The NS&T Intensive Bioeffects Surveys: Design Strategies and Preliminary Results
Intensive bioeffects surveys are conducted in selected areas where chemical data from the National Status and Trends (NS&T) Program indicate greatest potential for contaminant-related...

The Specific Peculiarities of Relief Transformation and Shelly Sediment Differentiation in Coastal Zone
The settling velocities values of shelly sediment considerably differ from ones of the same particles of terrigeneous material and for this reason character and intensity of hydrodynamic...

Trace Metal Distribution in the Sediments of the Bight of Bonny, South Eastern Nigeria
Coastal sediments are important hosts for pollutant trace metals. The concentration and distributions of heavy metals depend on factors such as grain size of sediments, availability and...

Storm Precipitation in Southwest British Columbia
The storm precipitation in a mountainous watershed in the southwestern British Columbia has been studied. Analysis of the spatial distribution of the storm features showed that the precipitation...

Development of an Isohyetal Analysis for Oregon Using the Prism Model
PRISM (Precipitation-elevation Regressions on Independent Slopes Model) is an analytical model that uses point data and a digital elevation model (DEM) to generate gridded estimates of...

Hydraulic Modeling of Alluvial Plains (Slopes) and Alluvial Fans Using DAMBRK
The design of hydraulic structures such as bridges on distributary flow areas and alluvial fans require methods that can adequately determine discharges at the structures. Flow conditions...

RCHARC: A New Method for Physical Habitat Analysis
The Riverine Community Habitat Assessment and Restoration Concept (RCHARC) is applied to the Gavin's Point tailwater of the mainstem Missouri River as part of studies by the U.S. Army...

Statistical Analysis of Extreme Hydrological Droughts
The study examined several works about extreme droughts for their validity with different parameters by the statistical experimental method. The results showed that the analytical method...

Robust Estimators in Hydrologic Frequency Analysis
This paper applies a specific robust estimation procedure known as 'trimming' in flood frequency analysis. The trimming technique consists in censoring the series of recorded floods by...

The Method of Derived Distributions Applied to Peak Flows
Random variables which are functionally related have their probability distributions also related in a prescribed manner. Thus, in theory, the probability distribution of peak discharge...

A Comparison of L-Moments with Method of Moments
A comparison of the Conventional Moments Method (CMM) with the L-Moments Method (LMM) for selecting a distribution is made. Five distributions GEV (Generalized Extreme Value), LNO (Lognormal),...

A Physically Based Methodology for Regional Flood Frequency Analysis
The problem of flood frequency estimation in ungauged catchments is approached by using statistical procedures jointly with derived distribution techniques. The application of this methodology...

A New Look at the Statistical Estimation of PMP
The statistical base of Hershfield's Kmvalue Method and its application for estimating Probable Maximum Precipitation (PMP) were reviewed. The mathematical...

Estimating Exceedance Probabilities of Extreme Floods
Estimates of the exceedance probabilities of extreme floods are needed for risk analysis of dams and nuclear energy facilities. A new approach using a joint probability distribution of...

Acidity and Chemistry of Arizona's Snowpacks
Acid snow, the frozen version of the acid rain phenomena, has been sampled in several western states, e.g., California, Nevada, Montana, and Oregon. Measurements of snowpack acidity in...

Spatial and Temporal Characterization of Drought
Drought is difficult to define for common understanding. Several definitions are presented. The Palmer Drought Severity Index (PDSI), the Palmer Drought Hydrologic Index (PDHI) and the...

Probabilistic Characteristics of Elapsed Time Between Rainfalls
The elapsed time between rainfalls is analyzed statistically using the hourly rain data at two locations: the flat-plain at Urbana, Illinois and the northwestern Appalachian foothills...

CPIVOT v 2.0 Center Pivot Analysis and Design Software
A micro-computer based software package is presented which can be used for hydraulic design and/or analysis of center pivot irrigation systems. The software is written in C and requires...

Simulation of Buoyant, Miscible Liquid Plumes in Heterogeneous Aquifers
Laboratory experiments have been conducted in a sand tank with a single heterogeneity into which NaNO3 is continuously injected. From samples along, across and over the depth of the tank...

Modeling the Fate and Transport of Toxic Heavy Metals in South San Francisco Bay
A two-dimensional vertically-averaged finite element model for the fate and transport of cohesive sediments and associated toxic heavy metals was utilized to predict the spatial and temporal...

 

 

 

 

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