The phrase "a rapid decline of" is correct and usable in written English.
It can be used to describe a quick or sudden decrease in something, such as a population, quality, or performance.
Example: "The region experienced a rapid decline of its bee population, raising concerns about the ecosystem's health."
Alternatives: "a swift drop in" or "a quick decrease of".
This has lead to a rapid decline of local self-sufficiency and a heavy dependence on foreign imports.
Since the 1990s, the once-abundant west African waters have seen a rapid decline of fish stocks.
The one exception was subject 4, where a rapid decline of CD3+ cells coincided with progression to acute myeloid leukemia (Figure 3a).
Across the economy, the biggest cuts last month came among construction companies, which have suffered from a slight drop in home building and a rapid decline of corporate investment in new buildings.
Because large farmers receive the largest subsidies, they are buying out smaller farmers, leading to what the Agriculture Department calls a "rapid decline" of family farms under 100 acres and the rise of old-fashioned tenant farming.
It was the beginning of a rapid decline of the island's population; historian Laurence Bergreen estimates that there were 300,000 natives on Hispaniola when Columbus arrived; by 1550, there were just 500.
Global emissions derived from these observations peaked at 3.1 kt in 2011, followed by a rapid decline of ∼0.5 kt yr−2 to reach 1.5 kt yr−1 in 2014.
The findings suggest taste buds and their progenitor cells are particularly sensitive to damage from inflammatory chemicals that are raised in obesity, resulting in a rapid decline of the overall number.
The report forecasts a "rapid decline of the public health system towards a possible collapse" and "no access or limited access to preventive programs" like immunization for a large part of the population.
It has had a checkered maritime history, suffering a rapid decline of its whaling industry and losing to other ports on the Haven its naval dockyard and Irish packet service, all before 1860.
Public use of the Cherokee language and, indeed, any indigenous language was discouraged to the point of physical punishment in government-run Indian boarding schools, with the result of a rapid decline of native speakers.
