A foundational element in determining Total Maximum Daily Loads (TMDLs) is the determination of the relative impacts of point and nonpoint source impacts on the dissolved oxygen concentration (DO) of an impaired stream. It is not uncommon that the ultimate oxygen demand during a rain event can be greater than the effects of the fully permitted point source loading to the stream. Traditionally, ...

The introduction and advancement of spatial information technologies such as remote sensing and geographic information systems (GIS) have provided many (software) tools that assist in natural resource planning and management. GIS technology has particularly provided many cost-effective tools for evaluating land use/land cover (LU/LC) and the implications of different land use practices within a...

Using distributed hydrological models to evaluate the effectiveness of reducing non-point source pollution by applying best management practices (BMPs) is an important support to decision making for watershed management. However, complex interfaces and time-consuming simulations of the models have largely hindered the applications of these models. We designed and developed a prototype web-based...

Many of the continuous watershed models perform all their computations on a daily time step, yet they are often calibrated at an annual or monthly time-scale that may not guarantee good simulation performance on a daily time step. The major objective of this paper is to evaluate the impact of the calibration time-scale on model predictive ability. This study considered the Soil and Water Assess...

On megaparsec scales the Universe is permeated by an intricate filigree of clusters, filaments, sheets and voids, the Cosmic Web. For the understanding of its dynamical and hierarchical history it is crucial to identify objectively its complex morphological components. One of the most characteristic aspects is that of the dominant underdense Voids, the product of a hierarchical process driven b...

The Morro Bay estuary, located on the central Coast of California approximately half way between Los Angeles and San Francisco, is one of the most important wetlands on the west Coast as it supports wide variety of habitats including numerous sensitive and endangered plant and animal species. Various studies have identified accelerated erosion and subsequent sedimentation as a major threat for ...

beneficial management practices (bmps) are important measures for reducing agricultural non-point source (nps) pollution. however, selection of bmps for placement in a watershed requires optimizing available resources to maximize possible water quality benefits. due to its iterative nature, the optimization typically takes a long time to achieve the bmp trade-off results which is not desirable ...

Agricultural runoff can be a source of P, a limiting factor for freshwater eutrophication. To develop a simple method to estimate P export from the cropland, we studied 1.2-p.m filtered dissolved phosphorus (DP) output from four tiles draining areas ranging from 8 to 25 ha, and from a river draining a 48 173 ha watershed in eastcentral Illinois during 1993 to 1996. The land was under maize (Zea...

411 Abstract: Expected effects of wildland fires on hydrologic values have been indexed by 11 hydrologic parameters of floods, sedimentation and water supply. Coefficients and watershed attributes from 10 multiple-regression models are used to distribute measured hydrologic parameters throughout each watershed. Other coefficients are used with present fire condition and fire frequency to estima...