| Autor: |
Juan DU, Xiaojing YU, Xiaodong LI, Tianqi AO |
| Jazyk: |
čínština |
| Rok vydání: |
2024 |
| Předmět: |
|
| Zdroj: |
Gaoyuan qixiang, Vol 43, Iss 4, Pp 826-840 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
1000-0534 |
| DOI: |
10.7522/j.issn.1000-0534.2023.00095 |
| Popis: |
The Three River Headwaters （TRH） region， known as the “Water Tower of China”， is a crucial freshwater source and an ecological barrier in China.Changes in precipitation concentration， seasonal precipitation amount， frequency， and intensity is a key process of water cycle in the context of global warming， holding significant implications for vegetation growth and water resource management in the TRH region.In this study， utilizing the CN05.1 daily precipitation gridded dataset from 1961 to 2020 prepared by the China Meteorological Administration， the Precipitation Concentration Index （PCI） were calculated， and the evolving patterns of precipitation concentration and intra-annual distribution in the TRH region were clarified.The climatology， relative interannual variability， long-term trends， and anomalies of annual and seasonal precipitation amount， frequency， and intensity were investigated.The results find that： （1） Precipitation in the TRH region exhibits a certain degree of concentration with PCI of 17.5.PCI increased from southeast to northwest， suggesting an increased precipitation concentration.Over the past 60 years， PCI has declined at a rate of -1.71% per decade， indicating a trend towards more evenly distributed monthly precipitation throughout the year.It’s noteworthy that the reduction in the proportion of precipitation during the growing season may have ramifications for agricultural production and ecosystem maintenance in the TRH region.（2） Over the past six decades， there has been a significant overall increase in precipitation amount and intensity during different seasons.However， precipitation frequency decreased during summer while increasing in other seasons.Enhanced precipitation intensity has predominantly contributed to the rise in precipitation amount during spring， summer， and autumn， while increased precipitation frequency has played a dominant role in elevating precipitation amount during winter.The increase rate in humidity during winter and spring was higher than that during summer and autumn.In spring， precipitation amount and intensity increased by 8.09% and 6.94% per decade respectively， while winter saw snowfall amount and frequency grow by 7.27% and 4.4% per decade.Also noteworthy is the distribution of droughts and floods in parts of the Yangtze River source area tends towards extreme， exacerbating the ecosystem vulnerability.（3） The regional average precipitation amount， frequency， and intensity in the TRH region have shown an increase of 1.36 mm， 0.024%， and 0.0056 mm·d-1 per year over the past 60 years.The cumulative anomalies of precipitation amount， frequency， and intensity in the last 60 years were negative， with abrupt changes occurring in 2003， 1989， and 2003， respectively.There has been a significant decrease in precipitation frequency during the rainy season， coupled with a substantial increase in precipitation intensity.In contrast， both precipitation frequency and intensity during the dry season have experienced significant increases.These changes have been particularly pronounced in the past decade.This study can serve as a valuable reference for research concerning soil erosion， agricultural production， water resource management， and climate change in the TRH region. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
