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1.
A.C. Teodoro L. Duarte 《International journal of geographical information science》2013,27(4):699-720
Forest fires are widely recognized as one of the most critical events in global change. Successful fire management depends on effective fire prevention, detection, and presuppression, having an adequate fire suppression capability, and consideration of fire ecology relationships. Geographical information systems (GIS) provide tools to create, transform, and combine georeferenced variables. In Portugal, as in many other countries, it is mandatory that all the municipalities produce forest fire risk maps on an annual basis, following the rules of the Portuguese Forest Authority, a governmental association. This article presents the results of a research project aimed at producing forest fire risk maps in a GIS open source environment in Portugal. The requirements of an open source application are better quality, higher reliability, more flexibility, lower cost, and an end to predatory vendor lock-in. Three different open source desktop GIS software projects were evaluated: Quantum GIS (QGIS), generalitat valenciana, Sistema d'Informacio Geografica, and Kosmo. Taking into account the skills and experience of the authors, the main advantage of QGIS relies on the easiness and quickness in developing new plug-ins, using Python language. Therefore, this project was developed in QGIS platform and the interface was created in Python. This application incorporates seven procedures under a single toolbar. The production of the forest fire risk map comprises several steps and the production of several maps: probability, susceptibility, hazard, vulnerability, economic value, potential loss, and finally the forest fire risk map. The forest fire risk map comprises five classes: very low risk (dark green), low risk (green), medium risk (yellow), high risk (orange), and very high risk (red). This application was tested in three different municipal governments of the Norwest zone of Portugal. This application has the advantages of grouping in a unique toolbar all the procedures needed to produce forest fire risk maps and is free for the institution/user. Beyond being an open source application, this application may be faster and easier when compared with the GIS proprietary solutions that usually comprise several steps and the use of different software extensions. This work presents several contributions for the area of the GIS open source applications to forest fire risk management. 相似文献
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YUXinfang ZHUANGDafang HOUXiyong CHENHua 《地理学报(英文版)》2005,15(2):239-246
The role of remote sensing in phenological studies is increasingly regarded as a key to understand large area seasonal phenomena. This paper describes the application of Moderate Resolution Imaging Spectroradiometer (MODIS) time series data for forest phenological patterns. The forest phenological phase of Northeast China (NE China) and its spatial characteristics were inferred using 1-km 10-day MODIS normalized difference vegetation index (NDVI) datasets of 2002. The threshold-based method was used to estimate three key forest phenological variables, which are the start of growing season (SOS), the end of growing season (EOS) and growing season length (GSL).Then the spatial patterns of forest phenological variables of NE China were mapped and analyzed. The derived phenological variables were validated by the field observed data from published papers in the same study area. Results indicate that forest phenological phase from MODIS data is comparable with the observed data. As the derived forest phenological pattern is related to forest type distribution, it is helpful to discriminate between forest types. 相似文献
4.
《云南地理环境研究》2016,(2)
以云南省一平浪林场为研究对象,以Forest Simulator BWINPro为工作平台,通过建立云南松等主要造林树种的生长模型数据库,实现20年生云南松林动态生长经营模拟。结果表明:该模拟系统可以无缝衔接多树种的林分生长和收获模型,对云南松林生长经营从单木和林分两个层面进行可视化展示。应用森林经营模拟技术,可实现林分生长以及未来状态的可视化模拟,实现林分动态监测,为不同时期云南松林经营管理提供参考。 相似文献
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LIANGFuyuan SONGLinhua TANGTao 《地理学报(英文版)》2003,13(2):250-256
Lunan stone forest is a kind of typical karst in China,Which is mainly developed under red soil.In the winter of 1999,three study sites were chosen in stone forest national park according to vegetation cover,geomporphologic location and soil types,CO2 concentration was measured with Gastec punp at different dephts of soil (20,40,60cm) and at the same time soil samples were gatered and soil properties such as soil moisure,pH,soil organic content were analyzed and the total nmuber of viable microbes were counted in laboratory,In the study,dependent variable was chosen as the mean soil log(PCO2),and soil properties were chosen as the independent variables.Multiple stepwise regression analysis showed that the totla amount of microbes and soil moisture are the best indicators of the CO2 production,With the equation LOG(PCO2)=-0.039(TNM)-0.056 (Mo) 1.215 accounting for 86% of the variation of the soil CO2 concentration,where TNM is the total number of microbes in teh soil and Mo is the moisture of soil sample. 相似文献
6.
Patrick T. Hurley Angela C. Halfacre Norm S. Levine Marianne K. Burke 《The Professional geographer》2013,65(4):556-578
Despite growing interest in urbanization and its social and ecological impacts on formerly rural areas, empirical research remains limited. Extant studies largely focus either on issues of social exclusion and enclosure or ecological change. This article uses the case of sweetgrass basketmaking in Mt. Pleasant, South Carolina, to explore the implications of urbanization, including gentrification, for the distribution and accessibility of sweetgrass, an economically important nontimber forest product (NTFP) for historically African American communities, in this rapidly growing area. We explore the usefulness of grounded visualization for research efforts that are examining the existence of “fringe ecologies” associated with NTFP. Our findings highlight the importance of integrated qualitative and quantitative analyses for revealing the complex social and ecological changes that accompany both urbanization and rural gentrification. 相似文献
7.
Whose Norms Prevail? Policy Networks,International Organizations and “Sustainable Forest Management”
This article investigates the origin of international norms, arguing that one pathway is via the strategic action of sector-specific policy networks. Evidence is adduced from an examination of the contested norm of sustainable forest management (SFM). It is argued that a Canadian forestry policy network, under pressure internally and externally to demonstrate its environmental and social credentials, promoted an “economistic” SFM norm in regional negotiations known as the Montreal Process. The article outlines the policy network approach, applies it to the Canadian forest sector, and analyzes how a policy network centered in the Canadian Forest Service and the Canadian Council of Forest Ministers worked to have the network's preferred conception of SFM internationally endorsed. The article highlights the importance of investigating which social actors champion which international norms and encourages reflexive policymaking by calling into question the degree to which international norms actually reflect a genuine global consensus. 相似文献
8.
The subtropical Atlantic Forest is a highly diverse ecosystem in South America and one of the most endangered rain forests in the world. The present study focuses specifically on the Paraguayan part of the tri-national Atlantic Forest. Over the last decades, the Paraguayan Atlantic Forest presented one of the highest deforestation rates in the world, and today, only a small share remains. Hence, forest loss in Paraguay's Atlantic Forest was detected and analysed through remote sensing and GIS methodologies based on Landsat images obtained in 2003 and 2013. The objective of this study was to examine the spatial impact of forest loss in Paraguay's Atlantic Forest over the past decade with a special focus on biodiversity conservation. Classifications results obtained overall accuracies above 83% and revealed that over 6000 km2 of forest was cleared during the study period. The forest landscape and its fragmentation level were characterised through a set of landscape metrics, in particular the proximity analysis which support the identification of forest priority areas for nature conservation and potential biological corridors. In summary, the study revealed that deforestation and fragmentation of the Atlantic Forest area continued, but at a slower pace than that in the previous decade. Protected areas were conserved very effectively; however, forest core areas without any protection status require further attention. Intact forest patches and their connectivity are a crucial prerequisite to biodiversity conservation in a highly fragmented forest area. The combination of different remote sensing and GIS methods provides valuable information for sustainable forest management in the region. 相似文献
9.
Ramon Felipe Bicudo da Silva Mateus Batistella Emilio Federico Moran Dengsheng Lu 《The Professional geographer》2017,69(1):80-93
The Atlantic Forest biome has only 13 percent of its pristine vegetation cover left. This article analyzes the consequences of land changes on forest cover in the Paraíba Valley, São Paulo state, Brazil, from 1985 to 2011. Multitemporal satellite image classifications were carried out to map eight land use and land cover classes. The forest cover increased from 2,696 km2 in 1985 to 4,704 km2 in 2011, mostly over areas of degraded pastures. The highest rates of afforestation were observed within protected areas around eucalyptus plantations. On the other hand, deforestation processes were concentrated on areas covered by secondary forests. Socioeconomic changes taking place in particular Brazilian settings, such as industrialization and agricultural modernization, allied to the Paraíba Valley's natural biophysical constraints for agricultural production, have led the region to experience a remarkable case of forest transition. 相似文献
10.
To clarify broad-scale patterns and controls of treefall directionality from Hurricane Katrina, we examined fall directions across a 4,500 km2 landscape mosaic in southern Mississippi using georeferenced, planar-rectified aerial photographs. Analyses using directional statistics, measures of local spatial autocorrelation, and general linear modeling indicated that treefall was significantly directional for nearly all of our locations and constrained primarily by mesoscale surface wind directions and landscape setting. None of our plots exhibited fall angles consistent with damage caused by wind reversals following the passage of the storm or by microbursts or tornadoes spawned by the hurricane. When coupled with results from other studies focused on hurricane-caused damage, these results suggest that it is possible to develop empirical, landscape-scale models of wind impacts or stand vulnerability using basic site information (e.g., topography, soils), biotic conditions (e.g., land cover, forest attributes), and generalized, but readily available, estimates of surface wind flow patterns. 相似文献
11.
Forest parks provide important recreational and tourism bene?ts to residents, so it is essential to know what residents’ perceptions are regarding the recreational value of forest parks for participatory forest planning and management. This study investigated forest park recreational value in the physical, psychological, and social dimensions in Shanghai according to questionnaires completed by 658 respondents, and examined the relationships between recreational value and residents’ social variables by multiple correspondence analysis (MCA). The results show the following: 1) The recreational value of forest parks is perceived as most important in the psychological dimension, while in the social dimension it is appreciated the least. 2) In terms of the differences in forest park recreational value in suburbs and rural areas, the social value in rural areas had significantly higher scores than in the suburbs, and the psychological value in suburbs is much higher than that in the rural areas. 3) Regarding the social variables which characterize residents in suburbs and rural areas, females and younger groups tended to assign higher scores to recreational value than males and older groups. Moreover, citizens with low education or low income also assigned higher scores to recreational value compared to more educated or higher-income residents. The results of this study reveal the recreational value characteristics of Shanghai forest parks in the three dimensions, which can provide a scientific basis for the sustainable development of urban forest resources and contribute to reasonable planning and management. 相似文献
12.
《Urban geography》2013,34(8):732-754
Little attention is paid to the ways that labor market inequalities within urban institutions enforce governance regimes that (re)produce urban environmental unevenness. Milwaukee's Bureau of Forestry is one such institution that has historically been dependent on state-sanctioned labor market inequalities to perpetuate an explicitly White/male regime of environmental governance and production. Historically, the Bureau's management employed and promoted very few African Americans and women within its arboricultural workforce, based on its racist and gendered categories of laboring individuals. Furthermore, and for identical reasons, these workers—and by extension their communities—face distributional injustices as they are not allowed to channel their labors into the production of equitable and/or alternative forms of urban forests more suitable to their own social reproduction. This paper investigates the changing relations between Milwaukee's Bureau of Forestry and its African American and female employees as they attempt to legally (re)articulate their laboring identities and capabilities within a disempowering institution. We use in-depth interviews and archival materials to show that the Bureau of Forestry has consequently been forced to publicly confront its racist/patriarchal legacy in light of two recent high-profile lawsuits and an ambassadors program. We conclude by discussing how changes that allow some African Americans and women to work in Milwaukee's urban forest have affected the Bureau of Forestry and potentially the forest itself. 相似文献
13.
Out-migration from rural areas and generational shifts create conditions whereby increasing numbers of private forest owners live at a distance from their forestland. Geographical distance and non-residency have been raised as issues that may possibly weaken these owners’ relationships with their properties. Drawing on the “sense of place” concept as a frame of analysis for 51 qualitative interviews with resident and nonresident private forest owners from two areas in Sweden, this study provides in-depth understanding of how geographical distance and place of residency shape owners’ feelings about their forest properties. The study shows that sense of place is constructed in complex and multifaceted ways over time and that social and historical contexts and processes beyond the forest environment can make owners feel closeness to their distant properties. Thus, geographical distance or residency alone does not explain variations in these forest owners’ feelings of distance or closeness to their properties. 相似文献
14.
Increase in ownership and use of radios and mobile phones in Uganda may present opportunities for interactive and efficient agricultural extension services. Yet the impact of interactive radio on rural development has rarely been evaluated. In a participatory project, the International Union for the Conservation of Nature together with Farm Radio International and stakeholders from local government, radio, and community-based organizations promoted the increased use of forest landscape restoration activities though interactive rural radio programs, including innovative methods to reach populations not covered by radio. An evaluation found that 98% of people who listened to most or all of the broadcasts carried out one of the practices, whereas 84% of those who had listened to only one episode had used one of the practices. Inclusion of a wide range of community stakeholders from project inception was vital for presenting the project and embedding it within local institutional contexts. 相似文献
15.
Izabela Golebiowska Tomasz Opach Jan Ketil Rød 《International journal of geographical information science》2017,31(2):237-252
Geographic visualization tools with coordinated and multiple views (CMV) typically provide sets of visualization methods. Such configuration gives users the possibility of investigating data in various visual contexts; however, it can be confusing due to the multiplicity of visual components and interactive functions. We addressed this challenge and conducted an empirical study on how a CMV tool, consisting of a map, a parallel coordinate plot (PCP), and a table, is used to acquire information. We combined a task-based approach with eye-tracking and usability metrics since these methods provide comprehensive insights into users’ behaviour. Our empirical study revealed that the freedom to choose visualization components is appreciated by users. The individuals worked with all the available visualization methods and they often used more than one visualization method when executing tasks. Different views were used in different ways by various individuals, but in a similarly effective way. Even PCP, which is claimed to be problematic, was found to be a handy way of exploring data when accompanied by interactive functions. 相似文献
16.
Multi-proxy data, both lithostratigraphic and biostratigraphic, are presented from Efstadalsvatn, a lake in NW Iceland. The sequence covers the period 10,000 to 3500 14C yr B.P. The biostratgraphic data include the first Icelandic chironomid-based reconstruction of Holocene mean July air temperatures, using a Norwegian training set in the absence of modern Icelandic data. The results show that deglaciation and ecosystem development probably began before 10,000 14C yr B.P. and that July temperatures were around 4°C at ca. 9500 14C yr B.P. Temperatures then rose to ca. 8°C at the time of the deposition of the Saksunarvatn tephra (9100 14C yr B.P.), reaching ca. 10°C by 8500 14C yr B.P., high enough for the growth of tree birch, although successful birch colonisation did not take place until 6750 14C yr B.P. There is some evidence for cooling immediately preceding 9100 14C yr B.P. There is little firm biostratigraphic evidence for the 8200 cal. B.P. event, although this may be due to a relatively low resolution pollen sampling interval, but there are changes at this time in the total carbon (TC) and mass susceptibility (MS) data. Optimal temperatures and relative vegetation stability may have occurred between 8000–6100 14C yr B.P. but the chironomid assemblages indicate higher temperatures after 5000 14C yr B.P. This latter interpretation may, however, reflect delayed colonisation of thermophilous taxa and requires further investigation. There is evidence in the lithostratigraphy for greater local terrestrial instability after 6100 14C yr B.P. but it seems unlikely that this led to the redevelopment of ice in the catchment. The biostratigraphic records appear to show a degree of resistence to climate forcing throughout the early and middle Holocene. The new chironomid-based temperature reconstruction needs to be refined by further studies in Iceland, particularly the development of an Icelandic training set, but has already demonstrated the problems of paleoclimatic interpretations based on pollen and/or macrofossil evidence alone. 相似文献
17.
利用渭河流域21个气象站点1960-2015年逐日气象资料,应用一元线性趋势分析、Penman-Monteith模型和Morlet小波分析等技术手段分别研究年、月地表湿润指数,并对其进行标准化和气温、降水以及极端干旱事件的变化趋势计算,并分析年内变化规律,以期更好的揭示渭河流域近55 a气候的变化规律。结果表明：（1）渭河流域近55 a的气温总体上在波动中呈小幅增加的趋势,其中20世纪80年代中期到90年代初期气温的增长幅度较大,为气温升高的主要时期,年均降水量和极端干旱频率呈现小幅减少的趋势,下降的主要时期集中在80年代中后期到90年代初期和21世纪初。（2）小波周期分析发现渭河流域极端干旱事件的震荡周期尺度为13～15 a和25～30 a,气温震荡周期的时间尺度为13～15 a和25～30 a,年降水量的小波振荡周期为15～17 a和25～30 a。主震荡周期的时间尺度均为25～30 a,次震荡周期的时间尺度也较为接近,为13～15 a和15～17 a,说明三者的变化规律在一定程度上有一定的相似性。（3）研究区内5个区域的气候变化特征同时存在着一定的差异性,天水-西吉流域的年均降水量和极端干旱事件发生频率的减少幅度和年均气温的增加幅度是5个区域里变化最大的,吴其-状头区域的年均降水量和极端干旱事件的减少频率和年均温度的增加频率是5个区域里变化幅度最小的,但在总体上各区域气候要素变化趋势上是保持一致的。 相似文献
18.
Pedodiversity: a controversial concept 总被引：8，自引：1，他引：8
1 Conceptual introductionSpatial soil variation is a fundamental notion of pedology, formally expressed in the hierarchical system of soil taxonomy and soil associations[1,2]. Since the 1990s, a Spanish research team led by Ibá?ez has been presenting a possible approach to systematically analyze taxonomic diversity of pedosphere by methods employed in ecological studies, drawing a parallel with the concept of biodiversity in ecology. According to Ibá?ez et al., it would be quite reasonable … 相似文献
19.
Stig Roar Svenningsen Gregor Levin Martin Rudbeck Jepsen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2015,115(2):157-166
During the past century, the western hemisphere has seen a general trend of agricultural expansion on the behalf of semi-natural habitat types, such as heathlands and meadows. This has been documented in numerous studies of land use change. This trend is reflected in today’s European rural landscapes, which are dominated by intensive agriculture. However, many of these studies are based on cartographical sources, such as topographical and thematic maps, and thus prone to uncertainties regarding classification systems over time, variations in definitions of land use categories and lacking documentations of land use definitions. For this study, we conducted two change detection studies, covering the same four study areas in Denmark. The first study was based on topographic maps, and indicates a strong decline in the amount of semi-natural grassland (SNG). This was contrasted by the second study, which was based on an interpretation of aerial photos, and which indicated a much less pronounced reduction of SNGs. Year to year comparisons of these two analyses also revealed large discrepancies in the coverage of SNGs. Our results indicate that change detection studies must account for uncertainties in classifications and results should be interpreted with caution. 相似文献
20.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(2):127-151
This study deals with the use of quantitative methods to build up uniform or formal regions, the construction of farming-type regions in eastern Norway being used as an example. To achieve reasonable uniformity in the size of the basic areal units, some of the original administrative areas are first combined; the resulting areal units are then described by four orthogonal variables extracted by principal component analysis. Six different methods of aggregating the basic units to form regions are discussed, each method using the same measure of similarity (D2) between the basic units. The homogeneity of the regions produced by these methods is compared, and Ward's method (Ward 1963) shown to give the best (though not necessarily the optimal) solution. 相似文献