Identification and Assessment of Regional Drought Process of Middle Route Project of South-to-North Water Diversion Project
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
The study of drought in the water source and receiving areas of the middle route project of South-to-North Water Diversion Project is of great significance for the water resource scheduling and operation management of the project. Based on the NCEP-NCAR reanalysis data and the daily average temperature, precipitation, and meteorological drought composite index of all meteorological stations in the water source and receiving areas of middle route project of South to North Water Diversion Project from 1961 to 2023, this article conducts identification and evaluation of regional drought processes in water source area and water receiving area. The results show that the annual values of drought days in the water source area and water receiving area are 101 days and 114 days, respectively, showing an overall spatial distribution characteristic of "more in the middle and less at both ends". The northern part of Henan and the southern part of Hebei in the water receiving area are high-value areas for drought days. The number of drought days in most of the water source areas, most of the water receiving areas in Henan, and eastern Hebei is increasing, while the number of drought days in most of the water receiving areas in northern, western, and southern Hebei, Beijing, and Tianjin is decreasing. Using the dynamic regional drought process identification method, a total of 97 regional drought processes have been identified in the study area since 1961. Using the percentile method to divide the intensity index of regional drought processes, threshold values corresponding to different intensity levels are obtained, and a total of 4 "extremely strong", 15 "strong", 30 "relatively strong", and 48 "moderate" regional drought processes occur in the study area. The strongest three regional drought processes occurred in 1968, 2001, and 1997, and the differences in circulation characteristics led to significant differences in the spatial and temporal distribution of drought days and the proportion of drought stations at different levels among the three processes. Among the 97 regional drought processes in the study area, 54.6% are caused by drought in the water source area but not in the water receiving area, which is beneficial for engineering water diversion. At the same time, in some years, the entire region is uniformly dry or the water source area is dry while the water receiving area is not dry, which is not conducive to engineering water diversion. Therefore, water resource scheduling of the middle route project of South-to-North Water Diversion Project needs to carry out targeted water diversion work based on the actual situation.