Advanced GIS

Geochemical heat maps in complex geological structures via using QGIS: Maden (Elazığ) district

Mehmet Ali Ertürk — 2022-12-05

Geochemical analysis results are one of the most significant indicators that reveal the characteristics of the geological structures in a region. In particular, the differences in the composition of complex geological structures can be evident in field and Geographic Information Systems (GIS) studies. Turkey includes a character consisting of quite complex features with its geological structure. The Maden (Elazığ) complex has also attracted the attention of many researchers with its complex structure. The Maden Complex also contains basalts, basaltic andesite, andesite, dacite, diabase and pyroclastic rocks, which are intercalated and lateral-vertical transitive with all these sedimentary successions. Mapping and lithological differentiation of the Mineral Complex, which has a very complex structure, is quite difficult. Thematic maps are created to make the geological interpretations in this region cleaner and the field data more predictable. These maps also allow the correlation of major oxides and trace elements. In this study, the geochemical data obtained in the Maden Complex were analyzed in the QGIS program. The geochemistry of the region has been made more understandable and interpreted with heat maps. The diversification of thematic maps, which gives a new perspective to geochemical data, will provide more support to geological studies.

Heat Maps of U-Th Enrichments in Open Source Coded Geographical Information Systems (GIS); Arıklı (Çanakkale, Turkey) District

Cihan Yalçın — 2022-12-05

Uranium (U) and Thorium (Th) are both strategically important elements in the world. For this reason, it is exceedingly significant to explore for these elements, which are enriched in many geological environments. U-Th enrichments in Turkey were usually discovered in the Western Anatolian geography. U-Th anomalies were still observed in the Arıklı region in the south of Çanakkale. Remote sensing (RS) and geographic information systems (GIS) are platforms for the map-based evaluation of geological structures. In this study, RS and GIS were utilized in the QGIS program to carry out the geochemical data obtained in the field more understandable. GIS and remote sensing methods have been widely used to analyse the formation, origins, and processes of geochemical characters in ore deposits. U-Th values, which show high values in the fault zones in the Arıklı region, are immediately related to the CaO values. As in many geological studies, remote sensing and GIS studies suggest the opportunity to check out field data with a significant quality in the exploration of ore deposits.

Spatio-Temporal Analysis and Trend Prediction of Land Cover Changes using Markov Chain Model in Islamabad, Pakistan

Anum Gull — 2022-12-05

Rapid urbanization is changing the landscapes of urban areas and affecting the quality of life and environment. One of the most dynamic components of urban environment is land cover, which have been changing remarkably since after the industrial revolution at various scales and population growth. Frequent monitoring and land cover change detection provides a better understanding of functions and health of urban environment. Remote sensing and Geographical Information System (GIS) are advanced techniques to visualize these dynamics in the digital map. Therefore, this study aims to analyze the existing spatial extent of different land cover classes and predict the future trend in Islamabad; Capital city of Pakistan, by applying Cellular Automata (CA)-Markov model. For this aim, three consecutive-year Landsat imagery (i.e. 200, 2010, 2020) were classified using the Maximum Likelihood Classifier. From the classification, three LULC maps with four class (Barren Land, Vegetation, Water Body, built up were generated, and then change-detection analysis was executed. Using remote sensing data, we simulated Spatio-temporal dynamics of land use and land cover changes Simulation results reveal that the landscape of Islamabad city has changed considerably during the study period and the change trend is predicted to continue into 2030. The study observed a significant increase in built-up area from 2000 (9.53%) to 2020 (28.2%), followed by an increase in the cover of bare ground. On the contrary, vegetation cover declined drastically 2000 (28.61%) to 2020 (25.08%). Rapid population growth triggered by rural urban migration coupled with hasty socio-economic development post democracy are the main drivers of these changes. Under the business as usual scenario, prediction analysis for the year 2025 and 2030 show that built up area will consume almost all of the city area (47.04%) to (57.25%) with vegetation significantly reduced to patches making up only about (17.23%) to (14.4%) of the city. These findings demand for an urgent and effective planning strategies to protect the existing vegetation covers, agricultural land, and limit the growth of built-up land. The study has also potential in planning sustainable cities.

Spatial Assessment of Forest Cover Change in Azad Kashmir, Pakistan

Mujataba Shafiq — 2022-12-05

In this study spatial assessment of forest cover in Azad Kashmir was carried out. The study is based on secondary data. Satellite imageries of the past 20 years having temporal extent of five years were utilized for assessment of changes in vegetation covers. Supervised image classification and Normalized Difference Vegetation Index (NDVI) techniques were used to achieve objective of the study. The results indicated that forest cover is declining leading to different environmental problems. Increase in population acted as booster for the factors such as deforestation, conversion of forest land into agriculture and built-up land. These anthropogenic activities put pressure on the forest of the study region. After 2005 disastrous earthquake, rapid development of built-up environment was the leading factor behind clearing of forest. It was found from the analysis that forest cover has significantly declined in the last two decades and affected ecosystem services. Location specific management strategies are highly recommended to reduce the rapid decline in forest cover. Strategy must also consider the population growth and traditional forest conservation strategies. Alongside, keeping in view the agricultural activities and infrastructural development in the dense forest cover areas are also recommended.

Valuation of Commercial Real Estate in Ankara Middle East Industry and Trade Center (MEITC)

Gülsüm Yüksel — 2022-12-05

Commercial real estate is an important part of the real estate sector. In the commercial real estate market, value estimates are made with the help of the characteristics of the samples that are subject to purchase and sale, and they are used in transactions such as taxation, insurance and privatization. In this study, collective valuation processes are aimed by applying the Multiple Regression Analysis (MRA) statistical method to the commercial properties offered for sale in the Middle East Trade and Industry Center (MEITC) in Yenimahalle district of Ankara. In this direction, 31 office sales data were collected for valuation, 29 criteria affecting the value were determined, and a mathematical model was developed according to independent variables. R², Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and Mean Absolute Percent Error (MAPE) were considered. Their results were found as 0.938; 0.00; 0.04; 0.42 respectively. Based on these values, it has been concluded that the regression method, which is seen to produce high accuracy, can be used in commercial real estate valuation. Geostatistical analyzes were made using market values and estimated values, and value maps were produced in the Geographical Information Systems (GIS) environment.