Fig 1.
Hambantota district (the area of study) in a map of Sri Lanka.
Hambantota district is shaded in yellow color in contrast to the other 24 districts. Kandy, Anuradhapura and Kurunegala districts that we mention in our discussion are also identified in this map. This map is a modification of the map (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0231408) created under CC BY4.0.
Fig 2.
Changes of aggregated weekly leptospirosis incidence (LI) during the course of the year, for 2008–2017.
Panel 2a; Changes of aggregated mean (dotted line) and median weekly LI during the course of the year, for 2008–2017 period, mean LI excluding 2011 for the same period and weekly LI during the course of 2011 (all per 100,000 population). x-axis: weeks/ primary y- axis: aggregated LI / LI of 2011 with much high magnitudes depicted in secondary y-axis for clarity: 2b; Changes of aggregated median and mean weekly LI excluding year 2011 during the course of the year, for 2008–2017 period, weekly LI during the course of 2011 (all per 100,000 population).Weekly LI of 2011 with much high magnitudes and a different temporal pattern depicted in secondary y-axis and by a dotted line for clarity.
Fig 3.
Changes of aggregated weekly rainfall, average hours of sunshine and average evaporation rates versus aggregated median weekly leptospirosis incidence during the course of the year, for 2008–2017.
Panel 3a; Changes of aggregated weekly rainfall (in mm) and of average weekly leptospirosis incidence (per 100,000 population) during the course of the year, for 2008–2017. x-axis: weeks/ primary y- axis: median weekly leptospirosis incidence (per 100,000 population). / secondary y-axis: aggregated weekly rainfall (mm). Panel 3b; Changes of aggregated sunshine (hours per day) and of median weekly leptospirosis incidence (per 100,000 population) during the course of the year, for 2008–2017. x-axis: weeks/ primary y- axis: average weekly leptospirosis incidence (per 100,000 population). / secondary y-axis: hours of sunshine (per day). Panel 3c; Changes of aggregated evaporation rate (mm per day) and of median weekly leptospirosis incidence (per 100,000 population) during the course of the year, for 2008–2017. x-axis: weeks/ primary y- axis: median weekly leptospirosis incidence (per 100,000 population). / secondary y-axis: evaporation rate (mm per day).
Fig 4.
Changes of aggregated weekly minimum and maximum atmospheric temperatures, and soil temperature (at 5 p.m.) versus aggregated median weekly leptospirosis incidence during the course of the year, for 2008–2017.
Panel 4a; Changes of aggregated maximum temperature (in degrees Celsius) and of median weekly leptospirosis incidence (per 100,000 population) during the course of the year, for 2008–2017. x-axis: weeks/ primary y- axis: median weekly leptospirosis incidence (per 100,000 population). / secondary y-axis: maximum temperature (in degrees Celsius). Panel 4b; Changes of aggregated mean minimum temperature (in degrees Celsius) and of median weekly leptospirosis incidence (per 100,000 population) during the course of the year, for 2008–2017. x-axis: weeks/ primary y- axis: median weekly leptospirosis incidence (per 100,000 population). / secondary y-axis: minimum temperature (in degrees Celsius). Panel 4c; Changes of aggregated soil temperature (in degrees Celsius) and of median weekly leptospirosis incidence (per 100,000 population) during the course of the year, for 2008–2017. x-axis: weeks/ primary y- axis: median weekly leptospirosis incidence (per 100,000 population). / secondary y-axis: soil temperature (in degrees Celsius).
Fig 5.
Comparison of weekly weather parameters of 2011 against aggregated averages of those weather parameters of other nine years are illustrated in six panels (a-f) of this figure.
Time series of 2011 are shown in maroon whilst aggregated averages of other years are in blue. 5a: Rainfall, 5b: Evaporation rate, 5c: Hours of sunshine, 5d: Soil temperature, 5e: Maximum air temperature, 5f: Minimum air temperature.
Fig 6.
Results of wavelet analyses of weekly average soil temperature (at 5pm) versus weekly leptospirosis incidence for 2008–2017: (Panel 6a) continuous wavelet transform (CWT) variations; (Panel 6b) wavelet power of CWT; (Panel 6c) crosswavelet transform (XWT) variations; (Panel 6d) wavelet power of XWT; (Panel 6e) wavelet coherence (WTC); (Panel 6f) wavelet power of WTC; and (Panel 6g) reconstructed time series for 2006–2015 period.
Table 1.
Combined summary of wavelet analysis and cross-correlation analysis (SPSS) results.