Remote sensing and on-site characterization of wetlands as potential habitats for malaria vectors – A pilot study in southern Germany

Abstract

Wetlands, particularly in developing countries, are common hotspots of insect-borne diseases that are a constant threat to public health, such as malaria. To help identify and characterize potential breeding grounds for mosquitoes, we utilize freely available satellite image data and software in combination with a mosquito trap system. Multispectral time-series analysis of Sentinel-2 and Landsat 5–8 satellite images of Lake Schmiechen (Swabian Alb, southern Germany), used here as a pilot and analog site for other lake and wetland areas potentially populated by malaria vector mosquitoes, reveals non-seasonal periods of flooding and drying and concomitant changes in the distribution of open shallow water. Water distribution maps are derived from spectral indices commonly used for wetland mapping (e.g., the NDWI2) and should be ground-truthed. In combination with the identification and counting of mosquitoes and the integration of other environmental parameters on-site, this approach provides a powerful tool to remotely monitor relatively small bodies and narrow networks of open shallow water that may provide habitats for mosquitoes. Combined remote sensing and on-site monitoring of potential malaria vector habitats can be implemented at low cost and with little effort in regions worldwide where the disease is established or emerging, and can be used to create or refine risk maps on small to large scales. The present approach can, moreover, complement public health programs and humanitarian efforts to fight insect-borne diseases.