Hydrological Design of Two Low-ImpactDevelopment Techniques in a Semi-Arid ClimateZone of Central Mexico

Abstract: This paper deals with the design of a bioretention cell and an in?ltration trench in a semi- arid micro watershed. The study area was analyzed by characteristics such as slope changes (S), direction and maximum length of the urban runoff (L), and soil use (runoff coef?cient, R ). The bioretention cell was designed by the calculation of variables such as drainage area (A), concentrationtime (T c ), rainfall intensity (i), maximum peak drained (Qmax ), inlet and outlet runoff (Q, respectively), temperature (T), evaporation (Ev), potential evapotranspiration (PE), consumptive use (U) for tolerant plants to semi-arid climates, and soil in?ltration capacity (Inf ). To design thein?ltration trench, only T c , Q , and i were taken into account. The results showed that the designedbioretention cell could retain between 5.37% and 2.25% of runoff volume. As the ef?ciency of thebioretention cell can be de?ned by the need for additional irrigation, our results showed that the cell is inef?cient in some of the dry months (November and December), even in years characterized by abundant rainfall. Besides, it was shown that the designed in?ltration trench could store orin?ltrate the water from typical rain events. Based on these results, it is the implementation of more Low-Impact Development (LID) for runoff management in the study area is recommended. max m a c and Q out