The effect evaluation of slope on rain garden performance

The low impact development best management practices (LID-BMPs) method have proved the ability to runoff controlling and reduction in recent years, But the little of research has focused on the effective factors on LID control s performance such as average slope, area of study, types of soil, the number of LID control in subcatchment, etc. That s why this article presents an evaluation of the effect of area slope on rain garden performance. The results of this article demonstrate the amount of flow frequency percentage, average flow, maximum flow, total volume, and total TSS in normal slope conditions are respectively equal to 75.35%, 0.361 in/m, 0.837 in/m, 7.341liters and 5.982 kg, and with ten percentage increasing slope of the area, the amount of flow frequency percentage, average flow, maximum flow, total volume and total Tss will be equal to 76.61%, 0.365 in/m, 0.837 in/m, 7.332 liters, and 6.014 kg. according to these results the amount of slope is effective on runoff quality than other indicators.