scholarly journals Changes in rainfall patterns on the upper Ecuadorian Andean mountains: Analysis of extreme precipitation, ENSO effects and shifts of annual rainfall variation

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Paulina Rosana Lima Guamán ◽  
Jorge Luis Santamaría Carrera ◽  
Margarita Flor

Rainfall in the upstream drainage area of the Ecuadorian Andean Mountains (EAM) is an important source of water supply in populated areas. Managing water resource projects depend on rainfall-runoff variation. Even though, it is difficult to understand the mechanism that controls rainfall variation because of the influence of several global and local hydrological processes, this type of research is needed to improve the management of water resources. Understanding these processes is complex due to inaccessibility to these remote zones leading to inefficacy in the monitoring of these gauge stations. Furthermore, there are reports that exposed that climatic anomalies are affecting rainfall-runoff processes around the world. These climate changes cause two main problems in urban infrastructure. First, the occurrence of extreme precipitation events increasing the risk of flooding. Second, changes on annual rainfall variation that could lead to water scarcity in the management of water resource projects. This study focuses on improving the understanding of rainfall trends at EAM and its implications in the management of water resources. The results indicate that 71% of extreme precipitation events were registered in the second period of the last twenty years (1995 – 2015) with severe short rainfall events, during ENSO years in the EAM, threatening hydraulic facilities.

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xianghu Li ◽  
Qi Hu

Spatiotemporal changes in extreme precipitation at local scales in the context of climate warming are overwhelmingly important for prevention and mitigation of water-related disasters and also provide critical information for effective water resources management. In this study, the variability and trends of extreme precipitation in both time and space in the Poyang Lake basin over the period of 1960–2012 are analyzed. Also, changes in precipitation extremes with topography are investigated, and possible causes are briefly discussed. The results show that extreme precipitation over the Poyang Lake basin is intensified during the last 50 years, especially the increasing trends are more significant before the end of the 1990s. Moreover, high contribution rates of extreme precipitation to the total rainfall (40–60%) indicated that extreme precipitation plays an important role to the total water resources in this area. The precipitation extremes also exhibited a significant spatial dependence in the basin. The northeastern and eastern areas are exposed to high risk of flood disaster with the higher frequency of extreme precipitation events. In addition, the distribution of precipitation extremes had a clear dependence on elevation, and the topography is an important factor affecting the variability of extreme precipitation over the Poyang Lake basin.


Ecology ◽  
2021 ◽  
Author(s):  
Alison K. Post ◽  
Kristin P. Davis ◽  
Jillian LaRoe ◽  
David L. Hoover ◽  
Alan K. Knapp

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 218
Author(s):  
Changjun Wan ◽  
Changxiu Cheng ◽  
Sijing Ye ◽  
Shi Shen ◽  
Ting Zhang

Precipitation is an essential climate variable in the hydrologic cycle. Its abnormal change would have a serious impact on the social economy, ecological development and life safety. In recent decades, many studies about extreme precipitation have been performed on spatio-temporal variation patterns under global changes; little research has been conducted on the regionality and persistence, which tend to be more destructive. This study defines extreme precipitation events by percentile method, then applies the spatio-temporal scanning model (STSM) and the local spatial autocorrelation model (LSAM) to explore the spatio-temporal aggregation characteristics of extreme precipitation, taking China in July as a case. The study result showed that the STSM with the LSAM can effectively detect the spatio-temporal accumulation areas. The extreme precipitation events of China in July 2016 have a significant spatio-temporal aggregation characteristic. From the spatial perspective, China’s summer extreme precipitation spatio-temporal clusters are mainly distributed in eastern China and northern China, such as Dongting Lake plain, the Circum-Bohai Sea region, Gansu, and Xinjiang. From the temporal perspective, the spatio-temporal clusters of extreme precipitation are mainly distributed in July, and its occurrence was delayed with an increase in latitude, except for in Xinjiang, where extreme precipitation events often take place earlier and persist longer.


Author(s):  
Maurizio Iannuccilli ◽  
Giorgio Bartolini ◽  
Giulio Betti ◽  
Alfonso Crisci ◽  
Daniele Grifoni ◽  
...  

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