Distress indicators and maps for Covid-19.

In its simplest form, a pandemic like Covid-19 progresses roughly according to a logistical law – exponentially at first till a peak rate is reached and then the curve turns and finally levels off. However, this textbook feature is interrupted by lockdowns, other pandemic mitigating protocols, and the emergence of new variants and so the picture becomes complex with multiple wavelike interferences. In this paper, we identify two components – the death rate per million of population (N) and the fractional rate of change (f) at each stage. We propose a series of hierarchically ordered indicators with a final second-order indicator X = f²N. This serves as a single number metric summarising the criticality of the rate of progress of the pandemic at that stage. We use as examples, the progress of Covid-19 at the global level, and within India. This helps to reveal the complex features of the evolution of a pandemic in a region. [ABSTRACT FROM AUTHOR]