Application of Remote Sensing and GIS in identifying and mapping Sandfly Distribution in endemic and Non-endemic Kala-azar foci in Bihar and Jharkhand

摘要

Remote Sensing and GIS techniques have been used to study the environmental factors associated with diseases like malaria and snail borne communicable diseases in North America, Asia and Africa (Anyamba Assaf et al. 2002, Brooker Simon et al. 2002, McKenzie J.S. et al. 2002, Omumbo J.a. et al. 2002, Rogers David J.et al. 2002, Seto Edmund et al. 2002). This study is an attempt to study the geo-environmental parameters responsible for the propagation of sandfly vector (P. argentipes) in an endemic (Vaishali district, Bihar, India) and non-endemic area (Lohardagga district, Jharkhand, India) using remote sensing and GIS. The term Leishmaniasis denotes diseases caused by genus Leishmania, a flagellate protozoan related to Trypansoma. In Indian sub-continent only two forms of Leishmaniasis, viz. cutaneous leishmaniasis (L.Tropica) and visceral leishmaniasis (L. donovani) or Kala-azar are endemic. In all these areas, the disease shows direct correlation with the distribution of P. argentipes (sandfly). Moist sandy soils, high humidity, moderate temperature, dwellings surrounded with soft stemmed vegetation are important geo-environmental paramenters controlling the abundance of sandfly. IRS LISS-Ⅲ satellite data pertaining to endemic (Vaishali district, Bihar, India) and non-endemic area (Lohardagga district, Jharkhand, India) has been used for generation of information on vegetation, cropping pattern, water bodies/marshy land etc. Temperature, humidity, man-hour-density of sandfly, peri-domestic vegetation was collected from field based observations. Soil samples collected from fields were also analysed for its constituents. Geo-environmental parameters derived from satellite as Landuse and NDVI, and collateral data of soil moisture, temperature, humidity, soil constituents have been correlated with man-hour density of sandfly in endemic and non-endemic area using multi-variate analysis. It was observed that satellite derived NDVT, Landuse and soil moisture, temperature, humidity data have very good correlation with man-hour density of sandfly. The study provided an insight into the micro-ecosystem, i.e. the association of vegetation, water bodies, soil type, human setdements and associated peri-domestic vegetation, and other landuse features of relevance in distribution of vector sandfly.