29-05-2014, 11:26 AM
Water and Development: The Importance of Irrigation in Developing Countries
Water and Development.ppt (Size: 149 KB / Downloads: 119)
Water policy concerns-quality
Water quality concerns in the tropics are not limited to human health. Contamination of water by arsenic and mercury in mining activities are major concerns in the tropical forest. Such contamination is hazardous to the forest ecosystems and their bio-diversity.
When the miners are small, informal organizations, the regulation of toxic material in mining is a difficult non source point pollution problem. Solutions are difficult to implement because of the population density, large scale and weak government.
Establishing of mobile unit that can track violators and a legal system to prosecute is a major priority.
Social Concerns.
Waterborne diseases. Bad project planning resulted in spread of malaria and other water born diseases as vector spread in canal and dams.
Displacement of native populations. The development of water projects in the last century has led to the displacement of 40 – 80 million people. Compensation for these forced changes has usually been minimal, if it occurs at all.
International conflicts and water supply. There are 261 rivers that cross international boundaries. The division of water resources between countries can either be a source of conflict or a reason for necessary cooperation. 162 treaties were signed an implemented for cooperative water management.
Heterogeneity of water
There are differences in water availability within regions-in Brazil,Mexico, California, Hawaii, Russia, there are regions of floods and surpluses and deserts.
Differences in water availability over time matter - at the same year you may have floods and shortages
Differences in water quality are crucial- consumption, farming of various crops and production require minimum quality.
Value and use of water dependent on
location
Time
Quality
Agriculture Values of water vary
Agricultural value of water r varies between crops and locations. A relatively small faction of the water (20%) generates much of the value (more than 70%).
Crops such as flowers and strawberries can pay more than $500/AF, cotton can afford paying $40-100/AF and pasture $30/AF and less.
Values of water vary by location,land quality and according to market conditions.
Industry and residential users are able to afford to pay much more than agricultural field crops. Their demand is relatively small (33%) but is continually growing.
Overview of irrigation
irrigated land has increased from 50 mha (million hectares) in 1900 to 267 mha today.
Between 1962 and 1996 the irrigated area in developing countries increased at 2% annually.
Irrigation has been crucial in meeting the food demand of doubling world population since WWII.
Irrigation projects have been costly in terms of capital, environmental degradation& human health.
Design and management of water resources have been flawed. There is a growing perception of water supply crisis,but we have a water management crisis.
As population is likely to grow double again, we need to reform water institutions and policies.
This presentation first assesses water situation and then introduces direction for reform.
BENEFITS OF IRRIGATION
Irrigation increases crop yields.- The 17% of land that is irrigated is producing 40% of the global food
The value of production of irrigated cropland is about $625/ha/year ($95/ha/year for rain-fed cropland and $17.50/ha/year for rangelands).
Irrigation affects total factor productivity (TFP) beyond the input value of the water(evanson,pray,Rosegrant).,
Irrigation allows improve timing and spatial distribution of water. It allows double cropping, it enables supply stabilization. It enable production of vegetables and fruits.
Increases consumer well being& employment & farm income(net income increase per family in Africa was $150 - $1000)
The high productivity of agriculture slowed expansion of deforestation.
Water Governance institutions
There are economics of scale in implementing water diversion and mining projects. Some are executed and financed by government agencies. There is also large scope for collective action among private parties in cooperating to manage and develop water resources.
Water user associations (or water districts) are being established to have better cooperation and local representation in developing water and other natural resources. These organizations are collectively obtain resources needed for investment and establish and enforce rules that lead to socially beneficial water and resource management,.
Such organizations may be responsible to water distribution and control of non point source pollution.