CONCLUSIONS
Rainfall in the urban area of the city of Manizales is quite variable
despite being such a small area (35 km2). However,
there doesn’t seem to be a relationship with the height of each stations
and rainfall.
For all stations, bimodal behavior can be seen in the diurnal cycle and
in the monthly cycle, the latter associated with the Intertropical
Confluence Zone (ITCZ). In general, it is observed that the stations
have monthly averages close to each other, but when their annual value
is totaled, variations of up to 70% are observed between the station
with the lowest rainfall (La Nubia in the east) and the one with the
highest rainfall (El Carmen to the west), indicating a high spatial
variability in the city.
As for the diurnal cycle, a decrease in rain is observed between 09:00 h
and 11:00 h throughout the city, while the highest rains occur in the
afternoon for the eastern zone stations, presumably due to the
convective effect of warming during the day. Rains can also be
identified in the early hours of the morning particularly in the western
part of the city.
The knowledge of the diurnal cycle of rain, of the intra-annual
structure of the precipitation and of the rainstorms becomes a planning
tool for the territory and a reference input for city builders. For
instance, the works in the city of Manizales will be able to schedule
their concrete or pavement castings at the most convenient day or month
of the year to guarantee construction efficiency. Finally, the knowledge
of the diurnal cycle of the rain allows to understand the dynamics of
the climate in the Andean region of Colombia, which is strongly
influenced by climatic variability.
Regarding the spatial distribution of rainfall, the highest rainfall
occurs in El Carmen and Yarumos, the former located to the west while
the latter is located to the north-east of the city in a forest reserve.
Generally, it rains more to the west of the city, but there are some
points of high precipitation in the center (Hospital) and east
(Posgrados). Alcázares and Hospital have the highest hourly maximum
precipitation values, while the stations with the lowest diurnal maximum
precipitation values are La Nubia and Posgrados. Posgrados, Emas,
Hospital, Yarumos, La Nubia and Bosques are the stations with the
highest relative frequencies, located in the north and center of the
city.
The resulting temporal distribution of the rain serves for the designers
of hydraulic infrastructures to use design storm more realistically in
the city of Manizales, where 20 to 30-minutes rainstorms are prevalent
in the city.
Therefore, the dimensionless patterns found serve as a tool for design
storms that the different hydraulic infrastructures require in the city
of Manizales.
Studies that connect intra-annual, interannual and diurnal cycle
variability are recommended, once information is available with a
greater number of years (at least 30 years of data). This study is a
basis for future researches of this kind.