O. I. Apeh, O. C. Nwaka, R. Ndukwu, Ikechukwu Maduako, Olatomiwa O. Arilewola
The interplay between Geographical Information System (GIS) and Computer Science has continued to yield improved methods of carrying out many surveying-related activities. In the past, survey control points were stored in file systems and at the best in Database Management applications thereby leading to the limited usage of the survey control points since they are difficult to locate in the field. This study however, suggests another approach for the storage of these survey control points which makes them to be easily accessible and gives room for faster update and geo-visualization of the survey control points. This was achieved by means of web programming applications such as Node-JS, Leaflet Javascript Mapping API, MONGODB, HTML and CSS, integrating GIS into web technologies. The end product is an interactive web application that can be accessed using any smart device with the control points rendered on the user interface. The Survey Control Finder application (E-Beacon) is a WebGIS platform for the geovisualisation of survey control stations in the University of Nigeria, Enugu campus (UNEC), Nigeria. This study gives insight into what the latest trend in technology has in store for surveying and the need to arouse the interest of learners in web application programming in order to develop more surveying-related applications.
地理信息系统（GIS）和计算机科学之间的相互作用继续改进了开展许多测量相关活动的方法。过去，测量控制点存储在文件系统中，最好存储在数据库管理应用程序中，因此导致测量控制点的使用有限，因为它们很难在现场定位。然而，这项研究提出了另一种存储这些测量控制点的方法，使其易于访问，并为更快地更新和地理可视化测量控制点提供了空间。这是通过网络编程应用程序实现的，如Node-JS、传单Javascript映射API、MONGODB、HTML和CSS，将GIS集成到网络技术中。最终产品是一个交互式网络应用程序，可以使用任何智能设备访问，并在用户界面上呈现控制点。Survey Control Finder应用程序（E-Beacon）是一个WebGIS平台，用于尼日利亚大学埃努古校区（UNEC）的测量控制站的地理可视化。本研究深入了解了测量技术的最新趋势，以及激发学习者对网络应用程序编程的兴趣以开发更多与测量相关的应用程序的必要性。
{"title":"E-beacon: a web-based survey control finder application","authors":"O. I. Apeh, O. C. Nwaka, R. Ndukwu, Ikechukwu Maduako, Olatomiwa O. Arilewola","doi":"10.4314/sajg.v8i2.5","DOIUrl":"https://doi.org/10.4314/sajg.v8i2.5","url":null,"abstract":"The interplay between Geographical Information System (GIS) and Computer Science has continued to yield improved methods of carrying out many surveying-related activities. In the past, survey control points were stored in file systems and at the best in Database Management applications thereby leading to the limited usage of the survey control points since they are difficult to locate in the field. This study however, suggests another approach for the storage of these survey control points which makes them to be easily accessible and gives room for faster update and geo-visualization of the survey control points. This was achieved by means of web programming applications such as Node-JS, Leaflet Javascript Mapping API, MONGODB, HTML and CSS, integrating GIS into web technologies. The end product is an interactive web application that can be accessed using any smart device with the control points rendered on the user interface. The Survey Control Finder application (E-Beacon) is a WebGIS platform for the geovisualisation of survey control stations in the University of Nigeria, Enugu campus (UNEC), Nigeria. This study gives insight into what the latest trend in technology has in store for surveying and the need to arouse the interest of learners in web application programming in order to develop more surveying-related applications.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44131890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toko Mouhamadou Inoussa, Oladejo Sunday Olukayode, Obayelu Igbekele Stephen
Most natural forests throughout the world have been destroyed and converted to human land uses to meet the ever growing demands for resources while the remaining forest landscapes consequently have a mosaic of human-modified land areas such as urban, agricultural, and plantation lands. Forest and forest products provide myriad of economic, financial and health importance. The threat to the rainforest compelled the establishment of forest reserves with the introduction of exotic tree species. The Oluwa forest is located between latitudes 6º37’ and 7 º20’ north and longitudes 4 º27’ and 5º05’ east in Ondo state, Nigeria. Species richness and abundance data are crucial for conservation priority setting, and long-term vegetation monitoring. Few studies have been carried out on the composition of Terminalia spp, diversity and richness in the institutional-based landuse. The aim of this work is to analyze the influence of topography on Terminalia species diversity for conservation purpose. Complete enumeration of the Natural forest was carried out to determine the varieties of Terminalia species in the study site. In all, two variety, Terminalia, superba and Terminalia ivorensis were identified. GPS coordinate their locations was overlaid on Elevation, Slope, Aspect and Hillshad. The area with low elevation, and low slope, high hillshade, and the west aspect showed maximum species abundance. The Shannon diversity index of Terminalia species was calculated and the result implies that the diversity/abundance is low in the study site. It was observed that the spatial distribution and relative abundance of these species was influenced by topographic factors. Despite the limited range of altitudinal variation (399 m), species richness increases with elevation. This work has provided evidence of variability in Terminalia species composition, richness and diversity across the topographic gradient. The information could be crucial for monitoring and providing conservative measure for management of species sustainability. A future study would be required to isolate proximate factors of tree species distribution.
{"title":"Topographic influence on Terminalia species diversity in Oluwa forest reserve, Ondo State (Nigeria)","authors":"Toko Mouhamadou Inoussa, Oladejo Sunday Olukayode, Obayelu Igbekele Stephen","doi":"10.4314/sajg.v8i2.9","DOIUrl":"https://doi.org/10.4314/sajg.v8i2.9","url":null,"abstract":"Most natural forests throughout the world have been destroyed and converted to human land uses to meet the ever growing demands for resources while the remaining forest landscapes consequently have a mosaic of human-modified land areas such as urban, agricultural, and plantation lands. Forest and forest products provide myriad of economic, financial and health importance. The threat to the rainforest compelled the establishment of forest reserves with the introduction of exotic tree species. The Oluwa forest is located between latitudes 6º37’ and 7 º20’ north and longitudes 4 º27’ and 5º05’ east in Ondo state, Nigeria. Species richness and abundance data are crucial for conservation priority setting, and long-term vegetation monitoring. Few studies have been carried out on the composition of Terminalia spp, diversity and richness in the institutional-based landuse. The aim of this work is to analyze the influence of topography on Terminalia species diversity for conservation purpose. Complete enumeration of the Natural forest was carried out to determine the varieties of Terminalia species in the study site. In all, two variety, Terminalia, superba and Terminalia ivorensis were identified. GPS coordinate their locations was overlaid on Elevation, Slope, Aspect and Hillshad. The area with low elevation, and low slope, high hillshade, and the west aspect showed maximum species abundance. The Shannon diversity index of Terminalia species was calculated and the result implies that the diversity/abundance is low in the study site. It was observed that the spatial distribution and relative abundance of these species was influenced by topographic factors. Despite the limited range of altitudinal variation (399 m), species richness increases with elevation. This work has provided evidence of variability in Terminalia species composition, richness and diversity across the topographic gradient. The information could be crucial for monitoring and providing conservative measure for management of species sustainability. A future study would be required to isolate proximate factors of tree species distribution.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42885263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study highlights the usage of deep learning artificial neural networks in the assessment of groundwater vulnerability of a coalfield. The network uses the DRIST model with parameters (depth to water level, recharge, impact of the vadose zone, soils and topographic slope) as training inputs and borehole sulphate concentration as training output. This technique was applied to Witbank coalfield, where acid mine drainage emanating from coal mining operations is a huge concern for surrounding environment and groundwater resources. The generated groundwater vulnerability model was validated with another sulphate dataset not used during model training. The deep neural network model with dropout and decaying learning rate regularisers correlated very well with sulphate data from another source as compared to the index and overlay DRIST model. The approach, differentiated areas in terms of vulnerability to acid mine drainage, which can aid policy, and decision makers to make scientifically informed decisions on land use planning. The approach developed in this research can be applied to other coalfields in order to evaluate its robustness to different hydrogeological and geological conditions.
{"title":"Groundwater vulnerability mapping of Witbank coalfield in South Africa using deep learning artificial neural networks","authors":"E. Sakala, F. Fourie, M. Gomo, H. Coetzee","doi":"10.4314/sajg.v8i2.12","DOIUrl":"https://doi.org/10.4314/sajg.v8i2.12","url":null,"abstract":"This study highlights the usage of deep learning artificial neural networks in the assessment of groundwater vulnerability of a coalfield. The network uses the DRIST model with parameters (depth to water level, recharge, impact of the vadose zone, soils and topographic slope) as training inputs and borehole sulphate concentration as training output. This technique was applied to Witbank coalfield, where acid mine drainage emanating from coal mining operations is a huge concern for surrounding environment and groundwater resources. The generated groundwater vulnerability model was validated with another sulphate dataset not used during model training. The deep neural network model with dropout and decaying learning rate regularisers correlated very well with sulphate data from another source as compared to the index and overlay DRIST model. The approach, differentiated areas in terms of vulnerability to acid mine drainage, which can aid policy, and decision makers to make scientifically informed decisions on land use planning. The approach developed in this research can be applied to other coalfields in order to evaluate its robustness to different hydrogeological and geological conditions.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41961544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
John Richard Otukei, Prossy Atolere, A. Gidudu, F. Martini
Information on deformation of the land surface is vital for planning of infrastructure especially in areas such as the Albertine graben with substantial amounts of oil discoveries. Traditionally, global positioning systems, precise leveling and geotechnical techniques have been used for assessing and monitoring ground deformations. While these techniques provide accurate information, they are point based, expensive, time consuming and labour intensive over large area monitoring. This study explored an interferometric synthetic aperture radar (InSAR) approach for mapping deformation over Buliisa oil discovery area located in the Western arm of the East African rift valley. The method was implemented by measuring the phase differences of ALOS PALSAR data acquired between 2007 and 2011. Deformation estimates varied between -0.45m to +0.34m while the mean displacements varied from –0.10m to 0.089m. High ground deformation was detected in the Southern, North Eastern and North Western parts contributed by agricultural activity and drilling pad constructions. Generally, analysis of ALOS PALSAR data using InSAR approach provides a viable option for assessing land surface deformation in Buliisa oil exploration area.
{"title":"Ground deformation assessment of the Albertine graben using inSAR","authors":"John Richard Otukei, Prossy Atolere, A. Gidudu, F. Martini","doi":"10.4314/sajg.v8i2.2","DOIUrl":"https://doi.org/10.4314/sajg.v8i2.2","url":null,"abstract":"Information on deformation of the land surface is vital for planning of infrastructure especially in areas such as the Albertine graben with substantial amounts of oil discoveries. Traditionally, global positioning systems, precise leveling and geotechnical techniques have been used for assessing and monitoring ground deformations. While these techniques provide accurate information, they are point based, expensive, time consuming and labour intensive over large area monitoring. This study explored an interferometric synthetic aperture radar (InSAR) approach for mapping deformation over Buliisa oil discovery area located in the Western arm of the East African rift valley. The method was implemented by measuring the phase differences of ALOS PALSAR data acquired between 2007 and 2011. Deformation estimates varied between -0.45m to +0.34m while the mean displacements varied from –0.10m to 0.089m. High ground deformation was detected in the Southern, North Eastern and North Western parts contributed by agricultural activity and drilling pad constructions. Generally, analysis of ALOS PALSAR data using InSAR approach provides a viable option for assessing land surface deformation in Buliisa oil exploration area.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48978561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Landsat-8 OLI imagery of Sokoto, Nigeria, was processed to emphasize the geology features and mineral potential of the area. Band ratios were assigned to RGB. Band ratio highlights ferric ion minerals, emphasizes ferrous minerals, and distinguishes iron oxide minerals from carbonate minerals. In a second technique, band ratio was replaced with in order to accentuate clay minerals with high reflectance within band 7. The last technique evaluated in this study used spectral information from minimum noise fraction image to map surface geology. Supervised classification training sites were selected using five classes (clay, ironstone, alteration zone, water and vegetation). The band ratio classification using maximum likelihood classification was fairly accurate and matched the geologic map of the area, also showing an alteration zone that coincided with the migmatite-quartz/mica schist contact. The classified image was finally passed through a filtering effect for generalization of the data. This filtering effect was helpful in discriminating the pixels of ironstone and those of the alteration zone on the classified map.
{"title":"Application of remote sensing method for geological interpretation of Sokoto Plain, Nigeria","authors":"Aisabokhae Joseph, O. Bamidele","doi":"10.4314/SAJG.V7I3.12","DOIUrl":"https://doi.org/10.4314/SAJG.V7I3.12","url":null,"abstract":"Landsat-8 OLI imagery of Sokoto, Nigeria, was processed to emphasize the geology features and mineral potential of the area. Band ratios were assigned to RGB. Band ratio highlights ferric ion minerals, emphasizes ferrous minerals, and distinguishes iron oxide minerals from carbonate minerals. In a second technique, band ratio was replaced with in order to accentuate clay minerals with high reflectance within band 7. The last technique evaluated in this study used spectral information from minimum noise fraction image to map surface geology. Supervised classification training sites were selected using five classes (clay, ironstone, alteration zone, water and vegetation). The band ratio classification using maximum likelihood classification was fairly accurate and matched the geologic map of the area, also showing an alteration zone that coincided with the migmatite-quartz/mica schist contact. The classified image was finally passed through a filtering effect for generalization of the data. This filtering effect was helpful in discriminating the pixels of ironstone and those of the alteration zone on the classified map.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/SAJG.V7I3.12","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44736908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Good redundancy is required to isolate gross errors and improve the qualities of derived parameters. Improving the weak redundancies of traditional traverses by traversing on double lines is now possible with total stations which provide for less cumbersome measurements than previously possible and more so now that control traverses are computed by least squares adjustment using readily available computer software. Traversing on double lines requires some care in choosing traverse stations with inter-visibility from two immediately preceding and two directly succeeding stations. Traverses were run on double lines resulting in redundancy increase of seven per station. Local accuracy precision parameters improved also by as much as 25% and 52% with implementation at 30% and 100% of the traverse stations respectively. A chart that may be used to determine percentage number of traverse stations where traversing on double lines would be implemented to achieve set local accuracy improvements is presented.
{"title":"Improving traverse redundancy and precision by running on double lines","authors":"A. C. Chukwuocha, Franklin Enyinnaya Onyeagoro","doi":"10.4314/SAJG.V7I3.13","DOIUrl":"https://doi.org/10.4314/SAJG.V7I3.13","url":null,"abstract":"Good redundancy is required to isolate gross errors and improve the qualities of derived parameters. Improving the weak redundancies of traditional traverses by traversing on double lines is now possible with total stations which provide for less cumbersome measurements than previously possible and more so now that control traverses are computed by least squares adjustment using readily available computer software. Traversing on double lines requires some care in choosing traverse stations with inter-visibility from two immediately preceding and two directly succeeding stations. Traverses were run on double lines resulting in redundancy increase of seven per station. Local accuracy precision parameters improved also by as much as 25% and 52% with implementation at 30% and 100% of the traverse stations respectively. A chart that may be used to determine percentage number of traverse stations where traversing on double lines would be implemented to achieve set local accuracy improvements is presented.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/SAJG.V7I3.13","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48226984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fire risk assessment is one of the most components of the management of fire that offers the framework for monitoring fire risk conditions. Whilst monitoring fire risk conditions commonly revolved around field data, Remote Sensing (RS) play key role in monitoring and quantifying fire risk indicators. This study presents a review of remote sensing data and techniques for fire risk monitoring and assessment with a particular emphasis on its implications for wildfire risk mapping in protected areas. Firstly, we concentrates on RS derived variables employed to quantify both the intrinsic and extrinsic factors that influence vegetation flammability. Thereafter, an evaluation of the prominent RS platforms such as Broadband, Hyperspectral and Active sensors that have been utilized for wildfire risk assessment Furthermore, we demonstrate the effectiveness in obtaining information that have operational use or immediate potentials for operational application in PA. RS techniques that involve extraction of landscape information from imagery were summarised. A review has concluded that in practices, a fire risk assessment that consider all factors that influence fire ignition and propagation is impossible to establish, however it is imperative to incorporate indicators or variables of very high heterogeneous.
{"title":"Review of the use of remote sensing for monitoring wildfire risk conditions to support fire risk assessment in protected areas","authors":"Olga Dipuo Molaudzi, S. Adelabu","doi":"10.4314/SAJG.V7I3.2","DOIUrl":"https://doi.org/10.4314/SAJG.V7I3.2","url":null,"abstract":"Fire risk assessment is one of the most components of the management of fire that offers the framework for monitoring fire risk conditions. Whilst monitoring fire risk conditions commonly revolved around field data, Remote Sensing (RS) play key role in monitoring and quantifying fire risk indicators. This study presents a review of remote sensing data and techniques for fire risk monitoring and assessment with a particular emphasis on its implications for wildfire risk mapping in protected areas. Firstly, we concentrates on RS derived variables employed to quantify both the intrinsic and extrinsic factors that influence vegetation flammability. Thereafter, an evaluation of the prominent RS platforms such as Broadband, Hyperspectral and Active sensors that have been utilized for wildfire risk assessment Furthermore, we demonstrate the effectiveness in obtaining information that have operational use or immediate potentials for operational application in PA. RS techniques that involve extraction of landscape information from imagery were summarised. A review has concluded that in practices, a fire risk assessment that consider all factors that influence fire ignition and propagation is impossible to establish, however it is imperative to incorporate indicators or variables of very high heterogeneous.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/SAJG.V7I3.2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47833489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Woody species on savannahs provide nutrition to wildlife and livestock ungulates. Understanding of leaf reflectance would benefit the application of remote sensing in analysis of these rangelands. This study sought to establish the influence of the leaf characteristics of size (leaf form) and chlorophyll content on the spectral reflectance characteristics of a sample of savannah woody species is investigated, and the applicability of these leaf characteristics in the context of abilities to remotely sense the state of the woody species using optical remotely sensed imagery. Two species that represented narrow leaf and broad leaf savannah woody species we studied: Acacia tortilis and Ziziphus mucronata , respectively. Forty seven woody individuals representing these species were sampled in northwestern South Africa. Chlorophyll content, leaf area index (LAI) and spectral reflectance were determined in the field using a chlorophyll metre, a canopy analyser and spectroradiometer, respectively. A SPOT 6 NAOMI image acquired at a time of year when grass reflectance was excluded from the spectral signature of non-senescent vegetation was used. The image data were converted to reflectance (%), and the reflectance of the field-sampled trees correlated with the in-situ data. The results showed that the woody species differed significantly in their chlorophyll content and green reflectance, but only the NIR reflectance broad leaf species correlated strongly with a leaf characteristic, LAI. From the results it can be concluded that leaf area index (LAI) is the more reliable leaf characteristic for analysing the characteristics of savannahs in terms of leaf content.
{"title":"Evaluating the effects of leaf characteristics on spectral signatures of savannah woody species on remotely sensed imagery","authors":"C. Munyati, L. Malomane, O. Malahlela","doi":"10.4314/sajg.v7i3.9","DOIUrl":"https://doi.org/10.4314/sajg.v7i3.9","url":null,"abstract":"Woody species on savannahs provide nutrition to wildlife and livestock ungulates. Understanding of leaf reflectance would benefit the application of remote sensing in analysis of these rangelands. This study sought to establish the influence of the leaf characteristics of size (leaf form) and chlorophyll content on the spectral reflectance characteristics of a sample of savannah woody species is investigated, and the applicability of these leaf characteristics in the context of abilities to remotely sense the state of the woody species using optical remotely sensed imagery. Two species that represented narrow leaf and broad leaf savannah woody species we studied: Acacia tortilis and Ziziphus mucronata , respectively. Forty seven woody individuals representing these species were sampled in northwestern South Africa. Chlorophyll content, leaf area index (LAI) and spectral reflectance were determined in the field using a chlorophyll metre, a canopy analyser and spectroradiometer, respectively. A SPOT 6 NAOMI image acquired at a time of year when grass reflectance was excluded from the spectral signature of non-senescent vegetation was used. The image data were converted to reflectance (%), and the reflectance of the field-sampled trees correlated with the in-situ data. The results showed that the woody species differed significantly in their chlorophyll content and green reflectance, but only the NIR reflectance broad leaf species correlated strongly with a leaf characteristic, LAI. From the results it can be concluded that leaf area index (LAI) is the more reliable leaf characteristic for analysing the characteristics of savannahs in terms of leaf content.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/sajg.v7i3.9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44093298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper presents the Talking Titler Network (TTN) database design, for conflict and post-conflict land records. In conflict and post-conflict situations, the constellation of interests from displaced persons, witnesses, and people who currently occupy the land that displaced persons once owned are often difficult to unravel, and conventional land record data models are often restricted in the type and scope of data to handle these complex situations. One solution is a database design that can capture multiple, overlapping and layered tenure relationships in a changing environment that are too complex for the relational data model to handle. The Triple Store graph database development system and its ontology languages were used to design and develop the TTN prototype. The authors’ observations from the Gaza Strip, an ongoing conflict situation, and Somaliland, a post-conflict situation, were used as illustrative contexts. The test results show that graph database flexibly captured, described, and automatically revealed tenure patterns. TTN simplified the complexity of tenure relationships among objects by organizing them into sets of connected triples, revealing tenure relationships, and visualizing tenure information as a graph network, and as a table. The design shows promise in capturing complex, contested tenure relationships.
{"title":"Network database design for conflict and post-conflict Land Tenure Information Systems (LTIS)","authors":"Alaa Dabboor, M. Barry","doi":"10.4314/SAJG.V7I3.8","DOIUrl":"https://doi.org/10.4314/SAJG.V7I3.8","url":null,"abstract":"The paper presents the Talking Titler Network (TTN) database design, for conflict and post-conflict land records. In conflict and post-conflict situations, the constellation of interests from displaced persons, witnesses, and people who currently occupy the land that displaced persons once owned are often difficult to unravel, and conventional land record data models are often restricted in the type and scope of data to handle these complex situations. One solution is a database design that can capture multiple, overlapping and layered tenure relationships in a changing environment that are too complex for the relational data model to handle. The Triple Store graph database development system and its ontology languages were used to design and develop the TTN prototype. The authors’ observations from the Gaza Strip, an ongoing conflict situation, and Somaliland, a post-conflict situation, were used as illustrative contexts. The test results show that graph database flexibly captured, described, and automatically revealed tenure patterns. TTN simplified the complexity of tenure relationships among objects by organizing them into sets of connected triples, revealing tenure relationships, and visualizing tenure information as a graph network, and as a table. The design shows promise in capturing complex, contested tenure relationships.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/SAJG.V7I3.8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43145000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study reports on the creation and evaluation of a spatio-temporal mapping of the Ciskei, one of the so-called ‘Bantustans’ or ‘Homelands’ located in South Africa. The Ciskei was created as a result of race-based legislation during the colonial and apartheid periods. Its geographical extent changed over time, and the spatial changes coincided with the promulgation of different legislation. Geographic Information Systems (GIS) technology was used to create a time series animation and a static map to display the spatial change of the Ciskei boundaries. Questionnaires and interviews were used to investigate two main aspects. The questionnaire’s purpose was to investigate and compare map-readers’ cognition at detecting change between static and animated maps. Interviews allowed the researchers to qualitatively assess the value of such an exercise. Both the animated and static maps have advantages over each other but neither one of them has an overall clear advantage, confirming previous research. There is value of such mapping to decision-makers in government, as this exercise can help to produce a better understanding of legislative, cadastral, planning and historical effects.
{"title":"GIS time series mapping of the Ciskei homeland","authors":"S. Ali, Siddique Motala","doi":"10.4314/sajg.v7i3.1","DOIUrl":"https://doi.org/10.4314/sajg.v7i3.1","url":null,"abstract":"This study reports on the creation and evaluation of a spatio-temporal mapping of the Ciskei, one of the so-called ‘Bantustans’ or ‘Homelands’ located in South Africa. The Ciskei was created as a result of race-based legislation during the colonial and apartheid periods. Its geographical extent changed over time, and the spatial changes coincided with the promulgation of different legislation. Geographic Information Systems (GIS) technology was used to create a time series animation and a static map to display the spatial change of the Ciskei boundaries. Questionnaires and interviews were used to investigate two main aspects. The questionnaire’s purpose was to investigate and compare map-readers’ cognition at detecting change between static and animated maps. Interviews allowed the researchers to qualitatively assess the value of such an exercise. Both the animated and static maps have advantages over each other but neither one of them has an overall clear advantage, confirming previous research. There is value of such mapping to decision-makers in government, as this exercise can help to produce a better understanding of legislative, cadastral, planning and historical effects.","PeriodicalId":43854,"journal":{"name":"South African Journal of Geomatics","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/sajg.v7i3.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42124286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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