Geodesy and Geomatics

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Design and Optimization of Geodetic Network: A Case of Ethiopia
(Addis Ababa University, 2023-09) Haileslassie Muluken; Andinet Ashagre (PhD)
The optimization of a geodetic network is to enhance precision and efficiency in surveying practices. Precision involves in controlling the quality of a geodetic network. The research objective is to strategically position control points and minimize errors to improve the overall geodetic network. Finding the optimal design of geodetic network of Ethiopia is the main objective of this thesis by solving the zero order design and first order design problems by applying one of the classical methods that is the trial and error technique using a MATLAB programing language. Zero order design problem was applied to a case study network consists of 30 points and 70 designed distances with a priori deviation equal to 5mm, to determine the best points in the network to consider as control points. The results showed that P18 and P19 having the minimum ellipse of error and considered as control points. These points are therefore chosen as the control points since they have an area of 0.094 and 0.101, respectively, making them the best points. First order design problem was applied on a selected network to be analysed using the objective function, with selected range of movement of 100m to each point in each direction. This first order design problem optimization is done by the trial and error method. By taking P18 and P19 as control points the optimal design of the geodetic network with high precision is developed
Development of Cadastral Information System by using Geographic Information System in Addis Ababa City: a Case Study in Akaki Kality Sub-City, Ethiopia
(Addis Ababa University, 2024-02) Atirsaw Chale; Hamere Yohannes (PhD)
Every developmental effort and human activity depends on land. Therefore, systematic recording of land ownership is essential to ensure the rights of landowners. This paper focuses on the developing a Cadastral Information System (CIS) using Geographic Information System (GIS). Parcel corner data were collected. Sampling data was gathered through key informant interviews, and existing analog (paper-based) attribute data, high-resolution aerial imagery, and Ground Control Point (GCP) data were also utilized. The collected parcel data and aerial imagery were digitized using ArcGIS software. The digitization yielded 126 parcels and 14 roads totally of 140 parcels. Subsequently, topology rule violations were addressed: "Must have no Gaps" and "Must not have overlaps" were fixed for parcels, and "Must not have dangles" was fixed for roads. Finally, the existing analog (paper-based) attribute data was converted to digital format using MS Excel and linked (joined) to the digitized spatial data via a unique id. Parcels were initially identified by using attribute data and existing land use, resulting in 95 registered residential parcels, 18 residential undocumented parcels, 1 sports field, 3 open spaces, 9 cutoff places from parcels, and 14 roads. Secondly, identification by adjudication right showed 71 lease hold, 36 free hold, and 33 unidentified parcels. Further identification by adjudication result revealed 50 parcels with eligible and 90 ineligible parcels. Lastly, ownership type identification categorized the parcels as 21 governments, 118 private, and 1 religious place. Additionally, an attribute data query was applied to quickly access the attribute data.The CIS map of ground data was compared with the CIS map of aerial imagery to assess the accuracy discrepancies between the two. The analysis revealed that the CIS map based on ground data exhibited higher accuracy compared to the map from aerial imagery.Five participants were selected based on their work experience and academic qualifications. They responded to questions based on their perceptions of the CIS in Ethiopia. Notably, more than half of the participants rated the current level of the CIS as low. Finally, these findings verified that the applied cadastral system effectively and efficiently manage land parcels in the study area and we recommend government sector to address concerns regarding CIS not applied area.
Evaluating The Status of Land Use Land Cover Change: A Case Study of East Gojjam Zone Debre Markos Town, Ethiopia
(Addis Ababa University, 2024-02) Dawit Belay; Andenet Ashagrie (PhD)
This research was conducted to evaluate the status of urban land use land cover change. To analyze the LULC change of this study satellite images (Landsat 1986, 2003 and 2020) have been used for retrieving information, adopting image classification method. In addition accuracy analysis has been done by comparing the reference data with the classification results to evaluate the effectiveness of the image classification. The changes between the defined years was evaluated using land use Land cover maps that belongs to different years adopting cross tabulation and overlay analysis methods. The main aim of this study was to evaluate the status of urban land use land cover change in the study area. The result indicates that the main changes in the study area were the transformation of Agricultural Lands 41.62%, 32.60 changes 22.5 % and converted into Built up lands in the study area. Accordingly, around 980 ha of area of Agricultural land were transformed to build up in the last two decades.
Evaluation Of EGM2008 by Means Of GPS/Levelling In Uganda
(Addis Ababa University, 2013-04) Dianah Rose Abeho; Roger Hipkin (PhD)
The global gravity model EGM2008 is evaluated in various regions of the country to assess if it is good enough for geodetic applications. The evaluation method involves comparison of geoid heights computed from the model with those computed at irregularly distributed GPS/levelling stations. For testing the model, a total of seven levelled benchmarks available in Uganda which belong to the New Khartoum datum are used. The spatial positions of these benchmarks were determined at mm accuracy, with respect to ITRF2008. The agreement between the EGM2008 geoid and the geoid undulation derived from GPS/levelling over the seven irregularly distributed benchmark points has a standard deviation of 0.255m, with a mean of -0.859m. The datum offset may be due the choice of Wo (potential of the geoid) and Uo (potential on the surface of the ellipsoid); using GRS80 for the gravitational reference system and WGS84 for the geometrical reference system; some possibly different tidal conventions; but, by using the same method of analysis for Ethiopia and Uganda, these absolute offset effects are eliminated when comparing the two so that the computed difference [0.118 m] in datum offset for the two states does tell us something about the differences in levelling datums. The standard deviation of 26 cm suggests that sparser, irregularly-distributed and inhomogenous gravity data for Uganda was used in the development of EGM2008 not ruling out errors in levelling since there is barely any documentation pertaining the accuracy of results obtained regarding the levelling network in Uganda.
Comparison of Geoid Determination Methods: A Case Study at the Central Part of Ethiopia.
(Addis Ababa University, 2024-02) Zenebe Ayele; Andenet Ashagrie (PhD)
Geoid is the equipotential surface that closely approximates to the mean sea level. Determining the geoid gravimetrically poses challenges, particularly when demanding precision is necessary. The precision of geoid determination depends on the methods that were applied during computation. The paper aimed at comparing the magnitude of geoid ellipsoidal separation which obtained from the three distinct geoid determination methods namely: the least square collocation, Stokes integral, and Hotine integral methods with an emphasis on evaluating their individual accuracies. SRTM1, gravity anomaly and disturbance, EGM08 and GPS/Levelling data were used for the computation of geoid determination methods. The downward continuation of the free-air gravity anomaly was performed for both the Stokes integral and least square collocation methods, and the gravity disturbance for Hotine integral method were used. In addition to this, the corrections were added for Stokes and Hotine integral methods to the approximate geoid. During comparison of the computed gravimetric geoid models, the GPS/leveling data was taken as a reference for validation. The standard deviation of the least square collocation, Stokes and Hotine integral methods were 0.154m, 0.061m, and 0.062m, respectively. Based on the standard deviation the Stokes integral, Hotine integral, and least square collocation methods demonstrated high, medium, and low accuracy, respectively, across diverse topographies. However, in plain areas, all the methods that applied in this study are significant for geodetic community. Whereas, in mountainous regions, only the Stokes and Hotine integral methods are preferred and had achieved effective accuracy. And also, the F-test statistics between the least square collocation and the Stokes/Hotine/ integral methods showed significance difference. Therefore, the least square collocation method needs further investigation to attain the permissible accuracy similar to Hotine and Stokes integral methods.
Agricultural Land Suitability Analysis Using GIS and Remote Sensing Techniques: The Case of Mecha Woreda, Amhara, Ethiopia
(Addis Ababa University, 2024-01) Abebe Negussie; Hamere Yohannes (PhD)
Agricultural land suitability study plays a vital role in determining forthcoming agricultural cropping patterns, as well as in the formulation of plans and activities related to agriculture. The assessment of land suitability is a critical endeavor that involves the evaluation of a specific area to ascertain its appropriateness and suitability for a particular use within a given locale. This process encompasses a comprehensive analysis that takes into consideration a multitude of factors, including soil characteristics, climate conditions, topographical features, and the availability of water resources. This analysis on land suitability employs a multi-criteria analytical approach in order to determine the most appropriate land for rain-fed purposes. The results of this analysis demonstrate that a considerable proportion of the region being examined exhibits a high level of suitability for agricultural activities. Approximately 20.92% of the region can be designated as significantly suitable for agricultural practices, and an additional 33.03% can be described as highly suitable. These statistics reveal that around 54% of the entire area possesses a substantial capacity for prosperous farming endeavors. According to the research's discoveries, a substantial segment of the evaluated territory is either highly suitable or very high suitable for irrigation, with a combined total of 82.66%.However, there are also notable areas that are only moderately or low suitable (13.96% combined), while a smaller proportion is not suitable (3.38%) for irrigation purposes In conclusion, the results suggest that a significant proportion of the region being examined exhibits a considerable level of suitability, ranging from high to extremely high, for agricultural purposes.
Developing a Model for Fire Emergency Response Using GIS Based Solution: A Case of Addis Ababa city, Ethiopia
(Addis Ababa University, 2024-01) Assenakew Tsegaw; Hamere Yohannes (PhD)
Emergency services are those that respond to various emergency situations in order to guarantee public safety. For cities, deciding where to put emergency stations is essential. When choosing the best incident location, the most crucial factors to consider are response time reduction, coverage maximization, and overall cost reduction. It is necessary to use Geographic Information Systems (GIS) in order to study on maps. The focus of this work is on developing a model for fire emergency response model based on GIS station; to deliver the fire emergency service in Addis Ababa city, locate the fire incident and the existing fire response station to arrive at the place where the incident occurs. This GIS-based approach followed identified elements such as fire response station, Addis Ababa city parcel, after identified elements then Geo coding existing fire response station and Addis Ababa city resident or parcel and to develop the database for this fire emergency response. To develop the model for the study area, Geo code at visual study code for x y coordinate of fire station and residential with attribute parcel ID. Finally the developed fire emergency response model and database integrate with web GIS. The overlay result indicates that the fire emergency response model and fire emergency database model access to locate a fire incident and timely intervention play a crucial role in managing urban fire, the Addis Ababa city parcel and existing fire response station were based on the inputs, parcel number or ID. The present study suggests GIS based fire emergency response model which helps to located fire incident with the corresponding fire response station location for the city as well as provides fire emergency response Database for the study area.
Forest Fire Risk Estimation and Modeling Using GIS and Remote Sensing Techniques: The Case Of Asebot Monastery, Oromia, Ethiopia
(Addis Ababa University, 2024-02) Birhanu Melkam; Hamere Yohannes (PhD)
Forest fires are a major threat to the environment, human health, and property. The Asebot forest area is particularly vulnerable to forest fires due to its unique geographical and environmental characteristics. To mitigate the risk of forest fires in this region, it is essential to identify the influential factors of forest fire risks and estimate post-fire degradation. This was achieved by using post-fire satellite images of 2021 and modeling the location of potential fire susceptibility in the Asebot forest area. Forest fires are a major threat to ecosystems and human populations, and early detection and monitoring are crucial for effective fire management. In this study, the weighted overlay analysis technique is being used for multi-criteria decision-making. The goal is to estimate the post-fire and model forest fire risk susceptibility. To perform this analysis, each data set is converted to raster format and reclassified to a common scale using ArcGIS spatial analysis. Pair-wise comparisons of factor layers are conducted to determine their relative importance or weight. Remote sensing techniques have become increasingly important for detecting and monitoring forest fires, as they offer a cost-effective and efficient way to gather data over large areas. In this study, the two commonly used remote sensing techniques are employed to estimate fire severity: Normalized Difference Vegetation Index (NDVI) and Burn Severity Index (NBR). The study found that approximately 38.419% of the area had very high and high burn severity, as classified by the Normalized Burn Ratio (NBR) index whereas, burn severity concerning NDVI, which is very high and high burn severity covered 52.277% of the study area. The findings of the study indicate that the area under consideration has varying levels of forest fire risk. The model produced in this study reveals that a substantial portion of the area is classified as having a high to very high risk of forest fires, with over 22% falling into these categories
Landslide Hazard Zonation by Using Geospatial Based Multi-Criteria Decision Analysis Techniques: The Case of Worra Jarso District, Central Ethiopia
(Addis Ababa University, 2024-02) Adisu Mersha; Hamere Yohannes (PhD)
The present study area is located in the Northern Shewa Zone of the Oromia Region, Worra Jarso District, Central Ethiopia, which is far 186km from Addis Ababa. Landslide is among mega geo-hazard that pose a significant damage to civil infrastructure, property, and loss of life. It can be induced by natural phenomena like heavy rainfall, earthquakes and volcanoes. As well, by human action such as deep excavation for mining, road network, building, urbanization, deforestation, unscientific slope cutting and improper agricultural practice. Therefore, the main aim of this study was to delineate landslide hazard-zones using Geospatial based Multi-Criteria Decision Analysis methods. To achieve the stated objective, the eight causative factors were identified namely; elevation, slope, aspect, curvature, soil type, lithology, land use/land cover and drainage density. These factors were identified and the weights were assigned based on the Expert opinion, literature review and nature of the study area. Accordingly, the assigned weights were computed using pair wise comparison matrix of Analytic Hierarchy Process (AHP) method. The spatial distribution of landslide was mainly influenced by slope angle >450, limestone lithological unit, high drainage density, shallowness of leptosoil, expansion of agricultural land on steep slope, falling of elevation class in between 1575m-2100m, concave slope curvature and northwest facing of slope aspect. Later, the landslide hazard zone map was produced by using Analytic Hierarchy Process and Weighted Linear Combination in Geographic Information System (GIS) weighted overlay analysis environment. The produced landslide Hazard Zone map shows that 0.001% (0.014km2)area fall within low hazard zone, 46.66% (555.25km2) of the area fall within moderate hazard zone, 50.02% (595.13km2) and 3.32% (39.48km2) of the area falls into high hazard and very high hazard zones respectively. Moreover, validation of landslide hazard zone map with 49 past landslide inventory data reveals that 85.7% of the known landslide events were falls in very high hazard and high hazard zone. Thus, the landslide hazard map produced by Geospatial based Multi-Criteria Decision Analysis Approaches with careful identified factors proved to be valuable tool for providing fundamental information about hazard assessment, land use planning, infrastructure development and disaster preparedness of the area.
Determining Ground Surface Deformation at Erta Ale Volcano and Assessing Lava Lake Reservoir Northern Afar, Ethiopia
(Addis Ababa University, 2024-02) Tilaye Sewnet; Andenet Ashgrie (PhD)
This research endeavors to ground surface deformation analysis using Persistent scatter interferometry at Erta Ale volcano and assessing its Lava Lake reservoirs in northern Afar Ethiopia spanning the period from 2017 to 2022, using Sentinel-1A data. Erta Ale is an active volcano located tectonically at the triple divergent junction of the Arabian, Nubian, and Somalian divergent plates. Geological setting of Erta Ale is highly extended and thin crust layer which is additional factor to Era Ale volvcanic activity. Studying the ground deformation of actively erupted volcanoes at the local level is one way of monitoring the continental refits. In this study, 26 sentinel-1A descending single look complex (SLC) SAR data are the main input for the study. SAR data covers large areas that enables to generate densified Ground control points to assess surface displacement at active volcano area. The latest InSAR processing method, PS-InSAR, is used to process SAR data. The commercial software SARPROZ used to process and analyze data in PS-InSAR techniques. Atmospheric phase error are removed by the amplitude-phase scattering (APS) method in this method. In the subsidence area, maximum horizontal and vertical displacement are~143±1.2674 mm and~91.89mm, respectively. Areas including Bora Ale and areas in the NW of the north pits are continuously subsiding. In the Northeast, the deforming rate of subsidence is 13.76mm per year, resulting in ~12mm of ground contraction and vertical deflation ~40m. Between Ali Bagu and Boral areas, there are some boreholes and temporary cracking that cause depression of the earth’s surface. uplifting area is ~60.23 ±1.2674 and ~93.04 mm, respectively, in the SW direction, resulting in horizontal extension of PSC ~12cm. North pit Lava Lake magma has decreased in area from the February2017 to December 2022 is ~0.061723km2 to ~0.036983km2.
Accuracy Assessment for Online GNSS Post Processing Services: Case Study in Central Part of Ethiopia
(Addis Ababa University, 2024-02) Abebaw Chanie; Andenet Ashagrie (PhD)
Currently, numerous organizations have designed online GNSS processing services for the processing of GNSS data. These services are user-friendly, have unlimited usage, and are largely free. They are also easy to use, as they do not require a license or extensive knowledge of GNSS processing software, unlike commercial software that necessitates expertise in GNSS and experience in processing. Furthermore, the cost of software licensing for post-processing and analyzing GNSS data is eliminated with these services. The objective of this research is to conduct accuracy assessment fo various online GNSS processing services used worldwide, including OPUS-project, AUSPOS, CSRS-PPP, and Trimble Center Point RTX-PPP. For comparison purpose the identical data was processed by two commercial software; Leica geo-office and Magnet-Tools. To evaluate the accuracy of online services the scientific software (BERNESE) was used as reference. The differences in coordinates between BERNESE and these services were calculated. The accuracy and precision of each online processing service was evaluated using the Root Mean Square Error (RMSE) method. From the evaluations, it was seen that the results for each online processing services in the horizontal and vertical directions were (2.4cm and 5.3cm) for OPUS-project, (2.1cm and 4.8cm) for AUSPOS, (0.8cm and 4.4cm) for CSRS-PPP, (1.6cm, and 4.4cm) for Trimble/PPP, (2.4cm, and 11.4cm) for Leica geo-office and (2.9cm and 10.9cm) for Magnet-Tools. Based on the findings, the use of precise point positioning (PPP) service provide reliable solution than relative services. Over all, as this study based on the accuracy, CSRS result surpassing other services. Following CSRS Trimble-RTX and AUSPOS produce closely the same result. The result show that, the solutions provided from online services can use for many geodetic practical applications.
Spatiotemporal Analysis of Land Use/Land Cover Change and Urban Sprawl using GIS and Remote Sensing: The Case of Bahir Dar City, Ethiopia
(Addis Ababa University, 2024-01) Habtamu Hulgizie; Hamere Yohannes(PhD)
Spatiotemporal analysis is a method used in Geographic Information Systems (GIS) and Remote Sensing to analyze changes in land use and land cover over specific time. This study was conducted to produce maps of the spatiotemporal changes over the study area from 2002 to 2022, quantify gain and losses of land use/land cover (LULC) classes, examine land use transitions, assess spatial trends of changes, and analyze the extent and patterns of urban sprawl over the study area. The LULC classes include Bare Land, Crop Land, Vegetation Area, Water Body, and Buildup Area. According to the analysis, the area of built-up land was increased time to time from 2002 to 2022, more than doubling in size, which increased from 1253.951 ha to 5519.19 ha. This indicates substantial urbanization and infrastructure development during the study period. With decrease in cropland and bare land but significant growth in built-up areas. To some extent, there was an increment of Vegetation area but water bodies remained relatively the amount of coverage area decrease in the first three consecutive period. Overall, the study highlights significant shifts in land use land cover over the 20-year timeframe. Moreover, the urban expansion intensity index analysis reveals fluctuations in the rate of urban expansion over the years, with periods of limited growth followed by accelerated expansion and then a slowdown. The urban expansion rates for the periods 2002-2007, 2002-2012, 2002-2017, and 2002-2022 were 4.204%, 10.763%, 7.332%, and 7.632%, respectively, these rates indicate fluctuations in urban growth within the region over the years.
GIS-Based Urban Land Property Valuation for Taxation Purpose: The Case of Akaki Kality sub city, Addis Ababa, Ethiopia
(Addis Ababa University, 2024-01) Tadilo Alemu; Hamere Yohannes (PhD)
Land valuation is the process of assessing the characteristics of a given piece of land grounded on experience and judgment, for different purposes like for transaction, mortgage, taxation, insurance, and so on. In this case the study concentrated on land property valuation for taxation purpose. It is considered that an owner should be able to pay taxes to the government in connection with his ownership, in terms of the government services he receives and the infrastructure provided to him. That is, a property owner who lives in an area with better infrastructure and government services will be taxed higher or vice versa. In the current situation, the land ownership registration and information agency of Addis Ababa city administration and land development management institutions in connection with land property valuation, especially the land property valuation service used for tax rate purposes follows the calculation method based on income capitalization and based on the current land property transaction value which, might not indicate whether the land property right holder is situated on well-developed infrastructures or not. That makes the system unfair, which does not follow the multiple requirements or parameters that affect a land property value. Therefore, this study will address and show the direction of the land and land-related valuation system especially for laving taxes, observed in the city administration specifically Akaki Kality sub city, for the study using multi-faceted criteria’s to develop land property valuation model and parcel data were integrated using ArcGIS to developed property valuation attribute table. The result indicated that the majority (35.16% and 28.88% respectively) of the total land area falls under the categories of very high land value and high land value. This indicated that these areas have high potential for development, so that should rate high tax. Whereas 15.37% of the study area are moderately offers some potential for development. The low value (12%) has limited development opportunities or undesirable locations, following to this property owner on this category should pay lower rate of tax. The remaining 8.59% of the area has the lowest development opportunity and infrastructures. In conclusion, the significant proportion of land falling under the very high and high categories have nice development opportunities for various purposes such as residential, commercial, or industrial projects. Developers and investors can focus their efforts on acquiring and utilizing these lands to capitalize on the high development opportunities associated with these areas. Additionally, the distribution of land across different categories provides valuable understanding for urban planners and policymakers relating to taxation. Following to this study concerned parties may elongate it throughout the city and gives coefficients to each categories’ of land values. This knowledge also allows decision-makers to prioritize areas with higher potential for growth and allocate resources accordingly.
Spatiotemporal Modeling of Urban Expansion: In a case of Robe Towen Using Remote sensing and GIS Techniques
(Addis Ababa University, 2023-07) Olana Adere; Asnake Mekuriaw (PhD)
Urbanization is the most powerful and visible force that has fundamental changes Land Use Land Cover around globe. This study was conducted in Robe town to model spatio-temporal of expansion during 2006–2021. SPOT image for 2006 and 2016 as well as Sentinel 2A for image were used for this study. Three different land-cover maps produced at different intervals between 2006 and 2021 were used to evaluate and analyze urban expansion visually and quantitatively. The satellite images were classified and land-use/land-cover maps were produced using Object Based Image Classification using KNN classification method using Envi 5.3 and predict Expansion of Robe Town using CA-Markov model. The classification process was checked by overall accuracy and Kappa statistic accuracy assessments from confusion metrics. Results show acceptable agreement between the classified maps and reference data with overall accuracy value 91% for 2006, 88% for2016 and 93% for 2021. Kappa accuracy value 0.89, 0.85 and 0.91 for classified satellite image of 2006, 2016 and 2021 respectively. Post classification change detection analysis and selected spatial metric indices calculation were made to detect, assess pattern of urban expansion in the study area. Change detection analysis indicated that Robe town is growing rapidly with an average growth rate of 7.8% year during2006–2021. The builtup area was 854 hectare, 1067hectare and 1740 hectare, respectively in 2006, 2016 and 2021, with annual growth rates of 2% and 7.8% in the two study phases respectively during the periods 2006-2016 and 2016-2021. From spatial metrics analysis, largest patch index of built-up area was 7%, 10% and 15% for the years 2006, 2016 and 2021. The increase in the number of largest patch index all through the study periods shows the rapid urban growth process in the study area.CA-Markov model used for modeling and validating kappa statistic is moderate and acceptable to predict for future (2050).Therefore, it is time for policy makers, city managers and urban planners to plan and cope up with the pace of Robe town urban expansion depending on with proper implementation.
Land Use Land Cover Prediction Using Cellular Automata-Markov Model in Kulfo River Watershed
(Addis Ababa University, 2023-05) Seble Gezahegn; Degefie Tibebe (PhD)
Land use land cover change is created principally by human activities, activities manipulating the Earth’s surface for some purpose such as agricultural, industrial and residential etc. Mapping and predicting of LULC is important to identify and evaluate the magnitude and the change within the watershed to ensure best future planning and management. This study was mainly focusing on predicting land use cover change in kulfo river watershed through remote sensing, geographic information system integrated with IDRISI selva software and CA-Markov chain model. Cellular automata coupling with Markova model was used to predicting and modeling land use cover change for the year 2036 and 2051. Land use map of 2000, 2011 and 2021 were generated from Landsat satellite images. Analyzing the pixel based image classification method. The land use cover maps were computed using Maximum Likelihood algorithm of supervised classification technique, in ENVI 5.3 and GIS 10.8. Predicted LULC is developed using IDRISI Selva Software, and calibrated and validated using classified 2021 LULC maps. Hence the quality and location coefficient were calculated based on compassion of the predicted LULC for 2021 with the actual 2021 for first scenarios. The outcome demonstrate that bare land that was 14.5 % in 2021 decrease to 13.3% and change to 12.5% in 2051, forest land will decline from 18.3 % in 2021 to 17.7% in 2036 and also 18.5 % in 2051, water body that was 0.9% in 2021 to 0.6% in 2031 and change to 0.4 % in 2051.In general, the forecast result shows that except for built up area and cultivated land all land use type decreased per year respectively. Hence the observed LULC changes were generated by the increase of population, this lead to the demand for cultivated land, rural settlement and the extraction of forest for fuel and other construction materials.
Positional Accuracy Validation of Base Map and Investigating its Impact on Road Projects: A Case of Addis Ababa City, Ethiopia
(Addis Ababa University, 2023-06) Solomon Woldeyesus; Tulu Besha (PhD)
Positional accuracy is a topic that of renewed interest and concerns not only the distance between the geographic object and its actual or real location on the earth surface but also the accuracy with which map features are located. Collecting the highest quality independent ground-based data is a key factor in validating the useful location accuracy of digital geospatial data. This information simplifies geographic analysis and promotes better judgment. In this research the accuracy of the horizontal position of an orthophoto/line map had been investigated. The global positioning system and total station survey had been employed to access the accuracy of the horizontal coordinate of the line map. The horizontal coordinates of the terrestrial position of the points are observed using Sokkia Atlas GR5+ Differential Global Positioning System (GPS) device and the row data are post-processed using various processing tools such as Leica Geo-Office and Topcon Tools v.8.2.3 reference with to local GNSS reference stations. In this study, we evaluated the 2D positional accuracy of the line map by matching its horizontal coordinates with the associated ground control point observed as in-suit data. Comparing the digital line map coordinates to the corresponding in-situ ground control points, RMSE between the digital line map and the GPS/total station position of the twenty-five reference points is 0.813 m in x and 0.903m in y respectively. Furthermore, in comparison to GNSS/Total Station data acquired through LGO processing, the digital line map exhibited a horizontal precision of 2.103 m at a 95% confidence interval. This inaccuracy can potentially impact the drainage line or buildings that are constructed parallel to the road center line. Specifically, for the Saris site, it results in a 1.398 m deviation from the road design center line. This discrepancy has had a discernible effect on ground surveys and the design of road projects in Addis Ababa city, necessitating repeated right-of-way surveys and redesign efforts. Consequently, the precision of digital line maps falls short of the national error budget requirement (30cm) for Standard Mapping tasks under all circumstances. However, it may be suitable for imagining and small demanding tasks. In its current status, it is applicable to projects like master plans and general economic development plans.
GEOID QUASI-GEOID Separation Computation Using the Grace And GOCE Global Geopotential Model in Semien Mountains, Ethiopia
(Addis Ababa University, 2023-08) Tadege Getie; Tulu Basha (PhD)
Different reference systems are used to determine height,which are quasi-geoids and geoids. The definition of the geoid and telluroid (or, more generally, the quasi-geoid) is connected to these height systems. The optimal technique for computing orthometric heights has been a topic of discussion for more than a century. In mountainous regions, it is challenging to determine geoid and quasi-geoid features using GPS technology. The highest point of a mountain in Ethiopia's highlands is known as Ras Dashen. To tackle boundary issues for mountainous places such as the Ethiopian Semein plateau, a satellite data model is required to ascertain the distinction between geoid and quasi-geoid. We have written this research article to support this investigation. For individuals working in this field, determining the distance between the two references is quite helpful. Calculating the distance between them is important to transform what we receive from one to another.Although there are other ways to determine this gap, we employed satellite earth models created using satellite data for this work. There are three different kinds of models: models created only using GRACE satellite data, models created only using GOCE satellite data, and models created using both GRACE and GOCE data. Our search for the model reference height type was based on E Topo. As a result, Sjoberg's exact formula was used to calculate it in this study using the geoid-quasi-geoid separation model. Using the ETOPO 1 and TC programs from the GRAVSOFT package, the gravity anomaly in the case area was determined. This study investigated variations in the results of the order factor in the application of gravity in addition to the type of data. Models from the International Center for Global Earth Models, including SGG-UGM-2, IGGT_R1C, GO_CONS_GCF_2_TIM_R6, and ITSG-Grace2018, were used in this determination of Geoid-Qusigeoid separation.With the help of these models, we searched for various gravitational field functions, but primarily we searched for the separation between the geoid and quasi-geoid separation in all four models, and we discovered that the minimum and maximum results are, respectively, 0.388, 0.356, 0.365, 0.360 and 4.730,3.798,3.755,and 3.760 meter.
Harmonization Of Vehicle Location Tracking and Speed Control Systems in Addis Ababa City Using Open-Source Platformsa city using open-source platforms
(Addis Ababa University, 2023-06) Tesfayesus Yimenu; Hamere Yohannes (PhD)
The Internet of things (IoT), with real-time monitoring of assets, has become the order of the day in this contemporary world. One such application is vehicle tracking and monitoring in real-time. The number of frequent traffic accidents and car burglaries in Addis Ababa is mounting daily. It has become easier to monitor valuable assets, including vehicles, of an individual and organization, from tracking their exact location to monitoring associated assets like speed, fuel, or driver behavior because of modern technology. The traffic management agency (TMA) of Addis Ababa has started an initiative to grant a license to providers of such services that meet its mandatory standard. Almost all service providers have their systems and platform to monitor the location and check the speed limit of automobile owners and motorcycles. Consequently, dozens have already obtained the license and are in operation. However, using these so many platforms also have its disadvantage. They have different properties and focus. It has become overwhelming to TMA and other fleet managers to synchronize all the data from the various devices mounted on motorbikes, automobiles, and platforms. There is a pressing need for a centralized platform from which TMA and other fleet managers for a centralized platform from which TMA and other fleet managers can monitor service providers and vehicle and motorcycle owners. Therefore, this research project focused on developing and using a common platform for all integrators where TMA as a system administrator, will oversight the overall work. The licensed integrators, on the other hand, will deal with the routine work of dealing with end users. Open-source vehicle tracking platforms and affordable platforms were used to achieve the intended result. These open-source resources include Open-Source GPS Tracking System (OpenGTS) and other free software like Structured Query Language (MySQL) server database; open street maps and Apache Tomcat were utilized for synchronization of vehicle location tracking and speed control in Addis Ababa.
Assessing the impacts of urbanization on agricultural land using Remote Sensing and GIS techniques: The case of Adet town, Ethiopia
(Addis Ababa University, 2023-06-16) Yechale Mulu; Asnake Mekuriaw (PhD)
Urbanization was one of the main problems that threaten the limited highly fertile and very productive agricultural land in the periphery of Adet town for residential construction and its related infrastructure. The general objective was to assess the impacts of urbanization on agricultural land using remote sensing and GIS techniques and within it classified the land use land cover dynamics during the time periods of 2000, 2010 and 2020, mapped horizontal expansion of urban boundary and analyzed its effect on the surrounding agricultural land and identified the major trigger factors for horizontal expansion. By using Landsat satellite images generated change detection analysis and mapped horizontal expansions in this particular study. Additionally conducted interviews and identified the trigger socio-economic contributing factors of horizontal expansion. The supervised classification algorithm and Anderson (1976) land use/ land cover classification scheme ware adopted and identified: agricultural land, built up area, vegetation and bare land. The result revealed that agricultural land coverage 66% in 2000, 64% in 2010 and 51% in 2020. The built up area coverage 29% in 2000, 27% in 2010 and 36% in 2020. The vegetation coverage increased 2% from 2000 to 2010, 5% from 2010 to 2020 and 8% from 2000 to 2020 and the bare land coverage 2% in 2000, 4% in 2010 and 5% in 2020. The factors that were responsible for horizontal expansion was increasing the demand for residential house of dwellers, growth and transformation plan (GTP), asphalt and gravel road construction, rural-urban migration, demographic dynamics, reclassification of the former rural settlement into new urban settlement, supporting housing policy and informal settlements. Generally urbanization was loss of agricultural land continuously. So, to prevent the loss of highly fertile and very productive agricultural land effective land use and land management strategies should be strongly encouraged. Furthermore, a sound policy at the local level is urgently needed. This study can be contributed to the government especially Adet town municipality and surroundings of Adet town, yilmana densa wereda, to ensure the developmental plans in certain areas other than highly fertile and very productive agriculture land and strengthen the zoning regulation and enact policies to reduce agriculture land losses and reclassification of the peripheral rural kebeles being as part of an administrative body to the town municipality. The finding of this study will also be significant in providing realistic information and initial input for urban planning experts, stakeholders, governmental and nongovernmental organizations and other researchers.
GIS Based Evaluation of Urban Road Network Structure and their Accessibility to service areas in case study of Addis Ababa Ethiopia
(Addis Ababa University, 2023-07) Yetnayet Abdulle; Degefie Tibebe (PhD)
On this research the study evaluate the road network structure, by employing GIS technology taking four selected sub cities in Addis Ababa Akaki Kality, Nefaselke Lafo,Kirkose and Arada sub-cities and accessibility of road network to service areas. The data collected by using hand GPS to collect point data which primary data and Secondary data was collected visiting relevant offices in Addis Ababa. The study area's development is negatively impacted by the poor level of road network service in some areas, which limits mobility, creates inequalities of accessibility, and people travel unnecessary distances to get there destination. Because of this reasons findings of this study revealed by determining the road density, proximity, accessibility of the road and pin point areas that has been totally loose there road connectivity are also described. Further, recommendations are made to improve the existing road network structure by using upgraded software like ARC GIS.

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