Spatial and temporal variations of precipitation in Haihe River basin in the recent 53 years

Abstract. In the context of climate change, the precipitation of the Haihe River basin undergoes significant changes. Based on the daily precipitation data from 58 stations over 53 years in and around Haihe River basin, the spatial and temporal variation of precipitation was analysed by the M-K test method using the ArcGIS platform. The results showed that there is a descending trend in the annual precipitation and after the mutations, 97.9% of the area experiences a precipitation reduction by the amount of 0–200 mm. The proportion of precipitation in the flood season demonstrates a decreasing tendency, in which the proportion of precipitation in July declines significantly. Meanwhile, precipitation in July also experiences a downward tendency and after the mutations, the decrement of precipitation in July amounts to 0–84 mm. However, annual precipitation and the proportion of precipitation in June all experience a rising trend. After the mutations, the added precipitation concentrates in 0–36 mm. With the increase of the proportion of non-flood season precipitation, the precipitation and proportion of precipitation in May both exhibit an increasing tendency. After the mutations, the added value of precipitation concentrates as 0–29 mm.