watershed runoff Articles | Environmental XPRT

Improving capability of conceptual modeling of watershed rainfall–runoff using hybrid wavelet-extreme learning machine approach

Rainfall–runoff process identification, due to uncertainties and complexities, requires advanced modeling strategies. For this end, this study presented different strategies to explore spatio-temporal variation of rainfall–runoff process for the Ajichay watershed located in northwest Iran. Extreme learning machine (ELM) was used to predict the runoff in conceptual models. First, a ...

Nov. 2, 2017

By IWA Publishing

Impact of land use/land cover changes on surface runoff from a rural watershed, Tamilnadu, India

Watershed is a geographically dynamic unit area that contributes runoff to a common point. The effect of land use/land cover (LU/LC) changes on runoff from watersheds has long been recognised. Remote sensing (RS) and GIS techniques can be used effectively in watershed runoff models. Manimuktha sub–watershed, the study area, for which base map, soil map and LU/LC map were prepared by using ...

Feb. 11, 2013

By Inderscience Publishers

Comparing influence of combinations of precipitation loss and rainfall excess-runoff transform models to flood flow rate in a flatland watershed

Hydrologists can use many different precipitation loss rate functions and rainfall-excess transform techniques to develop watershed runoff hydrographs. For the most part, they can apply the loss and transform approaches in nearly any combination. To evaluate some of the many possible groupings, we formed a matrix of three commonly used precipitation loss rate models and three rainfall-excess ...

Jan. 1, 2012

By Inderscience Publishers

City of Santa Monica Airport Watershed Management Plan

ABSTRACT The City of Santa Monica implements best management practices (BMPs) to address urban stormwater runoff and uses a “hierarchy” of BMPs to prioritize implementation based on the principles of protecting public safety and the environment, maximizing environmental benefits, and minimizing costs. The hierarchy of BMPs includes the following (in order of priority): 1) harvesting, treating, ...

Oct. 13, 2007

By Water Environment Federation (WEF)

A new hybrid algorithm for rainfall–runoff process modeling based on the wavelet transform and genetic fuzzy system

In this paper, two hybrid artificial intelligence (AI) based models were introduced for rainfall–runoff modeling. In the first model, a genetic fuzzy system (GFS) was developed and evolved for the prediction of watersheds' runoff one time step ahead. In the second model, the wavelet-GFS (WGFS) model, wavelet transform was also used as a data pre-processing method prior to GFS ...

Sep. 25, 2014

By IWA Publishing

Dry-Weather Metals and Bacteria Loading in an Arid, Urban Watershed: Ballona Creek, California

Dry-season urban runoff from watersheds in arid regions can contribute substantial concentrations and loads of bacteria and metals to downstream receiving waters. However, there are few studies that have evaluated the relative contributions of different sources of these constituents along a specific creek or channel. This study involved analysis of the relative contribution of various storm drain ...

Mar. 9, 2005

By Southern California Coastal Water Research Project Authority (SCCWRP)

Surface Runoff

Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, snowmelt, or other sources flows over the land. This is a major component of the hydrologic cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source. If a nonpoint source contains man-made contaminants, the runoff is called nonpoint source ...

Dec. 15, 2011

By IWA Publishing

Temporal variations of runoff in a rapidly urbanizing semi-arid Chinese watershed

Rapid urbanization on streamflows may directly affect or be restricted by the sustainability of local water resources. This is particularly true for arid/semiarid areas such as the Wulanmulun River watershed in the rapidly-developing Ordos region of north central China. From 1997 to 2012, the gross domestic product (GDP) of the region increased fifty-fold, while the urban area grew by a ...

Feb. 9, 2016

By IWA Publishing

Availability and Security of Water Services

Water has become a crucial resource worldwide. Surface water and groundwater are the primary sources of water. The impacts for the the availability of water were generated from work from a variety of sources (FCO 2010). At present, approximately 1.5 billion people, out of a total world population of around 6 billion, live in major watersheds where average river runoff is less than 1000 ...

Aug. 27, 2011

By IWA Publishing

A tiered watershed PCB runoff loading approach for unmonitored tributaries in a TMDL process

Runoff volume from unmonitored tributaries is estimated using three methods for the initial stage of the Delaware Estuary TMDL for Polychlorinated Biphenyls. The first is a simplified rainfall-runoff depth estimate determined from a modified rational formula approach. The second method uses runoff volumes from USGS streamflow gages in watersheds characteristic of the physiographic provinces and ...

Oct. 13, 2007

By Water Environment Federation (WEF)

With a stormy future ahead, study offers new tools for managing runoff

These two words might make you sleepy: stormwater management. But they should make you scared. Or, if a new study can help shake things up, hopeful. Runoff carrying oil, salt, fertilizer, sediment and other pollutants is a top threat to lakes across the U.S., and several factors — including rising population, growing cities and changing climate — are loading the future’s dice ...

Nov. 27, 2015

By Ensia

Assessing potential climate change impacts on the seasonality of runoff in an Alpine watershed

The aim of this study is to investigate potential impacts of climate change on the seasonality of runoff in a mountainous watershed, located in the Austrian Alps. In order to consider the full range of possible climate variation, hypothetical climate change scenarios were used to force a hydrological model to simulate runoff time series for potential future climate conditions. The variation of ...

Jun. 1, 2015

By IWA Publishing

Cementitious porous pavement in stormwater quality control: pH and alkalinity elevation

A certain level of alkalinity acts as a buffer and maintains the pH value in a stable range in water bodies. With rapid urban development, more and more acidic pollutants flow to watersheds with runoff and drop alkalinity to a very low level and ultimately degrade the water environment. Cementitious porous pavement is an effective tool for stormwater acidic neutralization. When stormwater ...

Jan. 1, 2011

By IWA Publishing

A simplified approach for the design of infiltration trenches

The use of infiltration trenches has proven to be useful to reduce runoff in urban surfaces. The design of these structures is based on the continuity equation taking into account inflow, outflow and detention water volumes. Basic procedures evaluate entering flow rates and relative volumes directly as a function of rain event characteristics, without taking into account rain-runoff processes ...

Jan. 1, 2011

By IWA Publishing

Pyrethroids in southern California coastal sediments

Little is known about pyrethroid fate and effects in estuarine and marine environments. In the present study, the extent and magnitude of pyrethroids in coastal embayments of the Southern California Bight (SCB), USA, were assessed. Using a stratified probabilistic design, 155 sediment samples were collected from four embayment habitats (estuaries, marinas, open bays, and ports) and analyzed for ...

May 3, 2012

By John Wiley & Sons, Ltd.

Assessing Risk Information Concerning Coastal Runoff

Executive Summary In coastal urban watersheds, runoff from the landscape eventually reaches the ocean. If beaches along the ocean are used for recreation, three vital and interrelated questions arise. First, whether and to what extent does urban runoff degrade the quality of ocean water that is used for recreation? Second, to what extent docs this runoff-related ocean pollution pose a risk to ...

Feb. 1, 2003

By National Water Research Institute

Recent changes in patterns of western Canadian river flow and association with climatic drivers

Climatic variability and change can have profound impacts on the hydrologic regime of a watershed, especially in regions that are sensitive to changes in climate, such as the northern latitudes and alpine-fed regions of western Canada. Quantifying historical spatial and temporal changes in hydrological data can provide useful information as to how water resources are affected by climatic and ...

Jul. 20, 2015

By IWA Publishing

Assessment of the effect of slope on runoff potential of a watershed using NRCS–CN method

The rainfall–runoff is a very complex hydrological phenomenon, as this process is highly non–linear, time–varying and spatially distributed. The average slope within the watershed together with the overall length and retardance of overland flow are considered to be the main factors which govern the runoff process. The Natural Resources Conservation Service curve number (NRCS–CN), formerly known ...

Nov. 18, 2013

By Inderscience Publishers

Ecohydrologic Impacts of Climate and Land Use Changes on Watershed Systems: A Multi-Scale Assessment for Policy

Maintaining flows and quality of water resources is critical to support ecosystem services and consumptive needs. Understanding impacts of changes in climate and land use on ecohydrologic processes in a watershed is vital to sustaining water resources for multiple uses. This study completes a continental and regional scale assessment using statistical and simulation modeling to investigate ...

Feb. 18, 2014

By IWA Publishing

Hydrologic impacts of climate change and urbanization in the Las Vegas Wash Watershed, Nevada

A cell-based model for the Las Vegas Wash Watershed in Clark County, Nevada, USA, was developed by combining the Thornthwaite water balance model and the Soil Conservation Survey's Curve Number method with pixel-based computing technology. After the model was validated, it was used to predict the 2030 and 2050 hydrologic conditions under future scenarios of climate and land-use changes. The ...

Mar. 10, 2016

By IWA Publishing

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