Fig. 2.

The framework of the integration model. The component of epidemic progression divides people into ten stages, including: susceptible (S), exposed (E), presymptomatic (P), severely symptomatic (I), mildly symptomatic or asymptomatic (A), hospitalized (H), quarantined at home (Q), false-positive isolated (F), recovered (R), and dead (D). People in some of stages would be potential requesters for testing resources (blue arrow), and others may drive testing willingness of the public (green arrow). These two parts are regarded as dynamic demand (red arrow), which is used to evaluate spatial accessibility (SA) to testing resources. Then, SA is further transformed into match level (ML) to measure the proportion of people who can get tested. This parameter determines the rate of infected people being transferred to isolation state (red arrow). These three parameters are integrated into the epidemic progress model for forming a loop to continually evaluate the spatial accessibility and epidemic progression over time.