Spatio-Temporal Modeling of Malaria Risk Mapping Using Gi’s: A Case Study of Rawalpindi District

Abstract

Malaria is a vector borne disease spreading in tropical and sub tropical regions of the world. Nearly 40% of world’s population lives in high risk malaria zones. Suitable environmental parameters including temperature, humidity, vegetation and standing water bodies are necessary for life cycle and survival of mosquitoes. A study was conducted to identify malaria risk area and determine spatio-temporal seasonal variation in Rawalpindi district using remote sensing and GIS techniques. Air temperature and humidity maps were generated from land surface temperature maps and weather data obtained from meteorological department. Due to flight range of mosquito, 1.5 km area around water bodies and vegetation covers was considered suitable for mosquitoes. Temperature range of 25°C to 35 °C and relative humidity range of 50% to 80% was considered suitable for malaria outbreak. Each suitable environmental parameter acts as a criterion map. These four criterion maps were overlaid using weighted sum method to produce final malaria risk map. The results showed that 25%, 68%, 18% and 16% of the total area was subjected to danger zone (including very high and high risk areas) for June 2009, October 2009, January 2010 and June 2010 respectively. The population at risk analysis depicts that 26%, 75%, 26% and 5% of the total population resided in danger zone for June 2009, October 2009, January 2010 and June 2010 respectively. The study also illustrated that danger zones were found in Rawalpindi throughout the year and were mainly concentrated in Murree, Kotli Sattian, Kallar Syedan and Kahuta Tehsil. The results were in agreement with health department temporal malaria incidence situation. The study recommends that risk maps should be used as an input for targeting priority areas with control activities, such as insecticide house spraying and larviciding and to establish an early warning system for future malaria outbreak.