is an important factor contributing to the peak flood discharge as can be seen in Equation (1).
As shown in Equation (1), Q is the flowrate in [m.sup.3]/s, C is the dimensionless rational method runoff coefficient
, i is the rainfall intensity in mm/hr for a storm duration equal to [T.sub.c], and A is the watershed area in ha:
The objectives of this study are intended to solve the following issues: (1) the spatial distribution of the built-up area of China in 2014; (2) the spatial distribution of annual runoff coefficient
; (3) the spatial distribution of annual average precipitation in China from 1961 to 2011; (4) the annual average runoff interception of the built-up area in China from 1961 to 2011, where the annual precipitation is greater than or equal to 400 mm; and (5) the impacts of sponge cities construction on surface runoff in the watersheds.
Comparison between Coefficient of Infiltration and the Runoff Coefficient
. Coefficient of infiltration refers to the ratio of the accumulation infiltration to the precipitation calculated by the moisture content, while the runoff coefficient
is the ratio of the amount discharge to the amount precipitation.
Thus the DCIA roads and roofs have a higher contribution to the runoff and pollution load, even though the overall runoff coefficient
was found to be less at 0.18.
Furthermore, using the available information on triggering basin-average precipitation, we have computed multiple descriptors (summarized in Table 1) for each event, including runoff coefficient
, base flow index, and first- and second-order moments of both precipitation and flow (Zoccatelli et al.
Runoff rates and sediment concentration were used to calculate the sediment yield, total runoff, runoff coefficient
, and erosion rates.
Among them, solutions (i.e., expected income values and planting areas) corresponding to the lower bounds were obtained under the conditions when parameters such as planting return, available land area, and allowed pollutant discharge amounts reached their lower bounds, and other parameters such as economical punishment on excessive pollutant emissions, surface runoff coefficient
, and pollutant emission coefficient reached to their upper bounds.
Finally, the runoff zonation map was generated by using a runoff coefficient
. The runoff coefficient
is the ratio between runoff and rainfall.
Pg precipitation during wheat growing period; Pf precipitation during fallow period; g runoff coefficient
during wheat growing period; f runoff coefficient
during fallow period; P annual precipitation; ETf evapo- transpiration during the fallow period.