Comprehensive two-dimensional gas chromatography (GC×GC) is a powerful technology for separating complex samples. The typical goal of GC×GC peak detection is to aggregate data points of analyte peaks based on their retention times and intensities. Two techniques commonly used for two-dimensional peak detection are the two-step algorithm and the watershed algorithm. A recent study [4] compared t...

This paper describes estimation of stream channel geometry with multiple regression analysis of GISderived watershed characteristics including drainage area, catchment-averaged precipitation, mean watershed slope, elevation, forest cover, percent area with slopes greater than 30 percent, and percent area with north-facing slopes greater than 30 percent. Results from this multivariate predictor ...

Understanding the effects of intensive agricultural land use activities on water resources is essential for natural resource management and environmental improvement. In this paper, multi-scale nested watersheds were delineated and the relationships between two representative water quality indexes and agricultural land use intensity were assessed and quantified for the year 2000 using multi-sc...

The watershed transformation is a popular image segmentation algorithm for grey scale images. In this paper, we present a deenition of the watershed segmentation, based on sets of neighboring pixels. The deenition is consistent with the behavior of most implementations of the watershed algorithm which do not construct watersheds lines, namely, to chose one arbitrary label in the case of competi...

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 ...

Soil erosion, due to intensive agricultural practices, has been and continues to be of significant concern in the Whitewater Watershed, a coldwater tributary of the Mississippi River, in southeastern Minnesota. Conservation efforts, in the form of best management practices (BMPs) have been underway for many years and a number of residents have enrolled in various government programs designed to...

[1] Watershed export of phosphorus (P) from anthropogenic sources has contributed to eutrophication in freshwater and coastal ecosystems. We explore impacts of watershed urbanization on the magnitude and export flow distribution of P along an urban-rural gradient in eight watersheds monitored as part of the Baltimore Ecosystem Study Long-Term Ecological Research site. Exports of soluble reactiv...

Title of Thesis: CALIBRATING SHENANDOAH WATERSHED SWAT MODEL USING A NONLINEAR GROUNDWATER ALGORITHM Yan Wang, Master of Science, 2011 Directed By: Dr. Kaye Brubaker Water Resources Engineering Department of Civil and Environmental Engineering This study contributes to a project with the Interstate Commission on the Potomac River Basin to build a model of the Potomac watershed using the Soil Wa...

Image segmentation is an important process that separates objects from the background and also from each other. Applied to cells, the results can be used for cell counting which is very important in medical diagnosis and treatment, and biological research that is often used by scientists and medical practitioners. Segmenting 3D confocal microscopy images containing cells of different shapes and...

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake ar...