Evaluation of the gridded CRU TS precipitation dataset with the point raingauge records over the Three-River Headwaters Region

Abstract

This study evaluated the performance of the gridded CRU TS precipitation dataset in describing the spatial and temporal characteristics of precipitation over the Three-River Headwaters Region (TRHR) during 1961–2014, and the results were compared with those derived from the point raingauge records (RGR) at 29 meteorological stations. It indicated that: (1) temporally, the TRHR has experienced a significant increasing trend in the annual precipitation during 1961–2014; (2) spatially, the mean annual precipitation (MAP) in the TRHR showed the southeast-to-northwest decreasing trend; (3) a close correlation of the MAP with elevation was found, and statistical equations to estimate the MAP derived from the gridded CRU TS dataset were established based on longitude, latitude and elevation. Through comparing the results derived from these two datasets, it is concluded that the CRU TS dataset gave a lower estimation of annual precipitation than that from the RGR data but similar variation characteristics. Moreover, the MAP values derived from the gridded CRU TS dataset could be well estimated by the equations derived from the RGR data. The results would be valuable for the researchers to make better use of this gridded precipitation dataset and have a clearer understanding of the spatio-temporal patterns of precipitation in similar high-elevation mountainous regions such as the TRHR, where ground precipitation measurements are not widely available.