19-Jun-2013
22:39:38 IST
|
NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
NISCAIR PUBLICATIONS >
Research Journals >
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP) >
BVAAP Vol.20 [2012] >
BVAAP Vol.20(1) [June 2012] >
| Title: | Curve number applications in surface water management |
| Authors: | Mishra, S K
Singh, P K
Agarwal, P K |
| Issue Date: | Jun-2012 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Mathematical
modelling of watershed responses is employed to address a wide range of
environmental and water resources related problems ranging from watershed
management to engineering design. At the field scale, models are used for
planning and designing soil conservation practices, irrigation, water
management, wetland restoration, stream restoration, and water-table
management. On a large scale, models are used for flood protection projects,
rehabilitation of aging dams, floodplain management, water-quality evaluation
and water-supply forecasting.
Central
to addressing these issues is surface water management which in turn largely
focuses on the problem of rainfall-runoff modelling, which, in particular, is
used in water resources assessment, flood and drought mitigation, irrigation
and drainage engineering, and water resources planning and management. The Soil
Conservation Service Curve Number method is one of the most widely used
rainfall-runoff models. The SCS-CN method was developed in 1954 and it is
documented in Section 4 of the National Engineering Handbook (NEH-4) published
by the Soil Conservation Service (now called as Natural Resource Conservation
Service), U.S. Department of Agriculture in 1956. The document has since been
revised in 1964, 1965, 1971, 1972, 1985, and 1993. It computes the volume of
surface runoff for a given rainfall event from small agricultural, forest, and
urban watersheds (SCS, 1986). The passage of Watershed Protection and Flood
Prevention Act (Public Law 83-566) in August 1954 led to the recognition of the
method at the Federal level and the method has since witnessed myriad
applications all over the world. Because of its simplicity, the SCS-CN method
has been applied for handling a number of problems in
hydrology
and water resources, even for the problems it was not originally intended to
solve. The method requires basic descriptive inputs that are converted to
numeric values for estimation of direct runoff volume. Curve number which is
descriptive of watershed’s runoff potential is required to be estimated as its
only parameter. The method is widely used by engineers and hydrologists and
watershed managers as a simple watershed model, and as a runoff estimating
component in more complex watershed models. Since its inception, the SCS-CN
method has
witnessed
myriad applications in realm of hydrology. Recently, Singh and Frevert (2002)
edited a book titled ‘Mathematical Models of Small Watershed Hydrology and
Applications’, in which at least 6 of the 22 chapters have mathematical models
of watershed hydrology based on SCS-CN approach. This reflects the robustness
and everlasting popularity of the SCS-CN technique. The SCS-CN method is a
conceptual model of hydrologic abstraction of storm rainfall, supported by
empirical data. Its objective is to estimate direct runoff volume from storm
rainfall depth, based on a curve number CN. Its popularity is rooted in
convenience, simplicity, authoritative origin and responsiveness to four
readily grasped catchment properties viz., soil type, land use/treatment,
surface condition and antecedent moisture condition. This paper describes the
existing SCS-CN method, its theoretical background, strengths and weaknesses,
its recent advancements, and applications in various fields of hydrology, water
resources, environmental and sedimentation engineering.
|
| Page(s): | 13-23 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-2412 (Online); 0771-7706 (Print) |
| Source: | BVAAP Vol.20(1) [June 2012]
|
|
