The Impact of the Construction of Sponge Cities on the Surface Runoff in Watersheds, China

Abstract

In order to study the effect of the construction of the sponge cites on the process of urban water circulation in China, we analyzed the precipitation data from 756 stations across China between 1961 and 2011 and national land-use data in 2014. The spatial distribution characteristics of built-up area and amount of annual average runoff interception in sponge cities were explored in five different zonal scale levels. Assuming that the sponge cities have been built at the national-level construction land and the volume capture ratio of annual runoff is taken as 85%, the amount of annual average runoff interception in sponge cities is 988.58 × 108 m3 during 1961 to 2011 in China, where the annual precipitation is greater than or equal to 400 mm. The cities with more amount of annual average runoff interception are mostly distributed in Beijing-Tianjin-Hebei region, the Yangtze River Delta, and the Pearl River Delta. As to the Haihe River Basin, the annual average amount of surface water resources is 135.69 × 108 m3 between 2005 and 2014, and the amount of annual average runoff interception is 219.58 × 108 m3 from 1961 to 2011. The construction of sponge cities has the greatest impact on the surface water resources in the Haihe River Basin. Taking 80%–85% as the volume capture ratio of annual runoff in sponge cities is not reasonable, which may lead to the irrational exploitation and utilization of regional water and soil resources.

Rainfall intensity bursts and the erosion of soils: an analysis highlighting the need for high temporal resolution rainfall data for research under current and future climates

“…Using the SOFA subroutine "CAL2JD", hourly and daily rainfalls were extracted, as well as counts of rain days and rainless days. Rainfall events were identified using the minimum inter-event time (MIT) approach (Dunkerley, 2008). This identifies separate rainfall events by requiring a rainless period of a nominated duration before each event.…”

“…In the present work, this was taken to be 6 h with no rainfall. The choice of value for the MIT affects the delineation of rainfall events considerably (Dunkerley, 2008) but does not affect the identification of intensity bursts, since this is done from the unaggregated data on inter-tip times.…”

“…Simultaneous changes in global and regional hydroclimates, related to global warming and shifts in the nature of the hydrologic cycle, may result in increased frequency and erosivity of rainfall events (Hatfield et al, 2013), as well as related ecosystem changes including in floristics, plant architecture, and soil moisture content. At the same time, growth in urban areas and populations, and the associated impervious urban land surfaces, appears to be resulting in increased risk of urban flash flooding and associated sediment transport, especially in peri-urban areas (Esposito et al, 2018), though this may be partially offset by the growing adoption of "sponge city" and similar approaches to building more absorbent cities Dong et al, 2018). Archer and Fowler (2018) have illustrated the effects of short-term "intensity bursts" in UK flooding, emphasising that short-period intensity was more significant than total rainfall.…”

Water–energy nexus of the Eastern Route of China's South-to-North Water Transfer Project

“…China has become the world's largest energy consumer, accounting for around 23% of global energy consumption (Dale, 2017). Accordingly, China is the largest emitter of energy-related carbon dioxide.…”

Rainfall intensity bursts and the erosion of soils: an analysis highlighting the need for high temporal resolution rainfall data for research under current and future climates

“…Simultaneous changes in global and regional hydroclimates, related to global warming and shifts in the nature of the hydrologic cycle, may result in increased frequency and erosivity of rainfall events (Hatfield et al 2013), as well as related ecosystem changes including in floristics, plant architecture, and soil moisture content. At the same time, growth in urban areas and populations, and the associated impervious urban land surfaces, appears to be resulting in increased risk of urban flash flooding and associated sediment transport, especially in peri-urban areas (Esposito et al 2018), though this may be partially offset by the growing adoption of 'sponge city' and similar approaches to building more absorbent cities (Li et al 2017, Li et al 2018, Dong et al 2018). Archer & Fowler (2018) have illustrated the effects of short-term intensity bursts in UK flooding, emphasising that short-period intensity was more significant than total rainfall.…”