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Beijing University of Civil Engineering and Architecture (2021)

Research on Drought Monitoring Methods Taking into Account the Impact of Climatic Indices

王思宇

Titre : Research on Drought Monitoring Methods Taking into Account the Impact of Climatic Indices

Auteur : 王思宇

Grade : Master 2021

Université : Beijing University of Civil Engineering and Architecture

Résumé partiel
Drought is one of the world’s most severe natural disasters,which is characterized by high frequency,long duration and large impact area.The occurrence of drought has an impact on agricultural production,ecology and socio-economics.It causes different degrees of loss in the global scope.Climate anomalies caused by global climate change and sea-air interactions increase the likelihood of extreme events.Further analysis and understanding of the remote-related mechanisms of drought occurrence and the construction of integrated drought monitoring models that take into account climatic anomalies are the main ways to prevent and reduce the impact of droughts and reduce losses.In China,which has a vast territory,the mechanisms by which drought is influenced by the ENSO and MJO vary within different eco-geographical regions.Through the study of the teleconnection of the ENSO and MJO with drought in different regions,the mechanism of drought occurrence can be further understood.On the basis of this analysis,a comprehensive drought monitoring model was established based on a machine learning random forest algorithm by integrating the meteorological drought index,remote sensing drought index,land cover and other factors reflecting regional differences in drought.The main research methods and conclusions are as follows. :(1)Meteorological drought indices(PDSI/SC_PDSI/SPEI of 1,3,6,9,and 12 months scales)from 1982 to 2018 were constructed based on the meteorological data of 577 stations in China,and the remote sensing drought indices(VCI/TCI)were obtained for the 2006–2019.The spatial and temporal correlations between climate anomalies and drought events in48 eco-geographic regions of China were analyzed to obtain the characteristics and spatial and temporal variations of the effects of climate anomalies on drought.The results show that,in general,climate anomalies have a strong correlation with drought,and the spatial correlation differs in different ecological regions.When ENSO cold and warm events occur or MJO oscillations are abnormally high or low,the response of drought to extreme events varies in different regions.The impact of climate anomalies on agricultural drought was higher than that of meteorological drought,with the highest correlation coefficient of 0.72 in regions such as the Qinghai-Tibet Plateau and Xinjiang,while the impact of ENSO and MJO on meteorological drought was significant in Jiangnan with the highest correlation coefficient of0.40.Compared with meteorological drought,the response of agricultural drought to climate anomalies also showed a significant lag,with a lag time of 6 months,and the correlation between the two was most pronounced and highest,with a mean correlation coefficient of0.38 and a maximum of 0.75.

Mots clés : ENSO ;Drought monitoring ;Machine learning ;Global climate change ;

Présentation (CNKI)

Page publiée le 30 octobre 2021