Suitability assessment of CMA multi-source precipitation analysis products for short-term heavy rainfall monitoring in Shaanxi
Based on the precipitation data from Shaanxi Province from 2016 to 2021 and real-time products of two-source and three-source precipitation from the CMA Multi-source Precipitation Analysis System(CMPAS-V2.1)during 2018-2021,the spatial and tem-poral characteristics of short-term heavy rainfall in Shaanxi Province over the past 6 years were analyzed.Furthermore,statistical tests were applied to evaluate the accuracy of the multi-source precipitation products,with the aim of providing reference for correction of multi-source precipitation products in short-term heavy rainfall processes.The results are as follows:(1)In Shaanxi Province,the short-term heavy rainfall frequency peak was at 19:00 pm,with heavy precipitation primarily occurring from 16:00 to 02:00 in a day and pre-dominantly in the months of June to August.The diurnal extreme value of heavy rainfall shows relatively higher from 17:00 to 01:00 and from 04:00 to 07:00 in the morning.Short-term heavy rainfall is more frequent in southern Shaanxi compared to Guanzhong and north-ern Shaanxi.The regions with relatively larger extreme values include northern Shaanxi,eastern Guanzhong,and central-eastern of southern Shaanxi.(2)Both two types of precipitation products tend to underestimate precipitation compared to observed values.The mean absolute errors of the three-source product exhibit smaller in southern of northern Shaanxi,most part of Guanzhong and southern of southern Shaanxi,while the two-source product performs relatively better in other region.The mean absolute error increases with pre-cipitation increase.For heavy precipitation ranging from 20 to 50 mm,three-source product is recommended,while two-source product is more suitable for heavy precipitation above 50 mm.(3)The diurnal variations in mean absolute errors for both two types of multi-source products are relatively larger from 13:00 to 19:00,23:00 to 01:00 and from 04:00 to 06:00,and relatively smaller from 08:00 to 12:00,20:00 to 22:00 and from 02:00 to 03:00.The three-source product outperforms two-source product from May to August,while two-source product performs better from September to October.(4)The accuracy rate of multi-source precipitation products increases as the threshold of short-term heavy rainfall decrease.Both mean absolute error and accuracy rate indicate that the three-source product outperforms two-source product.Multi-source precipitation products exhibit higher accuracy from September to October compared to May to August.
multi-source precipitation productshort-term heavy rainfallassessmentShaanxi
NETL
NSTL
万方数据
