HYDROLOGY • FREE-TRANSLATOR.COM • Definition of Hydrology

... headwater reservoirs when they are needed to trap silt and reduce flooding—all these elements of watershed planning are effective not only against silt but against standard urban and suburban ugliness. The translation of rural techniques to city use cannot be literal, for both urban hydrology and urban land use are distinctive, and a good deal remains to be learned about making the techniques work better there. But their basic principles ...

— The Nation's River - The Department of the Interior Official Report on the Potomac • United States Department of the Interior