bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of BCL11A genetic variant (rs11886868) with severity in β-thalassaemia major & sickle cell anaemia
Authors: Dadheech Sneha , Madhulatha D. , Jain Suman , Joseph James , Jyothy A. , Munshi Anjana
Published: June 2016

Background & objectives:

The amount of foetal haemoglobin that persists in adulthood affects the clinical severity of haemoglobinopathies including β-thalassaemia major and sickle cell anaemia (SCA). The present study was undertaken to analyse β-thalassaemia as well as SCA patients for the single nucleotide polymorphism (SNP), rs11886868 (T/C) in BCL11A gene and to evaluate the association between this polymorphism and severity of β-thalassaemia major and SCA.

Methods:

A total of 620 samples (420 β-thalassaemia major and 200 SCA cases) were analysed before blood transfusion using basic screening tests like complete blood analysis and osmotic fragility and further confirmed by high performance liquid chromatography (HPLC), amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and reverse dot blot techniques. All patients were transfusion dependent. Patients with β-thalassaemia and SCA were classified into mild, moderate, severe according to the severity score based on Hb levels, age of onset, age at which patients received their first blood transfusion, the degree of growth retardation and splenectomy. β-thalassaemia as well as SCA patients were analysed for the SNP, rs11886868 (T/C) in BCL11A gene and association between this polymorphism and severity of β-thalassaemia major as well as SCA was evaluated.

Results:

There was a significant difference in genotypic and allelic frequencies of BCL11A gene polymorphism between mild and moderate and mild and severe cases in both the groups. A significant (P<0.001) difference was observed in the mean HbF levels between the three genotypes in different severity groups. HbF levels were found to be high in CC genotype bearing individuals followed by TC and TT in β-thalassaemia major as well as SCA.

Interpretation & conclusions:

This study confirms that the T/C variant (rs11886868) of the BCL11A gene causing downregulation of BCL11A gene expression in adult erythroid precursors results in the induction of HbF and ameliorates the severity of β-thalassaemia as well as SCA.
Species distribution & antifungal susceptibility pattern of oropharyngeal Candida isolates from human immunodeficiency virus infected individuals
Authors: Das Partha Pratim , Saikia Lahari , Nath Reema , Phukan Sanjib Kumar
Published: June 2016

Background & objectives:

The changing spectrum of Candida species in causation of oropharyngeal candidiasis and their antifungal susceptibility pattern among the HIV infected individuals has made the identification to species level mandatory and detection of drug resistance necessary for patient care. The present study was carried out to determine the species distribution and antifungal susceptibility profile of oral Candida isolates colonizing or infecting both HIV seropositive and seronegative individuals.

Methods:

A case-control study was conducted including 141 consecutive, non-repeat HIV-seropositive individuals and an equal number of sex and age matched HIV-seronegative control. Speciation of the oropharyngeal Candida isolates was done using standard yeast identification protocol. Antifungal susceptibility testing was done by the disk-diffusion method as well as by Fungitest method.

Results:

From the 59 culture positive HIV seropositive cases, 61 Candida isolates were recovered; Candida albicans (n=47, 77.0%), C. dubliniensis (n=9, 14.7%), C. parapsilosis (n=2, 3.2%), C. glabrata (n=2, 3.2%), and C. famata (n=1, 1.6%). Candida colonization in HIV-seropositive individuals was significantly higher than that of HIV-seronegative (control) group. Antifungal susceptibility testing revealed (n=6, 9.3%) C. albicans isolates resistant to voriconazole and fluconazole by disk-diffusion method whereas no resistance was seen by Fungitest method.

Interpretation & conclusions:

C. albicans was the commonest Candida species infecting or colonizing HIV seropositive individuals. Oropharyngeal Candida isolates had high level susceptibility to all the major antifungals commonly in use. Increased level of immunosuppression in HIV-seropositives and drug resistance of non-albicans Candida species makes identification and susceptibility testing of Candida species necessary in different geographical areas of the country.
Evaluation of carotid artery dynamics & correlation with cardiac & hepatic iron in β-thalassaemia patients
Authors: Merchant Rashid H. , Chate Someshwar , Ahmed Javed , Ahmad Noor , Karnik Alka , Jankaria Bhavin
Published: June 2016

Background & objectives:

Early atherosclerosis and vascular complication have been described in thalassaemia patients. There is lack of data or guidelines regarding monitoring of vascular health in thalassaemia. This study was conducted to compare carotid artery structural and functional indices such as carotid artery intima-media thickness (CIMT), stiffness index (SI) and Young's elastic modulus (YEM) in β-thalassemia patients with age and sex matched controls, and to correlate these parameters with serum ferritin, cardiac iron, and hepatic iron.

Methods:

This cross-sectional study included 53 β-thalassaemia patients receiving regular blood transfusions. Carotid artery indices such as CIMT, SI, and YEM were calculated by duplex ultrasound and colour Doppler. Serum ferritin levels were measured by chemiluminescence. Cardiac and hepatic iron estimation were done using MRI T2* sequences analyzed by a special thalassaemia software.

Results:

Mean CIMT of cases and controls were 0.48 ± 0.04 and 0.44±0.02 mm, respectively and these were significantly different (P<0.001). Similarly significant differences were noted in SI and YEM of cases (2.45±0.79 and 96.12±34.85, respectively) as compared to controls (1.98±0.54 and 68.60±24.29, respectively) (P<0.001). There was significant inverse correlation between stiffness index and cardiac iron overload assessed by MRI cardiac T2* (P=0.03). Mean SI and YEM of cases were (2.1736 ± 0.2986 and 107.3± 41.6, respectively) significantly higher among non-splenectomized patients compared to splenectomized patients (2.0136 ± 0.263 and 86.9 ± 25.2, respectively) (P<0.05).

Interpretation & conclusions:

CIMT and arterial stiffness indices were significantly increased in β-thalassaemia patients compared to controls which was indicative of early atherogenic changes. This study supports the hypothesis that iron overload is a risk factor for early atherosclerosis and cardiovascular disease.
Growth of nucleation mode particles in the summertime Arctic: a case study
Authors: Willis Megan D. , Burkart Julia , Thomas Jennie L. , Köllner Franziska , Schneider Johannes , Bozem Heiko , Hoor Peter M. , Aliabadi Amir A. , Schulz Hannes , Herber Andreas B. , Leaitch W. Richard , Abbatt Jonathan P. D.
Published: June 2016

Abstract. The summertime Arctic lower troposphere is a relatively pristine background aerosol environment dominated by nucleation and Aitken mode particles. Understanding the mechanisms that control the formation and growth of aerosol is crucial for our ability to predict cloud properties and therefore radiative balance and climate. We present an analysis of an aerosol growth event observed in the Canadian Arctic Archipelago during summer as part of the NETCARE project. Under stable and clean atmospheric conditions, with low inversion heights, carbon monoxide less than 80 ppbv, and black carbon less than 5 ng m−3, we observe growth of small particles,  <  20 nm in diameter, into sizes above 50 nm. Aerosol growth was correlated with the presence of organic species, trimethylamine, and methanesulfonic acid (MSA) in particles ∼ 80 nm and larger, where the organics are similar to those previously observed in marine settings. MSA-to-sulfate ratios as high as 0.15 were observed during aerosol growth, suggesting an important marine influence. The organic-rich aerosol contributes significantly to particles active as cloud condensation nuclei (CCN, supersaturation  =  0.6 %), which are elevated in concentration during aerosol growth above background levels of ∼ 100 to ∼ 220 cm−3. Results from this case study highlight the potential importance of secondary organic aerosol formation and its role in growing nucleation mode aerosol into CCN-active sizes in this remote marine environment.
Effect of aerosol sub-grid variability on aerosol optical depth and cloud condensation nuclei: Implications for global aerosol modelling
Authors: Weigum N. , Schutgens N. , Stier P.
Published: June 2016

Abstract. A fundamental limitation of grid-based models is their inability to resolve variability on scales smaller than a grid box. Past research has shown that significant aerosol variability exists on scales smaller than these grid-boxes, which can lead to discrepancies in simulated aerosol climate effects between high and low resolution models. This study investigates the impact of neglecting sub-grid variability in present-day global microphysical aerosol models on aerosol optical depth (AOD) and cloud condensation nuclei (CCN). We introduce a novel technique to isolate the effect of aerosol variability from other sources of model variability by varying the resolution of aerosol and trace gas fields while maintaining a constant resolution in the rest of the model. We compare WRF-Chem runs in which aerosol and gases are simulated at 80 km and again at 10 km resolutions; in both simulations the other model components, such as meteorology and dynamics, are kept at the 10 km baseline resolution. We find that AOD is underestimated by 13 % and CCN is overestimated by 27 % when aerosol and gases are simulated at 80 km resolution compared to 10 km. Processes most affected by neglecting aerosol sub-grid variability are gas-phase chemistry and aerosol uptake of water through aerosol/gas equilibrium reactions. The inherent non-linearities in these processes result in large changes in aerosol parameters when aerosol and gaseous species are artificially mixed over large spatial scales. These changes in aerosol and gas concentrations are exaggerated by convective transport, which transports these altered concentrations to altitudes where their effect is more pronounced. These results demonstrate that aerosol variability can have a large impact on simulating aerosol climate effects, even when meteorology and dynamics are held constant. Future aerosol model development should focus on accounting for the effect of sub-grid variability on these processes at global scales in order to improve model predictions of the aerosol effect on climate.
A Bayesian model to correct underestimated 3D wind speeds from sonic anemometers increases turbulent components of the surface energy balance
Authors: Frank John M. , Massman William J. , Ewers Brent E.
Published: June 2016

Abstract. Sonic anemometers are the principal instruments in micrometeorological studies of turbulence and ecosystem fluxes. Recent studies have shown that common designs underestimate vertical wind measurements because they lack a correction for transducer shadowing, with no consensus on a suitable correction. We reanalyze a subset of data collected during field experiments in 2011 and 2013 featuring two or four CSAT3 sonic anemometers. We introduce a novel Bayesian analysis with the potential to resolve the three-dimensional correction by optimizing differences between anemometers mounted both vertically and horizontally. A grid of 512 points (~ ±5° resolution in wind location) is defined on a sphere around the sonic anemometer, from which the shadow correction for each transducer-pair is derived from a set of 138 unique state variables. Using the Markov chain Monte Carlo (MCMC) method, the Bayesian model proposes new values for each state variable, recalculates the fast-response dataset, summarizes the five-minute wind statistics, and accepts the proposed new values based on the probability that they make measurements from vertical and horizontal anemometers more equivalent. MCMC chains were constructed for three different prior distributions describing the state variables: no shadow correction, the Kaimal correction for transducer shadowing, and double the Kaimal correction, all initialized with 10 % uncertainty. The final posterior correction did not depend on the prior distribution and revealed both self- and cross-shadowing effects from all transducers. After correction, the vertical wind velocity and sensible heat flux increased ~ 10 % with ~ 2 % uncertainty, which was significantly higher than the Kaimal correction. We applied the posterior correction to eddy covariance data from various sites across North America and found that the turbulent components of the energy balance (sensible plus latent heat flux) increased on average between 8-12 %, with an average 95 % credible interval between 6-14 %. Considering this is the most common sonic anemometer in the AmeriFlux network and is found widely within FLUXNET, these results provide a mechanistic explanation for much of the energy imbalance at these sites where all terrestrial/atmospheric fluxes of mass and energy are likely underestimated.
Simulation of sub-millimetre atmospheric spectra for characterizing potential ground-based remote sensing observations
Authors: Turner Emma C. , Withington Stafford , Newnham David A. , Wadhams Peter , Jones Anna E. , Clancy Robin
Published: June 2016

Abstract. The sub-millimetre is an understudied region of the Earth's atmospheric electromagnetic spectrum. Prior technological gaps and relatively high opacity due to the prevalence of rotational water vapour lines at these wavelengths have slowed progress from a ground-based remote sensing perspective; however, emerging superconducting detector technologies in the fields of astronomy offer the potential to address key atmospheric science challenges with new instrumental methods. A site study, with a focus on the polar regions, is performed to assess theoretical feasibility by simulating the downwelling clear-sky sub-millimetre spectrum from 30 mm (10 GHz) to 150 μm (2000 GHz) at six locations under annual mean, summer, winter, daytime, nighttime and low humidity conditions. Vertical profiles of temperature, pressure and 28 atmospheric gases are constructed by combining radiosonde, meteorological reanalysis, and atmospheric chemistry model data. The sensitivity of the simulated spectra to the choice of water vapour continuum model and spectroscopic line database is explored. For the atmospheric trace species hypobromous acid (HOBr), hydrogen bromide (HBr), perhydroxyl radical (HO2) and nitrous oxide (N2O) the emission lines producing the largest change in brightness temperature are identified. Signal strengths, centre frequencies, bandwidths, estimated minimum integration times and maximum receiver noise temperatures are determined for all cases. HOBr, HBr and HO2 produce brightness temperature peaks in the mK to K range, whereas the N2O peaks are in the K range. The optimal sub-millimetre remote sensing lines for the four species are shown to vary significantly between location and scenario, strengthening the case for future hyperspectral instruments that measure over a broad wavelength range. The techniques presented here provide a framework that can be applied to additional species of interest and taken forward to simulate retrievals and guide the design of future sub-millimetre instruments.
EVALUATION OF RAINFALL-RUNOFF MODELS FOR MEDITERRANEAN SUBCATCHMENTS
Authors: Cilek A. , Berberoglu S. , Donmez C.
Published: June 2016

Abstract. The development and the application of rainfall-runoff models have been a corner-stone of hydrological research for many decades. The amount of rainfall and its intensity and variability control the generation of runoff and the erosional processes operating at different scales. These interactions can be greatly variable in Mediterranean catchments with marked hydrological fluctuations. The aim of the study was to evaluate the performance of rainfall-runoff model, for rainfall-runoff simulation in a Mediterranean subcatchment. The Pan-European Soil Erosion Risk Assessment (PESERA), a simplified hydrological process-based approach, was used in this study to combine hydrological surface runoff factors. In total 128 input layers derived from data set includes; climate, topography, land use, crop type, planting date, and soil characteristics, are required to run the model. Initial ground cover was estimated from the Landsat ETM data provided by ESA. This hydrological model was evaluated in terms of their performance in Goksu River Watershed, Turkey. It is located at the Central Eastern Mediterranean Basin of Turkey. The area is approximately 2000 km2. The landscape is dominated by bare ground, agricultural and forests. The average annual rainfall is 636.4mm. This study has a significant importance to evaluate different model performances in a complex Mediterranean basin. The results provided comprehensive insight including advantages and limitations of modelling approaches in the Mediterranean environment.
STUDY OF WATER POLLUTION EARLY WARNING FRAMEWORK BASED ON INTERNET OF THINGS
Authors: Chengfang H. , Xiao X. , Dingtao S. , Bo C. , Xiongfei W.
Published: June 2016

Abstract. In recent years, with the increasing world environmental pollution happening, sudden water pollution incident has become more and more frequently in China. It has posed a serious threat to water safety of the people living in the water source area. Conventional water pollution monitoring method is manual periodic testing, it maybe miss the best time to find that pollution incident. This paper proposes a water pollution warning framework to change this state. On the basis of the Internet of things, we uses automatic water quality monitoring technology to realize monitoring. We calculate the monitoring data with water pollution model to judge whether the water pollution incident is happen or not. Water pollution warning framework is divided into three layers: terminal as the sensing layer, it with the deployment of the automatic water quality pollution monitoring sensor. The middle layer is the transfer network layer, data information implementation is based on GPRS wireless network transmission. The upper one is the application layer. With these application systems, early warning information of water pollution will realize the high-speed transmission between grassroots units and superior units. The paper finally gives an example that applying this pollution warning framework to water quality monitoring of Beijing, China, it greatly improves the speed of the pollution warning responding of Beijing.
REMOTE SENSING APPLICATION OF THE GEOPHYSICAL CHANGES IN THE COASTLINES AND RIVERS OF ZAMBALES, PHILIPPINES
Authors: Paz-Alberto Annie Melinda , Sison Melissa Joy M. , Bulaong Edmark Pablo , Pakaigue Marietta A.
Published: June 2016

Abstract. Geophysical changes in river outlet, river upstream and coastlines near the rivers of Bucao and Santo Tomas in Zambales, Philippines were analyzed using the Google Earth’s historical satellite imageries from 2004 to 2013. Data in 2015 were gathered from in situ field measurements ground validation. The study aimed to measure and determine changes in the width of river outlet, width of river bank upstream and shifting of coastline. Results revealed that there was a decrease and increase in the width size of the Bucao and Santo Tomas river outlets, respectively during the study period. Geophysical changes occurred in the two rivers due to the continuous supply of lahar as an after effect of the Mount Pinatubo eruption in 1991. Coastline positions near the two rivers also changed. The highest rate of erosion along the coastal area was prevalently observed near the river outlet of both rivers. Moreover, accretion was observed in the coastline of Santo Tomas and erosion phenomenon was observed in the North and South coastlines of Bucao River. The shifting was caused by natural processes such as erosion, sedimentation and natural calamities as well as anthropogenic processes such as reclamation/quarrying. Occurrence of erosion and sedimentation played active roles in the changes of coastlines during the study period. Furthermore, the upstream of the Bucao river changed physically due to deposits of lahar present in the upstream which are being discharged directly and continuously going down to the river. Generally, the width of the Bucao River upstream decreased its size because of the accumulated sediment in the riverbank. On the other hand, the observed erosion is caused by high velocity of river during heavy rains and typhoons. The width of the Santo Tomas river bank upstream did not change due to the construction of concrete dikes which prevent the lahar-filled river from breaching the embankment and flooding the agricultural, residential and commercial areas near the river.
QUANTIFICATION OF GLACIER DEPLETION IN THE CENTRAL TIBETAN PLATEAU BY USING INTEGRATED SATELLITE REMOTE SENSING AND GRAVIMETRY
Authors: Tseng K.-H. , Liu K. T. , Shum C. K. , Jia Y. , Shang K. , Dai C.
Published: June 2016

Abstract. Glaciers over the Tibetan Plateau have experienced accelerated depletion in the last few decades due primarily to the global warming. The freshwater drained into brackish lakes is also observed by optical remote sensing and altimetry satellites. However, the actual water storage change is difficult to be quantified since the altimetry or remote sensing only provide data in limited dimensions. The altimetry data give an elevation change of surface while the remote sensing images provide an extent variation in horizontal plane. Hence a data set used to describe the volume change is needed to measure the exact mass transition in a time span. In this study, we utilize GRACE gravimetry mission to quantify the total column mass change in the central Tibetan Plateau, especially focused on the lakes near Tanggula Mountains. By removing these factors, the freshwater storage change of glacier system at study area can be potentially isolated.
FORECASTING ANTARCTIC SEA ICE CONCENTRATIONS USING RESULTS OF TEMPORAL MIXTURE ANALYSIS
Authors: Chi Junhwa , Kim Hyun-Cheol
Published: June 2016

Abstract. Sea ice concentration (SIC) data acquired by passive microwave sensors at daily temporal frequencies over extended areas provide seasonal characteristics of sea ice dynamics and play a key role as an indicator of global climate trends; however, it is typically challenging to study long-term time series. Of the various advanced remote sensing techniques that address this issue, temporal mixture analysis (TMA) methods are often used to investigate the temporal characteristics of environmental factors, including SICs in the case of the present study. This study aims to forecast daily SICs for one year using a combination of TMA and time series modeling in two stages. First, we identify temporally meaningful sea ice signatures, referred to as temporal endmembers, using machine learning algorithms, and then we decompose each pixel into a linear combination of temporal endmembers. Using these corresponding fractional abundances of endmembers, we apply a autoregressive model that generally fits all Antarctic SIC data for 1979 to 2013 to forecast SIC values for 2014. We compare our results using the proposed approach based on daily SIC data reconstructed from real fractional abundances derived from a pixel unmixing method and temporal endmember signatures. The proposed method successfully forecasts new fractional abundance values, and the resulting images are qualitatively and quantitatively similar to the reference data.
THIN ICE AREA EXTRACTION IN THE SEA OF OKHOTSK FROM GCOM-W1/AMSR2 DATA
Authors: Cho K. , Sato Y. , Naoki K.
Published: June 2016

Abstract. Passive microwave radiometers on-board satellites can penetrate clouds and can monitor the global sea ice distribution on daily basis. The authors have developed an algorithm to extract thin ice area in the Sea of Okhotsk from the passive microwave sensor AMSR2 on-board GCOM-W1 satellite. The algorithm uses the brightness temperature scatter plots of AMSR2 19 GHz polarization difference(V–H) vs. 19 GHz V polarization. The results were verified using simultaneously collected MODIS images in the Sea of Okhotsk. The most of the thin ice areas visually identified in the MODIS images were automatically extracted from AMSR2 data using the algorithm.
MASS BALANCE CHANGES AND ICE DYNAMICS OF GREENLAND AND ANTARCTIC ICE SHEETS FROM LASER ALTIMETRY
Authors: Babonis G. S. , Csatho B. , Schenk T.
Published: June 2016

Abstract. During the past few decades the Greenland and Antarctic ice sheets have lost ice at accelerating rates, caused by increasing surface temperature. The melting of the two big ice sheets has a big impact on global sea level rise. If the ice sheets would melt down entirely, the sea level would rise more than 60 m. Even a much smaller rise would cause dramatic damage along coastal regions. In this paper we report about a major upgrade of surface elevation changes derived from laser altimetry data, acquired by NASA’s Ice, Cloud and land Elevation Satellite mission (ICESat) and airborne laser campaigns, such as Airborne Topographic Mapper (ATM) and Land, Vegetation and Ice Sensor (LVIS). For detecting changes in ice sheet elevations we have developed the Surface Elevation Reconstruction And Change detection (SERAC) method. It computes elevation changes of small surface patches by keeping the surface shape constant and considering the absolute values as surface elevations. We report about important upgrades of earlier results, for example the inclusion of local ice caps and the temporal extension from 1993 to 2014 for the Greenland Ice Sheet and for a comprehensive reconstruction of ice thickness and mass changes for the Antarctic Ice Sheets.
RECOGNITION OF DRAINAGE TUNNELS DURING GLACIER LAKE OUTBURST EVENTS FROM TERRESTRIAL IMAGE SEQUENCES
Authors: Schwalbe E. , Koschitzki R. , Maas H.-G.
Published: June 2016

Abstract. In recent years, many glaciers all over the world have been distinctly retreating and thinning. One of the consequences of this is the increase of so called glacier lake outburst flood events (GLOFs). The mechanisms ruling such GLOF events are still not yet fully understood by glaciologists. Thus, there is a demand for data and measurements that can help to understand and model the phenomena. Thereby, a main issue is to obtain information about the location and formation of subglacial channels through which some lakes, dammed by a glacier, start to drain. The paper will show how photogrammetric image sequence analysis can be used to collect such data. For the purpose of detecting a subglacial tunnel, a camera has been installed in a pilot study to observe the area of the Colonia Glacier (Northern Patagonian Ice Field) where it dams the Lake Cachet II. To verify the hypothesis, that the course of the subglacial tunnel is indicated by irregular surface motion patterns during its collapse, the camera acquired image sequences of the glacier surface during several GLOF events. Applying tracking techniques to these image sequences, surface feature motion trajectories could be obtained for a dense raster of glacier points. Since only a single camera has been used for image sequence acquisition, depth information is required to scale the trajectories. Thus, for scaling and georeferencing of the measurements a GPS-supported photogrammetric network has been measured. The obtained motion fields of the Colonia Glacier deliver information about the glacier’s behaviour before during and after a GLOF event. If the daily vertical glacier motion of the glacier is integrated over a period of several days and projected into a satellite image, the location and shape of the drainage channel underneath the glacier becomes visible. The high temporal resolution of the motion fields may also allows for an analysis of the tunnels dynamic in comparison to the changing water level of the lake.
CHANGE ANALYSIS OF ANTARCTIC ICE SHELVES BASED ON MULTIPLE REMOTE SENSING PRODUCTS
Authors: Tian Yixiang , Weng Hexia , Lv Da , Tong Xiaohua , Li Rongxing
Published: June 2016

Abstract. The Antarctic ice sheet is well known as the most sensitive and key issue in the global climate change research and is playing a more and more important role for the global sea level change. Measurement of changes in area and mass of the Antarctic ice sheet is critically important and has been made by using different remote sensing technologies and ground exploration data. Sequential mapping of Antarctic boundaries provides a simple and direct method for measuring the area and volume if ice sheet or ice shelves advances or retreats in the Antarctic coasts. Our results show that the total ice shelf area is retreated between 1963 and 2009. However, the trend for each ice shelf is quite different.
ANTARCTIC ICE SHEET SURFACE MASS BALANCE ESTIMATES FROM 2003 TO 2015 USING ICESAT AND CRYOSAT-2 DATA
Authors: Xie Huan , Hai Gang , Chen Lei , Liu Shijie , Liu Jun , Tong Xiaohua , Li Rongxing
Published: June 2016

Abstract. An assessment of Antarctic ice sheet surface mass balance from 2003 to 2015 has been carried out using a combination of ICESat data from 2003 to 2009 and CryoSat-2 data from 2010 to 2015. Both data sets are of L2 and are currently processed separately using different models. First, a repeat-track processing method that includes terms accounting for the trend and the first order fit of topography is applied to repeat-track measurements of all ICESat Campaigns. It uses the Least Squares fitting of the model to all observations in a box of 500 m x 500 m. The estimated trends in these boxes are then averaged inside a 30 km x 30 km cell. Similarly, the cells are used to estimate basin and ice sheet level surface elevation change trends. Mass balance calculating is performed at the cell level by multiplying the ice density by the volume change and then extended to the basin and the ice sheet level. Second, in CryoSat-2 data processing we applied a model within a cell of 5 km x 5 km considering that CryoSat-2 does not maintain repeated tracks. In this model the elevation trend, and a higher order topography are solved in an iterative way using the least squares technique. The mass change is computed at the cell level in the same way as the ICESat data. GIA correction is applied for both ICESat and CryoSat-2 estimates. Detailed information about the data processing, elevation and mass balance changes, and comparison with other studies will be introduced.
EVALUATION OF FOREST CANOPY AND UNDERSTORY GAP FRACTION DERIVED FROM TERRESTRIAL LASER SCANNING
Authors: Chen K. C. , Wang C. K.
Published: June 2016

Abstract. The quantification of forest carbon sequestration is helpful to understand the carbon storage on the Earth. The estimation of forest carbon sequestration can be achieved by the use of leaf area index (LAI), which is derived from forest gap fraction. The hemispherical image-based technique is the most popular non-destructive means for obtaining such information. However, only the gap fraction of the top canopy is derived due to the limitation of imaging technique. The gap fraction information of understory is thus neglected. In this study, we evaluate the use of a terrestrial laser scanner (TLS) to obtain the forest canopy and understory gap fraction. The forest TLS data were manually classified as the top canopy and understory layers to facilitate the estimation of top canopy and understory gap fraction, respectively.
ANALYSIS OF THE SIDE-LAP EFFECT ON FULL-WAVEFORM LIDAR DATA ACQUISITION FOR THE ESTIMATION OF FOREST STRUCTURE VARIABLES
Authors: Crespo-Peremarch P. , Ruiz L. A. , Balaguer-Beser A. , Estornell J.
Published: June 2016

Abstract. LiDAR full-waveform provides a better description of the physical and forest vertical structure properties than discrete LiDAR since it registers the full wave that interacts with the canopy. In this paper, the effect of flight line side-lap is analysed on forest structure and canopy fuel variables estimations. Differences are related to pulse density changes between flight stripe side-lap areas, varying the point density between 2.65 m−2 and 33.77 m−2 in our study area. These differences modify metrics extracted from data and therefore variable values estimated from these metrics such as forest stand variables. In order to assess this effect, 64 pairwise samples were selected in adjacent areas with similar canopy structure, but having different point densities. Two parameters were tested and evaluated to minimise this effect: voxel size and voxel value assignation testing maximum, mean, median, mode, percentiles 90 and 95. Student’s t-test or Wilcoxon test were used for the comparison of paired samples. Moreover, the absolute value of standardised paired samples was calculated to quantify dissimilarities. It was concluded that optimizing voxel size and voxel value assignation minimised the effect of point density variations and homogenised full-waveform metrics. Height/median ratio (HTMR) and Vertical distribution ratio (VDR) had the lowest variability between different densities, and Return waveform energy (RWE) reached the best improvement with respect to initial data, being the difference between standardised paired samples 1.28 before and 0.69 after modification.
TLS FIELD DATA BASED INTENSITY CORRECTION FOR FOREST ENVIRONMENTS
Authors: Heinzel J. , Huber M. O.
Published: June 2016

Abstract. Terrestrial laser scanning (TLS) is increasingly used for forestry applications. Besides the three dimensional point coordinates, the 'intensity' of the reflected signal plays an important role in forestry and vegetation studies. The benefit of the signal intensity is caused by the wavelength of the laser that is within the near infrared (NIR) for most scanners. The NIR is highly indicative for various vegetation characteristics. However, the intensity as recorded by most terrestrial scanners is distorted by both external and scanner specific factors. Since details about system internal alteration of the signal are often unknown to the user, model driven approaches are impractical. On the other hand, existing data driven calibration procedures require laborious acquisition of separate reference datasets or areas of homogenous reflection characteristics from the field data. In order to fill this gap, the present study introduces an approach to correct unwanted intensity variations directly from the point cloud of the field data. The focus is on the variation over range and sensor specific distortions. Instead of an absolute calibration of the values, a relative correction within the dataset is sufficient for most forestry applications. Finally, a method similar to time series detrending is presented with the only pre-condition of a relative equal distribution of forest objects and materials over range. Our test data covers 50 terrestrial scans captured with a FARO Focus 3D S120 scanner using a laser wavelength of 905 nm. Practical tests demonstrate that our correction method removes range and scanner based alterations of the intensity.
EXPLORING THE CONNECTIVITY OF ECOLOGICAL CORRIDORS BETWEEN LOW ELEVATION MOUNTAINS AND PINGTUNG LINHOUSILIN FOREST PARK OF TAIWAN BY LEAST-COST PATH METHOD
Authors: Huang Y. L. , Liu H. F. , Chen J. C. , Chen C. T.
Published: June 2016

Abstract. The primary purpose of this study was explored the variation of landscape process and its impact on the possibility of ecological corridors on Pingtung Linhousilin Forest Park. Developing the landscape change process in year 2002, 2005, 2012 and 2014 via the land-use definition of IPCC (forest land, cropland, grassland, wetlands, settlements and other land). In the landscape structure analysis, the cropland was gradually changed to forest land in this area. Moreover, the variation of gravity model showed that the interaction between Linhousilin Forest Park and low elevation mountains were gradually increased which means the function of ecological corridors has increased.
ESTIMATION OF STAND HEIGHT AND FOREST VOLUME USING HIGH RESOLUTION STEREO PHOTOGRAPHY AND FOREST TYPE MAP
Authors: Kim K. M.
Published: June 2016

Abstract. Traditional field methods for measuring tree heights are often too costly and time consuming. An alternative remote sensing approach is to measure tree heights from digital stereo photographs which is more practical for forest managers and less expensive than LiDAR or synthetic aperture radar. This work proposes an estimation of stand height and forest volume(m3/ha) using normalized digital surface model (nDSM) from high resolution stereo photography (25cm resolution) and forest type map. The study area was located in Mt. Maehwa model forest in Hong Chun-Gun, South Korea. The forest type map has four attributes such as major species, age class, DBH class and crown density class by stand. Overlapping aerial photos were taken in September 2013 and digital surface model (DSM) was created by photogrammetric methods(aerial triangulation, digital image matching). Then, digital terrain model (DTM) was created by filtering DSM and subtracted DTM from DSM pixel by pixel, resulting in nDSM which represents object heights (buildings, trees, etc.). Two independent variables from nDSM were used to estimate forest stand volume: crown density (%) and stand height (m). First, crown density was calculated using canopy segmentation method considering live crown ratio. Next, stand height was produced by averaging individual tree heights in a stand using Esri’s ArcGIS and the USDA Forest Service’s FUSION software. Finally, stand volume was estimated and mapped using aerial photo stand volume equations by species which have two independent variables, crown density and stand height. South Korea has a historical imagery archive which can show forest change in 40 years of successful forest rehabilitation. For a future study, forest volume change map (1970s–present) will be produced using this stand volume estimation method and a historical imagery archive.
VEGETATION COVER MAPPING BASED ON REMOTE SENSING AND DIGITAL ELEVATION MODEL DATA
Authors: Korets M. A. , Ryzhkova V. A. , Danilova I. V. , Prokushkin A. S.
Published: June 2016

Abstract. An algorithm of forest cover mapping based on combined GIS-based analysis of multi-band satellite imagery, digital elevation model, and ground truth data was developed. Using the classification principles and an approach of Russian forest scientist Kolesnikov, maps of forest types and forest growing conditions (FGC) were build. The first map is based on RS-composite classification, while the second map is constructed on the basis of DEM-composite classification. The spatial combination of this two layers were also used for extrapolation and mapping of ecosystem carbon stock values (kgC/m2). The proposed approach was applied for the test site area (~3600 km2), located in the Northern Siberia boreal forests of Evenkia near Tura settlement.
ASSESING GEOGRAPHIC ISOLATION OF THE GALAPAGOS ISLANDS
Authors: Orellana D. , Smith F.
Published: June 2016

Abstract. The Galapagos Archipelago is one of the most important ecological spots in the planet due its unique biodiversity, active geology, and relatively well-preserved ecosystems. These characteristics are strongly based on the geographical isolation of the islands. On the one hand this isolation allowed the evolution processes that gave the islands their international fame and on the other hand it kept them from major human impacts that affected the vast majority of the Earth’s surface. Galapagos’ geographical isolation is therefore of mayor value, but it is rapidly diminishing due to the increase of marine and air transportation among islands and with the rest of the world. This increased accessibility implies enhanced risks for the ecological dynamics on the archipelago (e.g. increased risk of biological invasions, uncontrolled tourism growth, more water and energy consumption). Here, we introduce a general accessibility model to assess geographical isolation of the Galapagos Islands. The model aims to characterize accessibility in terms of human mobility by evaluating travel time to each point of the archipelago using all available transportation modalities. Using a multi criteria cost surface for marine and land areas, we estimated travel time for each surface unit using the fastest route and mode of transportation available while considering several friction factors such as surface type, slope, infrastructure, transfer points, legal restrictions, and physical barriers. We created maps to evaluate the isolation of different islands and places, highlighting the potential risks for several habitats and ecosystems. The model can be used for research and decision-making regarding island conservation, such as estimating spreading paths for invasive species, informing decisions on tourism management, and monitoring isolation changes of sensitive ecosystems.
ASSESSMENT OF FIRE SEVERITY AND POST-FIRE REGENERATION BASED ON TOPOGRAPHICAL FEATURES USING MULTITEMPORAL LANDSAT IMAGERY: A CASE STUDY in MERSIN, TURKEY
Authors: Tonbul H. , Kavzoglu T. , Kaya S.
Published: June 2016

Abstract. Satellite based remote sensing technologies and Geographical Information Systems (GIS) present operable and cost-effective solutions for mapping fires and observing post-fire regeneration. Mersin-Gülnar wildfire, which occurred in August 2008 in Turkey, selected as study site. The fire was devastating and continued 55 days. According to Turkish General Directorate of Forestry reports, it caused two deaths and left hundreds of people homeless. The aim of this study is to determine the fire severity and monitor vegetation recovery with using multitemporal spectral indices together with topographical factors. Pre-fire and post-fire Landsat ETM+ images were obtained to assess the related fire severity with using the widely-used differenced Normalized Burn Ratio (dNBR) algorithm. Also, the Normalized Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) were used to determine vegetation regeneration dynamics for a period of six consecutive years. In addition, aspect image derived from Aster Global Digital Elevation Model (GDEM) were used to determine vegetation regeneration regime of the study area. Results showed that 5388 ha of area burned with moderate to high severity damage. As expected, NDVI and SAVI values distinctly declined post-fire and then began to increase in the coming years. Mean NDVI value of burned area changed from 0.48 to 0.17 due to wildfire, whilst mean SAVI value changed from 0.61 to 0.26. Re-growth rates calculated for NDVI and SAVI 57% and 63% respectively, six years after the fire. Moreover, NDVI and SAVI were estimated six consecutive year period by taking into consideration east, south, north and west facing slopes. Analysis showed that north-facing and east-facing slopes have higher regeneration rates in compared to other aspects. This study serves as a window to an understanding of the process of fire severity and vegetation regeneration that is vital in wildfire management systems.
USING SATELLITE DATA FOR ENVIRONMENTAL IMPACT ANALYSIS IN ECONOMIC GROWTH: THE CASE OF MONGOLIA
Authors: Tungalag A. , Tsolmon R. , Ochirkhuyag L. , Oyunjargal J.
Published: June 2016

Abstract. The Mongolian economy is based on the primary and secondary economic sectors of agriculture and industry. In addition, minerals and mining become a key sector of its economy. The main mining resources are gold, copper, coal, fluorspar and steel. However, the environment and green economy is one of the big problems among most of the countries and especially for countries like Mongolia where the mining is major part of economy; it is a number one problem. The research of the work tested how environmental elements effect to current Mongolian economic growth, which is growing economy because of mining sector. The study of economic growth but the starting point for any study of economic growth is the neoclassical growth model emphasizing the role of capital accumulation. The growth is analysed either in terms of models with exogenous saving rates (the Solow-Swan model), or models where consumption and hence savings are determined by optimizing individuals. These are the so-called optimal growth or Ramsey-Cass-Koopmans. The study extends the Solow model and the Ramsey-Cass-Koopmans model, including environmental elements which are satellite data determine to degraded land and vegetation value from 1995 to 2013. In contrast, we can see the degraded land area increases from 1995 (4856 m2) to 2013 (10478 m2) and vegetation value decrease at same time. A description of the methodology of the study conducted follows together with the data collected and econometric estimations and calibration with environmental elements.
ANALYSIS OF RELATIONSHIP BETWEEN URBAN HEAT ISLAND EFFECT AND LAND USE/COVER TYPE USING LANDSAT 7 ETM+ AND LANDSAT 8 OLI IMAGES
Authors: Aslan N. , Koc-San D.
Published: June 2016

Abstract. The main objectives of this study are (i) to calculate Land Surface Temperature (LST) from Landsat imageries, (ii) to determine the UHI effects from Landsat 7 ETM+ (June 5, 2001) and Landsat 8 OLI (June 17, 2014) imageries, (iii) to examine the relationship between LST and different Land Use/Land Cover (LU/LC) types for the years 2001 and 2014. The study is implemented in the central districts of Antalya. Initially, the brightness temperatures are retrieved and the LST values are calculated from Landsat thermal images. Then, the LU/LC maps are created from Landsat pan-sharpened images using Random Forest (RF) classifier. Normalized Difference Vegetation Index (NDVI) image, ASTER Global Digital Elevation Model (GDEM) and DMSP_OLS nighttime lights data are used as auxiliary data during the classification procedure. Finally, UHI effect is determined and the LST values are compared with LU/LC classes. The overall accuracies of RF classification results were computed higher than 88 % for both Landsat images. During 13-year time interval, it was observed that the urban and industrial areas were increased significantly. Maximum LST values were detected for dry agriculture, urban, and bareland classes, while minimum LST values were detected for vegetation and irrigated agriculture classes. The UHI effect was computed as 5.6 °C for 2001 and 6.8 °C for 2014. The validity of the study results were assessed using MODIS/Terra LST and Emissivity data and it was found that there are high correlation between Landsat LST and MODIS LST data (r2 = 0.7 and r2 = 0.9 for 2001 and 2014, respectively).
FORESTRY EXPANSION DURING THE LAST DECADES IN THE PARAIBA DO SUL BASIN – BRAZIL
Authors: Carriello F. , Rezende F. S. , Neves O. M. S. , Rodriguez D. A.
Published: June 2016

Abstract. from 1986 to 2010. In this region is situated the most important and largest extension of reminiscent of Mata Atlântica Biome reminiscent. This biome has been one the most exploited Brazilian biome since 1500, when Brazilian colonization begun. To achieve this goal, we use the GIS “SPRING” and images from Landsat 5 Satellite, TM sensor from 1986, 1990, 1995, 2000, 2005 and 2010, distributed by the Brazilian National Institute for Space Research - INPE. The non-supervised-classification was applied to images in order to produce land use and land cover maps. After that, we intersect each classification for each date with the precedent date, so we can analyze the paths of each land use change, focusing forestry expansion in native’s Mata Atlântica areas. The results show that eucalyptus plantations in the region have expanded mostly over fragments of Mata Atlântica. About 99.389 hectares of Mata Atlântica were transformed into forestry in 25 years, an average rate of 4000 ha per year. Clear-cut was largest between 1990 and 1995, when 22810 hectares of rain forest were cut, and between 1995 and 2000, when 21430 hectares were cut.