Geodetic work at the archaeological site Tell el-Retaba

The paper summarizes the geodetic contribution for the Slovak team within the joint Polish-Slovak archaeological mission at Tell el-Retaba in Egypt. Surveying work at archaeological excavations is usually influenced by somewhat specific subject of study and extreme conditions, especially at the missions in the developing countries. The case study describes spatial data development according to the archaeological conventions in order to document spatial relationships between the objects in excavated trenches. The long-term sustainability of surveying work at the site has been ensured by detailed metadata recording. Except the trench mapping, Digital Elevation Model has been calculated for the study area and for the north-eastern part of the site, with promising preliminary results for further detection and modelling of archaeological structures. In general, topographic mapping together with modern technologies like Photogrammetry, Satellite Imagery, and Remote Sensing provide valuable data sources for spatial and statistical modelling of the sites; and the results offer a different perspective for the archaeological research.

Modeling Malaria Prevalence Rate in Lagos State Using Multivariate Environmental Variations

The aim of this research is to establish the significant effect of environmental factors on malaria prevalence rate within the Local Government Areas of Lagos State. The methodology used was to carry out a statistical analysis of these various environmental factors with the malaria prevalence cases that was recorded in Lagos State using a 5 years data from 2009-2013 of malaria prevalence cases recorded with environmental data for the same time frame, and to further use GIS to show the various Local Government Areas with high severe malaria cases as well as low malaria cases. The result obtained from this analysis shows a significant relationship between the malaria prevalence cases and environmental factors of rainfall, temperature and relative humidity, this helped in developing a predictive model. The outcome from this research work can help the government, Lagos State Ministry of Health and donor agencies both local and international see the Local Government Areas within the state that are most vulnerable to malaria epidemic, and further aid them in policy formation, planning and strategy implementation.

Plotting the map projection graticule involving discontinuities based on combined sampling

This article presents new algorithm for interval plotting the projection graticule on the interval $\varOmega=\varOmega_{\varphi}\times\varOmega_{\lambda}$ based on the combined sampling technique. The proposed method synthesizes uniform and adaptive sampling approaches and treats discontinuities of the coordinate functions $F,G$. A full set of the projection constant values represented by the projection pole $K=[\varphi_{k},\lambda_{k}]$, two standard parallels $\varphi_{1},\varphi_{2}$ and the central meridian shift $\lambda_{0}^{\prime}$ are supported. In accordance with the discontinuity direction it utilizes a subdivision of the given latitude/longitude intervals $\varOmega_{\varphi}=[\underline{\varphi},\overline{\varphi}]$, $\varOmega_{\lambda}=[\underline{\lambda},\overline{\lambda}]$ to the set of disjoint subintervals $\varOmega_{k,\varphi}^{g},$$\varOmega_{k,\lambda}^{g}$ forming tiles without internal singularities, containing only "good" data; their parameters can be easily adjusted. Each graticule tile borders generated over $\varOmega_{k}^{g}=\varOmega_{k,\varphi}^{g}\times\varOmega_{k,\lambda}^{g}$ run along singularities. For combined sampling with the given threshold $\overline{\alpha}$ between adjacent segments of the polygonal approximation the recursive approach has been used; meridian/parallel offsets are $\Delta\varphi,\Delta\lambda$. Finally, several tests of the proposed algorithms are involved.

Variation detection and respondents’ feedback: the cause, effect, and solution of oil spills.

Centred on occurrences of pipeline explosion and oil spills in a host community; a supervised classification technique, of land use/land cover variation detection was carried-out, with Landsat imageries of three time intervals, to determine the percentage of variation between the time intervals. Also carried-out, was a random sampling of questionnaires; dispatch to acquire respondents’ feedback. It addressed respondents’ demographic and social-economic composition of the sample population, the perception on the cause and the impact, and the effect of the oil spill and finally considered the possible solutions. Information was subjected to descriptive analysis and an F-test statistical analysis in a 95% confidence interval. Reports showed that land use/land cover classification had undergone series of percentage variation within the time interval considered, indicating ‘remarks’ of a rise or a decline. While, the measure of insecurity (of about 36.7%) is a prevailing element to the unceasing attack on oil pipelines and only a sustaining security measure (of about 40.8%) will evidently pave a way-out. Wherefore advocating for community based policing, and a comprehensive technological sensor system, for monitoring of oil pipelines/facilities across the Nation.

Accurate Measurement of the Riverbed Model for Deformation Analysis using Laser Scanning Technology

<p>This paper presents an interesting application of the riverbed model shape and deformations monitoring using laser scanning technology and accurate local micro-network. The most interesting fact about this application is very high accuracy demand on deformation determination (maximum permissible error is only 2 mm) within quite large object (the size of the riverbed model is about 100 meters). Up to now, mechanical calipers in the selected profiles were used to detect the changes. This manual approach is very laborious and time-consuming and the gathered data resolution and accuracy is often not sufficient. The suggested solution contains two main parts. The first part deals with construction of highly accurate local micro-network for laser scanning needs (maximum required standard deviation in any coordinate is lower than 0.4 mm) and the second part deals with actual laser scanning and data processing. Design, measurement and processing of the experiment was conducted for the needs of the research project “Improvement of navigation conditions on the Elbe between Ústí nad Labem - state border CR / FRG - Navigation Step Děčín”. The main goal of this project is design and realization of the river regulation to improve the navigation conditions. The key benefit of using river model is the possibility to easily simulate various catastrophic scenarios (various degrees of the floods) and their impacts on riverbed changes.</p>

Implication of Human Induced Activities on Ecotourism in Ikogosi Warm Spring Centre, Ekiti State, Southern western, Nigeria

<p>The magnitude effect of human activities on the environment is of great concern. In this study investigation on the pattern of land use land cover change in the Ikogosi Ekiti, South Western and Nigeria was carried out. A 30 meter Landsat image of TM 1991, ETM+ 2002 and OLI 2015 were used for the study. The satellite images were digitally processed using Arcgis10.3 and Idrisi Selva 17.0 while Markov Chain Modeler was employed for prediction. Supervised Classification was performed through Maximum Likelihood Classification resulting into identification of five LULC classes which were built-up, rock outcrop, dense vegetation, light vegetation and water body; fragmentation analysis was done using Fragstat 4.0.</p><p>The results showed that anthropogenic activities resulted in 25.93% increase in built-up between the periods of 1991 and 2015 with a substantial loss (29.97%) of dense vegetation within the study area were detected. Fragmentation metric showed that the Number of Patches (NP) increased by 257, 268 and 281 while Shannon Diversity Index (SHIDI) correspondingly showed a decreased of 0.54, 0.47 and 0.21 for species diversity in year 1991, 2002 and 2015 respectively; indigenous respondents (70.1%) affirmed the extinction of biodiversity. Furthermore, the Markov Chain Modeler revealed that built-up was expected to increase by 36.7, 39.1 and 69.6% while dense vegetation will correspondingly decrease by 25.4, 22.9 and 18.7% in year 2030, 2050 and 2065 respectively. The result revealed that anthropogenic activities in the study area had contributed to massive removal of vegetation and this pattern had negatively affected the biomass condition of the study area indicting the region to experience an ecosystem imbalance and incidence of global warming. The changing spatial pattern was attributed to the tourism developmental phases in-around Ikogosi community which had increased deforestation, exotic plants and poaching by Ikogosi inhabitants and tourist visits to the study area.</p><p>The study concluded that various tourism development activities had adversely affected the nature of biodiversity, threatened land-use management and vegetation in the study area.</p>

An Alternative Choice in Heighting

Comparison of orthometric heights obtained from the combination of GPS/Levelling survey method with that obtained from Lidar, Srtm, and Astergdem data is an area of research which is of great interest to Geomaticians. This area of research makes possible the discovery of other suitable methods of determining orthometric height which can be selected for use depending on the region, extent and nature of the terrain where the project is to be executed.<p style="-qt-block-indent: 0; text-indent: 0px; margin: 0px;">The X, Y, Z coordinates and the geoidal heights for all the existing controls within university of Lagos were determined using the GPS/ Levelling survey method, the required orthometric height (H) was then obtained as the differences between ellipsoidal and geoidal heights. Extracting orthometric heights for the X and Y coordinates of observed control points overlaid on each of Lidar, Srtm and Astergdem required the use of spatial analysis tool in an arc map environment. From the profile plot (Figure 3.5) of all the orthometric heights, the heights relationship was easy established. From the descriptive statistics test (Table 3.4), the one way ANOVAs test at 1% and 5% level of significance (Table 3.8), the number of points in other methods whose orthometric height is closed to that of Levelling/GPS method (Table 3.7) and correlation test on the various orthometric heights obtained (Table 3.5) it is obvious that all the applied methods operates at different spatial resolutions, of all the four methods, GPS/Levelling method was the most reliable and most accurate method followed by lidar method, then by astergdem method and Srtm has the least. In a nutshell, Orthometric heights generated by method of Lidar are very close to that generated by GPS/Levelling method at several stations, thus method of Lidar was considered as the most suitable alternative to GPS/Levelling method, whenever the use of later method cannot be easily accomplished.</p><p style="-qt-block-indent: 0; text-indent: 0px; margin: 0px;"> </p>

Efficient plotting the functions with discontinuities based on combined sampling

This article presents a new algorithm for interval plotting of the function y = f(x) based on combined sampling. The proposed method synthesizes the uniform and adaptive sampling approaches and provides a more compact and efficient function representation. During the combined sampling, the polygonal approximation with a given threshold α between the adjacent segments is constructed. The automated detection and treatment of the discontinuities based on the LR criterion are involved. Two implementations, the recursive-based and stack-based, are introduced. Finally, several tests of the proposed algorithms for the different functions involving the discontinuities and several map projection graticules are presented. The proposed method may be used for more efficient sampling the curves (map projection graticules, contour lines, or buffers) in geoinformatics.

Land Surface Temperature Mapping using Geoinformation Techniques

General environmental management, which involves monitoring and modeling, requires the information of the Land surface temperature (LST) status of area concerned. Land surface temperature has gained relevance recognition over the years and there is need to develop approaches that can determine LST using satellite images. This study was conducted in Akure which has experienced rapid urbanization in recent time. The study utilized Landsat data of 1984, 1990, 2000, 2003, 2014 and 2016. The temperature data were derived from Landsat images using remote sensing algorithms for assessing LST from thermal infrared (TIR) data (bands 6 and 10). These data were processed and analyzed using tools in Idrisi and ArcGIS software systems. Satellite-derived land surface temperatures were validated with in-situ temperature data. The results revealed parabolic increase in temperature over the years and the changing pattern was investigated by adopting existing ecological indexes.. The validation operation revealed average bias value of between remote sensing- and ground-based data. This implies that remote sensing technique is reliable and therefore could be employed for large scale temperature mapping. The results could be used in mitigating urban heat island effectssuch as heat-related stress and ill-timed human deaths.

GeoEasy an open source project for surveying calculations

The development of the GeoEasy program started in 1997. Twenty years later in 2017 it became free software under GPL license, version 3.0.0 is freely available for everybody. The core development of GeoEasy is made on Linux operating system, using Tcl/Tk script language, thanks to the Tcl/Tk ports to other operating systems, the program can be run on Linux, Windows, Android and OSX machines. Objectives of the development are to create user friendly graphical user interface (GUI) for surveying calculations in a modular structure with flexible, open connections to other programs. Both educational and professional usages are supported.