Man and the water cycle: challenges for the 21st century

Abstract

Water is essential to life. Modern, technological societies use huge quantities of this precious liquid. The hydrologic (water) cycle represents the movement of water through the earth's environmental systems. Humankind primarily makes use of three parts of the hydrologic cycle for its water needs: rivers, lakes, and groundwater. Our use of these components of the water cycle has had a variety of deleterious effects. Many large rivers have had their flow regimes modified and suffered from pollution with attendant negative effects on riverine, estuarial, and oceanic ecosystems. Lakes have suffered most seriously from anthropogenic caused pollution but have been impacted by introduction of exotic biota and regime alteration as well. Groundwater, because of its slow rate of replenishment, has suffered from depletion and accumulating pollutants. Looking toward the next century, we must alter our mangement of water and put it on an ecologically sustainable footing. This involves three key actions: (1) developing an ecosystems approach, (2) improving the water knowledge base, and (3) promoting improved management and cooperation, both nationally and internationally.

Water in the Aral Sea Basin of Central Asia: Cause of Conflict or Cooperation?

“…An additional problem would be that during the high-flow season of maximum storage effort, riverbeds below the dams would be desiccated, with serious negative environmental and public health consequences. Hence, it would be environmentally harmful as well as economically unjustified to attempt to store all the seasonal surplus flow, and especially the surplus flow in high-water years, for times when flow is low and demand is high (Collier et al, 1996;Micklin 1996).…”

“…Water is a renewable resource, but in parts of the Earth, particularly the arid regions, human actions have pushed usage to or beyond sustainable limits. Furthermore, competition among and within nations for fresh water, already a widespread problem by the end of the 20th century, promises to become even more pervasive and acute in the new millennium (see Micklin, 1996;Gleick, 2000;and Goklany, 2002).…”

Elemental Iron (Fe0) for Better Drinking Water in Rural Areas of Developing Countries

“…This practice is a serious public health issue and has been addressed in the Millennium Development Goals, which aim to halve, by 2015, the proportion of people without access to safe water in 2000 (UN 2000). Looking toward the future, the water management must involve promoting improved international cooperation (Brown 2007, Micklin 1996.…”

“…Water pricing is considered as a key tool: (i) to promote water use efficiency, (ii) to prevent water pollution, and (iii) to make for a more rational allocation of water (Micklin 1996, Sobsey et al 2008. The idea behind water pricing is that the more one pays for water, the more careful he will use it.…”

Mitigando futuras crisis de agua y alimentos: reciclaje, desalinización y planes de contingencia ante sequías

“…Los grandes proyectos de ingeniería, a menudo subvencionados oficialmente, se han ocupado generalmente del diseño y construcción de presas para el almacenamiento de aguas superficiales (Micklin, 1996;Roos, 1998;del Moral y Giansante, 2000). El número de grandes presas ha aumentado, en todo el mundo, desde las 5.000 en 1950 hasta las 38.000 en 1995 (Goudie, 1993;Postel, 1997).…”