Author
Zhou Yang, Li Ning, Wu Jidong
Journal
JOURNAL OF CATASTROPHOLOGY
Paper Keyword
drought disaster; compound index of metrological drought; change point detection; Granger causality test; Inner Mongolia Autonomous Region
Abstract
In the context of global change， it is of importance to investigate the spatial distribution of regional drought and its possible mechanism to adapt the future climate change and mitigate the negative effect from drought disaster. Based on meteorological observation data， including the daily average temperature， precipitation and relative humidity and drought disaster area of crops for Inner Mongolia Autonomous Region from 1981 to 2010， firstly this study detected the abrupt change and trends for climatic variables and historical disasters using change point analysis; and secondly analyzed the spatiotemporal distribution of seasonal drought according to the compound index (CI) of meteorological drought for the study region; thirdly， the main drivers of drought disaster were identified through multiple regression model analysis; lastly， the Granger causality for drought disaster in the study region was explored. Results indicated that the annual average temperature and agricultural disaster area show significantly increasing trends over the past 30 years and the annual precipitation take a slight decrease trend． Significantly abrupt change points for the annual average temperature and relative humid were detected in late 1980s and early 1990s，and for annual precipitation and disaster acreage were in 1998． Most of areas in Inner Mongolia region showed no drought characteristics in spring and winter seasons， while there dominated by mild drought and without drought in summer and fall． In summer season， in addition to the central and southern of Chifeng city， Wuhai city， the eastern and southern part of the Alxa League， the Northwest of Xilingele League， the western of Yikezhao League show a moderate drought， these remaining areas appear to demonstrate mild drought． While the moderate drought only occurred in Western and northeastern regions of Hulun Buir League in autumn season， and the remaining regions belongs to the mild drought characteristics． Further investigations revealed that CI， which is controlled by temperature， precipitation and soil humidity， may be the main driver factor for crop drought disaster in the study region， and there is the granger causality between the relative humid and drought disaster． There was no the granger causality among the temperature， precipitation， CI and disaster areas． Meanwhile， no granger causality between CI and temperature， relative humidity and rainfall were observed in this study． These results showed that precipitation reduction in a region dose not necessarily lead to the occurrence of its drought， and drought disasters may be closely related to the relative humidity in this region．
