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ID: 61012
Title: Mapping forest biomass from space-Fusion of hyperspectral EO1-hyperion data and Tandem-X and WorldView-2 canopy height models.
Author: Teja Kattenborn, Joachim Maack, Fabian Fa?nacht, Fabian En?le, Jorg Ermert, Barbara Koch.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 359-367 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Biomass modeling, Hyperspectral, Tandem-X, Worldview-2, Canopy height models, Machine-learning-algorithms.
Abstract: Spaceborne sensors allow for wide-scale assessments of forest ecosystems. Combining the products of multiple sensors is hypothesized to improve the estimation of forest biomass. We applied interferometric (Tandem-X) and photogrammetric (WorldView-2) based predictors, e.g. canopy height models, in combination with hyperspectral predictors (EO1-Hyperion) by using 4 different machine learning algorithms for biomass estimation in temperate forest stands near Karlruhe, Germany. An iterative model selection procedure was used to identify the optimal combination of predictors. The most accurate model (Random Forest) reached a r2 of 0.73 with a RMSE of 14. 9 % (29.4 t/ha). Further results revealed that the predictive accuracy depended highly on the statistical model and the area size of the field samples. We conclude that a fusion of canopy height and spectral information allows for accurate estimations of forest biomass from space.
Location: T E 15 New Biology Building.
Literature cited 1: Anderson, J.E., Plourde, L.C., Martin, M.E., Braswell, B.H., Smith, M.L., Dubayah, R.O., Hofton, M.A., Blair, J.B., 2008. Integrating waveform LiDAR with hyperspectral imagery for inventory of a northern temperate forest. Remote Sens.Environ. 112, 1856-1870. Annighofer, P., Molder, I., Zerbe, S., Kawaletz, H., Terwei, A., Ammer, C., 2012. Biomass functions for the two alien tree species Prunus serotina Ehrh. And Robinia pseudoacacia L in floodplain forests of Northern Italy.Eur.J.Forest.Res. 131 (5), 1619-1635.
Literature cited 2: Bauer, E., Kohavi, R., 1999. An empirical comparison of voting classification algorithms: bagging, boosting, and variants.Mach.Learn. 36 (1-2), 105-139. Breiman, L., 2001. Random forests.Mach.Learn. 45 (1), 5-32.

ID: 61011
Title: Brown and green LAI mapping through spectral indices.
Author: Jesus Deegido, Jochem Verrelst, Juan P.Rivera, Antonio Ruiz-Verdu, Jose Moreno.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 350-358 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Brown LAI, Vegetation indices, Hyperspectral, Agroecosystem, Senescent vegetation, Sentinel-2
Abstract: When crops senescence, leaves remain until they fall off or are harvested. Hence, leaf area index (LAI) stays high even when chlorophyll content degrades to zero. Current LAI approaches from remote sensing techniques are not optimized for estimating LAI of senescent vegetation. In this paper a two-step approach has been proposed to realize simultaneous LAI mapping over green and senescent croplands. The first step separates green from brown LAI by means of a newly proposed index, ' Green Brown Vegetation Index (GBVI) ' . This index exploits two shortwave infrared (SWIR) spectral bands centered at 2100 and 2000 nm, which fall right in the dry matter absorption regions, thereby providing positive values for senescent vegetation and negative for green vegetation. The second step involves applying linear regression functions based on optimized vegetation indices to estimate green and brown LAI estimation respectively. While the green LAI index uses a band in the red and a band in the red-edge, the brown LAI index uses bands located in the same spectral region as GBVI, i.e. an absorption band located in the region of maximum absorption of cellulose and lignin at 2154 nm, and a reference band at 1635 nm where the absorption of both water and dry matter is low. The two-step approach was applied to a HyMap image acquired over an agroecosystem at the agricultural site Barrax, Spain.
Location: T E 15 New Biology Building.
Literature cited 1: Baret, F., Hagolle, O., Geiger, B., Bicheron, P., Miras, B., Huc, M., Berthelot, B., Nino, F., Weiss, M., Samain, O., Roujean, J.L., Leroy, M., 2007. LAI, fAPAR and fCover CYCLOPES global products derived from VEGETATION. Part 1: Principles of the algorithm. Remote Sens.Environ. 110, 275-286. Broge, N.H., Leblanc, E., 2000. Comparing prediction power and stability of broad-band and hyperspectral vegetation indices for estimation of green leaf area index and canopy chlorophyll density. Remote Sens. Environ. 76, 156-172.
Literature cited 2: Brown, L., Chen, J., Leblanc, S., Cihlar, J., 2000. A shortwave infrared modification to the simple ratio for LAI retrieval n boreal forests: an image and model analysis. Remote Sens. Environ. 76, 156-172. Bsibes, A., Courault, D., Baret, F., Weiss, M., Olioso, A., Jacob, F., Hagolle, O., Marloie, O., Bertrand, N., Desfond, V., Kzemipour, F., 2009. Albedo and LAI estimates from FORMOSTART-2 data for crop monitoring. Remote Sens.Environ.113 (4), 716-729.

ID: 61010
Title: SAR interferometry and optical remote sensing for analysis of co-seismic deformation, source characteristics and mass wasting pattern of Lushan (China, April 2013) earthquake
Author: John Mathew, Ritwik Majumdar, K. Vinod Kumar.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 338-349 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Differential SAR interferometry, Longmenshan fault zone, C0-seismic, Inversion modeling, Earthquake induced landslide.
Abstract: Co-seismic deformation associated with the Lushan (China) earthquake that occurred along the south-western segment of the Longmenshan Fault Zone (LFZ) on the 20th April 2013 has been estimated by differential interferometric SAR (DinSAR) technique using Radarsat-2 data. The Lushan earthquake resulted in the deformation of the Sichuan basin and the Longmenshan ranges in proximity to the LFZ. The line of sight (LOS) displacement values obtained from DInSAR techniques mainly range between -4.0 cm to +3.0 cm. The western Sichuan basin shows oblique westward movement with predominant downward movement in areas closer to the source fault. Inversion modeling has been used to derive the seismic source characteristics from DInSAR derived deformation values using elastic dislocation source type. The linear inversion model converged at a double-fault source solution consisting of a deeper, steep, NW dipping fault plane-1 of 60 km x 16 km dimension and a shallower, gentle, NW dipping fault plane 2 of 60 km x15 km dimension, with distributed slip values varying between 0 to 2.26 m. These fault planes (fault planes-1 and -2) coincide with the Dachuan-Shuangshi fault and the buried Range Front Fault respectively. The inversion model gives a moment magnitude of 6.81 and geodetic moment of 2.07x1019 Nm, comparable to those given in literature, derived using teleseismic body wave data. Thus DInSAR technique helped to quantify the co-seismic deformation and to retrieve the source characteristics from the estimated deformation values. The study also evaluated the distribution pattern of earthquake and found that they show spatial association with the seismic source zone and also with various pre-conditioning factors of slope instability.
Location: T E 15 New Biology Building.
Literature cited 1: Askne, J., Nordius, H., 1987. Estimation of tropospheric delay for microwaves from surface weather data. Radio Sci. 22 (3), 379-386. Atzori, S., Hunstad, I., Chini, M., Salvi, S., Tolomei, C., Bignami, C., Stramondo, S., Trasatti, E., Antonioli, A., Boschi, E., 2009. Finite fault inversion of DInSAR coseismic displacement of the 2009 L ' Aquila earthquake (central Italy). Geophys.Res.Lett. 36, L15305/1-6.
Literature cited 2: Buck, A.L., 1981. New equations for computing vapor pressure and enhancement factor. J. Appl.Meteorol. 20 (12), 1527-1532. Chen, G., Ji, F., Zhou, R., Jie, X., Ben-gang, Z., Xiao-gang, L, You-qing, Y., 2007. Primary research of active segmentation of Longmenshan fault zone.Chin.Sci.Bull.58 (28-29), 3475-3482.

ID: 61009
Title: An assessment of a collaborative mapping approach for exploring land use patterns for several European metropolises.
Author: Jamal Jokar Arsanjani, Eric Vaz.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 305-319 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Landuse mapping, Comparative assessment, GMESUA, OpenStreetMap, Collaborative mapping, Citizen Science.
Abstract: Until recently, land surveys and digital interpretation of remotely sensed imagery have been used to generate land use inventories. These techniques however, are often cumbersome and costly, allocating large amounts of technical and temporal costs. The technological achievements, stimulating the participatory role in collaborative and crowd sourced mapping products. This has been forested by GPS-enabled devices, and accessible tools that enable visual interpretation of high resolution satellite images/air photos provided in collaborative mapping projects. Such technologies offer an integrative approach to geography by means of promoting public participation and allowing accurate assessment and classification of land use as well as geographical features. OpenStreetMap (OSM) has supported the evolution of such techniques, contributing to the existence of a large inventory of spatial land use information. This paper explores the introduction of this novel participatory phenomenon for land use classification in Europe ' s metropolitan regions. We adopt a positivistic approach to assess comparatively the accuracy of these contributions of OSM for land use classifications in seven large European metropolitan regions. Thematic accuracy and degree of completeness of OSM data was compared to available Global Monitoring for Environment and Security Urban Atlas (GMESUA) datasets for the chosen metropolises. We further extend our findings of land use within a novel framework for geography, justifying that volunteered geographic information (VFGI) sources are of great benefit for land use mapping depending on location and degree of VGI dynamism and offer a great alternative to traditional mapping techniques for metropolitan regions throughout Europe. Evaluation of several land use types at the local level suggests that a number of OSM classes (such as anthropogenic land use, agricultural and some natural environment classes) are viable alternatives for land use classification. These are highly accurate and can be integrated into planning decisions for stakeholders and policymakers.
Location: T E 15 New Biology Building.
Literature cited 1: Bakillah, M., Lauer, J., Liang, S., Zipf, A., Jokar Arsanjani, J., Loos, L., Mobasheri, A., 2014. Exploiting big VGI to improve routing and navigation services. In: Big Data Techniques and Technologies in Geoinformatics., pp.177-192. Bontemps, S., Defourny, P., Van Bogaert, E., Arino, O., Kalogirou, V., Ramos, P., Jose, J., 2011. GLOBCOVER 2009. Products Description and Validation Report.In: Universite catholique de Louvain (UCL) & European Space Agency (esa), vers.2.2., pp 53.
Literature cited 2: Buettner, G., Feranec, J., Jaffrain, G., 2002. December.Corine land cover update 2000.EEA.Technical Report, vol.89 (Copenhagen). Cao, L., Luo, J., Gallagher, A., Jin, X., Han, J., Huang, T.S., 2010. A worldwide tourism recommendation system based on geotagged web photos. In: IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP), 2010., pp. 2274-2277.

ID: 61008
Title: The effect of atmospheric and topographic correction on pixel-based image composites: Improved forest cover detection in mountain environments.
Author: Steven Vanonckelen, Stef Lhermitte, Anton Van Rompaey.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 305-319 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Forest cover mapping, Classification accuracy assessment, Topographic correction, Landsat, Pixel-based composting, Mountain areas.
Abstract: Quantification of forest cover is essential as a tool to stimulate forest management and conservation. Image compositing techniques that sample the most suited pixel from multi-temporal image acquisitions provide an important tool for forest cover detection as they provide alternatives for missing data due to cloud cover and data discontinuities. At present, however, it is not clear to which extent forest cover detection based on compositing can be improved if the source imagery is firstly corrected for topographic distortions on a pixel-basis. In this study, the results of a pixel compositing algorithm with and without preprocessing topographic correction are compared for a study area covering 9 Landsat footprints in the Romanian Carpathians based on two different classifiers: Maximum Likelihood (ML) and support Vector Machine (SVM). Results show that classifier selection has a stronger impact on classification accuracy than topographic correction. Finally, application of the optimal method (SVM classifier with topographic correction) on the Romanian Carpathian Ecoregion between 1985, 1995 and 2010 shows a steady greening due to more afforestation than deforestation.
Location: T E 15 New Biology Building.
Literature cited 1: Alcantara, C., Radeloff, V.C., Prishchepov, A.V., Kuemmerle, T., 2012. Mapping abandoned agriculture with multi-temporal MODIS satellite data. Remote Sens.Environ. 124, 334-347. Arvidson, T., Gasch, J., Goward, S.N., 2001. Landsat 7 ' s long term acquisition plan-an innovative approach to building a global archive, Special Issue on Landsat 7. Remote Sens.Environ.78, 13-26.
Literature cited 2: Arvidson, T., Goward, S., Gasch, J., Williams, D., 2006. Landsat-7 long-term acquisition plan: development and validation.Photogram.Eng.Remote Sens. 72, 1137-1146. Balthazar, V., Vanacker, V., Lambin, E., 2012. Evaluation and parameterization of ATCOR3 topographic correction method for forest cover mapping in mountain areas.Int.J.Appl.Earth Obs.Geoinform. 18, 436-450.

ID: 61007
Title: Active extreme learning machines for quad-polarimetric SAR imagery classification.
Author: Alim Samat, Paolo Gamba, Peijun Du, Jieqiong Luo.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 305-319 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: PolSAR, Extreme learning machine, Ensemble learning, Active learning, Active extreme learning machines.
Abstract: Supervised classification of quad-polarimetric SAR images is often constrained by the availability of reliable training samples. Active learning (AL) provides a unique capability at selecting samples with high representation quality and low redundancy. The most important part of AL is the criterion for selecting the most informative candidates (pixels) by ranking. In this paper, class supports based on the posterior probability function are approximated by ensemble learning and majority voting. This approximation is statistically meaningful when a large enough classifier ensemble is exploited. In this work, we propose to use extreme learning machines and apply AL to quad-polarimetric SAR image classification. Extreme learning machines are ideal because of their fast operation, straightforward solution and strong generalization. As inputs to the so-called active extreme learning machines, both polarimetric and spatial features (morphological profiles) are considered. In order to validate the proposed method, results and performance are compared with random sampling and state-of-the-art AL methods, such as margin sampling, normalized entropy query-by-bagging and multiclass level uncertainty. Experimental results for four quad-polarimetric SAR images collected by RADARSAT-2, AirSAR and EMISAR indicate that the proposed method achieves promising results in different scenarios. Moreover, the proposed method is faster than existing techniques in both the learning and the classification phases.
Location: T E 15 New Biology Building.
Literature cited 1: Ainsworth, T.L., Kelly, J.P., Lee, J.S., 2009. Classification comparisons between dual-pool, compact polarimeric and quad-pol SAR imagery. ISPRS J.Photogr.Remote Sens. 64 (5), 464-471. Benediktsson, J.A, Palmason, J.A., Sveinsson, J.R., 2005. Classification of hyperspectral data from urban areas based on extended morphological profiles.IEEE Trans.Geosci.Remot Sens. 43 (3), 480-491.
Literature cited 2: Breiman, L., 1996.Bagging predictors.Mach.Learn. 24 (2), 123-140. Cloude, S.R., Pottier, E., 1996. A review of target decomposition theorems in radar polarimetry.IEEE Trans.Geosci.Remote Sens. 41 (1), 4-19.

ID: 61006
Title: Spectral anisotropy of subtropical forest using MISR and MODIS data acquired under large seasonal variation in solar zenith angle.
Author: Fabio Marcelo Breunig, Lenio Soares Galvao, Joao dos Santos, Anatoly A. Gitelson, Yhasmin Mendes de Moura, Thiago Sousa Teles, William Gaida.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 294-304 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: MISR, MODIS, View-illumination geometry, NDVI, EVI, PROSAIL.
Abstract: Recent studies in Amazonian tropical evergreen forests using the Multi-angle Imaging SpectroRadiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) have highlighted the importance of considering the view-illumination geometry in satellite data analysis. However, contrary to the observed for evergreen forests, bidirectional effects have not been evaluated in Brazilian subtropical deciduous forests. In this study, we used MISR data to characterize the reflectance and vegetation index anisotropies in subtropical deciduous forest from south Brazil under large seasonal solar zenith angle (SZA) variation and decreasing leaf area index (LAI) from summer to winter. MODIS data were used to observe seasonal changes in the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). Topographic effects on their determination were inspected by dividing data from the summer to winter and projecting results over a digital elevation model (DEM). By using the PROSAIL, we investigated the relative contribution of LAI and SZA to vegetation indices (VI) of deciduous forest. We also simulated and compared the MISR NDVI and EVI response of subtropical deciduous and tropical evergreen forests as a function of the large seasonal SZA amplitude of 33?. Results showed that the MODIS-MISR NDVI and EVI presented higher values in the summer and lower ones in the winter with decreasing LAI and increasing SZA or greater amounts of canopy shadows viewed by the sensors. In the winter, NDVI reduced local topographic effects due to the red-near infrared (NIR) band normalization. However, the contrary was observed for the three-band EVI that enhanced local variations in shaded and sunlit surfaces due to its strong dependence on the NIR band response. The reflectance anisotropy of the MISR bands increased from the summer to winter and was stronger in the backscattering direction at large view zenith angles (VZA), EVI was much more anisotropic than NDVI and the anisotropy increased from the summer to winter. It also increased from the forward scatter to the backscattering direction with the predominance of sunlit canopy components viewed by MISR, especially at large VZA. Modeling PROSAIL results confirmed the stronger anisotropy of EVI than NDVI for the subtropical deciduous and tropical evergreen forests. PROSAIL showed that LAI and SZA are coupled factors to decrease seasonally the VIs of deciduous forest with the first one having greater importance than the latter. However, PROSAIL seasonal variations in VIs were much smaller than those observed with MODIS data probably because the effects of shadows in heterogeneous canopy structures or/and cast by emergent trees and from local topography were not modeled.
Location: T E 15 New Biology Building.
Literature cited 1: Anderson, L.O., Aragao, L., Shimabukuro, Y.E., Almeida, S., Huete, A., 2011. Fraction images for monitoring intra-annual phenology of different vegetation physiognomies in Amazonia.Int.J.Remote Sens.32, 387-408. Asner, G.P., Alencar, A., 2010. Drought impacts on the Amazon forest: the remote sensing perspective. New Phytol.187, 569-578.
Literature cited 2: Atkinson, P.M., Dash, J., Jeganathan, C., 2011. Amazon vegetation greenness as measured by satellite sensors over the last decade.Geophys.Res.Lett.38, Lett.38, L19105. Baptista V.A., Leal-Zancher, A.M., 2010. Land flatworm community structure in a subtropical deciduous forest in Southern Brazil.Belg.J.Zool.140, 83-90.

ID: 61005
Title: Sub-footprint analysis to uncover tree height variation using ICESat/GLAS.
Author: Jinyan Tian, Le Wang, Xiaojuan Li.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 284-293 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: GLAS, Tree height, Sub-footprint analysis, Levenberg-Marquardt, Guassian decomposition.
Abstract: Detailed forest height data are an indispensable prerequisite for many forestry and earth science applications Existing research of using Geoscience Laser Altimeter System (GLAS) data mainly focuses on driving average or maximum tree heights within a GLAS footprint, i.e.an ellipse with a diameter of 65 m. However, in most forests, it is likely that the tree heights within such ellipse are heterogeneous. Therefore, it is desired to uncover detailed tree height variation within a GLAS footprint. To the best of our knowledge, no such methods have been reported as of now. In this study, we aim to characterize tree heights ' variation within a GLAS footprint as different layers, each of which corresponds to trees with similar heights. As such, we developed a new method that embraces two steps: first, a refined Levenberg-Marquardt (LM) algorithm is proposed to decompose raw GLAS waveform into multiple Guassian signals, within which it is hypothesized that each vegetation signal corresponds to a particular tree height layer. Second, for each layer, three parameters were first defined: Canopy Top Height (CTH), Crown Length (CL) and Cover Proportion (CP). Then we extracted the three parameters from each Guassian signal through a defined model. In order to test our developed method, we set up a study site in Ejina, China where the dominant species is Populus euphratica. Both simulated and field tree height data were adopted. With regard to the simulati0n data, results presented a very high agreement for the three predefined parameters between our results and simulation data. When our methods were applied to the field data, the respective R2 become 0.78 (CTH), CL (R2= 0.76), CP (R2= 0.74). Overall, our studies revealed that large footprint GLAS waveform data have the potentials for obtaining detailed forest height variation.
Location: T E 15 New Biology Building.
Literature cited 1: Anderson, J.E., Plourde, L.C., Martin, M.E., Braswell, B.H., Smith, M.L., Dubayah, R.O., et al., 2008. Integrating waveform lidar with hyperspectral imagery for inventory for a northern temperate forest. Remote Sens. Environ.112, 1856-1870. Boudreau, J., Nelson, R., Margolis, H., Beaudoin, A., Guindon, L., Kimes, D., 2008. Regional aboveground forest biomass using airborne and spaceborne LiDAR in Quebec.Remote Sens.Environ.112 (10), 3876-3890.
Literature cited 2: Ballhorn, U., Jubanski, J., Siegert, F., 2011. ICESat/GLAS data as a measurement tool for Peatland topography and peat swamp forest biomass in Kalimantan, Indonesia. Remote Sens. 3 (9), 1957-1982. Chen, Q., 2010a. Assessment of terrain elevation derived from satellite laser altimetry over mountainous forest areas using airborne lidar data.ISPRS J. Photogram. Remote Sens. 3 (9), 1957-1982.

ID: 61004
Title: Combination of multi-sensor remote sensing data for drought monitoring over southwest China.
Author: Cui Hao, Jiahua Zhang, Fengmei Yao.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 270-283 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Optimized meterological drought index (OMDI), Optimized vegetation drought index (OVDI), Standardized precipitation, evapotranspiration index (SPEI) Multi-source satellite data, Southwest China.
Abstract: Drought is one of the most frequent climate-related disasters occurring in South west China. Where the occurrence of drought is complex because of the varied landforms, climates and vegetation types. To monitor the comprehensive information of drought from meterological to vegetation aspects, this paper intended to propose the optimized meteorological drought index (OMDI) and the optimized vegetation drought index (OVDI) from multi-source satellite data to monitor drought in three bio-climate regions of Southwest China. The OMDI and OVDI were integrated with parameters such as precipitation, temperature, soil moisture and vegetation information, which were derived from Tropical Rainfall Measuring Mission (TRMM), Moderate Resolution Imaging Spectroradiometer Land Surface Temperature (MODIS LST), AMSR-E-Soil Moisture (AMSR-E SM), the soil moisture product of China Land Soil Moisture Assimilation System (CLSMAS), and MODIS Normalized Difference Vegetation Index (MODIS NDVI), respectively. Different sources of satellite data for one parameter were compared with insitu drought indices in order to select the best data source to derive the OMDI and OVDI. The Constrained Optimization method was adopted to determine the optimal weights of each satellite-based index generating combined drought indices. The result showed that the highest positive correlation and lowest root mean square error (RMSE) between the OMDI and 1-month standardized precipitation evapotranspiration index (SPEI-3), and had similar trend with soil relative water content (RWC) in temporal scale, suggesting it a potential indicator of agricultural drought. The spatial patterns of OMDI and OVDI along with the comparisons of SPEI-1 and SPEI-3 for different months in one year or one month in different years showed significantly varied drought locations and areas, demonstrating regional and seasonal fluctuations, and suggesting that drought in southwest China should be monitored in seasonal and regional level, and more fine distinctions of seasons and regions need to be considered in the future studies of this area.
Location: T E 15 New Biology Building.
Literature cited 1: Abdi, H., Williams, L.J., 2010. Principal component analysis. Wiley Interdiscip. Rev.Comput.Stat.2, 433-459. Abramowitz, M., Stegun, I.A., 1972. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. National Bureau of Standards Applied Mathematics Series 55.Tenth Printing.
Literature cited 2: Almazroui, M., 2011. Calibration of TRMM rainfall climatology over Saudi Arabia during 1998-2009.Atmos.Res.99, 400-414. Bhuiyan, C., Singh, R., Kogan, F., 2006. Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data.Int.J.Appl.Earth Observ.geoinf.8, 289-302.

ID: 61003
Title: Landsat 8 VS Landsat 5: A comparison based on urban and peri-urban land cover mapping.
Author: Dimitris Poursanidis, Nektarios Chrysoulakis, Zina Mitraka.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 259-269 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Landsat 8, SVM, GEOBIA, Peri-urban, Classification.
Abstract: An image dataset from the Landsat OLI spaceborne sensor is compared with the Landsat TM in order to evaluate the excellence of the new imagery in urban landcover classification. Widely known pixel-based and object-based image analysis methods have been implemented in this work like Maximum Likelihood, Support Vector Machine, k-Nearest Neighbor, Feature Analyst and Sub-pixel. Classification results from Landsat OLI provide more accurate results comparing to the Landsat TM. Object-based classifications produced a more uniform result, but suffer from the absorption of small rare classes into large homogenous areas, as consequence of the segmentation, merging and the spatial parameters in the spatial resolution (30m) of Landsat images. Based exclusively on the overall accuracy reports, the SVM pixel-based classification from Landsat 8 proved to be the most accurate for the purpose of mapping urban land cover, using medium spatial resolution imagery.
Location: T E 15 New Biology Building.
Literature cited 1: Blaschke, T., 2010.Object based image analysis for remote sensing.ISPRS 65 (1), 2-16. Chrysoulakis, N., Abrams, M., Feidas, H., Korei, A., 2010. Comparison of atmospheric correction methods using ASTERdata for the area of Crete, Greece, Int.J.Remote Sens.31, 6347-6385.
Literature cited 2: Chrysoulakis, N., Mitraka, Z., Stathopoulou, M., Cartalis, C., 2013. A comparative analysis of the urban web of the greater Athens agglomeration for the last 20 years period on the basis of Landsat imagery. Fresenius E nviron.Bull.22, 2139-2144. Collins, M.J.,Dymond, C., Johnson,E.A., 2004.Mapping subalpine forest types using networks of nearest neighbor classifiers.Int.J.Remote Sens.25, 1701-1721.

ID: 61002
Title: A Gestalt rules and graph-cut-based simplification framework for urban building models.
Author: Yuebin Wang, Liqiang Zhang, P.Takis Mathiopoulos, Hao Deng.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 247-258 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Urban buildings, Gestalt principles, Optimization, Scene Tree.
Abstract: To visualize large urban models efficiently, this paper presents a framework for generalizing urban building footprints and fa?ade textures by using multiple Gestalt rules and a graph-cut-based energy function. First, an urban scene is divided into different blocks by main road networks. In each block, the building footprints are portioned into potential Gestalt groups. A footprint may satisfy several Gestalt groups. A footprint may satisfy several Gestalt principles. We employ the graph-cut-based optimization function to obtain a consistent segmentation of the buildings into optimal Gestalt groups with minimal energy. The building footprints in each Gestalt group are aggregated in to different levels of detail (LODs). Buildings fa?ade textures are also abstracted and simplified into multiple LODs using the same approach as the building footptrint simplification. An effective data structure termed Scene Tree is introduced to manage these aggregated building footprints and fa?ade textures. Combined with the parallelization scheme, the rendering efficiency of large-scale urban buildings is improved. Compared with other methods, our presented method can be efficiently visualize large urban models and maintain the city ' s image.
Location: T E 15 New Biology Building.
Literature cited 1: Ali, S., Ye, Razdan, A., Wonka, P., 2009. Compressed fa?ade displacement maps. IEEE Trans. Vis. Comput.Graph. 15, 262-273. Andujar, C., Boo, J., Brunet, P., Fairen, M., Navazo, I, Vazquez, P., Vinacua, A., 2007. Omni-directional Relief Impostors, Computer Graphics Forum. Wiley online Library, pp. 553-560
Literature cited 2: Andujar, C., Brunet, P., Chica, A.Navazo, I., 2010. Visualization of large-scale urban models through multi-level relief impostors. Comput.Graph.Forum, 2456-2468. Andujar, C., Diaz, J, Brunet, P., 2008. Relief impostor selection for large scale urban rendering. In: IEEE Virtual reality Workshop on Virtual Citiscapes: Key Research Issues in Modelling Large-Scale Immersive Urban Environments.

ID: 61001
Title: Detecting forest damage after a low-severity fire using remote sensing at multiple scales.
Author: John T.T.R.Arnett, Nicholas C.Coops, Lori D. Daniels, Robert W. Falls.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 239-246 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Fire, Disturbance, Canopy damage, High-spatial resolution, RapidEye, Biomass.
Abstract: Remote sensing technologies are an ideal platform to examine the extent and impact of fire on the land-scape. In this study we assess that capacity of the RapidEye constellation and Landsat (Thematic Mapper and Operational Land Imager to map fine-scale burn attributes for a small, low severity prescribed fire in a dry Western Canadian forest. Estimates of burn severity from field data were collated into a simple burn index and correlated with a selected suite of common spectral vegetation indices. Burn severity classes were then derived to map fire impacts and estimate consumed woody surface fuels (diameter ? 2.6 cm). All correlations between the simple burn index and vegetation indices produced significant results (p< 0.01), but varied substantially in their overall accuracy. Although the Landsat Soil Adjusted Vegetation Index provided the best regression fit (R2 =0.56), results suggested that RapidEye provided much more spatially detailed estimates of tree damage (Soil Adjusted Vegetation Index, R2 = 0.51). Consumption estimates of woody surface fuels ranged from 3.38 ? 1.03 Mg ha-1 to 11.73 ?1.84 Mg ha-1, across four derived severity classes with uncertainties likely a result of changing foliage moisture between the before and after fire images. While not containing spectral information in the short wave infrared, the spatial variability provided by the RapidEye imagery has potential for mapping and monitoring fine scale forest attributes, as well as the potential to resolve fire damage at the individual tree level.
Location: T E 15 New Biology Building.
Literature cited 1: Adams, M.A., 2013. Mega-fires, tipping points and ecosystem services: managing forests and woodlands in an uncertain future. For.Ecol.Manage.294, 250-261. Allen, C.D., Savge, M., Falk, D.A., Suckling, K.F., Swetnam, T.W., Schulke, T., Klingel, J.T., 2002. Ecological restoration of southwestern ponderosa pine ecosystems: a broad perspective. Ecol.Appl.12, 1418-1433.
Literature cited 2: Arroyo, LA., Pascual, C., Manzanera, J.A., 2008. Fire models and methods to map fuel types: the role of remote sensing. For.Ecol.Manage.256, 1239-1252. Bolton, D.K., Coops, N.C., Wulder, M.A., 2013. Measuring forest structure along productivity gradients in the Canadian boreal with small-footprint Lidar.Environ.Monit.Assess.185, 6617-6634.

ID: 61000
Title: Behavior-based aggregation of land categories for temporal change analysis.
Author: Safaa Zakaria Aldwaik, Jeffrey A. Onsted, Robert Gilmore Pontius Jr.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 229-238 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Aggregation, Category, Change, Land, Map, Transition.
Abstract: Comparison between two time points of the same categorical variable for the same study extent can reveal changes among categories over time, such as transitions among land categories. If many categories exist, then analysis can be difficult to interpret. Category aggregation is the procedure that combines two or more categories to create a single broader category. Aggregation can simplify interpretation, and can also influence the sizes and types of changes. Some classification have an a priori hierarchy to facilitate aggregation, but an a priori aggregation might make researchers blind to important category dynamics. We created an algorithm to aggregate categories in a sequence of steps based on the categories ' behaviors in terms of gross losses and gross gains. The behavior-based algorithm aggregates net gaining categories with net gaining categories and aggregates net losing categories with net losing categories, but never aggregates a net gaining category with a net losing category. The behavior-based algorithm at each step in the sequence maintains net change and maximizes swap change. We present a case study where data from 2001 and 2006 for 64 land categories indicate change on 17 % of the study extent. The behavior-based algorithm reduces a set of 10 categories while reducing the change to 9 %. We offer a free computer program to perform the behavior-based aggregation.
Location: T E 15 New Biology Building.
Literature cited 1: Ahlqvist, O., Shortridge, A., 2010. Spatial and semantic dimensions of landscape heterogeneity.Landsc. Ecol. 25, 573-590. Aldwaik, S.Z., Pontius Jr., R.G., 2012. Intensity analysis to unify measurements of size and stationarity of land changes by interval, category and transition.Landsc. Urban Plan. 106, 103-114.
Literature cited 2: Aldwaik, S.Z., Pontius Jr., R.G., 2013. Map error that could account for deviations from a uniform intensity of land change.Int.J.Geogr.Inf.Sci 27 (9), 1717-1739. Anderson, J.R., Hardy, J.E.E., Roach, J.T., Witmer, R.E., 1976. A land use and land cover classification system for use with remote sensor data. Geological Survey Professional Paper, Vol.964. United States Government Printing Office, Washington, DC.

ID: 60999
Title: Remote sensing and GIS analysis for mapping spatio-temporal changes of erosion and deposition of two Mediterranean river deltas: The case of the Axios and Aliakmonas rivers, Greece.
Author: George P. Petropoulos, Dionissios P. Kalivas, Hywel M. Griffiths, Paraskevi P.Dimou.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 217-228 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Remote sensing, GIS, Landsat TM, Coastline mapping, Photo-interpretation, Support vector machines.
Abstract: Wetlands are among Earth ' s most dynamic, diverse and varied habitats as the balance between land and water surfaces provide shelter to a unique mixture of plant and animal species. This study explores the changes n two Mediterranean wetland delta environments formed by the Axios and Aliakmonas rivers located in Greece, over a 25-year period (1984-2009). Direct photo-interpretation of four Landsat TM images acquired during the study period was performed. Furthermore, a sophisticated, semi-automatic image classification method based on support vector machines (SVMs) was developed to streamline the mapping process. Deposition and erosion magnitude at different temporal scales during the study period were quantified using both approaches based on coastline surface area changes. Analysis using both methods was conducted in a geographical information systems (GIS) environment. Direct photo-interpretation, which formed our reference dataset, showed noticeable changes in the coastline deltas of both study areas, with erosion occurring mostly in the earlier periods (1990-2003) in both river deltas followed by deposition in more recent years (2003-2009), but at different magnitudes. Spatial patterns of coastline changes predicted from the SVMs showed similar trends. In absolute terms SVMs predictions of sediment erosion and deposition in the studied area were different in the order of 5-20 % in comparison to photo-interpretation, evidencing the potential capability of this method in coastline changes monitoring. One of the main contributions of our work lies to the use of the SVMs classifier in coastal mapping of changes, since to our knowledge use of this technique has been under-explored in this application domain. Furthermore, this study provides important contribution to the understanding of Mediterranean river delta dynamics and their behaviours, and corroborates the usefulness of EO technology and GIS as an effective tool in policy decision making and successful landscape management. The latter is of considerable scientific and practical value to the wider community of interested users, given the continued open access to observations from this satellite radiometer globally.
Location: T E 15 New Biology Building.
Literature cited 1: Amarnath, G., Murthy, M.S.R., Britto, S.J., S.J., Rajashekhar, G., Dutt, C.B.S., 2003. Dignostic analysis of conservation zones using remote sensing and GIS techniques in wet evergreen forests of the Western Ghats-an ecological hotspot, Tamil Nadu, India.Biodivers.Conserv. 12 (12), 2331-2359. Athanasiou, H., (M.Sc. Dissertatio) 1990. Wetland Habitat Loss in Thessaloniki Plain, Greece. Univrsity College, London.
Literature cited 2: Bausmith, J.M., Leinhardth, G., 1997. Middle school students ' map construction: understanding complex spatial displays.J.Geogr.97, 93-107. Boser, B.E., Guyon, I.M., Vapnik, V.N., 1992. A training Algorithm For Optimal Margin Classifiers. In: Proc. Annu.Workshop Comput.Learn.Theory, pp. 144-152.

ID: 60998
Title: Wavelet-based detection of bush encroachment in a Savanna using multi-temporal aerial photographs and satellite imagery.
Author: Munyaradzi D.Shekede, Amon Murwira, Mhosisi Masocha.
Editor: F.D.van der Meer
Year: 2015
Publisher: Elsevier B.V.
Source: Centre for Ecological Sciences
Reference: APPLIED EARTH OBSERVATION AND GEOINFORMATION. Vol. 35 (B) 209-216 (2015).
Subject: APPLIED EARTH OBSERVATION AND GEOINFORMATION.
Keywords: Dominant scale, Intensity, Wavelet transform, Bush encroachment, Savanna, Remote sensing.
Abstract: Although increased woody plant abundance has been reported in tropical savannas worldwide, techniques for detecting the direction and magnitude of change are mostly based on visual interpretation of historical aerial photography or textural analysis of multi-temporal satellite images. These techniques are prone to human error and do not permit integration f remotely sensed data from diverse sources. Here, we integrate aerial photographs with high spatial resolution satellite imagery and use a discrete wavelet transform to objectively detect the dynamics in bush encroachment at two protected Zimbabwean savanna sites. Based on the recently introduced intensity-dominant scale approach, we test the hypotheses that: (1) the encroachment of woody patches in to surrounding grassland matrix causes a shift in the dominant scale. This shift in the dominant scale can be detected using a discrete wavelet transform regardless of whether aerial photography and satellite data are used ; and (2) as the woody patch size stabilizes , woody cover tends to increase thereby triggering changes in intensity. The results show that at the first site where tree patches were already established (Lake Chivero Game Reserve), between 1972 and 1984 and 2012 while the intensity fluctuated during the same period. In contrast, at the second site which was formely grass-dominated site (Kyle Game Reserve), we observed an unclear dominant scale (1972) which later becomes distinct in 1985, 1996 and 2012. Over the same period, the intensity increased. Our results imply that using our approach we can detect and quantify woody bush patch dynamics in savanna landscapes.
Location: T E 15 New Biology Building.
Literature cited 1: Angassa, A., Oba, G., 2007. Effects of management and time on mechanisms of bush encroachment in southern Ethiopia.Afr.J.Ecol.46, 186-196. Ansley, R.J., Wu, X.B., Kramp, B.A., 2001. Observation: Long-term increases in mesquite canopy cover in a North Texas savanna.J.Range Manage. 54 (2), 171-176.
Literature cited 2: Archer, S., 1990. Development and stability of grass/woody mosaics in subtropical savanna Parkland, Texas, U.S.A.J.Biogeog.17 (4/5), 453-462. Archer, 1994.Woody plant encroachment into southwestern grasslands and savannas: rates, patterns and proximate causes. In: Vavra, M., Laycock, W.A., Pieper, R.D. (Eds), Ecological Implications of Livestock Herbivory in the west. Society for Range Management, Denver, pp. 13-68.