Figure 3

Prediction maps of malaria transmission in P.R. China by combining two factors: (i) the number of months in which temperature is suitable for malaria transmission, and (ii) relative humidity (%). Grey colour screens the regions with relative humidity less than 60%. Blue colour indicates the regions where the number of month suitable for malaria transmission is less than 4 successive months. The maps were created based on data derived for 1961–1970 (A), for 1971–1980 (B), for 1981–1990 (C), and for 1991–2000 (D), respectively.