A Study on the Caucasus Region: Crop Model Based on “Slow” Climate Change over the Last 60 Years

The study is based on the instrumental data (temperatures and precipitation) of 20 weather stations
located on the territory of the Caucasian region during 1961-2018. The methods of mathematical
statistics, trend analysis and the rescaled range method were used. It was found that the warming
trend prevailed in all climatic zones, it has intensified since the beginning of global warming (since
1976), while the changes in precipitation were not so unidirectional. The maximum warming was
observed in summer (average by 0.38°C/10 years) in all climatic zones. Persistence trends were
investigated using the Hurst exponent H (range of variation from 0 to 1), which showed a higher trend
persistence of annual mean temperature changes (H =0.8) compared to annual sum precipitations (H
=0.64). Spatial-correlation analysis performed for precipitations and temperatures showed a rapid
decrease in the correlation between precipitations at various weather stations from rp = 1 to rp = 0.5 on
a distance scale from 0 to 200 km. Taking into account the “slow” climate changes, a multiplicative
model of agrometeorological resources was proposed, during the construction of which it was
assumed that they are determined by seasonal values of average air temperature and precipitation.
Given the seasonal characteristics of the cultivation of crops (winter wheat, spring wheat), two models
of agro-climatic resources are proposed.