Mar 15, 2016
Spatial analysis and temporal trends of daily precipitation concentration in the Mantaro River basin: central Andes of Peru
by
,
Stochastic Environmental Research and Risk Assessment
- States that a high percentage of total annual precipitation can fall in just a few days, causing floods or landslides
- States that large economic losses from these events are particularly common in Peru, where the daily precipitation has been poorly investigated
- States that regions such as the Mantaro River basin (MRB) in the central Andes of Peru are highly vulnerable to extreme weather events associated with climate variability; this vulnerability will increase in coming years due to climate change
- Presents a spatio-temporal analysis of concentration index over the Mantaro River basin in the central Peruvian Andes
- Selects daily rainfall data recorded at 46 rainfall stations between 1974 and 2004
- Finds that daily rainfall (in terms of average values) indicates that low-intensity events account for 36 % of rainy days but only approximately 9 % of the total rain amount
- Finds, in contrast, high- and very high-intensity events account for 37 % of rainy days and approximately 72 % of the total rain amount
- The results also indicate higher concentration and lower intensity over the Northern and Central regions, compared to Southern region of the basin
- States that rainfall concentration gives evidence of why some of these places are more likely to be affected by extreme weather events; spatial distribution of event intensity can be partly explained by daily rainfall heterogeneity and orography
- Finds a significant change toward a weaker seasonality of daily precipitation distribution over high-mountain regions
- Estimates annual irregularity of daily precipitation (CI) to detect possible trends between 1974 and 2004
- Finds that for the heavy precipitation period (January–March), the number of rain stations with positive CI trends is much higher than those with negative trends