Representation of three-dimensional mass distribution of the Earth's interior by biorthogonal series and its use for studying internal structure of the planet

This paper utilizes the mathematical concept of approximation within an ellipsoid from a single viewpoint to present the spatial mass distribution function of the Earth's interior and its internal potential.The primary focus lies in constructing the volume distribution of masses in the planet's interior, with the expansion coefficients being linear combinations of the Stokes constants. Several possible approaches are suggested for determining accurately these coefficients employing three-dimensional(biorthogonal)polynomials. By expressing the mass distribution function of the Earth's interior and its internal potential as a series, an algorithm is introduced for the calculation of gravitational energy. It allows us to estimate fluctuations in gravitational energy. The implementation of this algorithm offers the means of establishing the extent to which the Earth deviates from a state of hydrostatic equilibrium as a celestial body.Due to the aforementioned method, calculations have been conducted to validate its effectiveness and reliability. This example is given as an illustration of a given method for studying the internal structure of planets.

Accessing the Potential of Satellite and Telemetric Data to Evaluate the Influence of the Heat Flux Exchange in the Water Column Mixing and Stratification

The objective of this work is to evaluate the feasibility of moderate resolution satellite data estimating the surface heat balance in a tropical hydroelectric reservoir. Each component of the heat flux balance was computed using the MODIS (Moderate Resolution Imaging Spectroradiometer) water surface temperature (WST) level 2, 1 km nominal resolution data (MOD11L2, version 5) from 2003 to 2008. The consequence of the heat flux exchange in the water column thermal structure is also investigated. The passage of cold front over a region decreases the atmospheric pressure and air temperature, enhancing the relative humidity. The sensible flux presents a small variability but an increase occurs due to a convective turbulence caused by front passage. The latent flux decrease but insufficiently to cause a condensation, just the evaporation decreases. The upwelling events are the responsible to maintain the loss of heat after the cold front pas- sage.

Multispectral Image Processing System Developed in CARTOMORPH Software—NDVI Module

In this paper, we have evaluated the multispectral module implemented in the CARTOMORPH software, which is a public domain software under development by the mathematical morphology research group at FCT/UNESP. The aim of CARTOMORPH is to provide an open software with feature extraction methods and a library that contains a variety of implemented code (functions) that can be easily operated by users through graphical interface. The multispectral image processing system has been developed to allow feature discrimination by operations between bands from Remote Sensing images. The normalized difference vegetation index (NDVI) was selected to be implemented on CARTOMORPH because of its acknowledged performance for monitoring of vegetation and cartographic applications. The experiments were applied to multispectral bands from Quick Bird image and the results were compared with those provided by the SPRING and ENVI software. Former is a Brazilian free software, developed by National Institute for Space Research-INPE and dedicated to image processing and Geographic Information Systems (GIS) analysis, as well as ENVI, which is a traditional remote sensing image analysis system. The results prove that the implementation of this module is correct, allowing potential usage in the field of cartography and for environmental applications.

Woody Species Diversity and Forest Structure from Lowland to Montane Forest in Hyrcanian Forest Ecoregion

Alborz Mountains host Caspian Hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. Hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of great biogeographic importance. Altitudinal pattern and correlation between woody species biodiversity (DIV), forest structure ((stem density (DEN), mean basal area (MBA) and mean height class (MHC)) and disturbance (DIS) were explored along 2,400 m altitudinal gradient in Hyrcanian relict forest, Central Alborz Mountains. Vegetation changes from lowland forest (LoF) to mid- altitude forest (MiF) and montane forest (MoF) in this area. The altitudinal gradient was divided into twelve 200 m elevational belts. Point centered quarter method (PCQM) with 96 sampling points and 83 vegetation samples by plot method (PM) were used to record field data. Shannon-Wiener index and Pearson coefficient were used for diversity and correlation analysis. The results showed that DEN decreased linearly, MBA and MHC showed relatively hump shaped and DIS showed a reverse hump shaped pattern of change along altitudinal gradient. Woody species diversity decreased non-steadily from LoF to MoF. Transitional vegetations of Carpinus-Fagus and Fagus-Quercus represented higher diversity of woody taxa compared to adjacent homogenous communities. Significant correlation was observed between altitude and all parameters: DEN with MBA, DIS and DIV; MBA with DIS; MHC with DIS along with DIV; and DIS with DIV at the study area scale. Surprisingly,correlation between studied parameters differed within each vegetation type. Altitude probably acts as a proxy for human and environmental driving forces in this area. Stability of warm and wet condition, season length, soil depth along with forest accessibility probably influences the altitudinal pattern of the studied parameters. Disturbance affects forest structure and consequently diversity; especially in lowlands. The obtained results recommend using both forest biodiversity and mensuration data in management process of forest ecosystems.

An Integrated Remote Sensing and GIS in Monitoring Landuse and Land Cover Change in Egbeda Local Government Area, Oyo State, Nigeria

Effective planning relies on accurate and up-to-date information on existing land use and land cover. The timely detection of trends in land use and land cover change and a quantification of such trends are of specific interest to planners and decision makers. The aim of this research is to use remote sensing and GIS to monitor landuse and land cover change in Egbeda Local Government Area, Oyo State with a view to determining how useful such information can be to planners and decision makers for effective urban management. The research was conducted using remote sensing and Geographical information System at determining the trend and extent of land use and land cover change and its driving force in Egbeda Local Government Area, Oyo State. The methods used include: digitization, digital image processing and spatial analysis using an inverse distance weighted (IDW) technique, Maximum likelihood supervised classification and post classification change detection techniques were applied to Landsat imageries acquired in 1984, 2006 and 2018. Imageries were classified into built-up area, vegetation, bare surface, cultivation and water body. The results of the analysis obtained showed drastic change in built-up area which rose to 32.8% from 25.4% between 1984 and 2018 periods. To reduce the effect of land use expansion in the study areas, policy measures were recommended which include proper inventory of land use and land cover, regular monitoring of urban areas spread of development and regional development programs. These will enable the government, stakeholders, policy makers and planners to make informed decisions provided by these technologies to attain and sustain future urban development.

Shell Model Representation as a Substitute of LoD3 for 3D Modeling in CityGML

The OGC standard for 3D city modeling is widely used in an increasing number of applications.It defines five consecutive Levels of Detail(LoD0 to LoD4 with increasing accuracy and structural complexity),in which LoD3 includes all exterior appearances and geometrical details and subsequently requires much storage space.A new LoD is introduced as shell model with the exterior shell of the LoD3 model and the opening objects like windows,doors as well as smaller faade objects are projected onto walls.In this paper,a user survey is presented.The results of this survey show that the shell model can give users almost the same visual impression as the LoD3 model.Furthermroe,algorithms are developed to extract the shell model from LoD3 model.Experiments show that this shell model can reduce up to 90% storage of the original LoD3 model.Therefore,on one hand it can be used as a substitute for a LoD3 model for the visualization on small displays.On the other hand,it can be treated as a sub-level of detail(SLoD3) in CityGML,since it retains almost the same amount of information but requires much less storage space.

Normalized evaluation of the performance,capacity and availability of catalogue services:a pilot study based on INfrastruture for SPatial InfoRmation in Europe

Geographic information has a great potential to be re-used when supported by mechanisms for its discovery.Above all,the quality of a catalogue service is the key feature supporting users in the discovery process.So far,there have been in existence various methodologies dealing with the normalized evaluation of quality with respect to catalogue services.Their biggest weakness seems to be in the depth of quality testing,i.e.some influences are beyond the scope of evaluation of these methodologies with respect to quality in catalogue services.In this study,the quality of 45 catalogue services across Europe was verified with the proposed normalized evaluation methodology originating from documents within the INfrastruture for SPatial InfoRmation in Europe(INSPIRE)framework.This paper discusses the(statistical)influence of factors that may significantly change the results of catalogue service testing.The proposals for improving the existing INSPIRE normalized evaluation procedure are applicable for any spatial data infrastructure and/or Digital Earth component using the Open Geospatial Consortium Catalogue Service for the Web as a basis.

Measuring user preferences and behaviour in a topographic immersive virtual environment(TopoIVE)of 2D and 3D urban topographic data

This paper investigates user preferences and behaviour associated with 2D and 3D modes of urban representation within a novel Topographic Immersive Virtual Environment(TopoIVE)created from official 1:10,000 mapping.Sixty participants were divided into two groups:the first were given a navigational task within a simulated city and the second were given the freedom to explore it.A Head-Mounted Display(HMD)Virtual Reality(VR)app allowed participants to switch between 2D and 3D representations of buildings with a remote controller and their use of these modes during the experiment was recorded.Participants performed mental rotation tests before entering the TopoIVE and were interviewed afterwards about their experiences using the app.The results indicate that participants preferred the 3D mode of representation overall,although preference for the 2D mode was slightly higher amongst those undertaking the navigational task,and reveal that different wayfinding solutions were adopted by participants according to their gender.Overall,the findings suggest that users exploit different aspects of 2D and 3D modes of visualization in their wayfinding strategy,regardless of their task.The potential to combine the functionality of 2D and 3D modes therefore offers substantial opportunities for the development of immersive virtual reality products derived from topographic datasets.

Enrichment of topographic road database for the purpose of routing and navigation

With growing demand on multi-purpose or multi-modal navigation,the route calculation needs to traverse semantically enriched road networks for different transportation modes.Currently,operational route planning algorithms reveal rather limited performances or their potential for comprehensive applications are constrained by the unavailable or insufficient interoperation among the under-lying geo-data that are separately maintained in different spatial databases.To overcome this limitation,a novel approach has been proposed to integrate the routing-relevant information from different data sources,which involves three processes:(1)automatic matching to identify the corresponding road objects between different datasets;(2)interaction to refine the automatic matching result;and(3)transferring the routing-relevant information from one data-set to another.In process(1),the Delimited Stroke Oriented algorithm is employed to achieve the automatic data matching between different datasets,which has revealed a high matching rate and certainty.However uncertain matching problems occur in areas where topological conditions are too complicated or inconsistent.The remaining unmatched or wrongly matched objects are treated in process(2),with the help of a series of interaction tools.On the basis of refined matching results after the interaction,process(3)is dedicated to automatic integration of the routing-relevant information from different data sources.

Redistribution of Soil Organic Carbon Triggered by Erosion at Field Scale Under Subhumid Climate,Hungary

Soil organic carbon(SOC) has primary importance in terms of soil physics, soil fertility and even of climate change control. One hundred soil samples were taken from an intensively cultivated Cambisol to quantify SOC redistribution triggered by soil erosion under a subhumid climate, by the simultaneous application of diffuse reflectance(240–1 900 nm) and traditional physico-chemical methods.The representative sample points were collected from the solum along the slopes at the depth of 20–300 cm with a mean SOC content of 12 g kg^(-1). Hierarchical cluster analyses were performed based on the determined SOC results. The spatial pattern of the groups created were similar, and even though the classifications were not the same, diffuse reflectance had proven to be a suitable method for soil/sediment classification even within a given arable field. Both organic and inorganic carbon distributions were found to be a proper tool for estimations of past soil erosion processes. The SOC enrichment was found on two sedimentary spots with different geomorphological positions. Soil organic matter composition also differed between the two spots due to selective deposition of the delivered organic matter. The components with low-molecular-weight reached the bottom of the slope where they could leach into the profile, while the more polymerised organic matter compositions were delivered and deposited even before on a higher segment of the slope in an aggregated form. This spatial difference appeared below the uppermost tilled soil layer as well, referring the lower efficiency of conventional ploughing tillage in soil spatial homogenisation.

Landslide inventory validation and susceptibility mapping in the Gerecse Hills, Hungary

Landslides pose a threat to property both in the populated and cultivated areas of the Gerecse Hills (Hungary). The currently available landslide inventory database holds the records from many sites in the area, but the database is out-of-date. Here we address the problem of revising the National Landslides Cadastre landslide inventory database by creating a landslide suscept-ibility map with a multivariate model based on likelihood ratio functions. The model is applied to the TanDEM-X DEM (0.4″ res.), the current landslide inventory of the area, and data acquired from geological maps. By comparing the distributions of four variables in the landslide and non-landslide area with grid computation methods, the model yields landslide susceptibility estimates for the study area. The estimations show to what extent a certain area is similar to the sample areas, therefore, its likelihood to be affected by landslides in the future. The accuracy of the model predictions was checked in the field and compared to the results of our previous study using the SRTM-1 DEM for a similar analysis. The model gave accurate estimates when certain correction measures were applied to the input datasets. The limitations of the model, the input datasets, and the suggested correction measures are also discussed.

基于GIS模拟的Votkinsk水库流域积雪和融化过程（英文）

Coupled hydrological and atmospheric modeling is an efficient method for snowmelt runoff forecast in large basins. We use short-range precipitation forecasts of mesoscale at- mospheric Weather Research and Forecasting （WRF） model combining them with ground-based and satellite observations for modeling snow accumulation and snowmelt processes in the Votkinsk reservoir basin （184,319 km2）. The method is tested during three winter seasons （2012-2015）. The MODIS-based vegetation map and leaf area index data are used to calculate the snowmelt intensity and snow evaporation in the studied basin. The GIS-based snow accumulation and snowmelt modeling provides a reliable and highly detailed spatial distribution for snow water equivalent （SWE） and snow-covered areas （SCA）. The modelling results are validated by comparing actual and estimated SWE and SCA data. The actual SCA results are derived from MODIS satellite data. The algorithm for assessing the SCA by MODIS data （ATBD-MOD 10） has been adapted to a forest zone. In general, the proposed method provides satisfactory results for maximum SWE calculations. The calculation accuracy is slightly degraded during snowmelt periods. The SCA data is simulated with a higher reliability than the SWE data. The differences between the simulated and actual SWE may be explained by the overestimation of the WRF-simulated total precipitation and the unrepresentativeness of the SWE measurements （snow survey）.

Extracting commuter-specific destination hotspots from trip destination data-comparing the boro taxi service with Citi Bike in NYC

Taxi trajectories from urban environments allow inferring various information about the transport service qualities and commuter dynamics.It is possible to associate starting and end points of taxi trips with requirements of individual groups of people and even social inequalities.Previous research shows that due to service restrictions,boro taxis have typical customer destination locations on selected Saturdays:many drop-off clusters appear near the restricted zone,where it is not allowed to pick up customers and only few drop-off clusters appear at complicated crossing.Detected crossings imply recent infrastructural modifications.We want to follow up on these results and add one additional group of commuters:Citi Bike users.For selected Saturdays in June 2015,we want to compare the destinations of boro taxi and Citi Bike users.This is challenging due to manifold differences between active mobility and motorized road users,and,due to the fact that station-based bike sharing services are restricted to stations.Start and end points of trips,as well as the volumes in between rely on specific numbers of bike sharing stations.Therefore,we introduce a novel spatiotemporal assigning procedure for areas of influence around static bike sharing stations for extending available computational methods.