Mathis Loïc Messager

Non-perennial rivers and streams that periodically cease to flow are ubiquitous but seldom mapped, let alone monitored. Scaling models that include even the tiniest rivulets estimate that up to 78% of the world’s watercourses naturally stop flowing at least one day per year.

1 Introduction Most streams and rivers on Earth are non-perennial, that is, cease to flow or dry during some time of the year (Messager et al., 2021). While streamflow intermittence is most prevalent in semi-arid and arid regions of the globe, it is also widespread in humid regions.

Introduction Click to copy section linkSection link copied! Rivers and streams make up the very fabric of human societies and vice versa. Societal structures evolved from and are still entwined with river networks. (1−3) To this day, flowing waters are essential to meet basic human needs and enable people’s well-being, livelihoods, and cultures. (4−6) At the same time, rivers and streams are hybrid features of the landscape, both social and natural.