MODELING THE SUITABILITY OF LANDS FOR CULTIVATING AGRICULTURAL CROPS IN THE SAMARA REGION UNDER CLIMATE CHANGE

Abstract

The paper presents the results of applying the Maximum Entropy (MaxEnt) method for modeling thesuitability of agricultural land for the cultivation of major grain crops in the Samara Region under changing climateconditions.The territory of the Samara Region is characterized by a high proportion of arable lands and developed agriculturalproduction. About half of the cultivated areas are used for grain crops (barley, spring and winter wheat, grain maize).The yield of these agricultural crops is primarily influenced by abiotic factors, especially temperature and precipitation. According to forecasts, global warming will significantly change the geography of land suitable for the cultivationof grain crops.The MaxEnt presence-only modeling tool, implemented in the ArcGIS Pro software package, was used in the studyas the main instrument.The MaxEnt model is based on the principles of logistic regression. The model is trained using specified locationsand values of explanatory (independent) and dependent variables associated with them. The trained model allows forpredicting the value of the dependent variable for any values of the predictors.In our model, the distribution of agricultural land for the cultivation of major grain crops in the Samara Regionserves as the specified known locations. 19 bioclimatic variables were used as explanatory variables. The predicted variable values were calculated according to the SSP3-7.0 climate scenario for the year 2050.We obtained two maps of land suitability, current and future, for the cultivation of wheat, barley, and maize in theSamara Region, with an assessment of the probability of presence. The quality of the model was assessed using the AUC(area under the curve) statistic, which reflects the relationship between presence points that are correctly classified by themodel and incorrectly classified background points.The study has found that in the future, the territory suitable for the cultivation of major grain crops will significantly decrease, primarily in the southern districts, and will shift toward the northern part of the region.