How Close Do We Live to Water? A Global Analysis of Population Distance to Freshwater Bodies

Abstract

Traditionally, people have inhabited places with ready access to fresh water. Today, over 50% of the global population lives in urban areas, and water can be directed via tens of kilometres of pipelines. Still, however, a large part of the world's population is directly dependent on access to natural freshwater sources. So how are inhabited places related to the location of freshwater bodies today? We present a high-resolution global analysis of how close present-day populations live to surface freshwater. We aim to increase the understanding of the relationship between inhabited places, distance to surface freshwater bodies, and climatic characteristics in different climate zones and administrative regions. Our results show that over 50% of the world's population lives closer than 3 km to a surface freshwater body, and only 10% of the population lives further than 10 km away. There are, however, remarkable differences between administrative regions and climatic zones. Populations in Australia, Asia, and Europe live closest to water. Although populations in arid zones live furthest away from freshwater bodies in absolute terms, relatively speaking they live closest to water considering the limited number of freshwater bodies in those areas. Population distributions in arid zones show statistically significant relationships with a combination of climatic factors and distance to water, whilst in other zones there is no statistically significant relationship with distance to water. Global studies on development and climate adaptation can benefit from an improved understanding of these relationships between human populations and the distance to fresh water.

A framework for global river flood risk assessments

“…Since the aim of the paper is to demonstrate the potential application of flood risk modelling techniques on a global scale, we used a simple classification of land cover into three classes: high-density urban; low-density urban; and non-urban. For the reference time period (2010), we firstly used land cover data from two sources: MODIS (Schneider et al, 2009); and the GRUMP dataset (CIESIN and CIAT, 2009) to create a discrete land cover map showing urban and peri-urban areas, using the approach of Kummu et al (2011). Secondly, we created a set of three fractional land cover maps (high-density urban, low-density urban, and non-urban).…”

Preface: Flood-risk analysis and integrated management

“…Increasing flood losses in the past have been mainly attributed to the growing amount of people and economic assets in flood-prone regions (Barredo, 2009;Bouwer, 2010). Despite the risk of flooding, the latter provide otherwise favourable conditions, such as access to fresh water and means for transportation (Kummu et al, 2011). In the future, the trend in increasing losses could be further aggravated due to the increasing frequency and intensity of some climate related hazards in several regions (IPCC, 2013).…”

Fish navigation of large dams emerges from their modulation of flow field experience

“…The issue is particularly relevant for rivers, which make up only 0.0002% of water on Earth (1) but support more than 40% of the world's human population (2,3). River regulation to meet society's needs has accelerated in the past two centuries (4), leaving over half of the world's major rivers now fragmented by >50,000 large dams providing water, energy, flood control, and transportation (3,5,6).…”