QuickOSM is a QGIS plugin designed to make it easy to download and integrate OpenStreetMap data. It utilizes the Overpass API for querying. As you probably already know, OSM is an invaluable resource for GIS tasks thanks to its vast repository of user-contributed mapping data. It includes features like streets, buildings, administrative boundaries etc. In…

When you are working with raster data (e.g., digital terrain models), you may need to do several mathematical calculations using the pixel values, depending on your purpose. In this post, I am going to demonstrate how to sum all the pixel values in a digital surface model using Python. I will use a Digital Surface…

Land use/land cover maps are used in many areas, such as climate change, natural resource management, and urban/regional planning, and the accuracy of these maps is of critical importance. The OpenStreetMap project has been ongoing since 2004 and provides free geographic and thematic data on a global scale with the help of millions of volunteers.…

Land use changes, which mostly occur due to anthropogenic effects in urban areas, cause many problems such as urban heat islands and floods. In combating these problems, data on impervious surfaces and green spaces, which are two important components of urban areas, play a critical role. Some datasets such as CORINE Land Cover, Urban Atlas…

One of the most important data processing steps in GIS works is defining/changing coordinate system. It is crucial to get accurate results from our analysis. In this post, I will try to explain how to do it in QGIS with details. Change Coordinate System of the Project We first need to change the coordinate system…

As an initial step for land cover classification, we need to identify and visualize the satellite image for the specified study area. The image is often used to assign training points visually. In this post, i will try to explain how to image Landsat 8 image for a selected study area. As a case study,…

Understanding what covers the Earth’s surface—such as forests, cities, water, or farmland—is essential for many purposes. This process, called land cover classification, is an important tool for studying the environment, managing resources, and predicting changes like shifts in climate. It is valuable for tasks such as planning cities and forecasting weather. Accurate land cover information…

In some cases, we may need to transfer the pixel values of our raster data to corresponding points and use them as attribute information. In this blog post, I will explain how to do it in GIS environment. There are two cases. First; we may create points corresponding to each raster pixel. Second; we may…

Map algebra is a method that allows raster data to be analyzed with mathematical and logical operations in geographic information systems (GIS). Developed by Dr. Dana Tomlin in the 1980s, this method offers a wide range of applications from topographic analysis to hydrological models, from ecological modeling to urban planning. Map algebra works by performing…