Abstract：[Background] Rainwater harvesting, as one of the important soil and water conservation measures to alleviate shortage of water resources and to relieve pressures on water supply and drainage systems in urban areas, has been increasingly used as an effective practice for the Sponge City and Water Saving City construction. Design and construction of rainwater harvesting systems should meet future water demand scenarios and rainfall conditions, however, most of current studies of rainwater harvesting systems use only historical climate and water demand data. Rainwater harvesting systems designed with historical data may not be able to sustainably meet water saving or stormwater management requirements under future climate conditions.[Methods] In this study, the plausible impacts of rainfall change on water saving and stormwater management performance of rainwater harvesting systems were investigated by comparing the water supply reliability (g), tap water saving efficiency (w) and runoff reduction efficiency (η) of rainwater harvesting systems in Fuzhou and Urumqi calculated using the future (2020-2050) and historical (1985-2015) daily rainfall time series. A downscaling technique based on linear and nonlinear regression analysis and the CLIGEN model was evaluated and employed to generate the future daily rainfall with the projections of 21 Global Circulation Models. A daily water balance model was developed to simulate the hydrologic operation of rainwater harvesting systems. Toilet flushing water demand was considered in this investigation.[Results] The simulated rainfall data of Fuzhou and Urumqi from 1960 to 2005 using the regression analysis for spatial downscaling and the CLIGEN model for temporal downscaling is close to the measured rainfall data. The downscaling technique performs well in simulating the occurrence of daily rainfall at both of the cities. Therefore, the CLIGEN model could alternatively be used at Fuzhou and Urumqi for rainwater harvesting system analysis. The downscaling rainfall data shows that mean annual rainfall in Fuzhou and Urumqi in 2020-2050 is going to increase by 2.67% and 28.23% compared with that in 1985-2015, respectively. The water saving performance of rainwater harvesting systems is positively affected by the increases in future rainfall, as rainwater harvesting systems with smaller tank sizes and/or smaller catchment areas could supply adequate water for demand at a desired tap water saving efficiency or water supply reliability. The stormwater management performance, however, is negatively affected under the conditions of future rainfall change, as a larger tank size or larger catchment area is required to achieve desired runoff reduction efficiency.[Conculsions] The responses of water saving and stormwater management performance of rainwater harvesting systems to rainfall change are varying with not only the system dimensions (i.e., storage capacity and catchment area), but also locations with different rainfall conditions. Rainwater harvesting systems in a drier city with less rainfall are more sensitive to rainfall change. Rainwater harvesting systems with larger storage capacity and/or larger catchment area are expected to be more resilient to rainfall change. Therefore, the ability of rainwater harvesting systems to adapt to rainfall change could be increased by designing larger reservoirs and catchment areas.
岳桐葭, 张守红. 降雨变化对雨水收集系统节水及径流的调控效应[J]. 中国水土保持科学, 2020, 18(2): 43-51.
YUE Tongjia, ZHANG Shouhong. Impacts of rainfall change on water saving and runoff control performance of rainwater harvesting systems. SSWC, 2020, 18(2): 43-51.
王浩. 城市化进程中水源安全问题及其应对[J]. 给水排水, 2016, 42(4):1. WANG Hao. Water resources security and its response in the process of urbanization[J]. Water and Wastewater Engineering, 2016, 42(4):1.
[2]
张建云, 宋晓猛, 王国庆, 等. 变化环境下城市水文学的发展与挑战:Ⅰ.城市水文效应[J]. 水科学进展, 2014, 25(4):594. ZHANG Jianyun, SONG Xiaomeng, WANG Guoqing, et al. Development and challenges of urban hydrology in a changing environment:Ⅰ:Hydrological response to urbanization[J]. Advances in Water Science, 2014, 25(4):594.
[3]
JING Xue'er, ZHANG Shouhong, ZHANG Jianjun, et al. Analysis and modelling of stormwater volume control performance of rainwater harvesting systems in four climatic zones of China[J]. Water Resources Management, 2018(10):1.
[4]
LI Yi, HUANG Youyi, YE Quanliang, et al. Multi-objective optimization integrated with life cycle assessment for rainwater harvesting systems[J]. Journal of Hydrology, 2018(558):659.
[5]
刘昌明. 节水优先需水控制开源节流统一观[J]. 水利发展研究, 2001,1(1):3. LIU Changming. Water saving, water controlling and the uniform view of increase income and reduce expenditure[J]. Water Resources Development Research, 2001,1(1):3.
[6]
车武, 李俊奇. 城市雨水利用技术与管理[M]. 北京:中国建筑工业出版社, 2006:22. CHE Wu, LI Junqi. Urban rainwater utilization technology and management[M]. Beijing:China Architecture and Building Press, 2006:22.
[7]
左建兵, 刘昌明, 郑红星. 北京市城市雨水利用的成本效益分析[J]. 资源科学, 2009,31(8):1295. ZUO Jianbing, LIU Changming, ZHENG Hongxing. Cost-benefit analysis of urban rainwater harvesting:A case study of Beijing[J]. Resouces Science, 2009,31(8):1295.
[8]
WALSH T C, POMEROY C A, BURIAN S J. Hydrologic modeling analysis of a passive, residential rainwater harvesting program in an urbanized, semi-arid watershed[J]. Journal of Hydrology, 2014, 508(2):240.
[9]
GHISI E, BRESSAN D L, MARTINI M. Rainwater tank capacity and potential for potable water savings by using rainwater in the residential sector of southeastern Brazil[J]. Building and Environment, 2007, 42(4):1654.
[10]
ZHANG Xingqi, HU Maochuan, CHEN Gang, et al. Urban rainwater utilization and its role in mitigating urban waterlogging problems:A case study in Nanjing, China[J]. Water Resources Management, 2012, 26(13):3757.
[11]
LITOFSKY A L E, JENNINGS A A. Evaluating rain barrel storm water management effectiveness across climatography zones of the United States[J]. Journal of Environmental Engineering, 2014, 140(4):04014009.
[12]
PALLA A, GNECCO I, LA B P. The impact of domestic rainwater harvesting systems in storm water runoff mitigation at the urban block scale[J]. Journal of Environmental Management, 2017(191):297.
[13]
STOCKER T F, QIN D, PLATTNER G K, et al. Technical summary. In:Climate Change 2013:The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change[J]. Computational Geometry, 2013, 18(2):95.
[14]
YOUN S G, CHUNG E S, KANG W G, et al. Probabilistic estimation of the storage capacity of a rainwater harvesting system considering climate change[J]. Resources Conservation and Recycling, 2012(65):136.
[15]
ALMAZROUI M, ISLAM M N, BALKHAIR K S, et al. Rainwater harvesting possibility under climate change:A basin-scale case study over western province of Saudi Arabia[J]. Atmospheric Research, 2017, 189:11.
[16]
COWDEN J R, WATKINS D W, MIHELCIC J R. Stochastic rainfall modeling in West Africa:Parsimonious approaches for domestic rainwater harvesting assessment[J]. Journal of Hydrology, 2008, 361(6):64.
[17]
BASINGER M, MONTAITO F, LALL U. A rainwater harvesting system reliability model based on nonparametric stochastic rainfall generator[J]. Journal of Hydrology, 2010, 392(3/4):105.
[18]
WALLACE C D, BAILEY R T, ARABI M. Rainwater catchment system design using simulated future climate data[J]. Journal of Hydrology, 2015(529):1798.
[19]
HAQUE M M, RAHMAN A, SAMALI B. Evaluation of climate change impacts on rainwater harvesting[J]. Journal of Cleaner Production, 2016(137):60.
[20]
PIAO S, CIAIS P, HUANG Y, et al. The impacts of climate change on water resources and agriculture in China[J]. Nature, 2010, 467(7311):43.
[21]
CHOU C, CHIANG J C H, LAN C, et al. Increase in the range between wet and dry season precipitation[J]. Nature Geoscience, 2013, 6(4):263.
徐军红, 刘舜. 屋面雨水收集回用的应用分析[J]. 给水排水, 2010, 46(s2):117. XU Junhong, LIU Shun. Application analysis of roof rainwater harvesting[J]. Water & Wastewater Engineering, 2010, 46(S2):117.
[25]
DB 11/685-2013. 雨水控制与利用工程设计规范[S]. 北京:北京市质量技术监督局办公室, 2013:54. DB 11/685-2013. Code for design of stormwater management and harvest engineering[S]. Beijing:Bureau of quality and technical supervision of Beijing, 2013:54.
[26]
ZHANG Xunchang. A comparison of explicit and implicit spatial downscaling of GCM output for soil erosion and crop production assessments[J]. Climatic Change, 2007, 84(3/4):337.
[27]
LI Zhi, LIU Wenzhao, ZHANG Xunchang, et al. Assessing the site-specific impacts of climate change on hydrology, soil erosion and crop yields in the Loess Plateau of China[J]. Climatic Change, 2011, 105(1/2):223.
[28]
NICKS A D, GANDER G A. CLIGEN:A weather generator for climate inputs to water resource and other models. In:Joseph S. Proceedings of the 5th International Conference on Computers in Agriculture[J]. American Society of Agricultural Engineers, 1994:3.
[29]
ZHANG Xunchang. Spatial downscaling of global climate model output for site-specific assessment of crop production and soil erosion[J]. Agricultural and Forest Meteorology, 2005(135):215.
[30]
ZHANG Yongguang, NEARING M A, ZHANG Xunchang, et al. Projected rainfall erosivity changes under climate change from multimodel and multiscenario projections in Northeast China[J]. Journal of Hydrology, 2010, 384(1/2):97.
[31]
ZHANG Yan, LIU Baoyuan, WANG Zhiqiang, et al. Evaluation of CLIGEN for storm generation on the semiarid Loess Plateau in China[J]. Catena, 2008, 73(1):1.
[32]
SIL V A C M, SOUSA V, CARVALHO N V. Evaluation of rainwater harvesting in Portugal:application to single family residences[J]. Resources Conservation and Recycling, 2015, 94:21.
[33]
郭亚男. 量化气候变化对水文影响的降尺度方法的不确定性[J]. 水利水电快报, 2012, 33(8):15. GUO Yanan. The uncertainty of climate change impacts on the method of downscaling of the hydrological[J]. Express Water Resources & Hydropower Information, 2013, 33(8):15.
[34]
PERKINS S E, PITMAN A J, HOLBROOK N J, et al. Evaluation of the AR4 climate models' simulated daily maximum temperature, minimum temperature, and precipitation over Australia using probability density functions[J]. Journal of Climate, 2007(20):4356.
2020, Vol. 18 
