Wind energy is a promising alternative energy source to cover large amounts of electricity demand in African countries. Djibouti’s proximity to the Red Sea and its arid and semi-arid climate generate consistent and robust winds, contributing to its potential for wind energy. Notwithstanding its considerable potential, Djibouti has not been adequately examined in earlier studies to determine suitable sites for wind farms. The objective of this study is to develop a model by integrating CRiteria Importance Through Intercriteria Correlation and Combined Compromise Solution methods into a Geographic Information System-based decision-support system to establish a comprehensive framework for the selection of wind farm sites in Djibouti. Following an in-depth review of the literature, seven main criteria were identified to assess the suitability of potential sites for wind farm construction: wind velocity, changes in wind direction, ground slope, distance to urban areas, distance to road network, distance to energy transmission networks, and land use. The CRiteria Importance Through Intercriteria Correlation method objectively determines the relative importance of the criteria, identifying wind speed and proximity to power transmission networks as the most important, and ground slope and land use as less important than the other criteria. The Combined Compromise Solution method is employed to prioritize potential sites for wind farms, considering seven specified criteria. To enhance the reliability of the results derived from the Combined Compromise Solution method, validation was conducted utilizing the Multi-Attribute Ideal–Real Comparative Analysis method. The comparative analysis revealed a robust correlation between the results of the two methods, providing convincing evidence for the accuracy and reliability of the proposed decision-support system employed to determine the most suitable sites for wind farms in Djibouti. This study is expected to assist professionals and researchers in dealing with the wind farm site selection problem on an unprecedented scale and with exact coordinates through a decision-support system that concurrently integrates the most recent multi-criteria decision-making methods and Geographic Information System tools.

The escalating energy demand in Djibouti requires the investigation of renewable energy sources, with wind energy emerging as a promising solution. To ensure the long-term efficiency and sustainability of wind energy projects, it is imperative to determine suitable sites for wind farm construction. When selecting a suitable site for a wind farm, there are multiple criteria to consider, such as wind velocity, ground slope, and distance to urban areas. Nevertheless, the current body of the literature reveals that no previous research has been conducted to explore an approach which involves multiple criteria to determine suitable sites for wind farms in Djibouti, as opposed to solely considering wind energy potential. This study proposes a spatial decision-support system to address the research gap in the selection of wind farm sites. Seven criteria are simultaneously evaluated in this system, including wind velocity, changes in wind direction, ground slope, distance to urban areas, distance to road network, distance to energy transmission networks, and land use. The CRITIC (Criteria Importance Through Intercriteria Correlation) method is used to objectively calculate the weights of the criteria. According to the results of performing the CRITIC method, wind velocity and distance to energy transmission networks were determined to be the most important criteria, while ground slope and land use were determined to be the least important criteria in comparison to others. A final suitability map showing the possible locations of wind farms in Djibouti was generated by considering the said criteria and their respective weights. The final suitability map reveals that the most suitable sites for the development of wind farms in Djibouti are located in the northeastern area between Obock and Khor-Angor, the southeastern area encompassing Lakes Ghoubet and Bara, and the southwestern area stretching from Lake Abbe to the Hanlé region. Using the proposed spatial decision-support system, decision makers would be empowered to make strategic and well-informed decisions when selecting the most suitable site for a wind farm in Djibouti.

In recent years, the efficiency of Terrestrial Laser Scanner (TLS) data for dendrometry has been widely tested and it becomes more widely accepted in small and large scale forests due to its millimeter accuracy. Although TLS products provide high accurate measurements, the high costs of field data collection could be a challenge in some forest stand. Unmanned Aerial Vehicle (UAV) imagery could be an alternative for modeling and monitoring of the dendrometric parameters, specifically on sparse forest. For this purpose, the potential of UAV imagery for diameter at breast height (DBH) estimation, one of the key forest tree parameters, is discussed against TLS based DBH measurements in a Stage D(4) low stem density Oak stand, using point cloud data (PCD)-based ellipse fit. No significant difference was seen between the DBH measurements in regards to the stem diameter. However, the UAVbased DBH measurements had a high variance in the ellipse fit process.

Two of the very basic forestry parameters, the Breast Height Diameter (DBH) and Tree Height (TH) are very effective when characterizing forest stands and individual trees. The traditional measurement process of these parameters takes a lot of time and consumes human power. On the other hand, 3D Point Cloud (PC) quickly provides a very detailed view of forestry parameters, because of the development of computer processing power and digital storage in recent years. PC data sources for forestry applications include Airborne LiDAR Systems (ALS), Terrestrial Laser Scanning (TLS) and most recently the Unmanned Air Vehicle (UAV). In this study, the PC datasets from these sources were used to study the feasibility of the DBH and TH values of a d development stage (i.e. DBH > 52 cm in mature stage) oak stand. The DBH and TH estimates are compared with the onsite measurements, which are considered to be fundamental truths, to their performance due to overall error statistics, as well as the cost of calculation and the difficulties in data collection. The results show that the computer data obtained by TLS has the best average square error (0.22 cm for DBH and 0,051 m for TH) compared to other computer data. The size of Pearson correlation between TLS-based and on-site-based measurements has reached 0.97 and 0.99 for DBH, respectively.

The North Anatolian Fault (NAF) is a fault zone that produced destructive earthquakes (Erzincan 1939 and 1992, Ladik 1943, Gerede 1944, Duzce 1999, Izmit 1999) in the last century. After this destructive earthquake migration, it is forecasted that the next seismic event on the NAF could be in the western part of the fault, which passes through the Marmara region. Due to the possibility of an earthquake in Istanbul, the most crowded and historical city in Turkey, researchers have increasingly paid attention to the western segment of the NAF within the Marmara Sea since the 1999 earthquakes. Many scientists from different disciplines such as geodesy, geology, geophysics, etc. have been trying to understand this phenomenon. However, it is understood from the literature that a comprehensive geodetic study is crucial to constrain the NAF segment between Istanbul and Tekirdag provinces. Therefore, we created a new network consisting of continuous GPS stations with 10-km interdistances along the shoreline, which was integrated with existing GNSS networks in the Marmara region. Data acquisition was carried out between August 2017 and February 2020. In this study, preliminary results obtained from the integration of the newly established network with the other GNSS networks are presented.

Leaf Area Index (LAI) is a dimensionless parameter that has a significant impact on forestry applications. With conventional methods, LAI can be calculated with destructive sample collection or with a relatively new non-destructive method called hemispherical photography. With the engagement of surveying instruments in forestry, obtaining LAI value for large areas in a short time has recently become more prominent and possible with the use of Terrestrial Laser Scanners (TLS). Although promising, TLS data evaluation techniques for LAI calculation are still subject to development. This paper aims to make a comparative evaluation of existing novel techniques with newly proposed methods and incorporates the use of neural networks and connected component analysis for segmentation purposes. The in-situ measurements, as a case study, were conducted in Istanbul- University-Cerrahpasa research forest – a part of Belgrad forest – Istanbul, Turkey. The Results obtained from the study show that segmentation and removal of wood materials from forest point cloud data, by using neural network algorithms and connected component analysis methods, albeit time and resource consuming, have a promising future on the calculation of effective LAI values of large areas.

This paper presents one of the applications of monitoring mechanical tests carried out in Construction Materials Laboratory of Istanbul Technical University. In Turkey, as in many countries, large amount of existing buildings exposed to seismic hazard, therefore various analytical and experimental studies are being conducted to contribute to the solution of the problem. One of the new generation retrofitting techniques is to strength the structural members by using Fiber Reinforcing Polymer (FRP). This study summarize the results of monitoring of deformations short concrete column samples under the incremental compression load. In this study, result of two rectangular short columns are given. One of them was tested as a reference sample, the other sample were tested after strengthening by PET reinforced polymer composite materials. Besides conventional displacement and strain measurement systems, laser scanning method was used to get three dimensional deformed shape of sample at each selected steps.

Carbon products, growth trend, volume, stress and annual products of vegetation, especially perennial vegetation canopy is very important for forestry, ecology and economics. Leaf Area Index (LAI) is an important parameter to observe and determine these parameters. It can be defined as the upward looking green leaf area to ground area ratio. There are direct and indirect methods to determine this parameters. Direct methods are considered old and destructive for the vegetation canopy, they are also time and resource consuming methods which are considered ineffective. With developing technology in Remote sensing and Photogrammetry it can be foreseen that it is possible to determine this parameter faster and for wider areas more accurately. When compared with conventional optic methods Terrestrial Laser Scanning Technique becomes prominent in determination of Leaf Area Index, with its high accuracy-high density point data. The procedure conducted in this work aims to bring an alternative approach to use Laser Scanning data and Mathematical models of Geodetic Projection in the estimation of Leaf Area Index.

Terrestrial Laser Scanning is a popular and widely used technique to scan existing objects, document historical sites and items, and remodel them if and when needed. Their ability to collect thousands of point data per second makes them an invaluable tool in many areas from engineering to historical reconstruction. There are many scanners in the market with different technical specifications. One main technical specification of laser scanners is range and illumination. In this study, it is tested to be determined the optimal working times of a laser scanner and the scanners consistency with its specifications sheet. In order to conduct this work, series of GNSS measurements in Istanbul Technical University have been carried out, connected to the national reference network, to determine precise positions of target points and the scanner, which makes possible to define a precise distance between the scanner and targets. Those ground surveys has been used for calibration and registration purposes. Two different scan campaigns conducted at 12 am and 11 pm to compare working efficiency of laser scanner in different illumination conditions and targets are measured with a handheld spectro-radiometer in order to determine their reflective characteristics. The obtained results are compared and their accuracies have been analysed.

SUMMARY 3D models are widely used in many different applications, such as medical industry, movie making, video games and scientific researches. Also architectures and engineers use them to design new devices, vehicles and structures. In the Geomatics Engineering, 3D modelers can be used to create landscape models, process digital elevation models and modeling cities in 3D for GIS. In this study, 3D models of Civil Engineering Faculty Building of Istanbul Technical University was realized and obtained model was textured with the photographs in order to generate a photorealistic model of the building. Due to different height level of the building, they have been conducted as separate blocks and they have been merged to produce only one block. After obtaining the 3D model, photos of facades were taken to texture the blocks. The photos are processed to correct perspective of textures. The model is then uploaded to Google Earth for further evaluation. The model is currently accepted and visible in Google Earth as 3D layer. This study was conducted in limited time and tools. In this study Google SketchUp and Adobe PhotoShop were used as main software.

SUMMARY 3D models are widely used in many different applications, such as medical industry, movie making, video games and scientific researches. Also architectures and engineers use them to design new devices, vehicles and structures. In the Geomatics Engineering, 3D modelers can be used to create landscape models, process digital elevation models and modeling cities in 3D for GIS. In this study, 3D models of Civil Engineering Faculty Building of Istanbul Technical University was realized and obtained model was textured with the photographs in order to generate a photorealistic model of the building. Due to different height level of the building, they have been conducted as separate blocks and they have been merged to produce only one block. After obtaining the 3D model, photos of facades were taken to texture the blocks. The photos are processed to correct perspective of textures. The model is then uploaded to Google Earth for further evaluation. The model is currently accepted and visible in Google Earth as 3D layer. This study was conducted in limited time and tools. In this study Google SketchUp and Adobe PhotoShop were used as main software.

D Modeling technique is being used in many areas varying from engineering to medical applications. The involvement of Geomatics engineering with spatial data and the increasing use of spatial data and Geographical Information systems, both in our country and around the world, has resulted with intense use of digital maps and 3D models along with it. At this Project creation and publishing steps of a 3D model of Istanbul Technical University, Civil Engineering Faculty by using a web based service is being explained. At this project various programs we used to process the obtained data such as AutoCAD, Photoshop,and the programming macro of Google Earth, "Google SketchUp".