Tumiar Katarina Malik et al, presenting poster from their research in the field of agriculture. At American Geophysical Union (AGU) 2021 fall meeting they display poster about theirs study with the title “Food Crops Field Area Projection in 2020 until 2049 in Lampung Province Indonesia Based on RCP 4.5 and RCP 8.5 Scenarios”.
The study main object are Lampung Province which in the field agriculture earned the nickname as Indonesia’s Food Barn. But with the presence of climate change, there are many challenges that occur and will affected to the agricultural sector, especially in the province of Lampung.
Data sources in this study were various: rainfall daily data of 1975-2019 from 52 rainfall stations was obtained from Indonesian Bureau of Meteorology (BMKG) as well air temperature data but only from two stations in lowland area and mountainous area. Data of air temperature and rainfall of Representative Concentration Pathways (RCP) 4.5 and 8.5 scenarios in net CDF (.nc) form of CORDEX-SEA model with 25 x 25 km resolution in period of 2020-2049 was obtained from Center of climate change information Indonesian Weather and Climate Bureau.
The method for this study was as follow: from the projected air temperature and rainfall following those scenarios, evapotranspiration of the crops was calculated using Thornthwaite and Matter method and crop coefficients from the FAO list. Evapotranspiration and rainfall used to calculate crops water requirements and then the water availability. The water availability was divided in 5 criteria based on percentage of water availability which were: certainly enough (water availability was more than 90%), enough (water availability was between 90% to 60%), moderate (water availability was between 60% to 40%), not enough (water availability was between 40% to 10%) and extremely not enough (water availability was less than 10%). Overlaid the spatial of water availability with the basic map of Lampung Province would give the predicted area available for Paddy, Maize and Cassava plantation in the future
The result of the study showed that in general air temperatur will rise 1.34°C (RCP 4.5) and 1.49°C (RCP 8.5). Air temperature will rise both in highland and lowland area. From temperature rising it was calculated that evaporation would rise 4.4 mm/day (RCP 4.5) and 4.7 mm/day (RCP 8.5). The annual average monthly rainfall will rise 105.6 mm/year (RCP 4.5) and 298.2 mm/year (RCP 8.5). However, observed individual station the pattern did not always the same. As observed, rainfall in lowland area might decrease especially in dry season. Even in Highland area there was a station that showed decreasing rainfall both in rain and dry season. For the full report, please download the following files.