Surface hydrology (DOCUMENTATION NEEDS UPDATING)

As the hydrology is somewhat “external” to the main mechanics of vector and parasite lifecycles, it is described in this separate section.

To convert the precipitation at a location into the availability of breeding sites that permit vector proliferation, the VECTRI model includes a simple, physically-based surface hydrology model that at each timestep provides a calculation for the fractional coverage of each model gridcell by potential breeding sites for the malaria vector, $w$. This fraction consists of two components since the model distinguishes between breeding sites provided by temporary ponds, $w_{pond}$, and those associated with permanent water bodies such as lakes, rivers and streams that contain water year-round, $w_{perm}$:

$$w = w_{perm}+ w_{pond}.$$ (14)