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1.
Specific Conductance and pH as Indicators of Watershed Disturbance in Streams of the New Jersey Pinelands, USA 总被引:2,自引:0,他引:2
/ We used linear regression to independently and jointly relate specific conductance and pH measured at New Jersey Pinelands stream sites to the percentage of altered land in a watershed. Percentage altered land included developed and agricultural land uses and represented watershed disturbance for a given site. Median values calculated for a 2-year period (September 1992 through August 1994) characterized pH and specific conductance at the study sites. We found the relationships between the median values for both water-quality measures and percentage altered land for a site to be consistent across subregion and dominant altered-land use. Our results also demonstrated that the water-quality/altered-land relationships developed using median values were similar to relationships developed using data from any single-sample period within the entire study period. Individually, pH and specific conductance explained 48% and 56%, respectively, of the variability in watershed disturbance among study sites. The joint use of pH and specific conductance explained 79% of the watershed disturbance variability among sites. The joint use of these easily obtained water-quality measures can provide a quick assessment of instream water-quality impacts from upstream watershed disturbance at any Pinelands stream site. Additionally, a range in pH and specific conductance, and hence a range in ambient water quality, can be predicted for a given altered-land percentage or a change in existing altered-land conditions. 相似文献
2.
Joanna Burger 《Environmental management》1998,22(6):869-876
/ Management of ecosystems has advanced by an improvement in our understanding not only of how ecosystems function, but of how people perceive their functioning and what they consider to be environmental problems within those systems. Central to such management is understanding how people view estuaries. In this article I explore the perceptions and attitudes of people about coastal recreation, environmental problems, and future land use along the New Jersey shore (USA) by interviewing people who attended a duck decoy and craft show on Barnegat Bay. The people who were interviewed engaged in more days of fishing than any other recreational activity and engaged in camping the least. There were significant differences in recreational rates as a function of gender and location of residence, with men hunting and fishing more than women and photographing less than women. Jet skis were perceived as the most severe environmental problem, with chemical pollution, junk, oil runoff and overfishing as second level problems. Birds were perceived as not an environmental problem at all. Fishing, hiking, preservation, and camping ranked as the highest preferred future land uses for the two sites examined (Oyster Creek Nuclear Generating Station, Naval Weapons Station Earle). The preferred future land uses for these two sites, which are not under consideration for land-use changes, were very similar to those of people living near the Department of Energy's Savannah River Site in South Carolina, despite the media attention and considerations of nuclear storage.KEY WORDS: Recreation; Perceptions; Environmental problem; Gender; Land use; Coastal 相似文献
3.
Monica Goigel Turner 《Environmental management》1987,11(2):237-247
Land use since 1935 was quantified for Georgia, USA, and for a sample of 20 counties from the major physiographic regions within the state. Statistical data on crop production, pasture productivity, and forest growth were used to estimate net primary production. Appropriate harvest indices (ratio of crop yield to total plant production) were used to correct crop yield data for different decades. Net primary production (NPP) of the Georgia landscape increased from 2.5 to 6.4 tonnes/ha from 1935 to 1982, but varied considerably among land uses and physiographic regions. NPP in the piedmont and mountains reached a plateau between 1960 and 1982, but the upper and lower coastal plains showed a continued linear increase in NPP. In all regions, NPP rose most between 1960 and 1982, coinciding with increases in inputs such as fertilizer and irrigation. Natural ecosystem NPP for Georgia is approximately 16–18 tonnes/ha, and the estimated actual NPP is thus considerably less than the potential. Spatial and temporal patterns of NPP may be a useful basis for evaluating the biological performance of a landscape. 相似文献
4.
Land use/cover in Northeast China went through extensive changes during the 1990s. This report explores the interaction between
these changes and the environment, and the implication of these changes for rational allocation of water resources. Two maps
of land use/cover produced from 1990 and 2000 Landsat TM satellite images were overlaid in ArcInfo to reveal changes in land
cover. Results indicate that farmland and grassland decreased by 386,195 and 140,075 ha, respectively, while water, built-up
areas, and woodland increased by 238,596, 194,231, and 192,682 ha, respectively. These changes bore a mutual relationship
with the environmental change. On the one hand, climate warming made some of these changes (e.g., conversion of woodland and
grassland to farmland) possible. On the other hand, the changed surface cover modified the local climate. These changes, in
turn, caused severe environmental degradation and increased flooding. The change between dry field and rice paddy, in particular,
raised severe implications for the proper allocation of limited water resources in the Northeast. Efforts are needed to coordinate
their rational allocation to reap maximum and sustainable return over the entire area, not just in some localities. Results
obtained in this study should be of interest to the international audience of Environmental Management in that they highlight the interactive nature of human activities and the environment and the off-site impact of these activities
on the environment. 相似文献
5.
This paper describes a remote sensing approach used to monitor temporal land use/cover (LULC) changes in Cukurova, an extensive coastal plain in the southeast Mediterranean coast of Turkey. The area has varied terrain ranging from low-lying alluvial deposits to rocky hills and mountains characterized by limestone outcrops. The ecological and economic importance of the area can be attributed to the existence of important coastal ecosystems (e.g., wetlands and sand dunes) and a wide range of industries located along the eastern coast. Temporal changes in the coastal landscape between 1984 and 2000 were evaluated using digital interpretation of remotely sensed satellite data. Pairwise comparison methods were used to quantify changes from 1984 to 1993 and 1993 to 2000 using multitemporal Landsat TM and ETM+ images, acquired in 1984, 1993, and 2000, respectively. Total change area was 2448 ha from 1984 to 1993 and increased more than twofold, to 6072 ha from 1993 to 2000. Change trends were determined using the information provided from individual change detection outputs of different periods. The most prominent changes were estimated to have occurred in agriculture, urban, and natural vegetation cover. Agriculture has increasingly grown over marginal areas, whereas urban development occurred at the expense of prime croplands across both time steps. 相似文献
6.
基于梁子湖自然保护区1987年和2004年Landsat-TM影像遥感数据,在Erdas Imagine 8.5图像处理软件的支持下,结合野外实地考察,获得了土地利用现状图,通过对数据的统计分析,研究了保护区近20年来土地利用/土地覆盖的动态变化。研究表明:耕地和水域是保护区内的主要土地利用类型;近20年来,耕地、园地、林地、草地的面积都有减少,其中耕地面积减少了2320.816hm^2,减少比例达到11.78%,是面积减少最多的土地利用类型;居民点、交通、水域用地有所增加,其中池塘面积变化最大,增幅达到213.4%,是面积增加最多的土地利用类型,居民点用地增加了551.18hm^2,增幅达到59.07%,是增长幅度较大的土地利用类型。变化的原因主要是经济的发展、人口数量的增长和旅游业的发展。 相似文献
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8.
Land Use and Land Cover Change Analysis and Prediction in the Upper Reaches of the Minjiang River,China 总被引:1,自引:1,他引:1
Scientists have aimed at exploring land use and land cover change (LUCC) and modeling future landscape pattern in order to
improve our understanding of the causes and consequences of these phenomena. This study addresses LUCC in the upper reaches
of Minjiang River, China, from 1974 to 2000. Based on remotely sensed images, LUCC and landscape pattern change were assessed
using cross-tabulation and landscape metrics. Then, using the CLUE-S model, changes in area of four types of land cover were
predicted for two scenarios considering forest polices over the next 20 years. Results showed that forestland decreased from
1974 to 2000 due to continuous deforestation, while grassland and shrubland increased correspondingly. At the same time, the
farmland and settlement land increased dramatically. Landscape fragmentation in the study area accompanied these changes.
Forestland, grassland, and farmland take opposite trajectories in the two scenarios, as does landscape fragmentation. LUCC
has led to ecological consequences, such as biodiversity loss and lowering of ecological carrying capacity. 相似文献
9.
The wilderness use simulation model applied to Colorado River boating in Grand Canyon National Park,USA 总被引:1,自引:0,他引:1
A modification of the Shechter-Lucas Wilderness Use Simulation Model (WUSM) for peak season boating on the Colorado River through Grand Canyon National Park, USA, is evaluated as a tool for making management decisions. A new microcomputer program to select trip itineraries for inclusion in the WUSM that was developed as part of this study is presented. This program simplifies user input and expands the WUSM's usefulness as a tool for management decisions by randomizing itinerary schedules based on probabilities developed from actual use of sites by canyon visitors. Model usefulness is demonstrated by simulating various management changes and comparing use levels of attraction sites and campgrounds as well as numbers of encounters between parties. The WUSM is being used as part of an ongoing study, to reflect the impact of fluctuating flow regimes through the turbines at Glen Canyon Dam on river trips. 相似文献
10.
This research demonstrates the contribution of phenomenological inquiry within the realm of geographic and environmental planning. The contention is that a focus on the wide range of individual meanings and values ascribed to landscapes, a marginalized element in many planning assessments, can bring out data to more substantively inform decision making, A case study of user meanings imparted to residual waterfront land in Hoboken, New Jersey, USA, suggests that such property provides an array of amenities to residents. Most importantly, it expands the range of recreational activities, creates visual relief from the monotonous urban milieu, and provides scenic vistas to promote an awareness of the quality of life still possible in cities. The study concludes that planners can use phenomenology to generate data for more judicious decision making. 相似文献
11.
Entangling the Complexity of Protected Area Management: The Case of Wolong Biosphere Reserve,Southwestern China 总被引:5,自引:1,他引:5
Protected Area (PA) management is a complex issue that requires the consideration of many factors and relationships. A conceptual framework for the analysis of biodiversity change, local human communities, and PA management was put forward, accordingly. Under the framework, we investigated the economic status, livelihood activities, biodiversity use and perceptions of local communities, and the land use history in Wolong Biosphere Reserve, southwestern China through household survey and document review in order to gain a better understanding of the complexity of PA management. According to the land use history, the preservation of agro-biodiversity, and the raising of productivity, ecological rehabilitation and the regulation of the human pressures are indispensable in the management of the reserve. Livelihood activities and the perceptions of local communities were largely determined by the socioeconomic background, which has important implications in solving the conflicts or incompatibilities in the reserve. In Wolong Biosphere Reserve, it is beneficial to support local farmers in solving their socioeconomic problems such as the overabundance of labor force and the lack of livelihood alternatives. Without this, there will be scarcely any effective biodiversity conservation and successful reserve management in the long term. 相似文献
12.
Impact of land use and land cover changes on the ambient temperature in a middle scale city, Takamatsu, in Southwest Japan 总被引:1,自引:0,他引:1
Atsuko Nonomura Mutsuko Kitahara Takuro Masuda 《Journal of environmental management》2009,90(11):3297-3304
There is a lack of information on urban heat island impact on the thermal environment due to low populated urban sprawl, although densely populated urban sprawl impact has been identified by several researchers. The Takamatsu area has recently developed in a low populated urban sprawl style without any increase in population. This paper examined the impact of a low populated urban sprawl on the thermal environment through an analysis of the last 30 years data set and investigated the contribution of vegetation fraction and population density to the temperature trend. As a consequence, it was shown that one of the most significant causative factors of temperature increase is an expansion of non-vegetated area even without population growth. This result implied that vegetated zones should be maintained in urban areas in order to realize sustainable urbanization. 相似文献
13.
The importance of the surrounding landscape to aquatic ecosystems has been well established. Most research linking aquatic
ecosystems to landscapes has focused on the one-way effect of land on water. However, to understand fully the complex interactions
between aquatic and terrestrial ecosystems, aquatic ecosystems must be seen not only as receptors of human modification of
the landscape, but also as potential drivers of these modifications. We hypothesized that the presence of aquatic ecosystems
influences the spatial distribution of human land use/cover of the nearby landscape (≤1 km) and that this influence has changed
through time from the 1930s to the 1990s. To test this hypothesis, we compared the distribution of residential, agricultural,
and forested land use/cover around aquatic ecosystems (lakes, wetlands, and streams) to the overall regional land use/cover
proportion in an area in southeast Michigan, USA; we also compared the distribution of land use/cover around county roads/highway
and towns (known determinants of many land use/cover patterns) to the regional proportion. We found that lakes, wetlands,
and streams were strongly associated with the distribution of land use/cover, that each ecosystem type showed different patterns,
and that the magnitude of the association was at least as strong as the association with human features. We also found that
the area closest to aquatic ecosystems (<500 m) was more strongly associated with land use/cover distribution than areas further
away. Finally, we found that the strength of the association between aquatic ecosystems and land use/cover increased from
1938 to 1995, although the overall patterns were similar through time. Our results show that a more complete understanding
is needed of the role of aquatic ecosystems on the distribution of land use/cover. 相似文献
14.
Smith JH 《Environmental management》2003,31(2):0252-0262
The BOSAWAS Natural Resource Reserve of Nicaragua was established in 1991, to protect a portion of the remaining tropical
rain forest and to promote the sustainable use of the region's resources. Information required to effectively manage the reserve
includes the extents and locations of present land-cover types and recent land-cover changes in the management use zones that
were delineated by local indigenous communities. These zones include areas designated for conservation, limited resource extraction,
agriculture, and watershed protection. Land-cover for 1986 and 1995 was identified for three of the communities from remotely
sensed images and then input into a geographic information system database to identify land-cover types within these management
use zones. For both dates of the analysis, advanced forest was the dominant land cover, with the conservation zones entirely
forested. The amount of both agricultural land and scrub/early secondary forest increased between the two dates, with much
of these land-cover classes occurring in the agriculture zones. Conflicts between the land-cover present and designated use
were identified in some of the limited-use buffer and watershed protection zones. Changes between 1986 and 1995 were identified
by overlaying the two land-cover data sets. Three change processes were identified as occurring: deforestation, reforestation,
and reconversion. Changes were concentrated in the agriculture zones but were found to occur in every type of zone, except
for conservation. The results of this study will establish baseline information for the future management of the BOSAWAS Reserve,
an important component in uniting conservation areas along the Central American isthmus. 相似文献
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17.
Monica Lipscomb Smith Weiqi Zhou Mary Cadenasso Morgan Grove Lawrence E. Band 《Journal of the American Water Resources Association》2010,46(2):429-442
Smith, Monica Lipscomb, Weiqi Zhou, Mary Cadenasso, Morgan Grove, and Lawrence E. Band, 2010. Evaluation of the National Land Cover Database for Hydrologic Applications in Urban and Suburban Baltimore, Maryland. Journal of the American Water Resources Association (JAWRA) 46(2):429-442. DOI: 10.1111/j.1752-1688.2009.00412.x Abstract: We compared the National Land Cover Database (NLCD) 2001 land cover, impervious, and canopy data products to land cover data derived from 0.6-m resolution three-band digital imagery and ancillary data. We conducted this comparison at the 1 km2, 9 km2, and gauged watershed scales within the Baltimore Ecosystem Study to determine the usefulness and limitations of the NLCD in heterogeneous urban to exurban environments for the determination of land-cover information for hydrological applications. Although the NLCD canopy and impervious data are significantly correlated with the high-resolution land-cover dataset, both layers exhibit bias at <10 and >70% cover. The ratio of total impervious area and connected impervious area differs along the range of percent imperviousness – at low percent imperviousness, the NLCD is a better predictor of pavement alone, whereas at higher percent imperviousness, buildings and pavement together more resemble NLCD impervious estimates. The land-cover composition and range for each NLCD urban land category (developed open space, low-intensity, medium-intensity, and high-intensity developed) is more variable in areas of low-intensity development. Fine-vegetation land-cover/lawn area is incorporated in a large number of land use categories with no ability to extract this land cover from the NLCD. These findings reveal that the NLCD may yield important biases in urban, suburban, and exurban hydrologic analyses where land cover is characterized by fine-scale spatial heterogeneity. 相似文献
18.
Landscape--wildfire interactions in southern Europe: implications for landscape management 总被引:5,自引:0,他引:5
Moreira F Viedma O Arianoutsou M Curt T Koutsias N Rigolot E Barbati A Corona P Vaz P Xanthopoulos G Mouillot F Bilgili E 《Journal of environmental management》2011,92(10):2389-2402
Every year approximately half a million hectares of land are burned by wildfires in southern Europe, causing large ecological and socio-economic impacts. Climate and land use changes in the last decades have increased fire risk and danger. In this paper we review the available scientific knowledge on the relationships between landscape and wildfires in the Mediterranean region, with a focus on its application for defining landscape management guidelines and policies that could be adopted in order to promote landscapes with lower fire hazard. The main findings are that (1) socio-economic drivers have favoured land cover changes contributing to increasing fire hazard in the last decades, (2) large wildfires are becoming more frequent, (3) increased fire frequency is promoting homogeneous landscapes covered by fire-prone shrublands; (4) landscape planning to reduce fuel loads may be successful only if fire weather conditions are not extreme. The challenges to address these problems and the policy and landscape management responses that should be adopted are discussed, along with major knowledge gaps. 相似文献
19.
Georelational Analysis of Soil Type, Soil Salt Content, Landform, and Land Use in the Yellow River Delta, China 总被引:4,自引:0,他引:4
The Yellow River Delta, one of China’s three major river deltas, is becoming a major region for the development of agriculture and fisheries. Protecting the delicate ecology of newly formed aquatic systems as well as the evolution of soils, natural vegetation, and fauna on older upland environments in the delta is a priority in planning for the wise use of the delta’s resources for future agricultural development. In this article, we use a Geographic Information System (GIS) to analyze relationships between land-use/land-cover characteristics in the Dongying municipality, one of the most intensely developed areas of the delta, and spatial variations in soil salinity and landforms. This analysis reveals that soil salt content decreases from regionally high values in isolated depressions to relatively moderate values in embanked former back swamps, with the lowest values occurring in abandoned river courses. Comparing the present land use on this soil salinity–landform pattern shows that it is basically at odds with general concepts of land suitability for agricultural utilization of saline soils. Crop-based agriculture in the region is probably overdeveloped, whereas more appropriate agricultural development, like cattle and forest production, is underrepresented. Future development should focus on converting farmland in embanked former back swamps and abandoned river courses into grasslands and forests. Crop-based agriculture (up to 151,000 ha) could be planned at the low-salinity terrace uplands and flood plains. The article provides guidelines for decision-makers regarding agricultural land use and wetland protection in the Yellow River Delta. 相似文献
20.
Land-cover change in upper Barataria Basin estuary,Louisiana, 1972-1992: increases in Wetland area 总被引:1,自引:0,他引:1
The Barataria Basin, Louisiana, USA, is an extensive wetland and coastal estuary system of great economic and intrinsic value.
Although high rates of wetland loss along the coastal margin of the Barataria Basin have been well documented, little information
exists on whether freshwater wetlands in the upper basin have changed. Our objectives were to quantify land-cover change in
the upper basin over 20 years from 1972–1992 and to determine land-cover transition rates among land-cover types. Using 80-m
resolution Landsat MSS data from the North American Landscape Characterization (NALC) data archive, we classified images from
three time steps (1972, 1985, 1992) into six land-cover types: agriculture, urban, bottomland hardwood forest, swamp forest,
freshwater marsh, and open water. Significant changes in land cover occurred within the upper Barataria Basin over the study
period. Urban land increased from 8% to 17% of the total upper basin area, primarily due to conversions from agricultural
land, and to a lesser degree, bottomland forest. Swamp forest increased from 30% to 41%, associated with conversions from
bottomland hardwood forest and freshwater marsh. Overall, bottomland forest decreased 38% and total wetland area increased
21%. Within the upper Barataria, increases in total wetland area may be due to land subsidence. Based on our results, if present
trends in the reduction of bottomland forest land cover were to continue, the upper Barataria Basin may have no bottomland
hardwood forests left by the year 2025, as it is subjected to multiple stressors both in the higher elevations (from urbanization)
and lower elevations (most likely from land subsidence). These results suggest that changes in the upper freshwater portions
of coastal estuaries can be large and quite different from patterns observed in the more saline coastal margins. 相似文献