hydrothermal coefficient

In the article the comparative analysis of repeatability of droughts of different intensity is presented in the separate interval of vegetation period on the natural zones of the Saratov area in 1951–1980 years and after 1981–2015 years. Centers of origin of droughts and their repetition on the area of coverage of the territory are shown. Agrometeorological description of the cruelest droughts is given, and consequences over of their influence are brought on gross collections of grain in the Saratov area.

The article presents forecasts of the quality of spring wheat grain according to the method of V. Ya. Yaroshevsky and V. P.

The classification of spring-summer droughts into the categories of «weak», «moderate», «strong», «ecological catastrophe» derived from regional meteorological characteristics and the sensitivity scale of Scots pine to drought is discussed. It is proposed to evaluate the drought as an autonomous natural phenomenon, within a certain territory and its (dry) vegetative season.