Sponge City, as a new concept on urban stormwater management, implies well-adapted and resilient of a city on possible stormwater and the derived disaster consequently. It is similar to Low Impact Development (LID) in United States and Sustainable Drainage Systems (SuDS) in the United Kingdom, Sponge City emphasizes that the stormwater should be managed from source and origin. It has significance meaning to cities in the semi-arid loess region due to highly uneven precipitation distribution and serious water resources shortage. In order to explore the rational utilization mode of rainwater resources in loess region, the available amount of rainwater resources is evaluated taking the main urban area of Xi'an for example. Moreover, on the basis of the current land use situation of Xi'an derived from remote sensing image data, 7 green infrastructures renovation scenarios were set for simulating the possible effects of Sponge City construction in the city based on SWMM (Storm Water Management Model). The results show that, the potential available amount of rainwater resources in the main urban area of Xi’an is 1.42 × 10⁸m³ approximately, close to the annual public water consumption, this implies good economic and social benefits for a semiarid city in northwest China like Xi’an. The effects of different green infrastructure modes present quite differences on runoff control under conditions of the different rainstorm intensities and the combination four (green roof and rain garden and permeable pavement) is the best. For the decision maker, a practicable Sponge City renovation scheme should be determined based on the overall planning, all such factors as investments, negative influences in construction periods, and future developments should be all considered in advance.

海绵城市作为城市雨水管理的一个新概念，意味着城市对可能发生的雨水及其衍生灾害的适应性和弹性。类似于美国的低影响开发（LID）和英国的可持续排水系统（SuDS），海绵城市强调雨水应该从源头和来源进行管理。对降水分布极不均匀、水资源严重短缺的半干旱黄土地区城市具有重要意义。为探索黄土地区雨水资源的合理利用模式，以西安主城区为例，对可利用的雨水资源量进行了评价。此外，根据遥感影像数据得出的西安市土地利用现状，基于SWMM（Storm Water Management Model），设置了7个绿色基础设施改造场景，模拟海绵城市建设对城市可能产生的影响。结果表明，西安主城区雨水资源潜在可用量为1.42×10约⁸ m ³，接近每年的公共用水量，这对于像西安这样的西北半干旱城市来说意味着良好的经济和社会效益。不同的绿色基础设施模式在不同暴雨强度条件下对径流控制的效果存在较大差异，四种组合（屋顶绿化、雨水花园和透水路面）效果最好。对决策者而言，应在统筹规划的基础上，提前考虑投资、建设期负面影响、未来发展等因素，确定切实可行的海绵城市改造方案。