This chapter is enacted for the following purposes: to lessen congestion in the streets; to conserve health; to secure safety from fire, flood, panic, and other dangers; to provide adequate light and air; to prevent overcrowding of land; to avoid undue concentration of population; to encourage housing for persons of all income levels; to facilitate the adequate provision of transportation, water, water supply, drainage, sewerage, schools, parks, open space and other public requirements; to conserve the value of land and buildings, including the conservation of natural resources and the prevention of blight and pollution of the environment; to encourage the most appropriate use of land throughout the City, including consideration of the recommendations of the City's Master Plan, adopted by the Planning Board, and the Comprehensive Plan of the Pioneer Valley Regional Planning Commission; and to preserve and increase amenities by the promulgation of regulations to fulfill said objectives.