© 2012 Khatibi et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permi...
summary Accurate estimation of nutrient loads in rivers and streams is critical for many applications including determination of sources of nutrient loads in watersheds, evaluating long-term trends in...
[1] Water quality samples for most streams are collected at variable frequencies within monitoring periods of different lengths. On the basis of discrete concentration data obtained from these monitor...
[1] This paper presents an adjusted maximum likelihood estimator (AMLE) that can be used to estimate fluvial transport of contaminants, like phosphorus, that are subject to censoring because of analyt...
[1] Regression-type, hybrid empirical/process-based models (e.g., SPARROW, PolFlow) have assumed a prominent role in efforts to estimate the sources and transport of nutrient pollution at river basin ...
[1] Mercury (Hg) is one of the leading water quality concerns in surface waters of the United States. Although watershed-scale Hg cycling research has increased in the past two decades, advances in mo...
[1] Fluvial loads for total nitrogen, total oxidized nitrogen, total phosphorus, orthophosphate phosphorus, and total suspended solids were estimated for three watersheds of different sizes using a re...
[1] Assessment of constituent loads in rivers is essential to evaluate water quality of streams and estuaries; however, uncertainty in load estimation may be large and must be considered and communica...
We used the hydrochemical model GWLF to estimate terrestrial diffuse fluxes from ungauged areas of a coastal plain catchment, the Choptank River basin. The gauged area of the basin is 17% of the land ...
We synthesize and update the science supporting the Action Plan for Reducing, Mitigating, and Controlling Hypoxia in the Northern Gulf of Mexico (Mississippi River/Gulf of Mexico Watershed Nutrient Ta...
We propose the use of Bayesian hierarchical/multilevel ratio approach to estimate the annual riverine phosphorus loads in the Saginaw River, Michigan, from 1968 to 2008. The ratio estimator is known t...
We present an overview of national water databases managed by the U.S. Geological Survey, including surface-water, groundwater, water-quality, and water-use data. These are readily accessible to users...
We modeled nutrient export in the ChoptankRiver Basin on the coastal plain of the Chesapeakedrainage, using a modified version of alumped-parameter, hydrochemical model (GWLF).Calibration was performe...
We investigate the sensitivity of phosphorus loading (mass/time) in an urban stream to variations in climate using nondimensional sensitivity, known as elasticity, methods commonly used by economists ...
We describe a method for using spatially referenced regressions of contaminant transport on watershed attributes (SPARROW) in regional water-quality assessment. The method is designed to reduce the pr...
We consider estimating the total load from frequent flow data but less frequent concentration data. There are numerous load estimation methods available, some of which are captured in various online t...
We analyzed an ensemble of watershed models that predict flow, nitrogen, and phosphorus discharges. The models differed in scope and complexity and used different input data, but all had been applied ...
Water quality data may not be collected at a high frequency, nor over the range of streamflow data. For instance, water quality data are often collected monthly, biweekly, or weekly, since collecting ...
To better understand the transfer of particulate organic matter (POM) by small mountainous river systems (SMRS) to the ocean, we measured the concentration and composition of suspended particles from ...
Ths report addresses the following two questions: 1) What are the loads (flux) of nutrients transported from the Mississippi-Atchafalaya River Basin to the Gulf of Mexico, and where do they come from...