Extreme precipitation and rainfall island effect in Jinan City

Landsat remote sensing images of Jinan obtained in 1985, 2000 and 2015 were used to identify and classify changes in land use types in the built-up and downtown areas in Jinan．Daily precipitation data from 1972 to 2016 at 24 gauging stations in Jinan were used．Indicators of extreme precipitation (PRCPTOT, R30 mm, R50 mm, SDII, Rx5day and R95p) were selected. Spatiotemporal evolution for extreme precipitation on interannual scales was subject to Mann-Kendall trend test and Sen′s slope estimation．Built-up area in Jinan was found to have increased rapidly from 1985 to 2015; the entire city expanded more than 5.5 times, with downtown area almost doubled．Precipitation in downtown area and Shanghe Station was found to have increased, but increase in precipitation in central city slowed with urbanization．Indicators of extreme precipitation at inter-annual scales and for flood seasons were found have evolved similarly．Significant changes in precipitation sequences at some stations were found．Indicators of extreme precipitation in downtown area and Shanghe Station showed similar upward trend, closely relating to urbanization．Indicators Rx5day and R95p in downtown area increased at a rate of 1 mm·a⁻¹ in flood seasons．