Identify the major reasons causing the light pollution in urban areas. Examine the methods to control excessive usage of external lighting.
Light pollution is an issue that affects the livability of a city. Although it is not always considered as a serious environmental concern, it is an issue that has serious impact on the environment, ecology and society. Outdoor lighting is designed with a purpose. External lighting is considered as functional lighting. However, over-lit outdoor lamps including traffic lamps and advertisement spotlights have led to 377 complaints to various government departments in 2009 (Mingpao, 2010). The problem of light pollution have arouse much concerns. Are there any government policies that regulate the lighting at night and protect the dark sky of Hong Kong? This paper argues the main causes of light pollution as well as evaluating current policies on restricting unnecessary lighting in the city.
To begin with, the term light pollution must be defined first. According to the International Dark-sky Association (IDA), light pollution is defined as “any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste” (IDA, 2010). Urban sky glow is defined as “the brightening of the night sky over inhabited areas (IDA, 2009). Light trespass is defined as light falling to places where it is not intended, wanted or needed (IDA, 2009). Clutter is the bright, confusing and excessive groups of light sources commonly found in over-lit urban cities (IDA, 2009). The combined effects of sky glow, light trespass and clutter leads to light pollution in the city.
There are 2 main objectives of outdoor lighting. The first objective is to provide visibility (Narisada & Schreuder, 2004). Traffic light and headlights on motor vehicles are essential to provide a certain amount of visible distance for the drivers to drive safely. Headlights are designed such that the maximum amount of luminous flux is parallel to the road. However, there is always light escaped from the designed direction and reach the outer part of
To begin with, the term light pollution must be defined first. According to the International Dark-sky Association (IDA), light pollution is defined as “any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste” (IDA, 2010). Urban sky glow is defined as “the brightening of the night sky over inhabited areas (IDA, 2009). Light trespass is defined as light falling to places where it is not intended, wanted or needed (IDA, 2009). Clutter is the bright, confusing and excessive groups of light sources commonly found in over-lit urban cities (IDA, 2009). The combined effects of sky glow, light trespass and clutter leads to light pollution in the city.
There are 2 main objectives of outdoor lighting. The first objective is to provide visibility (Narisada & Schreuder, 2004). Traffic light and headlights on motor vehicles are essential to provide a certain amount of visible distance for the drivers to drive safely. Headlights are designed such that the maximum amount of luminous flux is parallel to the road. However, there is always light escaped from the designed direction and reach the outer part of