scholarly journals Identification of submerged large woody debris from single-beam echo soundings

2006 ◽  
Vol 8 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Laurent White ◽  
Ben R. Hodges ◽  
Barney N. Austin ◽  
Tim D. Osting

Submerged large woody debris (LWD) in rivers and streams appears as spikes in bathymetry data collected at a decimeter resolution with a single-beam echo sounder. The LWD signal distorts any subsequent interpolation of bathymetry to an hydraulic model mesh or to a triangulated irregular network (TIN) for Geographical Information Systems (GIS). Two methods for separating the submerged LWD from the background bathymetry are investigated: 1) a new σ-discrimination method and 2) an adaptation of prior scale-space analysis techniques. The former is shown to effectively separate LWD from the background bathymetry. However, the latter is shown to be ineffective for this purpose. Separation of the background bathymetry and LWD signal allows the quantity and distribution of LWD to be separately mapped, providing a resource for biologists, geomorphologists and hydraulic engineers whose studies may be affected by the presence of LWD.

Author(s):  
N. Bagheri ◽  
K. Wangdi ◽  
N. Cherbuin ◽  
K.J. Anstey

Geographical information systems (GIS) and geospatial analysis techniques will help to identify significant dementia risk clusters (hotspots) across communities and will enable policy makers to target prevention interventions to the right place. This review synthesises the published literature on geospatial analysis techniques for quantifying and mapping dementia risk, and reviews available dementia risk assessment tools. A systematic literature review was undertaken in four medical and life sciences databases (PubMed, Cochrane Central, Embase, and Web of Sciences) from their inception to March 2017 for all articles relating to dementia. The search terms included: ‘dementia’, ‘Alzheimer’s disease’, ‘general practice database’, ‘family physician’, ‘AD risk assessment tools’, ‘Geographical Information Systems’ and ‘geospatial analysis’, ‘geographical variation’ and ‘spatial variation’. To date, most geospatial studies on dementia have been carried out retrospectively using population based data. An alternative approach is utilisation of a rich source of general practice (family physician) databases to predict dementia risk based on available dementia risk assessment tools. In conclusion, the estimated risks of dementia can thus be geo-attributed and mapped at a small scale using geographical information systems and geospatial analysis techniques to identify dementia risk clusters across the communities and refine our understanding of the interaction between socio-demographic and environmental factors, and dementia risk clusters.


2020 ◽  
Vol 9 (2) ◽  
pp. 70 ◽  
Author(s):  
Naimat Ullah Khan ◽  
Wanggen Wan ◽  
Shui Yu

The aim of this study is to analyze and compare the patterns of behavior of tourists and residents from Location-Based Social Network (LBSN) data in Shanghai, China using various spatiotemporal analysis techniques at different venue categories. The paper presents the applications of location-based social network’s data by exploring the patterns in check-ins over a period of six months. We acquired the geo-location information from one of the most famous Chinese microblogs called Sina-Weibo (Weibo). The extracted data is translated into the Geographical Information Systems (GIS) format, and compared with the help of temporal statistical analysis and kernel density estimation. The venue classification is done by using information regarding the nature of physical locations. The findings reveal that the spatial activities of tourists are more concentrated as compared to those of residents, particularly in downtown, while the residents also visited suburban areas and the temporal activities of tourists varied significantly while the residents’ activities showed relatively stable behavior. These results can be applied in destination management, urban planning, and smart city development.


Author(s):  
Verónica Lango-Reynoso ◽  
Karla Teresa González-Figueroa ◽  
Fabiola Lango-Reynoso ◽  
María del Refugio Castañeda-Chávez ◽  
Jesús Montoya-Mendoza

Objective: This article describes and analyzes the main concepts of coastal ecosystems, these as a result of research concerning land-use change assessments in coastal areas. Design/Methodology/Approach: Scientific articles were searched using keywords in English and Spanish. Articles regarding land-use change assessment in coastal areas were selected, discarding those that although being on coastal zones and geographic and soil identification did not use Geographic Information System (GIS). Results: A GIS is a computer-based tool for evaluating the land-use change in coastal areas by quantifying variations. It is analyzed through GIS and its contributions; highlighting its importance and constant monitoring. Limitations of the study/Implications: This research analyzes national and international scientific information, published from 2007 to 2019, regarding the land-use change in coastal areas quantified with the digital GIS tool. Findings/Conclusions: GIS are useful tools in the identification and quantitative evaluation of changes in land-use in coastal ecosystems; which require constant evaluation due to their high dynamism.


2016 ◽  
Vol 78 ◽  
pp. 203-209 ◽  
Author(s):  
K.J. Hutchinson ◽  
D.R. Scobie ◽  
J. Beautrais ◽  
A.D. Mackay ◽  
G.M. Rennie ◽  
...  

To develop a protocol to guide pasture sampling for estimation of paddock pasture mass in hill country, a range of pasture sampling strategies, including random sampling, transects and stratification based on slope and aspect, were evaluated using simulations in a Geographical Information Systems computer environment. The accuracy and efficiency of each strategy was tested by sampling data obtained from intensive field measurements across several farms, regions and seasons. The number of measurements required to obtain an accurate estimate was related to the overall pasture mass and the topographic complexity of a paddock, with more variable paddocks requiring more samples. Random sampling from average slopes provided the best balance between simplicity and reliability. A draft protocol was developed from the simulations, in the form of a decision support tool, where visual determination of the topographic complexity of the paddock, along with the required accuracy, were used to guide the number of measurements recommended. The protocol was field tested and evaluated by groups of users for efficacy and ease of use. This sampling protocol will offer farmers, consultants and researchers an efficient, reliable and simple way to determine pasture mass in New Zealand hill country settings. Keywords: hill country, feed budgeting, protocol pasture mass, slope


2020 ◽  
pp. 78-98
Author(s):  
T. V. Kotova

Proceedings of the International conference (ИнтерКарто. ИнтерГИС, Russia) devoted to geographical information systems for sustainable development of territories have been published annually since 1994. The articles discuss theoretical and methodological aspects of geoinformation support for environmental, economic and social aspects of sustainable de­velop­ment, issues of geoinformatics, cartography, remote sensing of the Earth, problems of environmental sustainability and environmental impact assessment. Over a quarter of a century, the conference proceedings got more than 125 articles related to the use of geoinformation technologies to the study and mapping of vegetation. The review of proceedings gives the concrete examples how to solve problems of vegetation mapping using GIS, it is focused on publications providing some examples of GIS appli­cation to the vegetation studies. The review is organized into thematic sections according the field of application of Geoinformatics: 1.Vegetation, 2. Dynamics, state and ecological functions of vegetation, 3. Biodiversity and its assessment, 4. Plant resources, 5. Monitoring of vegetation. The Vegetation section contains publications on vegetation studies and mapping performed for some regions of Russia — the North of the Far East, the Republic of Sakha (Yaku­tia), the Tyva Republic, Central Siberia, and others. More than half of the articles are devoted to vegetation dynamics, state and ecological functions of vegetation at different hierarchical levels. Some papers present the results of the studies based on new types of information sources (photographs) and visualization methods (animation). The use of geoinformation technologies to study biological diversity was included in the agenda of five conference sessions and later reflected in more than ten publications. They cover the development and creation of GIS, the use of geoinformation technologies for the analysis, assessment and mapping of biodiversity, for its monitoring and conservation. Quite a large number of articles are devoted to the study of forest resources. GIS technologies were used to solve problems of forest management, cartometric analysis of forested areas, determination of taxation indicators, systematization of forest conditions, etc. Examples of geoinformation versatile research for medicinal plant resources are given to assess their quality, resources and productivity in the region, to identify growing areas, including ones to be protected. Most of the published materials concerning to vegetation monitoring mainly relate to forests and forest management.


Author(s):  
Е.М. Studenikina ◽  
Yu.I. Stepkin ◽  
O.V. Klepikov ◽  
I.V. Kolnet ◽  
L.V. Popova

The paper considers the problematic issues of the geographical information systems (GIS) use in the sociohygienic monitoring (SHM). We analyzed scientific and practical publications on this subject that are freely available on the largest Russian information portal of scientific electronic library eLIBRARY.RU during 2014- 2018, which allowed us to formulate the principles of organization and requirements for effective operation of geographic and information systems in the socio-hygienic monitoring. An analysis of the implementation of these principles at the present stage of development for the socio-hygienic monitoring system is presented, the results of which were used in formulating priority tasks in the area of geographic and information technology implementation into socio-hygienic monitoring and risk-based planning of control and supervisory measures: to determine the necessary level of detail and an information list depicted on electronic maps for the implementation of risk-based control planning; to provide organizational and regulatory and methodological support for the hierarchical principle of GIS within Rospotrebnadzor operating on a single software product of domestic developers for organizations and institutions; to work out the need to combine GIS with similar systems of other departments involved in the data collection of social and hygienic monitoring (Rosstat, Roshydromet, Rosprirodnadzor, Ministry of Health, etc.) to enable automated data export and import; to solve staffing issues to ensure customization and subsequent GIS operation; to provide budget funding for the purchase of licensed software products for GIS in SHM, preferably of Russian developers.


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