and specific parameters allow the model to be used to analyze and optimize possible solutions.