Using Satellite Imagery to Track the Development of the Green Belt of Astana, Kazakhstan

Abstract
The Astana green belt, an ambitious artificial forestry initiative, was implemented as part of the master plan accompanying the relocation of the capital city of Kazakhstan in 1997. This urban greening project aimed to combat harsh climatic conditions by creating a protective forestry barrier against strong winds, thus enhancing the local microclimate. Remote sensing techniques were employed to track the green belt's temporal evolution and evaluate changes in vegetation characteristics from its inception to the present. A temporal segmentation method was used to find the emergence of forestry per green belt patch. The relative success of the green belt patches over time was assessed based on median NDVI difference rasters across the monitoring intervals. Vegetation characteristics, including planting direction and median NDVI for the latest year, were mapped to visualise their spatial distribution. Finally, the current boundaries of the green belt were compared to those delineated in the master plan. The results show that planting efforts were maintained throughout the study period, leading to a notable expansion of greenery areas over time. While some patches were initially considered underperforming in each monitoring period, they demonstrated substantial improvement by the end of the study period. The strategic spatial design of the green belt was apparent, with an initial focus on the establishment of a central ring of forestry close to the city boundary, followed by outward expansion in the later periods. The planting directions of the forest rows were oriented to counter prevailing winds and optimise the belt's windbreak function. No major areas or directions of vegetation failure were apparent based on median patch NDVI. It was found that the current extent of the green belt has largely surpassed the expectations outlined in the master plan, indicating an expansion of the green belt project beyond its initial scope. This study enhances our understanding of the Astana green belt project’s success and the strategic considerations underlying its development. The findings of this study could inform further research surrounding the green belt of Astana, and may also provide valuable insights for comparable greening initiatives in other geographical contexts.