Amount Of Urban Area Research Articles

Temporal monitoring of land use/land cover change in Kahramanmaraş city

Irregular urbanization causes problems such as decrease in fertile agricultural areas, irregular industrialization and urbanization. To provide a healthier life opportunity for future generations without disturbing nature, it is essential to determine the temporal changes in land use and to make land management plans accordingly. In this study, land use/land cover (LULC) change occurred in Kahramanmaras province within 30 years was investigated by remote sensing and integration of Geographic Information Systems. Landsat satellite images of 1988-1998-2008-2018 were obtained for the production of LULC maps. Each image was classified according to supervised classification approach using the support vector machines (SVMs) algorithms. The confusion matrix was created for each year to examine the accuracy of the LULC maps. The overall accuracy of the thematic maps was obtained as 91.76%, 93.56%, 86.89% and 88.29%, respectively. Also, Kappa values of thematic maps for each year were obtained as 0.88, 0.91, 0.81 and 0.84, respectively. When the results were examined, the development of industry in the city area and the construction of the airport contributed to the development of the social and economic structure of the city. The increase in the number of housing in the related regions has led to an increase in the amount of urban areas and a decrease in agricultural areas.

Effects of landscape context and vegetation attributes on understorey bird communities of cloud forest riparian belts

In recent decades land cover change resulting from different types of human activity has severely reduced the original area of tropical montane cloud forest (TMCF). Deforested landscapes in neotropical America commonly have a heterogeneous structure (i.e. landscape context) with increasingly small forest patches immersed in an agricultural matrix. Often, this matrix is not completely devoid of trees, but contain numerous and widely spread arboreal elements. Many of these elements are remnants of the original forest, such as arboreal riparian belts. In 14 riparian belts of TMCF in central Veracruz, Mexico, we assessed the relationship between the attributes of the bird community that uses these belts and their vegetation attributes, as well as with landscape structure in their vicinity at four different scales (within 250, 500, 750 and 1000 m). Bird richness and abundance in riparian belts were positively related with mean tree height. Regarding landscape context, the amount of urban area in the vicinity of each belt was positively related with bird abundance at the four scales studied, explaining between 14 and 31% of spatial variation. However, the abundance of forest interior birds was negatively related with urban area, explaining from 46 to 50% of variation. Both, local (tree height) and landscape characteristics (urban and forest cover) influence differentially bird abundance in riparian belts of cloud forest. Thus, both kinds of variables should be relevant for designing management plans aimed at enhancing the conservation of the native avifauna of the cloud forest and its ecosystem services within transformed landscapes.

Fruit feeding butterflies as indicator taxon, pitfalls and concerns demonstrated in the Atlantic Forest

Abstract Aim In the search for the ideal indicator taxon, fruit feeding butterflies have attracted increased focus for use in ecosystem assessments in the tropics. This study aims to shed light on the usability of fruit feeding butterflies in ecosystem assessments by comparing the effect of two different measures of ecosystem degradation on the fruit feeding butterfly community. Location The Interior biogeographical sub region of the Atlantic Forest, southern Brazil. Methods In this study, the impact of tree cover and urban area on the abundance, richness and diversity of fruit feeding butterflies were investigated. Tree cover was measured within 200 and 1000 m of each trap while urban area was just measured within 1000 m. This was accomplished with the use of standardized trapping methods and geospatial tools that allowed for spatial analysis of the area surrounding each trap. In contrast to the common approach, the grouping of sampling units where based on the specific research question addressed, thus enhancing the statistical significance of the results. Results Within 200 m a moderate amount of tree cover (~35–50% tree cover), were found to be positively correlated with all community metrics, while a high amount of tree cover within both 200 and 1000 m (~>50% tree cover) displayed a pronounced negative correlation with all community metrics. Any amount of urban area within 1000 m (~0–30% urban area) showed a pronounced negative correlation with all community metrics. Main conclusions Considering the effect of tree cover, several commonly used community metrics for fruit feeding butterflies were shown to respond contradictorily to what might be expected. However, regarding urban area, the fruit feeding butterfly community were found to respond as expected and was extraordinarily sensitive to disturbances. These results highlight the need to be critical in the choice of community metrics when utilizing fruit feeding butterflies as indicator taxon, while also demonstrating their sensitivity to habitat changes and potential in future habitat assessments. In addition, grouping trap data in accordance to specific research questions was found to yield very robust results, thus allowing for reduced survey costs in future studies.

Estimation of Green Land to Urban Change Based on Cellular Automata (CA) Method in Singaraja City and its Surrounding Areas

Singaraja city is the second largest city in Bali which have a fairly rapid growth. Growth and development of the region in urban areas of Singaraja give the positive impact on the economy of the community but also give the negative impact on the environment. Land use change and land conversion into one of the negative issues of the development of urban areas in Singaraja. This study intends to calculate the amount of land conversion occur on the green land into urban areas within 14 years (2001-2015) and predict land use change in 2020 and 2025 in Singaraja City and Its Sorrounding Areas. Landsat 7 and Landsat 8 imageries were used to determine the land use map. Land use map obtained through the process of image classification using supervised method then verified using data field. Land use maps in 2015 and 2001 used to obtain the amount of change of urban areas and green land during the period of 14 years. This results show increasing amount of urban areas as 11,37% (3.153,74 ha) whereas green land decreased by 11,17% (3.097,68 ha). Land use change was predicted by Markov method. The projection results show the amount of urban areas in 2020 was 27,40% (7.598,45 ha) and 35,97% (9.974,55 ha) in 2025. The results obtained with this prediction accuracy rate of 0.91.

The role of urban habitats in the abundance of red squirrels (Sciurus vulgaris, L.) in Finland

Because the amount of urban areas has increased, it is important to investigate the abundance of wildlife species in relation to urban environments. Analyzing the impact of urbanization on the presence of forest-dwelling mammals is of interest due to the possible effects of urbanization on human-wildlife relationships and urban biodiversity. The Eurasian red squirrel (Sciurus vulgaris) is a declining forest species, and its occurrence in urban environments has been inadequately studied. The loss and fragmentation of forests due to urbanization may be detrimental for squirrels, whereas the abundant and predictable food resources and the low number of natural predators in urban areas may encourage squirrels to invade towns. We used large-scale data collected by volunteer bird watchers along a 950km south-north gradient to study whether the winter abundance of squirrels in Finland is dependent on urbanization, while controlling for effects of habitat type, food abundance (spruce cone crop; number of winter feeding sites), predator abundance (northern goshawk, Accipiter gentilis; feral cat Felis catus), season and latitude. We found that squirrel abundance increased with human population density, number of feeding sites and spruce cone crop and decreased with latitude and season. Feral cats showed weak negative connection with squirrel numbers, but there were no effect of goshawks. Relative squirrel abundance was approximately twice as high in urban habitats than in forests. Artificial feeding rather than a low number of predators may attract squirrels in urban environments. Planting spruce trees in urban environments will also benefit squirrels. Our results indicate that urban areas are an important habitat for the red squirrel even along the northern edge of their distribution range, where natural forest areas are still widespread. We conclude also that a citizen science −based bird survey protocol associated with mammal surveys seems to be a good large-scale monitoring method to study the urbanization of squirrels.

Assessment of urban growth in Guangzhou using multi-temporal, multi-sensor Landsat data to quantify and map impervious surfaces

ABSTRACTOver the past few decades, one of the most important global environmental issues has been the increasing transformation of natural landscape cover to impervious surface (IS) as a result of urbanization. A wide range of urban ecology fields, such as urban hydrology, urban climatology, urban planning, and urban ecosystem monitoring, demand accurate and timely information on land use and land cover in urban areas. As part of one of the fastest growing regions in China, Guangzhou is experiencing rapid urban expansion. We developed a combined method that integrates spectrum normalization, normalized spectral mixture analysis (NSMA), threshold segmentation, and a spatiotemporal modification approach to map the Guangzhou urban extent, through quantification of IS as a continuous variable using Landsat series images. We also developed a method to automatically extract water from Thematic Mapper (TM)/Enhanced Thematic Mapper Plus (ETM+)/Operational Land Imager (OLI) imagery. The results indicated that the integrated approach is accurate, powerful, and effective. The Guangzhou assessment showed that from 1973 to 2013 the amount of urban area with sub-pixel IS larger than or equal to 55% increased from 0.27% to 30.58%, an increase in urban extent of more than 100-fold over 40 years.

Una visión a escala de paisaje de las invasiones biológicas

González-Moreno, P., Domingo Delgado, J., Vilà, M. 2015. An overview of biological invasions at the landscape scale. Ecosistemas 24(1): 84-92. Doi.: 10.7818/ECOS.2015.24-1.13 Biological invasions and human landscape alteration are greatly increasing biodiversity loss. Furthermore, these factors might interact, as landscape characteristics affect the level of invasion of ecosystems and consequently its impact. Using invasions by non-native plants as study case, we review the importance of human landscape alteration on invasion patterns. In comparison with climate and habitat type, landscape characteristics exerts its major influence at intermediate or landscape scales (<200 km) and mainly mediated by the amount of urban area. The effect of landscape characteristics on invasions can be highly variable as it greatly depends on the ecological context. We also highlight the importance of landscape dynamics and its delayed effect on invasion patterns (i.e. invasion credit) as it might produce an underestimation of the future impact of invasions. Finally, we suggest management strategies for invasive species at the landscape scale, which incorporates the control of invasions both at the local scale and at the propagules sources.

Availability of Outpatient Substance Use Disorder Treatment Programs in the United States

The purpose of this study was to examine the availability of outpatient substance use disorder (SUD) treatment programs in the United States. A geographic information system (GIS) was used to spatially locate outpatient SUD treatment programs, calculate areas, and determine population density within specific areas. Urban areas were mapped using data from the US Census (2000). Addresses of outpatient SUD treatment programs were obtained from the Facility Locator Web site of the Substance Abuse and Mental Health Services Administration. A 15-mile service catchment around each outpatient SUD treatment program was drawn. The amount of urban area not covered by the service catchment represents the underserved. Total underserved urban area and population without access was computed for each state. Significant variability of underserved urban area and population was observed across the states. Moderate correlations among area and population suggest that some states are more effective in locating SUD treatment programs than other states.

Threats and biodiversity in the mediterranean biome

ABSTRACTAim Global conservation assessments recognize the mediterranean biome as a priority for the conservation of the world's biodiversity. To better direct future conservation efforts in the biome, an improved understanding of the location, magnitude and trend of key threats and their relationship with species of conservation importance is needed.Location Mediterranean‐climate regions in California‐Baja California, Chile, South Africa, Australia and the Mediterranean Basin.Methods We undertook a systematic, pan‐regional assessment of threats in the mediterranean biome including human population density, urban area and agriculture. To realize the full implications of these threats on mediterranean biodiversity, we examined their relationship with species of conservation concern: threatened mammals at the global scale and threatened plants at the subecoregional scale in California, USA.Results Across the biome, population density and urban area increased by 13% and agriculture by 1% between 1990 and 2000. Both population density and urban area were greatest in California‐Baja California and least in Australia while, in contrast, agriculture was greatest in Australia and least in California‐Baja California. In all regions lowlands were most affected by the threats analysed, with the exception of population density in the Chilean matorral. Threatened species richness had a significant positive correlation with population density at global and subecoregional scales, while threatened species were found to increase with the amount of urban area and decrease as the amount of natural area and unfragmented core area increased.Main conclusions Threats to mediterranean biodiversity have increased from 1990 to 2000, although patterns vary both across and within the five regions. The need for future conservation efforts is further underlined by the positive correlation between species of conservation concern and the increase in population density over the last decade. Challenges to reducing threats extend beyond those analysed to include human–environmental interactions and their synergistic effects, such as urbanization and invasive species and wildfires.

Urban flood plains analyzed by USGS

A recent U.S. Geological Survey study of 26 cities in the United States indicates that the amount of urban area that would be inundated by the 100‐year flood (the flood level that, on average, is exceeded once in 100 years) ranges from 81% for Monroe, Louisiana, to 2.4% for Spokane, Washington.The report is the latest in a series dealing with water in the urban environment and contains data on the areal extent and degree of occupancy of flood plains in the urbanized areas of the selected cities. The USGS was assisted in compilation of the data by the American Society of Civil Engineers, the Army Corps of Engineers, and the Tennessee Valley Authority.