Fig. 3.

Impacts of hydropower dam construction on economy, population, and greenness in five global regions. Note that the dashed red lines refer to the average value within the NAHD zones and reference zone. The boxes indicate one SD, and the whisker indicates two SDs. The outliers are defined as observations outside two SDs and are not included for better presentation of the distribution. Hydropower dam construction was associated with less economic development in NAHD zones than their reference areas at the global level, especially for the Global South, as indicated by the negative values of ΔGDP, ΔUrban, and ΔNTL of NAHDs, in contrast to their positive values in the respective reference areas or small increased values in NAHDs over those in reference areas. The decrease or smaller increase of the population indices in NAHDs is in contrast to the positive values of the reference areas. Greenness, measured by NDVI, decreased within NAHDs, with the highest reduction within 5-km distance of the dams. While recently constructed dams were associated with increased GDP in North America and urban areas in Europe in nearby areas, they were related with decreased GDP, urban land, and population in the Global South and greenness in Africa. * at the label means the change for that buffer zone is significant (P < 0.001).