Izabela Karsznia

Improving settlement selection for small-scale maps using data enrichment and machine learning

ABSTRACT Acquiring and formalizing cartographic knowledge still is a challenge, especially when the generalization process concerns small-scale maps. We concentrate on the settlement selection process for small-scale maps, with the aim of rendering it more holistic, and making methodological contributions in four areas. First, we show how written specifications and rules can be validated against the actual published map products, thus pointing to gaps and potential improvements. Second, we use data enrichment based on supplementing information extracted from point-of-interest data in order to assign functional importance to particular settlements. Third, we use machine learning (ML) algorithms to infer additional rules from existing maps, thus making explicit the deep knowledge of cartographers and allowing to extend the cartographic rule set. And fourth, we show how the results of ML can be transformed into human-readable form for potential use in the guidelines of national mapping agencies. We use the case of settlement selection in the small-scale maps published by the Polish national mapping agency (GUGiK). However, we believe that the methods and findings of this paper can be adapted to other environments with minor modifications.

Selected aspects of settlement generalization in the General Geographic Database in Poland

AbstractThe aim of the study was to investigate and highlight the specifics of settlements generalization in the General Geographic Database in Poland. As all the settlements are presented by signatures and selected, bigger ones by outlines – two important aspects were taken into consideration. First of all an attempt of formulating a formal criteria of settlements selection presented by signatures was conducted. The main challenge in this aspect was to achieve a high degree of formalization and automation in the generalization process with inclusion of the specifics of generalized features. In order to fulfil those conditions a concept of regional differentiation of parameters in the settlements selection process was proposed. Additionally the possibilities of contextual settlements’ outlines aggregation and simplification with the application of mathematical morphology operations were also investigated. By applying functions of modified erosion and dilation in the settlements’ outlines aggregation as we...

Georeferenced measurements of building objects with their simultaneous shape detection

The paper presents a new method of georeferenced measurements of building objects with their simultaneous shape detection. The method is based on a robust adjustment of a linear network localised on the measured object and connected to GNSS-surveyed points deployed near building corners. In the robust adjustment process, the angles of the object physically outlying from their theoretical design values are detected, the remaining angles retain the design values. The performed field surveying experiment underlined the effectiveness of the proposed method.

Comparative analysis of a characterization of the built-up area and settlement network on Polish topographic maps from the 19th, 20th and 21st centuries

Abstract Built-up area is a particularly important element of the content of topographic maps. Its presentation changes significantly when map scales are reduced, due to both conceptual and graphic generalization. What is more, historically, changes in the depiction of built-up area were consequences of changes in the intended use of topographic maps, development of technology and changes in the cultural landscape, of which the built-up area is an important component.1 The authors describe the method of presentation of built-up areas on six Polish topographic maps or series of maps. The above-mentioned maps include the following: – Topograficzna Karta Królestwa Polskiego (Topographic Map of the Polish Kingdom) at the scale of 1:126,000 developed in 1822–1843; – topographic maps of the Polish Military Geographical Institute (MGI) at the scales of 1:25,000 and 1:100,000, published in 1930s; – a series of military maps (or military-civilian maps) at the scales of 1:10,000, 1:25,000, 1:50,000 and 1:100,000, developed in 1956–1989, in accordance with the instruction for developing Soviet maps; – a series of civilian maps at the scales of 1:10,000, 1:25,000, 1:50,000 and 1:100,000 developed after 1995. The basis for a quantitative comparison of the content of the maps was the number of categories of objects (identifications) which constitute part of built-up area and are presented on individual maps as symbols, as well as the number of characteristics represented by these symbols. These characteristics are divided into two basic types: functional characteristics and physiognomic characteristics. The analysis shows that military maps issued after the Second World War differ from the civilian maps, as they contain a much larger share of physiognomic characteristics, which is caused mainly from the fact that the vast majority of military maps distinguish between wooden and brick buildings. This difference was to large extent already noticeable among the oldest of the analysed maps – the Quartermaster’s Map and nineteenth-century Russian maps, which were partly modelled on the Quartermaster’s Map, and later also Soviet maps. Due to political reasons, the model of these Soviet maps was later adopted for the development of post-war Polish military maps. Out of all maps drawn up by military services, the inter-war MGI map serves special attention, as it was modelled on German maps. The main difference between military and civilian maps is foremost the fact that civilian maps include more functional characteristics of buildings and take into consideration new physiognomic characteristics related to residential development (compact, dense, multifamily dwellings, single family dwellings). The analysed maps include not only the characteristics of buildings and built-up area, but also information on the features of the town – population size, number of village houses and the administrative function.

Methodology of the automatic generalization of buildings, road networks, forests and surface waters: a case study based on the Topographic Objects Database in Poland

Abstract This research presents the formalization and verification of the methodology for the automatic generalization of buildings, road networks, forests and surface waters from the Topographic Objects Database (BDOT10k) in Poland. The article makes the following contributions. First, the generalization methodology contained in the official documents was acquired and presented in the form of the knowledge base. Second, the possibilities and limitations of the implementation of the knowledge base in ArcGIS were discussed. Third, the suitability of the BDOT10k structure for the purpose of automatic generalization performance was verified. As a result of the conducted generalization tests, it was found that the formalization and implementation of the methodology contained in the official specifications, in the automatic mode are not entirely possible. The generalization results, however, are promising. The presented research is in line with the studies recently conducted not only by Polish but also other European National Mapping Agencies.

Visual clutter reduction in zoomable proportional point symbol maps

ABSTRACT Proportional point symbols are commonly used in map displays. However, when such displays are zoomed out, the available map space shrinks and consequently symbols overlap and the display suffers from visual clutter. Therefore, solutions are needed to reduce visual clutter in zoomable map displays that contain proportional point symbols. The authors add to the body of knowledge through the investigation of the performance of three solutions: aggregation of unit areas, the displacement of overlapping symbols, and modified symbolization; four variations of modified symbolization are examined in detail. The original study begins with a consideration of the strengths and weaknesses of the solutions, with an emphasis on information loss. Thereafter, user sessions with 165 participants are arranged to gain empirical evidence of the performance of the solutions. The results reveal that although participants zoom out the map to zoom levels that implement visual clutter reduction techniques, they tend to zoom in the map and pan it to examine specific areas. Moreover, they willingly use the map with aggregated unit areas in cases when the solution facilitates task accomplishment. A certain amount of skepticism attaches to the solution that displaces overlapping symbols.

Local GIS: development and assessment of the geoportal for local governments and local communities. Case study of a small town in Poland

Abstract Of the numerous applications of GIS, administration and public services count among the main fields of application. They are both the users and the owners of the largest amount of spatial data. Portals for higher authorities have been the subject of extensive discussions, but the development and possible use of GIS systems in the form of geoportals at local levels still seems to have been insufficiently discussed. This article presents the process of designing and developing a portal for the lowest authorities - local authorities and the local community. A small town in Poland, Sokółka, was assumed as the study area. The concept development was preceded by, among others: recognition of the needs of an administrative unit in conducting spatial policy; establishment of the objectives, functionalities and assumptions of the designed GIS; a SWOT analysis of the designed geoportal; and an analysis of data resources. Pilot implementation was completed with an evaluation of the geoportal encompassing various groups of potential users.

Methodology for mapping the average transaction prices of residential premises using GIS

Abstract Geographic information systems (GIS) and their tools support the process of real estate trading. Of key importance is the ability to visualise information about real estate in the form of maps of average real estate transaction prices. The following study presents a methodology for mapping average real estate transaction prices using GIS. The map development process comprised three main stages. In the first stage, the input data was processed and statistically analysed. Official data came from the Register of Real Estate Prices and Values, and open data from the National Register of Boundaries. The second stage involved the visualization of the data in the form of maps of average apartment prices using the cartographic methods of choropleth maps and diagrams. The commercial tool ArcMap 10.3 and the free Quantum GIS software were used in the design of the maps of average real estate transaction prices, to check the options for using these types of programs. As a result, eight maps were designed presenting the average transaction prices for residential properties in the Warsaw district of Ursynów in 2015. The final stage was the analysis of the designed maps. The influence of the selection of the reference units on the visualization content, and the impact of combining cartographic presentation methods on the complexity of the presentation of real estate information, were also analysed.