Fig4.pdf VersteeghEmma 2012 Fig. 4 Discharges categorised in five classes with respect to mean, minimum and maximum discharges during the season April–October 1912–1918 and 1969–1977 at Borgharen. For 1910 and 1911, no discharge data were available From: Versteegh, E.A.A., Vonhof, H.B., Troelstra, S.R., Kroon, D., 2011. Can shells of freshwater mussels (Unionidae) be used to estimate low summer discharge of rivers and associated droughts? International Journal of Earth Sciences 100(6): 1423-1432.