Mountain watershed management in the development and conservation of natural resources

Includes bibliography

Hydrosedimentological disequilibrium in a small, urbanized watershed

AIM: In this paper we estimate the sediment yield and other related information for a small urbanized watershed, located in Sorocaba, São Paulo State. The driving forces that produce the observed scenario are presented and discussed; METHODS: Over a year, water samples and hydrologic information concerning the river channel were collected monthly at one sampling site. In the laboratory, water samples were oven dried (80 ºC) and the total suspended solid weighed for each sample. To estimate sediment yield we used Colby's simplified method. The sediment delivery ratio (SDR) was estimated using two methods: the relief - length ratio and the bifurcation ratio; RESULTS: The annual sediment yield estimated for the period was 1,636.1 t. The total specific sediment yield was 541.7 t.km -2.y-1. Bedload was the predominant fraction. The SDR changed between 60 and 66% according to the method employed. CONCLUSIONS: The main driving forces of hydrosedimentological disequilibrium are the lack of riparian vegetation, the dumping of construction wastes at inadequate sites, and the launching of untreated sewage. Hence, if these three factors were controlled, a significant improvement in the environmental quality, particularly water quality, might be achieved.

River Size and Fish Assemblages in Southwestern South Dakota

We studied relations between river size, fish species diversity, and fish species composition along four major rivers in the Great Plains of southwestern South Dakota to assess patterns of species diversity and composition. We expected diversity to increase with river size and fish composition to change via species addition downstream. Previous surveys of 52 sampling stations provided fish assemblage data, and we used the Geographic Information System (GIS) to determine watershed area by station. Watershed area did not predict species richness or species diversity (Fisher's a), so species richness of 12 ± 3.5 SD species and Fisher's a of 2.3 ± 0.87 SD characterized species diversity in the study area. Cluster analysis of faunal similarity (Sorensen's Index) among the 52 sampling stations identified two geographically distinct faunal divisions, so species composition was variable within the study area, but changed via species replacements among faunas rather than species additions downstream. Nonnative species were a minor component of all faunas. Uniform species diversity may be a recent phenomenon caused by impacts of Missouri River dams on native large-river fishes and the unsuitability of rivers in the Great Plains for nonnative species. Variation in faunal composition may also be recent because it was affected by dams.

Herbicides in the upper Poxim River, Sergipe, and the risk of contamination of water resources

Increased agricultural activity in watershed areas has been causing concern over contamination by herbicides in agricultural areas. The problem becomes more important when contamination can affect water for human consumption, as happens with water from the Poxim river, which supplies the city of Aracaju, capital of the State of Sergipe. The aim of this study was to evaluate the risk of contamination by herbicides to both surface and groundwater in the upper sub-basin of the Poxim River, and to detect the presence of the active ingredients Diuron and Ametrine up-river from the sugar-cane plantations. Risk analysis was carried out using criteria from the Environmental Protection Agency (EPA), the GUS index, and the GOSS method. It was observed that several active ingredients are at risk of leaching, demonstrating the importance of monitoring the river to control both the quality of water and the frequency and volume of herbicides used in the region. Based on the results, monitoring was carried out bi-monthly from July 2009 to July 2010 at two sampling points. Water samples were analyzed in the laboratory, where the presence of Diuron and Ametrine was noted. Water quality in the Sub-basin of the Rio Poxim is being influenced by the use of herbicides in the region. There was an increase in herbicide concentration in the surface water during the rainy season, possibly caused by soil runoff.

GIS based Watershed Classification in Lao PDR

Every inclined land surface has a potential for soil and water degradation, the seriousness depends on a multitude of parameters such as slope, soil type, geomorphology, rainfall, land use and natural vegetation cover. In Laos this intensified land use leads to reduced vegetation cover, to increased soil erosion, decreasing yield, and finally is likely to influence the hydrological regime. Against this background the Mekong River Commission (MRC) elaborated a spatial explicit Watershed Classification (WSC) for the Lower Mekong Basin. Based on topographic factors derived from a high-resolution Digital Terrain Model, five watershed classes are calculated, giving indication about the sensitivity to resource degradation by soil erosion. The WSC allows spatial priority setting for watershed management and generally supports informed decision making on reconnaissance level. In the conclusions focus is laid on general considerations when GIS techniques are used for spatial decision support in a development context.

Investigation of surface water/groundwater relationships in a rural watershed in Southern Honduras

Despite failed attempts at obtaining a potable water system, the village of El Caracol in Southern Honduras remains committed to improving access to water resources. To assist in this endeavor, an investigation of the hydrogeological characteristics of the local watershed was conducted. Daily precipitation was recorded to examine the relationship between precipitation and approximated river and spring discharges. A Thornthwaite Mather Water Balance Model was used to predict monthly discharges for comparison with observed values, and to infer the percentage of topographic watersheds contributing to the respective discharges. As aquifer porosity in this region is thought to be primarily secondary (i.e., fractures), field observed lineaments were compared with those interpreted from remote sensing imagery in an attempt to determine the usefulness of these interpretations in locating potential water sources for a future project.

Atlas of the Songwe River Basin: Thematic Maps with Explanatory Text Sheets

This atlas presents a comprehensive set of thematic maps depicting a wide range of aspects of the Songwe river area. It includes baseline maps (such as topographic overview, hillshade), satellite images (years 1991, 2001, 2004), land cover and land cover change, biomass and biomass change, priority conservation areas, resource management (watershed classification, watershed classification combined with biomass, soil erosion), accessibility and special maps (such as historical river course). Map clippings of the most important maps facilitate the readability of the maps. The accompanying explanatory text sheets contain graphics and information about material, methods, results and interpretation.

Characterization of fecal contamination targeting 16S rRNA bacteroides molecular markers in the Santa Cruz River, Arizona

Understanding the origins, transport and fate of contamination is essential to effective management of water resources and public health. Individuals and organizations with management responsibilities need to understand the risks to ecosystems and to humans from contact with contamination. Managers also need to understand how key contaminants vary over time and space in order to design and prioritize mitigation strategies. Tumacacori National Historic Park (NHP) is responsible for management of its water resources for the benefit of the park and for the health of its visitors. The existence of microbial contaminants in the park poses risks that must be considered in park planning and operations. The water quality laboratory at the Maricopa Agricultural Center (in collaboration with stakeholder groups and individuals located in the ADEQ-targeted watersheds) identified biological changes in surface water quality in impaired reaches rivers to determine the sources of Escherichia coli (E. coli); bacteria utilizing innovative water quality microbial/bacterial source tracking methods. The end goal was to support targeted watershed groups and ADEQ towards E. coli reductions. In the field monitoring was conducted by the selected targeted watershed groups in conjunction with The University of Arizona Maricopa Agricultural Center Water Quality Laboratory. This consisted of collecting samples for Bacteroides testing from multiple locations on select impaired reaches, to determine contamination resulting from cattle, human recreation, and other contributions. Such testing was performed in conjunction with high flow and base flow conditions in order to accurately portray water quality conditions and variations. Microbial monitoring was conducted by The University of Arizona Water Quality Laboratory at the Maricopa Agricultural Center using genetic typing to differentiate among two categories of Bacteroides: human and all (total). Testing used microbial detection methodologies and molecular source tracking techniques.^

Poulston Bridge & Launceston [Material gráfico] : on the river Tamar : The picture in the possession of W. Prior Esqr.

Alcance y contenido: Descripción: paisaje diurno con el puente de Poulston y el río Tamar en Tasmania (Australia)

The X River tin field /

"Issued under the authority of the Hon. A.E. Solomon, Minister for Mines."

Chicago River/Lake Shore area assessment /

The Chicago River/Lake Shore area assessment, part of a series of statewide regional assessments, examines approximately 348 square miles in northeastern Illinois that falls within portions of two counties-- Cook and Lake. The area is defined by the watershed of the Chicago River and the areas of Cook and Lake counties that drain to Lake Michigan, excluding the area in southern Cook County that drains to the Calumet River. The report provides information on the natural and human resources of the area as a basis for managing and improving its ecosystems. The development of ecosystem-based information and management programs in Illinois are the result of three processes-- the Critical Trends Assessment Program, Conservation Congress, and Water Resources and Land Use Priorities Task Force.

Distribution of Diatoms Along Environmental Gradients in the Charlotte Harbor, Florida (USA), Estuary and Its Watershed: Implications for Bioassessment of Salinity and Nutrient Concentrations

The relative abundance of diatom species in different habitats can be used as a tool to infer prior environmental conditions and evaluate management decisions that influence habitat quality. Diatom distribution patterns were examined to characterize relationships between assemblage composition and environmental gradients in a subtropical estuarine watershed. We identified environmental correlates of diatom distribution patterns across the Charlotte Harbor, Florida, watershed; evaluated differences among three major river drainages; and determined how accurately local environmental conditions can be predicted using inference models based on diatom assemblages. Sampling locations ranged from freshwater to marine (0.1–37.2 ppt salinity) and spanned broad nutrient concentration gradients. Salinity was the predominant driver of difference among diatom assemblages across the watershed, but other environmental variables had stronger correlations with assemblages within the subregions of the three rivers and harbor. Eighteen indicator taxa were significantly affiliated with subregions. Relationships between diatom taxon distributions and salinity, distance from the harbor, total phosphorus (TP), and total nitrogen (TN) were evaluated to determine the utility of diatom assemblages to predict environmental values using a weighted averaging-regression approach. Diatom-based inferences of these variables were strong (salinity R 2 = 0.96; distance R 2 = 0.93; TN R 2 = 0.83; TP R 2 = 0.83). Diatom assemblages provide reliable estimates of environmental parameters on different spatial scales across the watershed. Because many coastal diatom taxa are ubiquitous, the diatom training sets provided here should enable diatom-based environmental reconstructions in subtropical estuaries that are being rapidly altered by land and water use changes and sea level rise.

Geochemical data and radiocarbon ages of organic matter fractions and bacteriohopanepolyol data of sediment core GeoB6518-1 from the Congo River basin

The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. While elevated ages in fluvially-transported organic matter are usually explained by erosion of soils and sediments, it is commonly assumed that mainly young organic material is discharged from flat tropical watersheds due to their extensive plant cover and high carbon turnover. Here we present compound-specific radiocarbon data of terrigenous organic fractions from a sedimentary archive offshore the Congo River in conjunction with molecular markers for methane-producing land cover reflecting wetland extent in the watershed. We find that the Congo River has been discharging aged organic matter for several thousand years with increasing ages from the mid- to the Late Holocene. This suggests that aged organic matter in modern samples is concealed by radiocarbon from nuclear weapons testing. By comparison to indicators for past rainfall changes we detect a systematic control of organic matter sequestration and release by continental hydrology mediating temporary carbon storage in wetlands. As aridification also leads to exposure and rapid remineralization of large amounts of previously stored labile organic matter we infer that this process may cause a profound direct climate feedback currently underestimated in carbon cycle assessments.

New contributions to the native and alien flora in riparian habitats of the Cantabrian watershed (Northern Spain)

As a result of a floristic survey carried out in riparian habitats of northern Spain, new chorological data are provided for 9 alien and 6 native plant species. Some species are reported for the first time at regional scale, such as Carex strigosa, Helianthus x laetiflorus and Persicaria pensylvanica in Cantabria. Also noteworthy is the finding of naturalised populations of the North American grass Muhlenbergia schreberi at the Urumea river basin, which represents the second reference for the Iberian Peninsula.

Status of river basin projects, Connecticut : October 1987 /

"March 1988."