| This paper is based on the National Science and Technology Program of"the tenth-five years plan", which name is"Study on the integrated key technology for reducing building's water consumption". The green building security system in water quantity was established grounded on a great of research papers and engineering cases. The water quantity index system was also founded for various zones and kinds of water recourses. Furthermore the guaranteed measures were put forwarded to ensure the water supply for green building.The conclusions of this paper are as follows:1. Safe water quantity for green building includes all periods from construction to use, which involves water quantity used in building, environment, water resource maintenance and accident.2. Based on the balance of carbon and oxygen, control of heat island effect, and restriction of water resource and land resource, the standard of planning and irrigation in Green Residential District and its model were established. The specific values were discussed in paper.3. It discusses the evaluation of the water safety system and builds up the evaluation indexes system and advances the theory which means evaluating the water safety system with the method of AHP and comprehensive Analysis with Distance Indexes.4. The guaranteed measures for various zones and kinds of water recourse are discussed. |