What is the largest country in the world based on the most suitable land area for human habitation?

Species distribution modeling (SDM) is widely used to predict suitable habitats of living organisms based on niche conservatism on the global scale.

I used a “Maxent” (machine-learning technique called “maximum entropy modeling”) to model comfortable habitat for Homo sapiens, based on current location of settlements. Maxent software (version 3.4.1) was downloaded from biodiversityinformatics.amnh.org

Maxent software for modeling species niches and distributions by applying a machine-learning technique called maximum entropy modeling. From a set of environmental (e.g., climatic) grids and georeferenced occurrence localities, the model expresses a probability distribution where each grid cell has a predicted suitability of conditions for the species. For the map cells predicted using Maxent, cells with values of 1 had the highest degree of habitat suitability, while cells with values of 0 had the lowest. Habitat suitability was determined based on the climatic similarity to sites where the species already occur. The predictive precision of Maxent was based on the area under the curve (AUC) of the receiver operation characteristic (ROC), which regards each value of the prediction result as a possible threshold; the corresponding sensitivity and specificity were obtained through calculations. AUC ranges from 0.5 (lowest predictive ability or not different from a randomly selected predictive distribution) to 1 (highest predictive ability).

I selected towns and cities in the world with 100, 1000, 10000 and 100000 inhabitants and used 19 bioclimatic variables to model the potentially suitable environmental distribution of Homo sapiens. Bioclimatic variables were downloaded from the global database WorldClim (www.worldclim.org) at a spatial resolution of 30 arcseconds.

The MaxEnt model generated continuous probability values for the presence of Homo sapiens, ranging from 0 to 1. To delineate the presence/absence map of Homo sapiens, those continuous probability values were converted to the binary prediction based on a threshold probability value. This threshold probability was determined according to the ‘maximum training sensitivity plus specificity’ criterion.

The MaxEnt model for Homo sapiens showed a reliable prediction with an AUC of 0.684 (settlement with 100 inhabitants), 0.671 (1000) 0.709 (10,000), 0.778 (settlement with 100,000 inhabitants), greater than the 0.5 of a random model.

The most important bioclimatic variable determining the geographical distribution of Homo sapiens is bio_1 (Annual Mean Temperature).

bio_1 = Annual Mean Temperature, bio_2 = Mean Diurnal Range, bio_3 = Isothermality, bio_4 = Temperature Seasonality, bio_5 = Max Temperature of Warmest Month, bio_6 = Min Temperature of Coldest Month, bio_7 = Temperature Annual Range (BIO5-BIO6), bio_8 = Mean Temperature of Wettest Quarter, bio_9 = Mean Temperature of Driest Quarter, bio_10 = Mean Temperature of Warmest Quarter, bio_11 = Mean Temperature of Coldest Quarter, bio_12 = Annual Precipitation, bio_13 = Precipitation of Wettest Month, bio_14 = Precipitation of Driest Month, bio_15 = Precipitation Seasonality, bio_16 = Precipitation of Wettest Quarter, bio_17 = Precipitation of Driest Quarter, bio_18 = Precipitation of Warmest Quarter, bio_19 = Precipitation of Coldest Quarter.

The most suitable habitats for Homo sapiens

Brazil is the biggest country in the World

The largest countries in the world by area suitable for a comfortable life

Population density

Alex Egoshin
www.vividmaps.com

Related post:
– Find cities with a similar climate