Statistical downscaling of meteorological time series and climatic projections in a watershed in Turkey     

S. Göncü  E. Albek 《Theoretical and Applied Climatology》2016,126(1-2):191-211

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GIS-based approach for flood analysis: case study of Keçidere flash flood event (Turkey)     

Isa Curebal  Recep Efe  Hasan Ozdemir  Abdullah Soykan  Süleyman Sönmez 《国际地球制图》2016,31(4):355-366

The purpose of this study is to explain the formation mechanism of the floods which occurred in the Keçidere basin in 2009. In this study, discharge data in between 1981 and 2009, digital elevation model (DEM), satellite images and field works were used as a main data sources. LPT3 was applied to 29-year maximum flow data to produce different flood return periods such as 2, 5, 50, 100, 200, 500 and 1000-year flood. The DEM was created using 1:25,000 topographic contours with Topo to Raster interpolation techniques in geographical information systems (GIS). Land use and some geometric data were digitized using high resolution satellite images for hydraulic modelling purposes. Simulation of the 2009 flash flood event and different return periods flow data was done using one-dimensional hydraulic modelling with HEC-RAS. In the last phase, results obtained from the simulations and field works were compared based on fits statistics and mean absolute error in terms of extent and depth. An analysis of water extent and depth features observed during the highest flow ever measured in the basin revealed that the result overlapped with 500-year inundation extent. Overall, the results of the research indicate that GIS is an effective environment for floodplain mapping and analysis.  相似文献   

The East African Rift System and the impact of orographic changes on regional climate and the resulting aridification     

Anja Sommerfeld  Kerstin Prömmel  Ulrich Cubasch 《International Journal of Earth Sciences》2016,105(6):1779-1794

Several proxy data indicate an aridification of the East African climate during the Neogene, which might be influenced by the orographic changes of the East African Rift System (EARS) induced by tectonic forcing during the last 20 million years. To investigate the impact of the orography and especially of the rifts, the regional climate model CCLM is used, covering the EARS with Lake Victoria in the centre of the model domain. CCLM is driven by the ERA-Interim reanalysis and applied with a double-nesting method resulting in a very high spatial resolution of 7 km. The resolution clearly shows the shoulders and rifts of the western and eastern branch of the EARS and the Rwenzoris within the western branch. To analyse the orographic influence on climate, a new technique of modifying the orography is used in this sensitivity study. The shoulders of the branches are lowered and the rifts are elevated, resulting in a smoothed orography structure with less altitude difference between the shoulders and rifts. The changes in 2 m-temperature are very local and associated with the changes in the orography. The vertically integrated moisture transport is characterised by less vortices, and its zonal component is increased over the branches. The resulting amount of precipitation is mainly decreased west of the western branch and increased in the rift of the western branch. In the eastern branch, however, the changes in the amount of precipitation are not significant. The changes in the precipitation and temperature patterns lead to a shift of biomes towards a vegetation coverage characterised by more humid conditions in the northern part of the model domain and more arid conditions in the South. Thus, the aridification found in the proxy data can be attributed to the orographic changes of the rifts only in the northern model domain.  相似文献   

Hybrid terrain rendering based on the external edge primitive     

E.G. Paredes  M. Amor  M. Bóo  J.D. Bruguera  J. Döllner 《International journal of geographical information science》2016,30(6):1095-1116

Hybrid terrain models combine large regular data sets and high-resolution irregular meshes [triangulated irregular network (TIN)] for topographically and morphologically complex terrain features such as man-made microstructures or cliffs. In this paper, a new method to generate and visualize this kind of 3D hybrid terrain models is presented. This method can integrate geographic data sets from multiple sources without a remeshing process to combine the heterogeneous data of the different models. At the same time, the original data sets are preserved without modification, and, thus, TIN meshes can be easily edited and replaced, among other features. Specifically, our approach is based on the utilization of the external edges of convexified TINs as the fundamental primitive to tessellate the space between both types of meshes. Our proposal is eminently parallel, requires only a minimal preprocessing phase, and minimizes the storage requirements when compared with the previous proposals.  相似文献   

Measures of transport mode segmentation of trajectories     

Adrian C. Prelipcean  Gyözö Gidofalvi  Yusak O. Susilo 《International journal of geographical information science》2016,30(9):1763-1784

ABSTRACT

Rooted in the philosophy of point- and segment-based approaches for transportation mode segmentation of trajectories, the measures that researchers have adopted to evaluate the quality of the results (1) are incomparable across approaches, hence slowing the progress in the field and (2) do not provide insight about the quality of the continuous transportation mode segmentation. To address these problems, this paper proposes new error measures that can be applied to measure how well a continuous transportation mode segmentation model performs. The error measures introduced are based on aligning multiple inferred continuous intervals to ground truth intervals, and measure the cardinality of the alignment and the spatial and temporal discrepancy between the corresponding aligned segments. The utility of this new way of computing errors is shown by evaluating the segmentation of three generic transportation mode segmentation approaches (implicit, explicit–holistic, and explicit–consensus-based transport mode segmentation), which can be implemented in a thick client architecture. Empirical evaluations on a large real-word data set reveal the superiority of explicit–consensus-based transport mode segmentation, which can be attributed to the explicit modeling of segments and transitions, which allows for a meaningful decomposition of the complex learning task.  相似文献   

Agent-based simulation for biogas power plant potential in Schwarzwald-Baar-Kreis,Germany: a step towards better economy     

Hafiz Ali Imran  Dietrich Schröder  Bilal Ahmed Munir 《国际地球制图》2017,32(1):59-70

Over the past decade, political framework in the energy sector all over the world has provoked a strong focus on the production of renewable energies. The study focuses on agent-based modelling approach to identify the suitable and economical distribution of biogas power plants over time in the area of interest. For sufficient supply of biomass (silage maize) on a regional basis to run biogas power plants economically and smoothly, different thematic layers with defined rules for Agent Analyst used to simulate the future installations of power plants. In conjunction with ArcGIS, the Agent Analyst software generates simulations that prove the robustness of the model in finding the suitable location of power plants. The resultant location from the model is analysed in different aspects. The designed methodology could be implemented in other areas with minor edits as per requirement of the area.  相似文献   

Towards a multi-scale approach for an Earth observation-based assessment of natural resource exploitation in conflict regions     

Elisabeth Schoepfer  Kristin Spröhnle  Olaf Kranz  Xavier Blaes  Jan Kolomaznik  Filip Hilgert 《国际地球制图》2017,32(10):1139-1158

The exploitation of resources, if not properly managed, can lead to spoiling natural habitats as well as to threatening people’s health, livelihoods and security. The paper discusses a multi-scale Earth observation-based approach to provide independent information related to exploitation activities of natural resources for countries which are experiencing armed conflict. The analyses are based on medium to very high spatial resolution optical satellite data. Object-based image analysis is used for information extraction at these different scales. On a subnational level, conflict-related land cover changes as an indication of potential hot spots for exploitation activities are classified. The regional assessment provides information about potential activity areas of resource exploitation, whereas on a local scale, a site-specific assessment of exploitation areas is performed. The study demonstrates the potential of remote sensing for supporting the monitoring and documentation of natural resource exploitation in conflict regions.  相似文献   

Impact of in-consistency between the climate model and its initial conditions on climate prediction     

Liu  Xueyuan  Köhl  Armin  Stammer  Detlef  Masuda  Shuhei  Ishikawa  Yoichi  Mochizuki  Takashi 《Climate Dynamics》2017,49(3):1061-1075

We investigated the influence of dynamical in-consistency of initial conditions on the predictive skill of decadal climate predictions. The investigation builds on the fully coupled global model “Coupled GCM for Earth Simulator” (CFES). In two separate experiments, the ocean component of the coupled model is full-field initialized with two different initial fields from either the same coupled model CFES or the GECCO2 Ocean Synthesis while the atmosphere is initialized from CFES in both cases. Differences between both experiments show that higher SST forecast skill is obtained when initializing with coupled data assimilation initial conditions (CIH) instead of those from GECCO2 (GIH), with the most significant difference in skill obtained over the tropical Pacific at lead year one. High predictive skill of SST over the tropical Pacific seen in CIH reflects the good reproduction of El Niño events at lead year one. In contrast, GIH produces additional erroneous El Niño events. The tropical Pacific skill differences between both runs can be rationalized in terms of the zonal momentum balance between the wind stress and pressure gradient force, which characterizes the upper equatorial Pacific. In GIH, the differences between the oceanic and atmospheric state at initial time leads to imbalance between the zonal wind stress and pressure gradient force over the equatorial Pacific, which leads to the additional pseudo El Niño events and explains reduced predictive skill. The balance can be reestablished if anomaly initialization strategy is applied with GECCO2 initial conditions and improved predictive skill in the tropical Pacific is observed at lead year one. However, initializing the coupled model with self-consistent initial conditions leads to the highest skill of climate prediction in the tropical Pacific by preserving the momentum balance between zonal wind stress and pressure gradient force along the equatorial Pacific.

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Terrestrial monitoring of a radio telescope reference point using comprehensive uncertainty budgeting   总被引：1，自引：1，他引：0  

Michael Lösler  Rüdiger Haas  Cornelia Eschelbach 《Journal of Geodesy》2016,90(5):467-486

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Lateral dispersion of low-energy protons precipitated in the auroral zones     

G.W. Prölss 《Planetary and Space Science》1974,22(2):341-344

Through the use of a Monte Carlo type calculation, the lateral dispersion of a fine proton beam of given energy and pitch angle in an atmosphere of given exospheric temperature is investigated. It is found that this lateral dispersion may be estimated by using a simple analytical expression.  相似文献