Analysis of ET and NDVI Correlation in Different Land Cover Types of Colorado

Abstract

Climate change and water scarcity are pressing public concerns, severely impacting agricultural production and ecological balance. Leveraging advanced remote sensing, this study analyzed 30m-resolution Landsat normalized difference vegetation index (NDVI) and evapotranspiration (ET) data during Colorado's growing seasons (April–August) from 2000 to 2018. Examining correlations across various land cover types, it detailed data processing, relation analysis at different lead times, and correlation classification. Results show a mostly positive correlation in Colorado, aligning with coarser-resolution studies, with some negative exceptions. Uniquely, ET's influence on NDVI weakens as lead time extends, regardless of correlation. Combining with land cover analysis, forests with high water storage maintain stable ET. Additionally, human intervention significantly affects these correlations.