Figure 1
From: Could drought conditions trigger Schmallenberg virus and other arboviruses circulation?
Drought conditions in Schmallenberg virus (SBV) circulation area in 2011. The sites of SBV detection until April 2012 are shown on Europe map (a). These sites were utilized to evaluate the area of virus circulation by kernel density estimation (KDE) (b). Then (c) 95% and 50% volume contours of KDE (yellow line and red line respectively) were overlaid to the map showing the interpolated 3 month standardized precipitation indices (SPI3) of May 2011. SPI3 value: red <-2, orange >-2 <-1, green >-1 <1, azure >1 <2 , blue>2. SPI3 indices were provided by European Drought Observatory [24], due to the improvement in measurements, future SPI values, referring to the same period, may be slightly different.