Rainfall Characteristics and Their Relation to Soils and Run-Off

Investigators of projects involving either flood control or the development of water resources frankly recognize the need for additional records of primary rainfall observations, and also for a fuller use of those already collected and published. Ever-increasing and voluminous reports appear from time to time dealing with meteorology, hydrography, and soil moisture; with the development, surveys, and classification of soils; with erosion and its control; with the varying yields of water-sheds; and with the volume of floods, and their probable frequency of occurrence. All these data must be rigorously condensed in some manner before they can be used to the best advantage. The purpose of this paper is to present summarized information regarding precipitation and its occurrence in various countries and latitudes; its relation to soils and run-off; the vegetative, topographic, and physiographic features of the water-sheds; and the resultant influence on designs of drainage structures and channels.