world day to combat desertification · source: after molden (ed) 2007. water for food, water for...
TRANSCRIPT
University of Natural Resources and Life Sciences, Vienna Department of Water, Atmosphere and Environment
Institute of Hydraulics and Rural Water Management
World Day to Combat Desertification BOKU, Vienna, 17th June, 2016
Rationale
Soil Water Functions
defined in terms of access to water, is a critical constraint to agriculture in many areas of the world.
Source: Comprehensive Assessment of Water Management in Agriculture (Online: http://www.iwmi.cgiar.org/assessment/files_new/synthesis/Summary_SynthesisBook.pdf)
Water Scarcity
Water Scarcity – Definitions and Indicators
Little or no water scarcity
• Abundant water resources relative to use, with less than 25% of water from rivers withdrawn for human purposes
Physical water scarcity
• Water resources development is approaching or has exceeded sustainable limits
• More than 75% of river flows are withdrawn for agriculture, industry and domestic purposes (accounting for recycling of return flows)
• This definition - relating water availability to water demand – implies that dry areas are not necessarily water scarce
Approaching physical water scarcity
• More than 60% of rivers flows are withdrawn. These basins will experience physical water scarcity in the near future
Economic water scarcity
• Human, institutional and financial capital limit access to water even though water in nature is available locally to meet human demands
• Water resources are abundant relative to water use, with less than 25% of water from rivers withdrawn for human purpose
• Malnutrition exists
Source: Comprehensive Assessment of Water Management in Agriculture (Online: http://www.iwmi.cgiar.org/assessment/files_new/synthesis/Summary_SynthesisBook.pdf)
Source: after Molden (ed) 2007. Water for Food, Water for Life. A comprehensive assessment of water management in agriculture. London, Earthscan and Colombo, IWMI.
Rainfall 100%
Landscape 56% Rainfed
agriculture 4.5%
Irrigated agriculture
2%
Evaporation 1.3%
Cities & Industry
0.1%
Ocean 36%
Green Water Soil Moisture
from Rain
Blue Water Rivers, Lakes Groundwater
Irrigated Agriculture 70% of “blue water”
Concept Green/Blue Water
Water Management
Water Management
Water Management Options
Source: Loiskandl, Tigray, Ethiopia, WATERMAN
Water Management Options
Source: Ruffeis, Tigray, Ethiopia, WATERMAN
Water Management Options
12 Source: Ruffeis, Yemen
Water Management Options
Water Management Options
Water Management Options
Source: Mwetu, k.k., 2008
Source: Miller, S.N., 2005
Summary
Institute of Hydraulics and Rural Water Management Department of Water, Atmosphere and Environment University of Natural Resources and Life Sciences, Vienna Muthgasse 18, 1190 Vienna E-Mail: willibald [email protected] [email protected] http://www.wau.boku.ac.at/ihlw.html
Thank you for your attention!
Institute of Hydraulics and Rural Water Management