DECADAL CHANGES IN NET PRIMARY PRODUCTIVITY (NPP) IN THE WEST KAZAKHSTAN REGION BASED ON MODIS SATELLITE MONITORING DATA

Abstract

The article assesses the spatiotemporal dynamics of net primary productivity (NPP) in the West Kazakhstan region for the period 2010–2022 based on MODIS satellite data. Data processing and calculation of indicators were performed using the Google Earth Engine cloud platform. Spatial patterns and trends in NPP changes were determined based on linear regression of time series for each pixel. The study results revealed pronounced spatial heterogeneity of NPP due to the natural and climatic conditions of the region. Higher productivity consistently tends to appear in the north and river valleys, while the south and southwest is less productive. The interannual dynamics of NPP are characterized by significant variability, with a sharp decline in 2015 and a subsequent recovery in 2016–2017. Trend analysis showed a predominance of positive, but spatially uneven, changes in NPP during the study period. Correlation analysis revealed that vegetation productivity in the West Kazakhstan region is primarily controlled by precipitation variability, while the influence of temperature is regionally heterogeneous and intensifies under conditions of moisture deficiency. The results highlight the high sensitivity of the region's ecosystems to climate variability and confirm the usefulness of the NPP indicator for monitoring vegetation status and assessing the resilience of arid and semi-arid landscapes.