Analysis of drought in the basin of the river Bonito through the standardized precipitation index

Abstract

The present work consisted in analyzing the drought of Río Bonito sub basin using standardized precipitation index and registers of pluviosity of meteorological stations close to the study zone, being found drought and wet events between 1958 and 2012.

It also shows a graph of maximum and minimum average precipitation, relation between El Niño (ENOS) and drought events, geospatial maps of meteorological stations with their precipitation index to key years and months of study, such as El Niño 1986-1998, Mitch hurricane, and drought periods affected to inhabitants of zone.

Precipitation data from seven weather stations were collected to find the occurrences of dry events and wet events in the area of the Rio Bonito subbasin throughout the period 1959 -. 2012 By transforming values o?f monthly precipitation values I?PE (SPI- 1, SPI-12, etc.), the data fit a normal probability distribution. From those results we analyze the presence of events in a given month, its characterization as dry or wet event with their degree of influence: mild, moderate or extreme. Finally, maps are generated for most influenced periods.

The overall results were analyzed and 3 periods of severe drought from 1986 to 1988, 1995, 2009-2010 were identified. Similarly, a period of high precipitation occurred from 2006 to 2008. Long periods of low-level maximum average precipitation were identified, ranging from 1983 to 1988 and 1991 to 1995. El Niño was present in most of these cases. By analysis of the SPI-12 in the period 1975 to 2012, there were characterized 18 different years as drought years, that is, the extreme dry events number was greater than wet events number over one calendar year.

DOI: http://dx.doi.org/10.5377/rct.v0i14.1794

Revista Ciencia y Tecnología No. 14, junio 2014: 25-41