A new assessment in total and extreme rainfall trends over central and southern Peruvian Andes during 1965-2010

2018 ◽  
Vol 38 ◽  
pp. e998-e1015 ◽  
Author(s):  
Haline Heidinger ◽  
Leila Carvalho ◽  
Charles Jones ◽  
Adolfo Posadas ◽  
Roberto Quiroz
2017 ◽  
Vol 8 (3) ◽  
pp. 441-455 ◽  
Author(s):  
C. Jana ◽  
N. M. Alam ◽  
D. Mandal ◽  
M. Shamim ◽  
Rajesh Kaushal

Globally, climate change and extreme weather events are occurring more frequently, impacting water resources and farming systems. Therefore, spatio-temporal analysis of long-term rainfall is much needed to understand the variability of rainfall occurrence. The present study attempts to analyse spatio-temporal rainfall change scenarios in the 20th century (1901–2000) over Bundelkhand, one of the drought hit regions of India. Analysis shows that major rainfall contributed from 3 months, i.e. July, August and September. However, decreasing rainfall trend during monsoon season and increasing trend during pre-monsoon and post-monsoon season indicates the scenario of shifting rainfall from normal occurrence. This result is supported by decreasing seasonality index (SI) (1.94–1.1). The northern part of the region witnessed positive annual and monsoon rainfall trend but the southern part observed negative trend. Pettitt's test indicates 1983 is the most probable change year with 0.95 probability, after which annual and monsoon rainfall was found decreasing. Wavelet analysis revealed that extreme rainfall occurrence was observed with a periodicity of 2–16 years. However, Bundelkhand rainfall pattern depicts declining rainfall trends, heading towards a further drier phase with more irregular rainfall in the coming era. The study will serve as future reference in similar regions in the world to determine vital weather patterns which may impact farming systems.


Water ◽  
2015 ◽  
Vol 7 (12) ◽  
pp. 6931-6945 ◽  
Author(s):  
Vincenza Notaro ◽  
Lorena Liuzzo ◽  
Gabriele Freni ◽  
Goffredo La Loggia

2021 ◽  
Vol 71 (1) ◽  
pp. 17
Author(s):  
Nelson Quispe-Gutiérrez ◽  
Vannia Aliaga-Nestares ◽  
Diego Rodríguez-Zimmermann ◽  
Martí Bonshoms ◽  
Raquel Loayza ◽  
...  

Cutoff lows (COLs) are infrequent events in the tropics that can cause extreme rainfall, flash flooding and landslides in arid areas, such as western South America. In this study, the life cycle of a COL in the southeastern Pacific at the beginning of April 2012 was analysed using the ERA-Interim reanalysis dataset. This paper examines: (1) the precursor flow evolution prior to the COL, its development and dissipation by applying the quasi-geostrophic and vorticity equations; and (2) the influence of the COL in the heavy precipitation events over the western Peruvian Andes. During April 2012, the highest amount of precipitation was recorded in Chosica (850 masl) with 37mm on 5 April. Days prior to the formation of the COL, a subtropical trough deepened by the amplification of a ridge over the tropical Pacific and the incursion of cold air from medium and low levels into the trough. The strong cyclonic vorticity advection was intensified by a short-wave trough embedded inside a long-wave one that strengthened the system on 5 April 2012. In the dissipation stage, warm vertical advection predominated, resulting in the reabsorption of the COL by a new trough. Understanding the behaviour COL systems is important for reducing the impact of these extreme weather events on lives and infrastructure in densely populated areas.


2021 ◽  
Vol 22 (2) ◽  
pp. 215-219
Author(s):  
HEMANT KUMAR SINHA ◽  
N. MANIKANDAN ◽  
J.L. CHAUDHARY ◽  
SAHDEV NAG

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