Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Correlation coefficients between urban land category and incidence number (blue line) and between vegetation land category and incidence number (red line). The slope of first order polynomial fitting to the yearly varying incidence number (black line).
