Building information is an essential part of geographic information system (GIS) applications in urban planning and management. However, it changes rapidly with economic growth. Unmanned aerial ...vehicles (UAV)-based photogrammetry works well in this situation with its advantages of quick and high-resolution data updating. In this paper, in order to improve building extraction accuracy in complex areas where buildings are characterized by various patterns, complex structures, and unique styles, we present a framework which applies deep learning (DL) semantic segmentation to UAV images with digital surface model (DSM) and visible-band difference vegetation index (VDVI). The results show that extraction accuracy improves. The combination of red, green, blue (RGB) and VDVI bands (RGBVI) can effectively distinguish the building area and vegetation. The application of RGB with DSM bands (RGBD) helps separate buildings from ground objects. The combination of RGB, DSM, and VDVI bands (RGBDVI) can identify small buildings which are usually not high and covered partly by tree branches. The proposed method is further applied to an open standard dataset to evaluate its robustness and results indicate an increased overall accuracy from RGB only (93%) to RGBD (97%).
Remote-sensing data has the potential to revolutionize social science. One of the most prominent examples of this is the Nighttime Lights data set, which provides digital measures of night-time ...luminosity from 1992 to 2013. This study evaluates the Nighttime Lights data against detailed rural electrification data from the 2011 Census of India. The results suggest that many night-time luminosity measures derived from satellite data are surprisingly accurate for measuring rural electrification, even at the village level and using simple statistical tools. We also demonstrate that this accuracy can be substantially improved by using of better GIS maps, basic geoprocessing tools, and particular aggregations of night-time luminosity. Night-time luminosity performs worse in measuring financial inclusion or proxies of poverty, however, and detects rural electrification less accurately when the supply of power is intermittent. These results offer guidelines for when and how remote-sensing data can be used when administrative data is absent or unreliable.
Spatial direction relationships act as links between visually perceived data and natural language in cartography and geographic information systems. Although the existing direction models are able to ...compute spatial direction relationships, their adaptability to unique users of Wemap, such as individuals with limited spatial orientation skills (ILSOS), is minimal. In particular, the ability to identify locations and directions on maps can pose serious challenges for ILSOS. As such, a Wemap‐based direction model was developed in this study to address this deficiency, specifically targeting ILSOS. To address these challenges, a model for calculating spatial direction relationships was constructed. Subsequently, a questionnaire was administered to verify the consistency of the proposed model with the spatial perceptions of ILSOS. The experimental results demonstrate that (1) the proposed model can calculate the spatial direction relationships between a reference object and source target based on absolute reference frames; (2) ILSOS account for a certain proportion of the population and have a superior ability to distinguish spatial over geographic directions; and (3) the calculation results of the proposed model are consistent with the spatial cognition of ILSOS.
The emergence of big data enables us to evaluate the various human emotions at places from a statistical perspective by applying affective computing. In this study a novel framework for extracting ...human emotions from large‐scale georeferenced photos at different places is proposed. After the construction of places based on spatial clustering of user‐generated footprints collected from social media websites, online cognitive services are utilized to extract human emotions from facial expressions using state‐of‐the‐art computer vision techniques. Two happiness metrics are defined for measuring the human emotions at different places. To validate the feasibility of the framework, we take 80 tourist attractions around the world as an example and a happiness ranking list of places is generated based on human emotions calculated over 2 million faces detected from greater than 6 million photos. Different kinds of geographical contexts are taken into consideration to find out the relationship between human emotions and environmental factors. Results show that much of the emotional variation at different places can be explained by a few factors such as openness. The research offers insights into integrating human emotions to enrich the understanding of sense of place in geography and in place‐based GIS.
Currently, orthophotos and Digital Terrain Models (DTMs) are commonly being generated from low-cost consumer-grade Unmanned Aerial Systems (UASs) using well-known workflows based on photogrammetric ...and structure-from-motion methods. To achieve high accuracy positioning standards Ground Control Points (GCPs) have to be used in the workflow. In this paper, we assess the impact of number and spatial distribution of GCPs on the positional accuracy of these two geospatial products. By using 3 well-known mapping accuracy standards and 170 checkpoints, the planimetric and altimetric accuracy is assessed for 13 cases of GCPs configuration. The results show that in general, the UAS workflow presents a better accuracy in planimetry than in altimetry. In addition, the application of the mapping standards shows that the two products are suitable for GIS and mapping applications requiring spatial details equivalent to scales less than or equal 1:3000. We also conclude that the insertion of GCPs in the central part of the block does not contribute significantly to an increase in the planimetric accuracy of the geospatial products. Finally, for the proposed minimum photogrammetric overlaps (70% and 35%), the ideal GCP distribution consists of a uniform distribution of GCPs. First, on the central part the block with a horizontal separation of 3 to 4 ground base units for the altimetric component. Second, on the periphery of the block with a separation of 7 to 8 ground base units for the planimetric component.
Progress toward developing a GIS of place can only follow from an understanding of what place is, and this understanding draws on geographical theory. Here—following Agnew, Tuan, and others—we ...consider place as being made up of three components—location, locale, and sense of place—which are recognizable at multiple scales and vary historically as a product of social and political processes. Using the testimonies of two survivors of the Holocaust, we sketch the components of a model for a GIS of place that allows for this theory of place to be visualized and analyzed. The model is, crucially, both multi‐scalar and sensitive to uncertainty, as a GIS of place needs to be able to zoom in and out of the different scales at which place is experienced, as well as capture both uncertain data and uncertainty as data. We see potential in the representations proposed for scaling up from the anecdotal to the general in the sense that any narrative can be grouped and classified according to places and scales as shown here. The challenge in developing a GIS of place along the lines we propose here is to design a new set of functionalities that can do so.
Global average temperature increases and causes extreme weather events, killing millions of people and affecting economic stability. Municipal solid waste (MSW) is one of the primary factors that ...contribute to climate change that is the main concern of various municipalities in the world. In this paper, a two-step systematic approach is proposed to analyze municipal solid waste collection (MSWC) in Sfax, the second most populated city in Tunisia. In the first step, three feasible waste collection scenarios were suggested and have gained the consensus of decision makers and stakeholders. In the second, a geographic information system–based multi-criteria decision aid approach is proposed to identify the most appropriate scenario. Firstly, the Network Analyst function in ArcGIS is used to determine the optimal routes with the traveling distances and operational time of vehicles associated to each scenario. Secondly, a ranking of scenarios is produced by ELECTRE III method. Six pseudo criteria such as fuel consumption cost, gas emission, reliability, road length, and compatibility with the national energy policy were taken into account. The results suggest a relatively efficient and environment-friendly scenario where all vehicles start their trips from the depot, collect garbage from the gather sites, and unload waste at a transfer station then travel back to the depot. The methodology can be adopted into similar contexts to improve the effectiveness of MSW collection through the systematic use of GIS.
Hospital site selection is an essential problem in all societies, and the allocation of the population to these centers are included as the important optimization issues to be considered in urban ...planning. The present paper aims at improving the genetic algorithm by using the effective and affectability rates for the combination of chromosomes. For evaluating the performance of the new algorithm, it was attempted to use the comparison of improved genetic algorithm (IGA) with GA and particle swarm optimization (PSO). For limiting the searching space, it was attempted to use the analysis capabilities of geospatial information systems (GIS) as well as the analytic hierarchy process (AHP) for selecting the candidate sites. Then, the abovementioned algorithms were implemented to determine six optimized sites and allocating the peer blocks in real data. The findings of this paper indicate that selecting proper combinations of chromosomes with high fitness function and chromosomes with low fitness function will result in an increased algorithm’s exploitation and exploration ability. As a result, the algorithm will not be involved with local minimums, the convergence process of the algorithm will improve, and the algorithm will indicate a high level of stability in different performances. Given the findings of this paper, IGA has a better performance in comparison to the other algorithms. The convergence velocity of IGA is higher than that of the GA and PSO. All algorithms showed a high level of repeatability. However, in comparison to the other algorithms, IGA has a higher level of stability. Moreover, the run time of IGA is much shorter than the other algorithms.
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