The runoff dynamics of mixed land use can be different from single land use and can provide a resultant runoff coefficient
that is different from the coefficient of single land use (Lee et al.
The database features event duration; first- (mass center) and second-spreading) order moments of both precipitation and flow, flow peak and percentile, event runoff coefficient
, base flow, and information on the basin geomorphology.
Therefore the direct precipitation was only estimated by multiplying rainfall depth with a runoff coefficient
, and runoff coefficient
Runoff rates and sediment concentration were used to calculate the sediment yield, total runoff, runoff coefficient
, and erosion rates.
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.
Where, Q was average daily discharge [m3/s], c was runoff coefficient
expressing the losses as a ratio (runoff/precipitation), Cs referred to snowmelt and Cr to rain, a was degree-day factor [cm/C/d] indicating the snowmelt depth resulting from 1 degree-day, T was number of degree- days [C d] T was the adjustment by temperature lapse rate when extrapolating the temperature from the station to the average hypsometric elevation of the catchment or zone [C d], S was ratio of the snow covered area to the total area, P was precipitation contributing to runoff [cm].
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.
Multiple Correspondence Analyses (MCA) (Abdi and Valentin, 2007) and Principal Component Analysis (PCA) (Abdi and Wiliams, 2010) were applied with R (R Core Team, 2013) to identify relations among the variables measured; these variables include: event date, maximum and mean intensity, event duration, total rainfall depth, family measuring the event, roof area, green roof drainage level, green roof drainage volume and three hydrological attenuation variables (lag-time K, runoff coefficient
C and water volume retained by the green roof Vp).
The collection of rain water is usually represented by a runoff coefficient
Using simple models, the unit area pollution loading is often calculated as a product of Event Mean Concentration (EMC), volumetric runoff coefficient
, Rv (or the effective impervious area), and annual total rain depth as shown in equations 1-2 (Burton and Pitt, 2001).
and Sediment Yield in Small Watershed under Land Use Changes in Taiwan.