Development of urban green space monitoring technique with remote sensing and its application

City is the important area of earth’s surface material, energy, and information exchanging; also it is the centre of national, regional political, economic, scientific and cultural aspects. A mere 10% of the global population were urban dwellers in 1900, but that percentage exceeds 50% now (Grimm et al. 2008). With the rapid economic development, city is suffering from a series of serious problems such as air pollution, solid waste pollution, vegetation reduction, deterioration of water quality and living environment. Threats to our environment represent a clear danger in the context of climate change, which is part of the “Global Change”, and it is obvious that action is needed right now to protect our quality of life, particularly for those most vulnerable to health threats from environmental and technological disasters. Therefore, our top priority should be to avoid human and material losses. The security area is not only defined by disaster management, but by a wide variety of events that could affect the environment and the population’s health. Following the rapid development of urban areas, a present tendency is represented by the study of those factors that place some areas in categories with high risk for natural and anthropic hazard.