基于IKONOS影像的城市住宅区中水回用空间分布估算

中水回用是解决城市水资源短缺和水环境污染问题的有效途径。开展分散式中水可行性研究，需要考虑中水原水与回用需求的数量、空间分布及平衡关系。论文以南京市住宅区为例，探索了基于IKONOS高分辨率遥感影像分类，估算中水回用空间分布的方法。通过引入单位面积用水定额，将遥感和GIS 分析得到的用地信息与中水原水产量和回用需求关联起来，计算了研究区域中27 个地块的中水原水产量和回用需求量，并分析了两者在空间上的水量平衡关系。结果表明，研究区域存在较大的中水原水供给潜力3.52 L/（m²·d）和较大的利用需求5.37 L/（m²·d）。住宅小区的单位面积原水产量与其建筑容积率成正比；以中高层住宅区为主的地区，中水原水产量能够基本满足本地区的中水回用需求。因此，在这些地区建立分散式污水处理系统，可减少废污水排放，节约自来水取用量，提高水资源利用率。

Analysis of Municipal Sewage Distribution and Reclaimed-Water Reusing in Residential Area Based on IKONOS Image

Reuse of reclaimed-water is an effective way to alleviate the crisis of both water resource shortage and sewage pollution. Decentralized wastewater reuse system is part of the regional water recycle system. The quantitative relation, spatial distribution and balance of raw water and reclaimed-water demand should be considered when researching the feasibility of decentralized wastewater reuse system in certain area. This study explores the potential of high-resolution IKONOS remote sensing data in calculating the quantitative relation and spatial distribution of raw water and reclaimedwater demand, taking the residential areas in Nanjing as a case. Object-oriented classification is applied to obtain land use information and shadow area method to estimate the height of buildings in order to calculate total building area. By introducing the water consumption norm per square meter, the land use information extracted from high-resolution IKONOS remote sensing image processing and GIS analysis became relevant to the raw water and reclaimed-water demand. The quantity and spatial distribution of raw water and reclaimed-water demand in 27 parcels are calculated and the balance between them is analyzed. Object-oriented classification performs well in extracting land use information, especially in distinguishing residential areas. The overall accuracy of classification is 84.41% and the Kappa coefficient is 0.81. Mean square error of building's height estimation using shadow area method is 0.69 m. The final results indicate that, the research area has relatively high production of raw water, 3.52 L/(m²·d), and demand of reclaimed-water, 5.37 L/(m²·d). Raw water in areas mainly consisting of mid-high rise residential buildings could meet the demand of reclaimed water. Therefore, establishing decentralized wastewater treatment systems in these areas can not only reduce sewage discharge, but also improve the utilization of water resources and reduce the clean water demand.