Satellite-based monitoring of lake Urmia basin health with focus on its ecosystem regulating services by applying total ecosystem health (TEH) model

In recent decades, most of the natural and semi-natural ecosystems around the world have experienced excessive environmental loads due to human unsustainable activities that threaten their health and sustainability. Accordingly, the idea of ecosystem health has been proposed to monitor simultaneously the structure, function as well as the services that an ecosystem provides. In this research, moderate resolution imaging spectroradiometer 8-day land surface temperature product was used to measure temperature and land cover changes of Lake Urmia Basin for three months of June, July and August in a time period of 2000–2018. Time series data analysis was carried out using linear regression, Fourier series and Mann–Kendall test. Moreover, Moran index was used to analyze changes of the spatial pattern of indicators. To show the influence of Lake Urmia ecosystem services on its overall health, Total Ecosystem Health model was established by introducing normalized difference vegetation index, lake temperature, Moran index and temperature of the basin as indicators of Vigor, Structure, Resilience and Ecosystem Services, respectively. Based on output of the model, 54, 41 and 4% of the regions have obtained weak, moderate and strong ecosystem health, respectively. The results showed that despite the moderating role of Lake Urmia as a temperature regulator for its surrounding areas especially within 10 km, the decline of ecosystem health status in 95% of regions has occurred during the years 2000–2018. Therefore, to benefit from the ecosystem regulating services, the sustainability of other components involved in the total ecosystem health should be also ensured.