CR prepress abstract  -  DOI:

Evaluation of extreme precipitation and drought monitoring in northeastern China using AOGCMs and pan evaporation-based drought indices

Muhammad Abrar Faiz, Liu Dong*, Fu Qiang, Dariusz WrzesiƄski, Baig Faisal, Ghulam Nabi, Muhammad Imran Khan, Tianxiao Li, Song Cui


ABSTRACT: The evaluation of precipitation extremes and the usage of appropriate drought indices are very important for assessment of natural disasters (i.e., floods and drought). For this purpose, values of indices that reflect precipitation extremes and three drought indices, Composite Index (CI), Standardized Precipitation Evapotranspiration Index (SPEI) and Reconnaissance Drought Index (RDI) with reformulation of pan evaporation and Penman–Monteith equation, (denoted as CI (Pan), RDI (Pan), RDI (PM), and SPEI (PM)) were calculated, based on observed data that cover the period from 1961 to 2005. Moreover, output from Coupled Model Intercomparison Project Phase 5 (CMIP5) historical model simulations were also used to identify the discrepancies in the model simulations. The results showed that wet-day precipitation (PRCPTOT) increased at a rate of 1.9 mm/year over the entire study area. During the whole time period, the simple daily intensity index (SDII) exhibited a non-significant decreasing trend compared to other precipitation indices. The number of consecutive wet days (CWD) showed a negative trend, while the number of consecutive dry days (CDD) showed a positive trend with a slope of 0.33 days/year. Furthermore, very small differences were found between the results of the multi-model ensemble mean and the values of the extreme precipitation indices assessed from the in situ stations. The performance of reformulated drought indices is significant in monitoring drought events in the study area. A comparison of the indices showed that the performance of reformulated drought indices is better than that of the standard RDI and SPEI at all the stations. The highest CI (Pan) value (0.23) was observed in July, and the two lowest values, -0.6 and -0.7 were observed in April and September, respectively. These results show that these two months are highly prone to drought.