Using GIS to identify critical areas for water quality protection in New York City\u27s water supply system

The protection of water quality at its source — the watershed — recognizes that minimizing land use impacts and allowing natural processes to provide in situ biological treatment can complement conventional engineering methods. In contrast to the enormous costs projected for drinking water filtration, the judicious application of watershed management principles and practices is a way to balance the needs of people with the capacity of the natural resource base over time. This paper describes the development and initial application of a geographic information system (GIS) to a ortion of New York City\u27s 2,000 square mile water supply system, the Esopus Creek watershed in the Catskill Mountains. Primary GIS layers depict topography, soils, vegetative cover, and land use. Secondary and derivative layers help to identify the primary streamflow and sediment source areas within the watershed. Although this method is a static representation of the landscape, it can serve as a guide to field inspections and related research to prioritize land for a conservation easement or protection program or to locate unstable areas in urgent need of restoration. Subsequent research includes the influence of contributing area, flow path, and soil properties on the travel time of subsurface flow

Evaluating forest harvesting to reduce its hydrologic impact with a spatial decision support system

Timber harvesting changes the condition of forest ecosystems, which are a major influence on the characteristics of headwater streams. Such characteristics include the quantity and timing of base flow and storm flow, concentrations of sediment and dissolved nutrients, water temperature, and the stability of the stream channels. This paper explores previous studies dealing with the relationship between timber harvesting and its hydrologic effects, especially long term water yield increase. The watershed disturbance threshold theory is raised and investigated in detail. The development and evaluation of a spatial decision support system, the Harvest Schedule Review System (HSRS), is then described. The HSRS will aid in the minimization of hydrological impacts of forest harvesting, along with its related, negative environmental influences. It provides a spatially and temporally explicit tool for users to analyze the hydrologic impact of forest harvest schedules

Different Patterns of Evolution in the Centromeric and Telomeric Regions of Group A and B Haplotypes of the Human Killer Cell Ig-Like Receptor Locus

The fast evolving human KIR gene family encodes variable lymphocyte receptors specific for polymorphic HLA class I determinants. Nucleotide sequences for 24 representative human KIR haplotypes were determined. With three previously defined haplotypes, this gave a set of 12 group A and 15 group B haplotypes for assessment of KIR variation. The seven gene-content haplotypes are all combinations of four centromeric and two telomeric motifs. 2DL5, 2DS5 and 2DS3 can be present in centromeric and telomeric locations. With one exception, haplotypes having identical gene content differed in their combinations of KIR alleles. Sequence diversity varied between haplotype groups and between centromeric and telomeric halves of the KIR locus. The most variable A haplotype genes are in the telomeric half, whereas the most variable genes characterizing B haplotypes are in the centromeric half. Of the highly polymorphic genes, only the 3DL3 framework gene exhibits a similar diversity when carried by A and B haplotypes. Phylogenetic analysis and divergence time estimates, point to the centromeric gene-content motifs that distinguish A and B haplotypes having emerged ∼6 million years ago, contemporaneously with the separation of human and chimpanzee ancestors. In contrast, the telomeric motifs that distinguish A and B haplotypes emerged more recently, ∼1.7 million years ago, before the emergence of Homo sapiens. Thus the centromeric and telomeric motifs that typify A and B haplotypes have likely been present throughout human evolution. The results suggest the common ancestor of A and B haplotypes combined a B-like centromeric region with an A-like telomeric region

Evaluating forest harvesting to reduce its hydrologic impact with a spatial decision support system

Timber harvesting changes the condition of forest ecosystems, which are a major influence on the characteristics of headwater streams. Such characteristics include the quantity and timing of base flow and storm flow, concentrations of sediment and dissolved nutrients, water temperature, and the stability of the stream channels. This paper explores previous studies dealing with the relationship between timber harvesting and its hydrologic effects, especially long term water yield increase. The watershed disturbance threshold theory is raised and investigated in detail. The development and evaluation of a spatial decision support system, the Harvest Schedule Review System (HSRS), is then described. The HSRS will aid in the minimization of hydrological impacts of forest harvesting, along with its related, negative environmental influences. It provides a spatially and temporally explicit tool for users to analyze the hydrologic impact of forest harvest schedules

Chaotic travelling rolls in Rayleigh-Bénard convection

SCOPUS: ar.jinfo:eu-repo/semantics/publishe