Modeling the spatiotemporal response of dew point temperature, air temperature and rainfall to land use land cover change over West Africa

The study validated the use of an updated MCD12Q1 MODIS Land Use Land Cover (LULC) data into Weather Research and Forecasting (WRF) model and investigated the effects of LULC change on the spatiotemporal pattern of dew point temperature (DPT), temperature, precipitation and some associated parameters over West Africa (WA). Series of WRF model simulations were carried out with 6 LULC scenarios, which include Built-up (Bu), Partial Deforest I and II (PDI/PDII), Partial Afforest (PA), Total Afforest (TA) and Total Deforest (TD). MCD12Q1 LULC data was integrated into WRF model to carry out eight simulations from May-September, 2012 at 12 km horizontal resolution over WA. The integration of updated MODIS LU data into WRF model showed improvement with lesser RMSE. The BU and TD scenario generally decreases dew point temperature while the areas with remarkable decrease (increase) in dew point temperature also have a decrease (increase) in evapotranspiration and an increase (decrease) in Sensible Heat (SH). Increased SH could be a factor for the increased precipitation over the urbanized area. All afforestation options decreased the temperature due to weakening of the SH. Afforestation of the Sahel led to an increase in rainfall, which is attributed to increase in ET. Deforestation of the Guinea zone (PDI/PDII) reduced the precipitation in Sahel and Sahel-Sahara interface and the entire area. Only the TA scenario increased precipitation over the Sahel-Sahara interface due to increased ET. The effects of LULC change on precipitation are complex as more in-depth analysis of the effects on major features of the general circulation of WA is recommended for future research.