Hot Humid Tropic Urban Climate Characteristic

For the purposes of architecture and urban planning and design, climate as most appropriate classification is based on considerations of human comfort (Szokolay, 1979). Based on these considerations, the climate is divided into;

• Climate (cold climates) where the main problem is the lack of hot almost all year round. Area with this climate lies in the polar regions.
• Moderate climate (moderate climates), where there is seasonal variation between the time when the excessive heat (overheating) and the lack of heat (underheating).
• The hot dry climate (hot dry climates), where there is excessive heat (overheating), but dry air
• Warm, humid climate (warm humid climates), where the main problem is excessive heat (overheating) and high humidity.

Tropical region is a region that lies between the Tropic of Cancer (23.5 ° N) and the Tropic of Capricorn (23.5 ° S). In regard to the climate, the "tropical" is an area located between 20 ° C isotherm line in the northern and southern hemisphere. (Lipsmeier, 1994). Tropical climate is divided into 2 (two) major climatic regions, namely the tropical humid and dry tropics.

Solar radiation is the main factor of all the general features of climate (Lipsmeier, 1994). Areas with a humid tropical climate receives average solar radiation - the daily average larger than other regions. This causes the humid tropics have different average temperature - the average annual low (2-3 ° C) while the average temperature difference - average daily high (8-9 ° C). Highest temperature reached about - about two hours after noon, because at that time joined the direct solar radiation and the temperature is already high.

The amount of solar radiation also causes evaporation of water so the moisture in the humid tropics is higher. The higher the temperature the greater the water vapor that can be conceived to approach the saturation point.

Urban Open Space Typology

Open space in a city is part of the urban space. In general, a typology of open space can be grouped into
- Geometric shape (Zucker, 1973; Krier, 1979; Moughtin, 1992)
- Function (Krier, 1979; Moughtin, 1992)
- Characters (Car, 1992)
- Degree ketertutupannya (Spreiregen, 1965)

Geometric form of urban open space is divided into two groups: square and street (Krier, 1979; Moughtin, 1992). Square is a form of urban open space that is static, such as squares, playing fields and city parks that usually are centered and inward looking. While the street is dynamic, linear oriented at both ends, such as roads, pedestrian paths and so on.

The basic square shape according to Krier, 1979, derived from basic geometric shapes are triangles, rectangles and circles. Modification of the form - the basic form is a concern with the technique of angled space, segment of the basic element, overlapping / merged, adding to and distortion.

Physical quality of urban open space is determined by the degree ketertutupannya / enclosurenya level (Moughtin, 1992). This degree of closure will affect the meaning of a place. Degree of closure is determined by the ratio of the height (H) around the building and the wide open spaces (D) of the open space. Quality enclosure according Spreiregen, 1965, namely:
- H: D  < 45: full enclosure
- H: D <30: treshold enclosure
- H: D <18: keterlingkupan minimum enclosure
- H: D <14: loss of enclosure

Urban Heat Island Phenomenon

"A Heat Island" is an area where the ambient temperature is higher than the surrounding temperature. The high temperature will increase the demand of electricity for refrigeration and air conditioning to increase the production of carbon dioxide and other pollutants. These pollutants will eventually play a role in rising global urban temperatures.

Urban Heat Island phenomenon is characterized by spatial and temporal variations related to climate, topography, physical layout and short-term weather conditions. Urban Heat Island is very strong pattern is controlled by the unique characteristics of each city. Factors that influence the Urban Heat Island effect them;

• Geometry of the hallway that lowers radiation shortwave radiation due to the displacement of the alley way between buildings and complex filtering the sky. Infrared radiation emitted from a variety of buildings and the road surface.
• The nature of the heat storage material that increases the sensible heat to the surface of the city during the day and release heat to the atmosphere of the city at night.
• The release of heat from fuel combustion from vehicles or other sources and animal metabolis
• The greenhouse effect that contributes to increase the acceptance of long-wave radiation from atmospheric-polluted city.
• Decrease in surface evaporation in the city led to increased sensible heat and latent heat decrease.

Some studies show a direct relationship between density and population of a city and the intensity of the Heat Island effect. Urban land use and the closure of the surface also influences the Urban Heat Island effect. Temperatures in the city center where there is usually a function - the function of commercial and office with the closing of the land, recorded higher than other functions. Hashim and Nugroho, 2003, reported that the temperature in the center of Malang with office and commercial functions, higher than the surrounding area. Research conducted Stabler, 2005, in the state of the United States Phoenics also shows that urban microclimate associated with land use.