Developing socio-hydrology:Research progress,opportunities and challenges

The development of industrialization and urbanization has intensified the coupling of human activities and hydrological processes and promoted the emergence of socio-hydrology.This paper addresses the issue of socio-hydrology due to new development and social demand for hydrological sciences and sustainable development.Four key scientific issues are identified through systematic analysis and summary of the relative research and international progress,i.e.,(1)the long-term dynamic process of socio-hydrological system evolution;(2)quantitative description and driving mechanism analysis of socio-hydrological coupling system;(3)prediction of the trajectories of socio-hydrological system co-evolution,and(4)integrated water resource management from the perspective of water systems.Moreover,opportunities and challenges for developing socio-hydrology are emphasized,including(1)strengthening the research of interdisciplinary theoretical systems;(2)improving and broadening socio-hydrological research technical methods,and(3)supporting integrated water resources management(IWRM)for sustainable utilization goals(SDGs).The review is expected to provide a reference for the future development of socio-hydrology discipline.

Chinese Built-up Land in Floodplains Moving Closer to Freshwaters

Human proximity to water and its dynamics are important to understanding the socio-hydrological dilemma between using floodplains and avoiding flood risk.However,previous studies have not distinguished between the water proximity of built-up land in floodplains(BLF)and the water proximity of built-up land outside floodplains(BLOF).This article provides a new and spatiotemporal perspective of the BLF water proximities for understanding the changing flood risk in China.The results show that China’s BLFs had an average water proximity of 5.41 km in 2014.Most of the BLFs(62%,25.889103 km2)were located within 3 km of waterbodies.From 1990 to 2014,China’s BLFs increased rapidly by 81%from23.069103 km2 to 41.749103 km2,of which a large portion(57%)was concentrated in water surroundings(≤km),shortening the distance between BLFs and waterbodies by 169 m.The BLF growth concentrated in water surroundings even in areas where BLFs have an overall increasing distance from waterbodies.Both the increases in the BLFs and their proximity to waterbodies can increase flood exposure and exacerbate flood risk.The scientific community and policymakers should pay attention not only to the volume of BLF growth,but also its spatial relationship with waterbodies.