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311.
We reconstructed the history of Chatthin Wildlife Sanctuary (CWS) to understand how social and economic events, and policy changes affected the sanctuary's condition. We surveyed 25 villages surrounding CWS to evaluate past and present ecological conditions, compare the results with historical accounts and identify causal relationships. During the first half of the 20th century, the primary threat was the government's reduction of old growth forest to supply fuel wood for the British-built railway. The railroad opened the area to colonization, but the villagers' impact on timber and wildlife was low. From 1945 to 1988, villagers became the primary force of landscape degradation. The post-war windfall of firearms increased hunting pressure, and populations of large mammal started to decline. With the economic decline of the 1970s and 1980s, the community's demand for game and forest products intensified, and the large mammal fauna was reduced from eleven to four species. From 1988-2003, the forests surrounding the sanctuary were fragmented and degraded. The absence of large predators rendered the park safe for livestock, and the combined effects of grazing and removal of forest products seriously degraded habitat within CWS. Major threats to CWS during the past two decades have resulted from land use decisions in which government-planned economic enterprises caused encroachment by villagers. Stabilization and recovery of this sanctuary will require management compatible with human needs, including expanded buffer zones, better core area protection, community forestry projects, and probably relocation of villages within the park.  相似文献   
312.
A wildland fire is a serious threat for forest ecosystems in Southern Europe affecting severely and irreversibly regions of significant ecological value as well as human communities. To support decision makers during large-scale forest fire incidents, a multidisciplinary system has been developed that provides rational and quantitative information based on the site-specific circumstances and the possible consequences. The systems architecture consists of several distinct supplementary modules of near real-time satellite monitoring and fire forecast using an integrated framework of satellite Remote Sensing, GIS, and RDBMS technologies equipped with interactive communication capabilities. The system may handle multiple fire ignitions and support decisions regarding dispatching of utilities, equipment, and personnel that would appropriately attack the fire front. The operational system was developed for the region of Penteli Mountain in Attika, Greece, one of the mountain areas in the country most hit by fires. Starting from a real fire incident in August 2000, a scenario is presented to illustrate the effectiveness of the proposed approach.  相似文献   
313.
Conservation planning is the process of locating and designing conservation areas to promote the persistence of biodiversity in situ. To do this, conservation areas must be able to mitigate at least some of the proximate threats to biodiversity. Information on threatening processes and the relative vulnerability of areas and natural features to these processes is therefore crucial for effective conservation planning. However, measuring and incorporating vulnerability into conservation planning have been problematic. We develop a conceptual framework of the role of vulnerability assessments in conservation planning and propose a definition of vulnerability that incorporates three dimensions: exposure, intensity, and impact. We review and categorize methods for assessing the vulnerability of areas and the features they contain and identify the relative strengths and weaknesses of each broad approach. Our review highlights the need for further development and evaluation of approaches to assess vulnerability and for comparisons of their relative effectiveness.  相似文献   
314.
ABSTRACT: With the recent increased exploration and mining activity in the Northwest Territories, there has been growing interest in streamflows. However, streamflow monitoring in Canada's north is limited, especially in the central Northwest Territories where the exploration activity is concentrated. To complicate matters, the standard approach of measuring discharge with current meters or weirs is often inadequate or prohibitively expensive, as many streams in the region are shallow, braided and rocky. In response, alternative techniques such as salt dilution can be used. A salt tracer's competence in turbulent and rocky channels makes it ideal for discharge measurements in these situations. This paper summarizes the work performed by Indian and Northern Affairs Canada and Canamera Geological Ltd. staff in determining the stream discharge of a lake outlet using a potassium chloride (KC1) tracer. A variety of streamflow measurement methods were performed and compared to determine the viability and rigor of the dilution method. Results suggest the dilution method compares favorably to other measurement techniques both in accuracy and operational ease.  相似文献   
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Companies undertaking TQEM programs must decide how to measure continuous improvement in the environmental field at the outset of their implementation activities. In the past three years, the leading TQEM companies have made these tough choices and have begun to share their findings with the larger professional community. The author proposes a model for classifying environmental measurement data and presents examples of approaches adopted by TQEM companies.  相似文献   
318.
The use and development of natural resources is becoming a critical concern, especially considering the economic development and stability of the world money market. The question here is one of resources as a political weapon. As resources become more scarce, it becomes necessary to make greater intensive use of resources that are presently available. One dimension that has been missing is the development of urban areas. Resources in this domain have been abused and the question now is how to incorporate these types of decisions into land-use planning to refurbish urban areas. Planning is the key to use of a resource. The world can no longer afford crisis planning. The key dimension to future success in resource problems is preventive planning.  相似文献   
319.
ABSTRACT

Protected areas are widely recognized as an important strategy for biodiversity conservation. Most of the sites are, however, poorly managed as resource exploitation by fringe communities and low government funding, among other things, threaten their management effectiveness. We used the World Commission on Protected Areas framework for designing management effectiveness evaluation systems, with the Rapid Assessment and Prioritization of Protected Areas Management (RAPPAM) methodology as a tool, to evaluate six components of the management cycle at six sites in Ghana for their management effectiveness. We examined the robustness of RAPPAM as an evaluation tool in the African context. The results showed that most of the sites evaluated are vulnerable and exposed to various degrees of pressure and threats, including poverty in the nearby communities, adjacent land-use and encroachment. On RAPPAM, we noted that apart from inconsistencies in some of the assessment scores due to the biases associated with the self-assessment approach of the methodology, the management effectiveness framework places little emphasis on financing and community participation, though both play major roles in the management process. We proposed a modification of the framework within the African context, to address effectively the underlying courses of pressure and threats facing Ghana’s protected areas.  相似文献   
320.
Many of todays agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38° incidence angle (8-m resolution) to map the distribution of winter shorebird (Charadriiformes) habitat on agricultural lands in the Willamette Valley of western Oregon. We acquired imagery on three dates (10 December 1999, 27 January 2000, and 15 March 2000) and simultaneously collected ground reference data to classify radar signatures and evaluate map accuracy of four habitat classes: (1) wet with 50% vegetation (considered optimal shorebird habitat), (2) wet with > 50% vegetation, (3) dry with 50% vegetation, and (4) dry with > 50% vegetation. Overall accuracy varied from 45 to 60% among the three images, but the accuracy of focal class 1 was greater, ranging from 72 to 80%. Class 4 coverage was stable and dominated maps (40% of mapped study area) for all three dates, while class 3 coverage decreased slightly throughout the study period. Among wet classes, class 1 was most abundant (30% coverage) in December and January, decreasing in March by 15%. Conversely, class 2 increased dramatically from January to March, likely due to transition from class 1 as vegetation grew. This approach was successful in detecting optimal habitat for shorebirds on agricultural lands. For modest classification schemes, radar remote sensing is a valuable option for wetland mapping in areas where cloud cover is persistent. Also, Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon 97331, USA  相似文献   
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