Mining pollution: The case of the Baguio mining district,the philippines

Environmental problems caused by improper mine tailings disposal in the Baguio district include pollution of the Lower Agno River system and its watershed and siltation of irrigation canals in the Pangasinan plains. Direct economic losses are from reduced agricultural production due to siltation of irrigation works and farmlands. To check the adverse ecological effects of improper mine tailings disposal, government regulations have been imposed on mining firms. Several disposal schemes have been proposed, including the use of the reservoir of a multipurpose project to be sited in the watershed where the mines are located. Because of siltation problems, however, trapping the tailings in the reservoir will diminish the economic benefits that can be derived from the project.     

Biomass and nutrient removals from commercial thinning and whole-tree clearcutting of central hardwoods

The objective of this research was to evaluate the impacts of increasing product removal on biomass and nutrient content of a central hardwood forest ecosystem. Commercial thinning, currently the most common harvesting practice in southern New England, was compared with whole-tree clearcutting or maximum aboveground utilization. Using a paired-watershed approach, we studied three adjacent, first-order streams in Connecticut. During the winter of 1981–82, one was whole-tree clearcut, one was commercially thinned, and one was designated as the untreated reference. Before treatment, living and dead biomass and soil on the whole-tree clearcut site contained 578 Mg ha^–1 organic matter, 5 Mg ha^–1 nitrogen, 1 Mg ha^–1 phosphorus, 5 Mg ha^–1 potassium, 4 Mg ha^–1 calcium, and 13 Mg ha^–1 magnesium. An estimated 158 Mg ha^–1 (27% of total organic matter) were removed during the whole-tree harvest. Calcium appeared to be the nutrient most susceptible to depletion with 13% of total site Ca removed in whole-tree clearcut products. In contrast, only 4% (16 Mg ha^–1) of the total organic matter and 2% of the total nutrients were removed from the thinned site. Partial cuts appear to be a reliable management option, in general, for minimizing nutrient depletion and maximizing long-term productivity of central hardwood sites. Additional data are needed to evaluate the long-term impacts of more intensive harvests.     

Firewood consumption in a Nepali village

People's dependence on firewood as a primary source of energy is causing serious deforestation problems in many developing countries. Reliable information on firewood consumption rates is needed to develop afforestation plans and to control deforestation. This study compares three methods used to determine firewood consumption in a Nepali village. Cultural and environmental factors that affect firewood consumption in the village are also examined.Theweight survey proved to be the most accurate method used. The less precisedaily recall andannual recall surveys overestimated actual firewood consumption by factors of 1.76 and 1.95, respectively. Overestimates are attributed to both physical and social factors. In view of the good agreement between daily and annual recall surveys, and the much greater ease of conducting the latter, annual recall surveys are recommended as the most practical method of monitoring firewood consumption rates. Validating the survey with occasional weighed measurements is suggested as a means of improving accuracy.     

Watershed Management and Organizational Dynamics: Nationwide Findings and Regional Variation

Recent attention has focused on resource management initiatives at the watershed scale with emphasis on collaborative, locally driven, and decentralized institutional arrangements. Existing literature on limited selections of well-established watershed-based organizations has provided valuable insights. The current research extends this focus by including a broad survey of watershed organizations from across the United States as a means to estimate a national portrait. Organizational characteristics include year of formation, membership size and composition, budget, guiding principles, and mechanisms of decision-making. These characteristics and the issue concerns of organizations are expected to vary with respect to location. Because this research focuses on organizations that are place based and stakeholder driven, the forces driving them are expected to differ across regions of the country. On this basis of location, we suggest basic elements for a regional assessment of watershed organizations to channel future research and to better approximate the organizational dynamics, issue concerns, and information needs unique to organizations across the country. At the broadest level, the identification of regional patterns or organizational similarities may facilitate the linkage among organizations to coordinate their actions at the much broader river basin or ecosystem scale.     

Nipped in the Bud: Why Regional Scale Adaptive Management Is Not Blooming

Adaptive management is an approach to managing natural resources that emphasizes learning from the implementation of policies and strategies. Adaptive management appears to offer a solution to the management gridlock caused by increasing complexity and uncertainty. The concept of adaptive management has been embraced by natural resource managers worldwide, but there are relatively few published examples of adaptive management in use. In this article, we explore two watershed management projects in southeastern Australia to better understand the potential of adaptive management in regional scale programs through qualitative, case study–based investigation. The program logic of one case implies the use of passive adaptive management, whereas the second case claims to be based on active adaptive management. Data were created using participant observation, semistructured interviews with individuals and groups, and document review. Using thematic content and metaphor analysis to explore the case data, we found that each case was successful as an implementation project. However, the use of both passive and active adaptive management was constrained by deeply entrenched social norms and institutional frameworks. We identified seven “imperatives” that guided the behavior of project stakeholders, and that have consequences for the use of adaptive management. Reference to recent evaluations of the Adaptive Management Areas of the Pacific Northwest of the United States suggests that some of these imperatives and their consequences have broad applicability. The implications of our findings are discussed, and suggestions for improving the outcomes of regional scale adaptive management are provided.     

黄土高塬沟壑区砚瓦川流域水沙关系及其对流域治理的响应

选取黄土高塬沟壑区砚瓦川流域作为研究对象,分析综合治理前后年水沙关系及次降雨水沙关系变化及其对流域治理的响应,研究结果表明：1997年为砚瓦川流域减水减沙作用明显生效的转折年。治理期（1998-2009年）与基准期（1981-1997年）相比,无论年尺度还是次降雨尺度上,径流深与输沙模数间的关系均发生显著变化,其单位径流输沙量显著降低。其中在次降雨尺度上水沙关系趋于稳定的临界径流深为3 mm;当降雨量<50 mm、雨强<4 mm/h或历时>3 h 时,治理期较基准期水沙关系变化显著。水土保持综合治理是造成年尺度和次降雨尺度上水沙关系变化显著的原因,并且可以显著降低中低降雨量、中低雨强和中长历时降雨的单位径流输沙量。     

Importance of Riparian Forests in Urban Catchments Contingent on Sediment and Hydrologic Regimes

Forested riparian corridors are thought to minimize impacts of landscape disturbance on stream ecosystems; yet, the effectiveness of streamside forests in mitigating disturbance in urbanizing catchments is unknown. We expected that riparian forests would provide minimal benefits for fish assemblages in streams that are highly impaired by sediment or hydrologic alteration. We tested this hypothesis in 30 small streams along a gradient of urban disturbance (1–65% urban land cover). Species expected to be sensitive to disturbance (i.e., fluvial specialists and “sensitive” species that respond negatively to urbanization) were best predicted by models including percent forest cover in the riparian corridor and a principal components axis describing sediment disturbance. Only sites with coarse bed sediment and low bed mobility (vs. sites with high amounts of fine sediment) had increased richness and abundances of sensitive species with higher percent riparian forests, supporting our hypothesis that response to riparian forests is contingent on the sediment regime. Abundances of Etheostoma scotti, the federally threatened Cherokee darter, were best predicted by models with single variables representing stormflow (r² = 0.34) and sediment (r² = 0.23) conditions. Lentic-tolerant species richness and abundance responded only to a variable representing prolonged duration of low-flow conditions. For these species, hydrologic alteration overwhelmed any influence of riparian forests on stream biota. These results suggest that, at a minimum, catchment management strategies must simultaneously address hydrologic, sediment, and riparian disturbance in order to protect all aspects of fish assemblage integrity.     

Effects of Habitat Disturbance from Residential Development on Breeding Bird Communities in Riparian Corridors

This study assessed the relationship among land use, riparian vegetation, and avian populations at two spatial scales. Our objective was to compare the vegetated habitat in riparian corridors with breeding bird guilds in eight Rhode Island subwatersheds along a range of increasing residential land use. Riparian habitats were characterized with fine-scale techniques (used field transects to measure riparian vegetation structure and plant species richness) at the reach spatial scale, and with coarse-scale landscape techniques (a Geographic Information System to document land-cover attributes) at the subwatershed scale. Bird surveys were conducted in the riparian zone, and the observed bird species were separated into guilds based on tolerance to human disturbance, habitat preference, foraging type, and diet preference. Bird guilds were correlated with riparian vegetation metrics, percent impervious surface, and percent residential land use, revealing patterns of breeding bird distribution. The number of intolerant species predominated below 12% residential development and 3% impervious surface, whereas tolerant species predominated above these levels. Habitat guilds of edge, forest, and wetland bird species correlated with riparian vegetation. This study showed that the application of avian guilds at both stream reach and subwatershed scales offers a comprehensive assessment of effects from disturbed habitat, but that the subwatershed scale is a more efficient method of evaluation for environmental management.     

流域水环境污染物总量控制技术及运用分析

本文首先阐述了TMDL在污染物总量控制中的应用,然后结合特点和存在的不足之处,对我国总量控制技术的实施现状进行了剖析,最后明确提出了水环境污染物总量控制技术实施体系的构建措施,旨在将流域水环境的污染物排放控制在合理范围内,确保良好的控制效果,最大程度地满足环境质量标准。所以现对流域水环境污染物总量控制技术及运用进行详细论述,希望为相关行业人士提供些许帮助。     

The Radial Increment and Stemwood Element Concentrations of Scots Pine in the Area Influenced by the Narva Power Plants in Northeast Estonia

Soil is an important component of a watershed. Understanding soils and their interactions with the other components are, thus, considered to be critical and essential for conservation of resources and management of the watershed. Development of soil sampling and analysis programs are crucial for these purposes. Site-specific soil data are needed to identify current soil characteristics, as well as to validate datasets gathered for watershed-scale modelling of non-point sources (NPS) of pollutants arising from various land-use activities, hydrodynamics and water quality. The Koycegiz Lake–Dalyan Lagoon watershed, located in the southwest of Turkey along the Mediterranean Sea Coast, was selected as the study area for watershed modelling purposes. Development of soil sampling plans, their practical optimization, soil analyses and interpretation are presented in this article. The soil analyses conducted include physical, chemical and specific soil characteristics. Within the framework of this study, soil fertility parameters are presented and evaluated. Such an approach used is recommended for especially developing countries where up-to-date data sets are not fully available and/or centrally publicized.