However, by means of increasing rainwater harvesting areas or decreasing the assumptive percentage of the replaced rainwater, the cost-effectiveness ratios can reach to 1.

• 在第1类集水地区除行政区、公园和学校外，实际的建蔽率大约是83.；41%25，建筑基地内剩馀的空地面积很小，而且不规则。