Subjects: Geosciences >> Atmospheric Sciences submitted time 2023-08-25 Cooperative journals: 《干旱区研究》
Abstract： Globally, China is one of the country’s most frequently and severely affected by drought. Thesefrequent drought events have subsequently caused serious economic, social development, and ecologicalenvironment losses. Drought simultaneously leads to alterations in both space and time, and this paper aims toidentify drought events and quantify their spatial and temporal dynamic evolution using a three- dimensionalclustering algorithm for mainland China, from 1981-2020. The three- dimensional clustering algorithm can beused to effectively identify drought events and describe their dynamic processes. From 1981-2020 there were102 drought events lasting 2 months or more in mainland China. Spatially, the trajectory of drought events wasfound to show a tendency to develop from east to west. Temporally, there are high time overlaps betweendifferent drought events. In addition, drought events with wide coverage and high severity were concentrated inthe period from 2005-2010. The findings of this paper will help to elucidate the spatial and temporal evolutionpatterns of drought events and provide scientific references for drought monitoring and drought risk managementin mainland China.
Subjects: Geosciences >> Atmospheric Sciences submitted time 2023-04-07 Cooperative journals: 《干旱区地理》
Abstract： This study aims to evaluate the accuracy of the multi- source weighted- ensemble precipitation (MS WEP) product for drought monitoring in the Yellow River Basin of China from 1981 to 2020 using several statistical indicators and the standardized precipitation index (SPI) with multiple time scales. The run theory was used to identify drought events and quantitatively analyze their spatial and temporal characteristics. The following results are presented. (1) The monthly precipitation from the MSWEP product is well correlated with that from the ground observation represented by the Chinese precipitation analysis product (CPAP), and the determination coefficient reaches 0.9347. (2) The MSWEP product could successfully capture the spatial pattern and temporal evolution of multiyear precipitation. (3) The SPI calculated on the basis of the MSWEP product could generally reproduce the SPI pattern calculated on the basis of CPAP. However, the correlations differ from region to region. MSWEP product has a satisfactory performance in the middle and lower reaches of the river basin despite its poor performance in capturing the wetness or dryness condition in the source area of the Yellow River Basin with correlation coefficients lower than 0.5. Notably, the capability of the MSWEP product for capturing drought decreases with the increase in the SPI time scales. (4) The performance of the MSWEP product in the middle and lower reaches of the watershed is significantly better than that in the upper reaches. (5) MSWEP product can effectively capture the characteristics of drought events, such as duration, intensity, and severity. Thus, the MSWEP product is generally suitable for drought monitoring in the middle and low reaches of the Yellow River Basin. However, further correcting the overestimation error of precipitation in the application of MSWEP in areas with complex terrain in the source region of the Yellow River Basin is necessary.
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