"varying levels of intensity" is correct and usable in written English.
You can use it to describe when something has different levels or degrees of intensity, often used to describe the varying intensity of emotions or physical sensations. For example, "I experienced varying levels of intensity throughout the massage, from very gentle to moderately intense at times."
Afghanistan has been at war, at varying levels of intensity, for thirty-one years.
Most had similar profiles, with pretty flavors of cherries and flowers of varying levels of intensity.
With varying levels of intensity, university are extensions of the societies that gave them life and meaning.
Shapiro: These talks have been going on and off at varying levels of intensity since at least 2011.
More than 2,000 schools in 42 states have unified athletic programs, with varying levels of intensity.
"It means the crisis will continue at varying levels of intensity throughout 2012 and probably beyond," the agency said.
The curves were generated for four different, preexisting, performance states that represented slight, moderate, extensive, and complete damage under varying levels of earthquake intensity.
Another used a photographic survey to examine coral distribution in relation to varying levels of fishing intensity in the Graveyard Seamount complex on the Chatham Rise [70].
Accelerometers have the ability to differentiate varying levels of PA intensity through the measurement of accelerations that occur during ambulation which are quantified as activity counts [ 23].
These misconceptions create an inertia that hinders the use of brief advice and varying levels of counselling intensity as effective interventions, and signify an urgent need for training.
Indeed, each complaint involving a specific type of voice disorders, although viewed as discrete here, might still be considered as a continuous gradation of varying levels of symptom intensity (i.e. as a latent trait).
