The Demographic Changes and Their Driving Forces on the Loess Plateau since 4000 Years BP

The intensity of human activities on the Loess Plateau (LP) could affect ecological health and socioeconomic development area lower reaches Yellow River (YR). Population size/density is used as an important indicator to evaluate activities, but there has been little research its variation in history. Therefore, this study provided a comprehensive analysis change characteristics, drivers stages population LP over past 4000 years. We found that: (1) significant increase after Warring States (475–221 BC) was due increasing cropland grain yield result agricultural technology compared that before States, exponential trend depended reductions procreation cost tax policies, particular abolition poll tax. (2) Peasant revolts wars for power each dynasty, military conflicts boundary between farming pasture areas during dry cold period, led mortality migration, causing show cyclical pattern decline with dynasties. (3) passed through four major stages: sparsely populated period primitive agriculture (2000–476 BC), fluctuation traditional (475 BC–1530 AD), growth (1531–1949 AD) rapid modern (1950–2000 AD).