The major problem in the assessment of relationships between rainfall and runoff occurs when a study is carried out in ungauged watersheds in the absence of hydro-climatic data. This study aims to evaluate the applicability of Natural Resources Conservation Service-Curve Number (NRCS-CN) method together with GIS in estimating runoff depth in a mountainous watershed. The study was carried out in...

Watershed management has different effects on the amount of runoff and sediment and alteration ofhydrological features in a watershed. In this study, the effects of watershed management on runoff was investigated in the Anbaranchaywatershed. For this purpose, the topography data in format of a digital elevation model, land use, soil hydrological groups and watershed managemetrigeon,and also usi...

[1] The Soil Conservation Service curve number (SCS-CN) method is widely used to predict storm runoff for hydraulic design purposes, such as sizing culverts and detention basins. As traditionally used, the probability of calculated runoff is equated to the probability of the causative rainfall event, an assumption that fails to account for the influence of variations in soil moisture on runoff ...

Urbanization can result in alteration of a watershed's hydrologic response and water quality. To simulate hydrologic and water quality impacts of land use changes, the Long-Term Hydrologic Impact Assessment (L-THIA) system has been used. The L-THIA system estimates pollutant loading based on direct runoff quantity and land use based pollutant coefficients. The accurate estimation of direct runo...

A major structural inconsistency of the traditional curve number (CN) model is its dependence on an unstable fixed initial abstraction, which normally results in sudden jumps in runoff estimation. Likewise, the lack of pre-storm soil moisture accounting (PSMA) procedure is another inherent limitation of the model. To circumvent those problems, we used a variable initial abstraction after ensemb...

Ogden and Stallard (1) argue that our estimates of the effect of reforestation on runoff in the Panama Canal watershed (2) are invalid because we use a particular phenomenological runoff model: the US Department of Agriculture–Natural Resources Conservation Service Curve Number (CN) model. The authors claim that the CN model, originally developed to describe runoff from single storm events in t...

Hydrological models are the simplified, conceptual and mathematical description of rainfall, runoff, oceans, rivers, groundwater, snow etc. Rainfall-runoff modeling in the broader sense a hydrological, mathematical model gives a detailed account of Rainfall-Runoff relationships of a catchment area or watershed. Conversion of rainfall into runoff takes place in the modelling. There are many meth...

The use of geographic information systems (GISs) and remote sensing to facilitate the estimation of runoff from watershed and agricultural fields has gained increasing attention in recent years. This is mainly due to the fact that rainfall-runoff models include both spatial and geomorphologic variations. The US Department of Agriculture, Natural Resources Conservation Service Curve Number (USDA...

the main goal of this paper is to propose a new practical method for hydrologic soil group estimation in surface runoff process based on geomorphology facieses and slop. the determination of cn based on this method can reduce the time and cost of project. in this research the upstream rivers of glinak watershed have been used as a case study to examine the efficiency of proposed method with a c...