Measurements from the Ozone Monitoring Instrument are used to investigate the temporal and spatial dynamics of global nitrogen dioxide (NO 2 ). The results show that the global tropospheric column NO 2 increased by 11.10% during 2005 to 2010 at a 1.76% annual growth rate. The largest tropospheric and total NO 2 columns are mainly concentrated in the industrialized regions of North America, Europe, and east Asia. The large values of column NO 2 are also observed and scattered in South America, Africa, and Indonesia due to biomass burning and savannah fires. Average tropospheric column NO 2 increased by 32.62% at a 4.82% annual rate over eastern Asia. On the contrary, the trend decreased by 35.47% at a 7.04% annual rate over eastern America. The trend was not significant over Europe as a whole, where a decrease was observed over western and southern Europe and an increase was observed over eastern and northern Europe. Over the polluted urban areas, the ratios of tropospheric to total column NO 2 are larger than 0.6 and the correlation coefficients are larger than 0.8. This can be mainly attributed to the anthropogenic NO x emissions over land, and it is noteworthy that the ratios are higher than 0.8 (correlation coefficients >0.95 ) over northern China.
The vegetation, as the main component of the ecosystems, is the main receptor of acid rain pollution. Because of the
discrepancy of the vegetation characteristics and environment, the responses of the different types of vegetation to acid
rain in different regions are different. In this paper, we chose 9 eco-regions in southern China as study area, based on
the acid rain and NOAA/NDVI data from 1992 to 2006, and revealed the impact of acid rain on the vegetation by using
spatial interpolation, cluster analysis and curve fitting. The result shows that the most tropical and subtropical moist
broadleaf forests were positively correlated with the acidity of precipitation and the growth was inhibited obviously. On
the contrary, the growth of temperate coniferous forests was promoted by acid rain to some extent. In generally, the
vegetation in the condition of the weak acid rain grew better, especially the Qin Ling Mountains deciduous forests and
the Changjiang Plain evergreen forests. For South China-Vietnam subtropical evergreen forest, Yunnan Plateau
subtropical evergreen forests and Qionglai-Minshan conifer forests, the significant difference of NDVI between the
different gradients of acid rain lasted almost the whole year, while that of the other eco-regions only appeared most
obviously in Winter.
The aerosol optical depth was affected by the chemical composition, the particle size and the shape of aerosol as well as
the water vapor in the atmosphere; it is an important indicator for air pollution. The special and temporal characteristics
of aerosol optical depth (AOD) was measured by CE318 sun-photometer, Angstrom wavelength exponent (Alpha) and
the aerosol turbidity coefficient (β) were calculated in Ningbo, Lin'an and Qiandaohu of Zhejiang province from 2007 to
2008. We also analyzed the relationship between AOD and Angstrom wavelength exponent (Alpha) in these stations.
The results show that there are different pattern of AOD in this gradient of urban and suburban region. Lin'an station had
two peaks of AOD, but Ningbo and Qiandaohu stations had single peak of AOD in measurement year. The difference of
AOD seasonal pattern exists in three sites. The Angstrom wavelength exponent (Alpha) analysis suggests that the aerosol
sizes in three stations various from fine particle in autumn to coarse particle in spring. The seasonal patterns show that
spring air pollution is serious, summer is relatively clean, and autumn and winter are relative serious in three stations.
Land structure and amount directly influence urban development, since it is an elementary resource for various activities
in urban systems. However, land use zoning in urban system is often conducted from the view of economic and social
benefits, not considering ecological benefit. Taking Nanjing city as the study area, the present paper studied land cover
constitution of different land use zoning and constructed the quantitative relationship between urban ecological
parameters of land surface temperature (LST) and land surface dryness (LSD) and land cover constitution. Land cover
information was acquired from IKONOS data based on a decision tree method, LST was retrieved from the thermal band
of Landsat ETM+ data using mono-window algorithm, and LSD was calculated from the LST/NDVI space. Analysis
results showed that land cover constitutions within different land use zonings have great variations, and the relationships
between ecological parameters and land cover constitution also showed a close correlation; the percent vegetated area
had strong negative relationship with LST and LSD, while the percent impervious surface showed obvious positive
relationship with LST and LSD. These conclusions should be considered in urban ecological environment management.
With the rapid development of remote sensing technology, the means of accessing to remote sensing data become
increasingly abundant, thus the same area can form a large number of multi-temporal, different resolution image
sequence. At present, the fusion methods are mainly: HPF, IHS transform method, PCA method, Brovey, Mallat
algorithm and wavelet transform and so on. There exists a serious distortion of the spectrums in the IHS transform,
Mallat algorithm omits low-frequency information of the high spatial resolution images, the integration results of which
has obvious blocking effects. Wavelet multi-scale decomposition for different sizes, the directions, details and the edges
can have achieved very good results, but different fusion rules and algorithms can achieve different effects. This article
takes the Quickbird own image fusion as an example, basing on wavelet transform and HVS, wavelet transform and IHS
integration. The result shows that the former better. This paper introduces the correlation coefficient, the relative average
spectral error index and usual index to evaluate the quality of image.
The technology of image fusion now has been used in the process of remote sensing data. It can integrate the information
from multi-sensor data so as to complement the shortage of single sensor image, then more suitable for the purpose of
human visual perception, computer-aided object detection, and target recognition. Currently, there are many methods of
image fusion we can get from other researcher's study, but these methods of image fusion have some disadvantages.
This paper presented the approach of image fusion in pixel level with the fuzzy theory, the source of data used in this
paper come from QuickBird image, the resolutions of multi-spectral with four bands and panchromatic image are 2.44m
and 0.61m respectively. The process of image fusion is implemented mainly in the fuzzy tool of Matlab. Lastly,
assessing the quality of resulting images and these methods of evaluation is based on visually and statistically. The
findings that the fused image has remained the attributes of multi-spectral image and high resolution image with 0.61m
instead of 2.44m. It is indicated that the fused image is finer than the original multi-spectral image. So the approach of
this paper has presented could be a good method to process remote sensing image fusion.
Acid rain has been a worldwide environmental problem for decades. China is one of the most serious acid deposition polluted regions in the world. How to effectively monitor acid deposition's severity and spatial distribution has constituted a great challenge to the traditionally chemistry methodology used to monitor acid rain.
Long-term acid stress will change foliar internal structure and the content of pigments (such as chlorophyll a and b). Generally, such changes of foliar attributes will result increased reflectance in the visible and near-infrared wavelength regions. In this study, field and greenhouse experiments were performed separately to illustrate the influence of both natural and simulated acid rain to the spectra reflectance and chlorophyll content of masson pine (Pinus Massoniana). As measured with a portable spectroradiometer and a portable chlorophyll meter, spectra reflectance was a more sensitive indicator than chlorophyll content to indicate the severity of acid stress. In most of our cases, the reflectance of masson pine (both natural and greenhouse) was increasing with the severity of acid stress in part or in the whole wavelength regions ranged from 400 to 800nm. Vegetation indices computed using simulated Landsat Thematic Mapper (TM) bands showed that light acid stress often caused higher indices' values, and it was suggested that multispectral image data might be used to monitor acid stress from a canopy level.
Wetland water quality is a critical issue in ecology and environment science, however to identify the quality and to detect the change of wetland are still knowledge gaps. In this paper, high spatial resolution IKONOS imagery was used to assess the water quality in a small urban wetland. A water-only image was created by masking out the terrestrial features from the image with unsupervised classification method. A three-class water quality map was created by a second unsupervised classification on the water-only image, and the relationship between water quality and spectral reflectance was examined. Based on the two classified water quality maps, the water quality changes from 2003 to 2006 were detected by map comparison and cross-tabulation analysis. It concluded that high spatial resolution satellite as IKONOS is essential for water research in a local scale. The unsupervised classification based on spectral reflectance of water surface is an effective and rapid way on mapping and assessing the general water quality.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.