44
E. A. Agosta et al.
Fig. 6 Decadal mean annual total precipitation due to precipitation days (R75p95pTOT, in mm)
averaged across stations in ESA (blue bars), across stations in ESA minus GBA (non-GBA; red bars),
and across stations in GBA (green bars). Decade 2010s is proportionally estimated from data in
the period 2010–2015. Corresponding linear trend equations, with t the sequential time; percentage
variance (%Var) explained by the linear trend. %Var > 45%, significant at two-tail 95%-probability
confidence
records for the GBA subregion (green bars), the positive trend is sharper, passing from
a mean about 380 mm per year in the 1960s to over 510 mm per year in the early
2010s. Therefore, the GBA subregion has undergone a long-term process toward
more extreme daily precipitation events, which would in turn increase local floods.
The latter could be one of the factors influencing the upward trend in the MFM index
values observed in the last decades for GBA (Fig. 4, green curve). It is worthy to note
the GBA recorded one of its worst flash flood events in the last century due to extreme
precipitation on April 2 and 3, 2013. La Plata City, in southern GBA, underwent the
highest impact in terms of lives lost and damages.
3 Therefore, potential change on
the population exposure in GBA subregion is a factor to assess.
In summary, in ESA region in which the national spatial flood risk structure maximizes has been recently subject to increasing precipitation. Thus, the conjunction of
both factors, a high flood risk structure and the increasing precipitation values, makes
population more susceptible to potential flooding-induced damages in the absence
of mitigation management.
River Flow Changes
While extreme precipitation days are crucial to flash flooding episodes on specific
localities, in contrast, river flow variations are related to precipitation changes over
large areas. We have examined the Paraná River, as representative of rivers in ESA,
3 Precipitation ranged from 150 mm to 390 mm in 24 h within southern GBA, affecting almost 78
thousand homes, causing at least 89 deaths and an economic loss of U$D 666 million in 2013 prices
(CEDLAS 2013).
E. A. Agosta et al.
Fig. 6 Decadal mean annual total precipitation due to precipitation days (R75p95pTOT, in mm)
averaged across stations in ESA (blue bars), across stations in ESA minus GBA (non-GBA; red bars),
and across stations in GBA (green bars). Decade 2010s is proportionally estimated from data in
the period 2010–2015. Corresponding linear trend equations, with t the sequential time; percentage
variance (%Var) explained by the linear trend. %Var > 45%, significant at two-tail 95%-probability
confidence
records for the GBA subregion (green bars), the positive trend is sharper, passing from
a mean about 380 mm per year in the 1960s to over 510 mm per year in the early
2010s. Therefore, the GBA subregion has undergone a long-term process toward
more extreme daily precipitation events, which would in turn increase local floods.
The latter could be one of the factors influencing the upward trend in the MFM index
values observed in the last decades for GBA (Fig. 4, green curve). It is worthy to note
the GBA recorded one of its worst flash flood events in the last century due to extreme
precipitation on April 2 and 3, 2013. La Plata City, in southern GBA, underwent the
highest impact in terms of lives lost and damages.
3 Therefore, potential change on
the population exposure in GBA subregion is a factor to assess.
In summary, in ESA region in which the national spatial flood risk structure maximizes has been recently subject to increasing precipitation. Thus, the conjunction of
both factors, a high flood risk structure and the increasing precipitation values, makes
population more susceptible to potential flooding-induced damages in the absence
of mitigation management.
River Flow Changes
While extreme precipitation days are crucial to flash flooding episodes on specific
localities, in contrast, river flow variations are related to precipitation changes over
large areas. We have examined the Paraná River, as representative of rivers in ESA,
3 Precipitation ranged from 150 mm to 390 mm in 24 h within southern GBA, affecting almost 78
thousand homes, causing at least 89 deaths and an economic loss of U$D 666 million in 2013 prices
(CEDLAS 2013).