# Identification of Land Use Mix Using Point-Based Geospatial Data in Urban Areas
## 2 Materials And Methods
### Datasets
#### 2.2.1 POI Data  
There are two primary data sources that we used to acquire POI data for our study. For residential areas, we scraped the data from an ad listings website. For non-residential areas, we used Google Maps API, which provides the locations of non-residential areas. A full list of place types offered by Google Maps API at the time of writing can be seen in Appendix A section. For each request to the API, a maximum of 60 results were returned for a particular area, which is limited due to the nature of Google Maps API.  
API calls were continuously made within smaller areas until we identified no additional new POIs. An initial search was performed within an area encompassing a radius of 1500 m (\(r=1500\)) without specifying any particular search query, thereby aiming to capture any available POIs. Following this, we systematically reduced the search radius in decrements until reaching 250 m (\(r=250\)). For each reduced radius, we repeated the API calls to ensure comprehensive coverage within the smaller segments of our study areas.  
This approach enabled us to progressively gather POIs that might have been missed in broader searches. Consequently, by July 2021, we had successfully collected a total of 19,943 non-residential POI locations for Ankara. Similarly, we replicated this methodology for the Kadikov region in November 2023. By employing the same systematic approach of reducing the search radius and making numerous API calls, we were able to obtain 15,527 non-residential data points for Kadikov.  
Figure 1: Map of the study areas: (1) Ankara and (2) Kadköy.  
For the ad listings data, we undertook a comprehensive web scraping exercise to gather all online ad listings for Ankara from Hepsiemlak ([[https://www.hepsiemlak.com/](https://www.hepsiemlak.com/)]([https://www.hepsiemlak.com/](https://www.hepsiemlak.com/)), accessed on 30 July 2019), one of Turkey's largest property ad listing websites, encompassing residential and non-residential properties. Hepsiemlak, initially established in 2006, has become a leading platform in the Turkish real estate market. We have conducted data collection from Hepsiemlak between June 2019 and July 2019. During this period, we managed to accumulate a total of 84,580 ad listings. Following a rigorous data cleansing process (the details are explained extensively in Section 2.3) we refined this dataset to 60,031 unique ads. The data cleansing involved procedures to remove duplicates, correct inconsistencies, and ensure the accuracy and reliability of the ad listings.  
In addition to the data from Hepsiemlak, in November 2023, we extended our data collection efforts to include Kadikoy by using the Sahibinden ([[https://www.sahibinden.com/](https://www.sahibinden.com/)]([https://www.sahibinden.com/](https://www.sahibinden.com/)), accessed on 29 November 2023). Sahibinden, established in 2000, is another prominent platform in Turkey that offers comprehensive listings for residential and commercial properties and various other categories and services. Like Hepsiemlak, Sahibinden has a significant user base and provides detailed listings.  
Using our established methodology, we collected 5942 ad listings from Sahibinden for Kadikoy. After applying the same rigorous data cleansing techniques, this dataset was narrowed down to 4847 unique ads. This additional dataset reinforces the robustness of our study by providing a broader geographical scope and adding temporal depth to our data.