HYDROMAL: Hydro-dynamic drivers of human malaria transmission hazard in Africa. Thomas, Macklin, Smith and Gamarra Summary Malaria is a vector borne disease - we become infected by the bite of an infected mosquito. There is currently great concern that climate change may improve conditions for many disease vectors, such as mosquitoes, and that diseases like malaria will increase. The main burden of this disease falls in Africa, where changes in rainfall and temperature are projected to occur over the next century. While we have a reasonably good understanding, from laboratory studies, of how changed temperature may effect mosquito populations, we have very little on the effect of changed rainfall, which controls the availability of mosquito breeding sites. The distribution of these breeding sites in relation to human hosts is the main driver of local epidemiology, and in many locations across Africa it is likely that changes in precipitation, not temperature, will drive changes in transmission. This is the critical gap our project aims to fill, not by developing new science, but by adding value to existing knowledge by coupling different disciplines. Modern challenges require interdisciplinary thinking, and our project is an example of this. We aim to link well-established tools from geophyscial hydrology with mathematical models of malaria transmission, models that have been around for over 50 years. To quantify this relationship we will spend a year in the field in Tanzania, with a parallel program of hydrology and entomology, working in a large valley with the highest levels of malaria transmission in the world. We will then spend a further year analyzing the data and linking the mathematics. Our idea is that if we can predict where the breeding sites for vector mosquitoes will be at any given time, based on rainfall and terrain, we can estimate the malaria transmission. If we can prove this simple idea works, it will pave the way for future studies linking climate change projections to impact on this disease in Africa. It may also prove useful for health planners: it may prove more effective to target resources in key locations, and it may be that different interventions are more effective in different landscapes.