Description of the model
The model is described in Bonnin et al, Predicting the effects of climate change on dengue vectors densities in Southeast Asia through process-based modeling, submitted
The original model was developped by Tran et al 2020
Tran, A. et al. Complementarity of empirical and process-based approaches to modelling mosquito population dynamics with Aedes albopictus as an example—Application to the development of an operational mapping tool of vector populations. PLOS ONE 15, e0227407 (2020).
The mosquito model was not designed to provide an absolute value of adult mosquito density (e.g. as a nb mosquitoes/Ha) but rather a relative index serving as a way to estimate spatial and temporal variations of adult mosquito density. This index of density has no unit.
Two mosquito species: Aedes aegypti and Aedes albopictus -> main vectors of arboviruses such as the Dengue virus (DENV).
Model outputs represent seasonal variations of adult mosquito densities of a typical year representative of a period (contemporary period, 2021-2040, 2041-2060, 2061-2080, 2081-2100), at a monthly resolution.
Model outputs are given at a spatial resolution of 1/6 degrees (~16-18km) for an area covering the following countries: Thailand, Vietnam, Lao PDR, Myanmar, Cambodia
Model outputs representative of the contemporary period rely on gridded observation of climate variables (temperature and rainfall) from the WorldClim data repository (https://www.worldclim.org/data/cmip6/cmip6climate.html) and Species Distribution Modelling (cf Bonnin et al)
Projected model outputs rely on gridded projections of climate variables from the WorldClim data repository, available for:
- 9 climate models: BCC-CSM2-MR, CNRM-CM6-1, CanESM5, IPSL-CM6A-LR, MIROC-ES2L, MIROC6, MRI-ESM2-0, CNRM-ESM2-1, GFDL-ESM4 + WCmodels_mean: an average of the outputs of all these climate models
- 4 scenarios of greenhouse gas emissions, the Shared Socio-Economic Pathways from the CMIP6: SSP1 2.6, SSP2 4.5, SSP3 7.0 and SSP5 8.5
- 4 periods: 2021-2040, 2041-2060, 2061-2080, 2081-2100
The density index was designed to vary between 0 and 1 over the spatial extent of the study for the contemporary period. Density indices representative of future projections can exceed the value of 1.
Model outputs data corresponding to future projections were also presented as anomalies, i.e. a ratio of projected to contemporary density indices. Values lesser than 1 correspond to a future decrease of densities. Values greater than 1 correspond to a future decrease of densities. An anomaly ratio of 2 correspond to a situation with twice the mosquito density in the future, relative to the contemporary situation.
Description of the model output data
Model outputs are available as Geotiff rasters, with 12 bands corresponding to the 12 calendar months.
Geotiff files are stored in the following folders:
> contemporary: This folder contains the following geotiffs:
- {species}_density_index.tif: Seasonal variations of the density index of the corresponding species (12 bands)
> projections: This folder contains the following geotiffs, describing future anomalies of density index
- {species}_anomaly_ratio_{scenario}_{period}_{model}.tif
species codes: aegypti, albopictus
scenario codes: ssp126, ssp245, ssp370, ssp585
period codes: 2021-2040, 2041-2060, 2061-2080, 2081-2100
model codes: BCC-CSM2-MR, CNRM-CM6-1, CanESM5, IPSL-CM6A-LR, MIROC-ES2L, MIROC6, MRI-ESM2-0, CNRM-ESM2-1, GFDL-ESM4