Urban Green Areas – their functions under a changing lifestyle of ...

Table 1.1: Climate indicators (2006-2010)
Year 2006 2007 2008 2009 2010
Sunshine duration (hours) 1363 1462 1234 1413 1256
Rainfall (mm) 1249.0 1659.0 2268.0 2268.0 1239.2
Mean humidity (%) 78 78 79 77 78
Source: GSUV (2010: 11); GSO (2010: n.p.)
The temperature characteristics of the study area are presented in the following table:
Table 1.2: Characteristic temperature ( 0 C) of Hanoi
Features Values ( 0 C)
Average annual temperature 23.5
Highest monthly average temperature 32.9
Lowest monthly average temperature 14.0
Absolute maximum temperature 42.8
Absolute lowest temperature 2.7
Daily amplitude 6.4
Source: GSO (2011: 18).
Summer begins in May and lasts until August. During this period the average temperature
is 27.5 0 C. The hottest months are June and July when the average temperature is 29.2 0 C.
During this period, the southwest monsoon blows in from Laos. These months are very hot
and muggy and parks and gardens with a lot of tree shadow and lakes are the popular places
of recreation. Usually, after a heat wave, there is intense rainfall and a drop in the
temperature (PHUC 1994:19-22).
The rainy season lasts 6 months, from May to October and 85 % of the annual rainfall
occurs during this time. In August temperatures are lower than in July, but there is more
rain. In the autumn the air temperature is cooler and the vegetation cover changes from
green to yellow.
Hanoi winters consist of a dry period followed by a wet period. However, because of the
low and flat terrain, the climate of the Red River Delta shows some peculiarities compared
to other regions of the northern Delta. Winter starts in November. Wind (northern) from the
central Asia, beyond Baikal lake, blows through Mongolia and China, through the northern
mountains of Vietnam, and is cold and dry when it reaches Hanoi.
At the end of winter and beginning of spring, air masses move into Hanoi, bringing
moisture and some rainfall from the Gulf of Thailand to the east coast of Vietnam.
Spring lasts for two months.
1.2 Hanoi – city plans and management
Urban planning deals with the design and organization of urban space to ensure a
coordinated development of the population and their basic needs and activities. The main
4