National Engineering Handbook: Chapter 11 - Snowmelt
Natural Resources Conservation Service, 2004
This chapter describes the basic physical processes that drive snowmelt and presents methods and guidance for estimating snowmelt runoff volumes and hydrographs for single events. These methods may also be used for short-term forecasts. In addition, a method is presented that may be used to derive flood frequency curves for snowmelt runoff from snow depth and temperature frequency data. Seasonal volume and long-range streamflow forecasting are not described here; the reader is instead referred to other publications for these topics (e.g., USDA SCS 1972band 1990, Garen 1992) as well as the NRCS National Water and Climate Center:(http://www.wcc.nrcs.usda.gov/wcc.html)
Snowmelt runoff is a major component of the hydrologic cycle in many regions and is an important consideration for water supply and design flood analysis. In some areas snowmelt event runoff may be more appropriate for the design of water storage facilities and hydraulic structures than rainfall storm runoffs de-scribed in National Engineering Handbook (NEH),section 4 (part 630), chapter 10 (USDA SCS 1972a). In addition, the annual peak flow in these areas can arise from either pure snowmelt or rainfall, or a combination of both, leading to a mixed frequency distribution, which is described in NEH, part 630, chapter 18 (USDANRCS 2000). The modeling methods in this chapter may be used together with the methods described in NEH, section 4 (part 630), chapters 10, 16 (USDA SCS1972a), and 18 to produce a mixed distribution flood frequency curve.
Revision ID: 5892
Revision Date: 12/16/2022