Modeling channel management impacts on river migration: a case study of Woodson bridge state recreation area,Sacramento river,California, USA

Understanding how hydraulic factors control alluvial river meander migration can help resource managers evaluate the long-term effects of floodplain management and bank stabilization measures. Using a numerical model based on the mechanics of flow and sediment transport in curved river channels, we predict 50 years of channel migration and suggest the planning and ecological implications of that migration for a 6.4-km reach (river miles 218–222) of the Sacramento River near the Woodson Bridge State Recreation Area, California, USA. Using four different channel management scenarios, our channel migration simulations suggest that: (1) channel stabilization alters the future channel planform locally and downstream from the stabilization; (2) rock revetment currently on the bank upstream from the Woodson Bridge recreation area causes more erosion of the channel bank at the recreation area than if the revetment were not present; (3) relocating the channel to the west and allowing subsequent unconstrained river migration relieves the erosion pressure in the Woodson Bridge area; (4) the subsequent migration reworks (erodes along one river bank and replaces new floodplain along the other) 26.5 ha of land; and (5) the river will rework between 8.5 and 48.5 ha of land in the study reach (over the course of 50 years), depending on the bank stabilization plan used. The reworking of floodplain lands is an important riparian ecosystem function that maintains habitat heterogeneity, an essential factor for the long-term survival of several threatened and endangered animal species in the Sacramento River area.     

Dynamics of Bacterial Abundance,Biomass, Activity,and Community Composition in the Oligotrophic Traunsee and the Traun River (Austria)

The holomictic Traunsee is the deepest and second largest lakein Austria. The special characteristic of this ecosystem isthe fact that local salt and soda industries presumably alterthe lake by the discharge of waste materials. Since thebeginning of the 20th century salt and soda works areannually releasing up to 50,000 tons of solid wastes and up to150,000 tons of chloride into Traunsee. To assess potentialeffects of these anthropogenic impacts on the bacterioplanktonthree sampling sites, influenced as well as not influenced bythe industrial discharge, were chosen for comparison andsampled monthly from November 1997 to October 1998. Bacterialabundance ranged between 0.4 to 3.0 × 10⁶ cells ml^-1 with decreasing numbers along the depth profile. Theproportion of actively respiring bacteria, i.e. INT [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride]reducing cells, never exceeded 10% of DAPI (4',6'-diamidino-2-phenylindole) stained cells. Fluorescence in situ hybridization (FISH) was used to examine the seasonal and spatial distribution of dominant phylogenetic groups of thebacterioplankton. Up to 84% of bacteria detected with DAPIcould be detected via FISH applying the universal bacterialprobe EUB338. Percentages of alpha- and beta-Proteobacteriaand members of the Cytophaga-Flavobacterium cluster did notexceed 60% of DAPI-stained cells.Beta-Proteobacteriaappeared to be the most abundant group, not only in Traunsee butalso in two reference lakes, Attersee and Hallstättersee. No significant differences in any of the bacterial parameters couldbe detected between the three sampling sites and all measurementswere found in the range reported for oligotrophic lakes. The highdischarge of the Traun River, resulting in a lake water renewaltime of only one year, may diminish possible effects of industrial waste discharge in the pelagic zone.     

The Transboundary River Nestos and Its Water Quality Assessment: Cross-Border Cooperation between Greece and Bulgaria

Transboundary water resources require the cooperation of the countries involved, not only on the various uses of the water, but also on overall water quality and the protection of ecosystems. Transboundary rivers and their management constitute a contemporary issue of great significance. Cooperation between neighboring countries is not always easy, due to different socio-economic and political conditions. Therefore, the different needs and priorities between the countries involved need to be solved first. Since pollution does not stop at a State border, it is an example of something that can be solved only at the cross-border level. This paper presents the cross-border cooperation between two transnational Institutions; the Aristotle University of Thessaloniki (Greece) and the University of Sofia (Bulgaria), within the framework of Interreg programs. The first collaborated attempt was to carry out a coordinated program for monitoring the pollution of the Nestos River. The second was the protection and restoration of the ecosystem through the education of young engineers and the transfer of experiences and scientific knowledge across the borders.     

INTEGRATED MODELING FOR WATERSHED MANAGEMENT: MULTIPLE OBJECTIVES AND SPATIAL EFFECTS1

ABSTRACT: This paper presents an optimization framework for prioritizing sites for wetlands restoration on a watershed or landscape scale. The framework is designed for analyzing the potential environmental impacts of alternative management strategies while accounting for economic constraints, thereby aiding decision makers in explicitly considering multiple management objectives. The modeling strategy consists of two phases. First, relationships between the configuration of land use types in a watershed and valued ecosystem services are specified mathematically. Second, those functions are incorporated into a spatial optimization model that allows comparisons of the expected environmental impacts and economic costs of management strategies that change the configuration of land use in the watershed. By way of a stylized example, this paper develops the general structure of the framework, presents simulation results based on two production functions for ecosystem services, and discusses the potential utility of the methodology for watershed management.     

Water supply and sanitation services for all: global progress during the 1990s

The Earth may be largely covered with water, but over one billion people are estimated to be without safe drinking water and almost 2.5 billion (40% of the world's population) without adequate sanitation at the outset of the new millennium. The provision of safe water and sanitation for all poses several serious institutional and economic challenges at international, national and local levels. Despite the various political commitments made from the late 1970s onwards, these commitments have remained largely unfulfilled. Even though some efforts to expand coverage have been made over the past two decades, much of those efforts have been undermined by socioeconomic problems and growing population, particularly in the urban areas of developing countries. The water supply and sanitation sector is actually in acute need of new investments for expansion and maintenance of facilities. Nonetheless, some positive trends can be discerned, such as, for example, the increasing recognition of integrated water resources management, environmental sanitation, public-private partnerships and women as a key for improvement and expansion of services.     

The ecological effects of trichloroacetic acid in the environment

Trichloroacetic acid (TCAA) is a member of the family of compounds known as chloroacetic acids, which includes mono-, di- and trichloroacetic acid. The significant property these compounds share is that they are all phytotoxic. TCAA once was widely used as a potent herbicide. However, long after TCAA's use as a herbicide was discontinued, its presence is still detected in the environment in various compartments. Methods for quantifying TCAA in aqueous and solid samples are summarized. Concentrations in various environmental compartments are presented, with a discussion of the possible formation of TCAA through natural processes. Concentrations of TCAA found to be toxic to aquatic and terrestrial organisms in laboratory and field studies were compiled and used to estimate risk quotients for soil and surface waters. TCAA levels in most water bodies not directly affected by point sources appear to be well below toxicity levels for the most sensitive aquatic organisms. Given the phytotoxicity of TCAA, aquatic plants and phytoplankton would be the aquatic species to monitor for potential effects. Given the concentrations of TCAA measured in various soils, there appears to be a risk to terrestrial organisms. Soil uptake of TCAA by plants has been shown to be rapid. Also, combined uptake of TCAA from soil and directly from the atmosphere has been shown. Therefore, risk quotients derived from soil exposure may underestimate the risk TCAA poses to plants. Moreover, TCE and TCA have been shown to be taken up by plants and converted to TCAA, thus leading to an additional exposure route. Mono- and di-chloroacetic acids can co-occur with TCAA in the atmosphere and soil and are more phytotoxic than TCAA. The cumulative effects of TCAA and compounds with similar toxic effects found in air and soil must be considered in subsequent terrestrial ecosystem risk assessments.     

The health sector gap in the southern Africa crisis in 2002/2003

The southern Africa crisis represents the first widespread emergency in a region with a mature HIV/AIDS epidemic. It provides a steep learning curve for the international humanitarian system in understanding and responding to the complex interactions between the epidemic and the causes and the effects of this crisis. It also provoked much debate about the severity and causes of this emergency, and the appropriateness of the response by the humanitarian community. The authors argue that the over-emphasis on food aid delivery occurred at the expense of other public health interventions, particularly preventative and curative health services. Health service needs were not sufficiently addressed despite the early recognition that ill-health related to HIV/AIDS was a major vulnerability factor. This neglect occurred because analytical frameworks were too narrowly focused on food security, and large-scale support to health service delivery was seen as a long-term developmental issue that could not easily be dealt with by short-term humanitarian action. Furthermore, there were insufficient countrywide data on acute malnutrition, mortality rates and performance of the public health system to make better-balanced evidence-based decisions. In this crisis, humanitarian organisations providing health services could not assume their traditional roles of short-term assistance in a limited geographical area until the governing authorities resume their responsibilities. However, relegating health service delivery as a long-term developmental issue is not acceptable. Improved multisectoral analytical frameworks that include a multidisciplinary team are needed to ensure all aspects of public health are dealt with in similar future emergencies. Humanitarian organisations must advocate for improved delivery and access to health services in this region. They can target limited geographical areas with high mortality and acute malnutrition rates to deliver their services. Finally, to address the underlying problem of the health sector gap, a long-term strategy to ensure improved and sustainable health sector performance can only be accomplished with truly adequate resources. This will require renewed efforts on part of governments, donors and the international community. Public health interventions, complementing those addressing food insecurity, were and are still needed to reduce the impact of the crisis, and to allow people to re-establish their livelihoods. These will increase the population's resilience to prevent or mitigate future disasters.     

Watershed scale assessment of nitrogen and phosphorus loadings in the Indian River Lagoon basin,Florida

There is a growing evidence that the ecological and biological integrity of the lagoon has declined during the last 50 years, probably due to the decline in water quality. Establishment of a watershed scale seagrass-based nutrient load assessment is the major aim of water quality management in the Indian River Lagoon (IRL). Best estimate loadings incorporate wet and dry deposition, surface water, groundwater, sediment nutrient flux, and point source effluent discharge data. On the average, the IRL is receiving annual external loadings of 832, 645 and 94,476kg of total nitrogen (TN) and total phosphorus (TP), respectively, from stormwater discharges and agricultural runoff. The average internal cycling of TN and TP from sediment deposits in the IRL was about 42,640kg TN and 1050kg TPyr(-1). Indirect evidence suggests that atmospheric deposition has played a role in the ongoing nutrient enrichment in the IRL. The estimated total atmospheric deposition of TN and TP was about 32,940 and 824kgyr(-1), while groundwater contribution was about 84,920 and 24,275kgyr(-1), respectively, to the surface waters of the IRL. The estimated annual contribution of point effluent discharge was about 60,408kg TN and 7248kg TP. In total, the IRL basin is receiving an annual loading of about 1,053,553kg TN and 127,873kg TP. With these results, it is clear that the current rate of nutrient loadings is causing a shift in the primary producers of the IRL from macrophyte to phytoplankton- or algal-based system. The goal is to reverse that shift, to attain and maintain a macrophyte-based estuarine system in the IRL.     

River systems as providers of goods and services: a basis for comparing desired and undesired effects of large dam projects

In developing countries, large dam projects continue to be launched, primarily to secure a time-stable freshwater supply and to generate hydropower. Meanwhile, calls for environmentally sustainable development put pressure on the dam-building industry to integrate ecological concerns in project planning and decision-making. Such integration requires environmental impact statements (EISs) that can communicate the societal implications of the ecological effects in terms that are understandable and useful to planners and decision-makers. The purpose of this study is to develop a basic framework for assessing the societal implications of the river ecological effects expected of a proposed large dam project. The aim is to facilitate a comparison of desired and potential undesired effects on-site and downstream. The study involves two main tasks: to identify key river goods and services that a river system may provide, and to analyze how the implementation of a large dam project may alter the on-site capacity and downstream potentials to derive river goods and services from the river system. Three river goods and six river services are identified. River goods are defined as extractable partly man-made products and river services as naturally sustained processes. By four main types of flow manipulations, a large dam project improves the on-site capacity to derive desired river goods, but simultaneously threatens the provision of desirable river goods and services downstream. However, by adjusting the site, design, and operational schedule of the proposed dam project, undesirable effects on river goods and services can be minimized.     

Forest Protection and Reforestation in Costa Rica: Evaluation of a Clean Development Mechanism Prototype

/ Costa Rica has recently established a program that provides funds for reforestation and forest protection on private lands, partly through the sale of carbon certificates to industrialized countries. Countries purchasing these carbon offsets hope one day to receive credit against their own commitments to limit emissions of greenhouse gases. Costa Rica has used the proceeds of the sale of carbon offsets to Norway to help finance this forest incentive program, called the Private Forestry Project, which pays thousands of participants to reforest or protect forest on their lands. The Private Forestry Project is accompanied by a monitoring program conducted by Costa Rican forest engineers that seeks to determine net carbon storage accomplished on these lands each year. The Private Forestry Project, which is officially registered as an Activity Implemented Jointly, is a possible model for bundled projects funded by the Clean Development Mechanism (CDM) established by the 1997 Kyoto Protocol to the UN Framework Convention on Climate Change. It also serves as an interesting example for the CDM because it was designed by a developing country host-not by an industrialized country investor. Accordingly, it reflects the particular "sustainable development" objectives of the host country or at least the host planners. Early experience in implementing the Private Forestry Project is evaluated in light of the main objectives of the CDM and its precursor-Activities Implemented Jointly. It is concluded that the project appears to meet the criteria of global cost-effectiveness and financing from non-ODA sources. The sustainable development implications of the project are specific to the region and would not necessarily match the ideals of all investing and developing countries. The project may be seen to achieve additional greenhouse gas abatement when compared against some (although not all) baselines.