2.03 Global freshwater situation <1% of the world's water is - - PowerPoint PPT Presentation

2.03

10.1

Global freshwater situation

• <1% of the world's water is available for agriculture and industry, drinking and domestic

purposes, and energy generation and transport. Increasing competition for water among such uses is degrades the natural resources.

• One-third of the world's population live in countries that are experiencing moderate to

high water stress and death due to water-borne diseases.

• Pollution from towns and cities, industry and agriculture directly affect water supplies

for people and freshwater ecosystems

• Diversion of water for agriculture and industry is destroying freshwater lakes and rivers
• Currently, 54% of accessible runoff is appropriated by humans. By the year 2025, two-

thirds of the world's population could be facing serious problems with water availability.

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What's at stake?

• 780 million people lack access to clean water and 2.5 billion lack adequate sanitation

services.

• Sanitation coverage in developing countries is 49% and 98% in developed world
• 80% of people without access to an adequate drinking water source live in sub-Saharan

Africa, Eastern Asia and Southern Asia (Quantity)

• 1.5 million deaths each year are caused by diarrhea (Water quality)
• Individuals need 20 to 50 litres of water free from harmful contaminants every day.
• Agriculture claims 70% of all the freshwater. 3,000 to 5,000 litres of water to grow 1 Kg of

rice

• 48 countries will be affected by water stress or scarcity - affecting around 35% of the

projected global population by 2025.

• Prof. R. Nagarajan, CSRE , IIT Bombay

10.1 People & environment suffer when rivers & systems are poorly managed

Dynamic, living systems - best approach to conserve the freshwater resources is through managing river basins sustainably - wise choices about resource use, understand and maintain river dynamics, living systems in the long term. Knock-on effects - The disposal of waste water or the cutting of forests and other activities impact the downstream. Highly toxic chemical swept downstream devastates aquatic life along the course of the river and contaminating the drinking water of people. Source of life, food and power - important in terms of hydrological, economic and ecological points of view. They absorb and channel the run-off from snow-melt and rainfall and which, provide fresh drinking water as well as access to food, hydropower, building materials, medicines and recreational opportunities. Critical passages – rivers are critical link between land and sea, providing transportation routes for people, and making it possible for fish to migrate between marine and freshwater systems. Purifying water - act as natural filters and sponges, play a vital role in water purification & retention and regulation of flood

• peaks. Seasonal flooding remains the key to maintain fertility for grazing and agriculture.

Mix of habitats - very large-scale ecosystems combine both terrestrial and aquatic components, providing a wide diversity of habitats for plants and animals.

GNR 639

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 624 : River basin management

9.03

Basis of Conflict - types of conflict

• Control of Water Resources (state and non-state actors): access to water is at the root of

tensions.

• Military Tool (state actors): water systems are used by a nation or state as a weapon during a

military action.

• Political Tool (state and non-state actors): water systems are used by a nation, state, or non-

state actor for a political goal.

• Terrorism (non-state actors): water systems are either targets or tools of violence or coercion

by non-state actors.

• Military Target (state actors): water resource systems are targets of military actions by nations
• r states.
• Development Disputes (state and non-state actors): water systems are a major source of

contention and dispute in the context of economic and social development.

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 639

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 624 : River basin management

0.05

Most

water-short regions

are supplemented with demand-management practices. To meet increased demands, natural water supply is augmented with desalination, water reuse, enhanced groundwater recharge and inter-basin transfers.

Abundant water regions adopt management practices that are particularly

adapted to those specific settings assuming that resources will remain relatively abundant. Environmental flows are the water regime provided within a river, wetland or coastal zone to maintain ecosystems and their benefits. Maintaining and restoring the flows under multi-use and competing demand situations are considered in many nations and basins and integrated into water policy.

River issues

• Land degradation in the Loess Plateau
• Risk of loss of life and economic losses due to major floods
• Build up of sediment within the river system
• shortage of water to meet all human and ecological demands
• Protection of the ecological values of the Delta
• maintaining water quality of an acceptable standard

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 624 : River basin management

10.1

Threats to rivers

• Salween (ASIA) faces heavy threat from damming, the Danube (Europe) from navigation

infrastructure, and La Plata (South America) from both.

• Rio Grande (USA) and the Ganges face very similar problems from over-extraction for increasing

irrigation and domestic consumption.

• Indus faces threat from climate change because of its high dependency on glacier water. The Nile

basin is very sensitive to increases in temperature because of its high rate of evaporation.

• Invasive species is a plant or animal that is intentionally or unintentionally introduced to a region in

which it did not naturally evolve, and where in its new environment, it grows to out-compete native species and communities. Murray-Darling (Asia-Pacific)

• Mekong (Asia), the importance of fisheries for human subsistence cannot be understated, but this

naturally bountiful resource is not being managed for future use.

• Freshwater ecosystems naturally filter and purify water. However, this ability is impaired by excessive

pollution and habitat degradation (Yangtze (Asia)

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Threats to

• Colorado River in the Grand Canyon. - A proposed industrial-scale construction project threaten the Grand Canyon’s wild nature and

unique experience that belongs to every American

• Columbia River- Outdated dam operations are putting healthy runs of salmon and other fisheries at risk.
• Holston River- Toxic chemicals from the Holston Army Ammunition Plant are putting local water supplies and the community’s health at risk.
• Smith River - A proposed copper mine could harm a nationally-renowned wild trout fishery.
• Edisto River - Excessive agricultural water withdrawals are putting water supply, water quality, fish and wildlife habitat, and recreation a

t risk.

• Chuitna River - A proposed mine threatens to destroy 30 square miles of irreplaceable wild river habitat.
• Rogue-Smith Rivers - Strip mining, road construction, and metal processing would devastate this fragile, precious wild area.
• St Louis River - Mining could destroy or degrade thousands of square miles of pristine forested wetlands and streams.
• Harpeth River- Sewage pollution and water withdrawals are putting clean water, fish and wildlife, and recreation at risk.
• Pearl River - A new dam threatens to ruin healthy wetlands and wildlife habitat

Summary of Threats

River basin Threat

Salween - Nu Infrastructure - Dams Danube Infrastructure - Navigation La Plata Infrastructure - Dams and Navigation Rio Grande - Rio Bravo Water Over-extraction Ganges Water Over-extraction Indus Climate Change Nile-Lake Victoria Climate Change Murray-Darling Invasive Species Mekong - Lancang Over-fishing Yangtze Pollution

GNR 639

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 624 : River basin management

0.05

Chronological phase Characteristic development Management methods Hydraulic civilization River flow regulation Irrigation Land reclamation Dam construction River diversion Land drainage Pre-industrial revolution Flow regulation Drainage scheme Water mills Navigation & timber transport In-channel structure Canal construction Dredging Local channelization Industrial revolution Industrial mills Cooling water Power generation Irrigation & water supply Dam building Canal construction Dredging Local channelization Nineteenth century River flow regulation Conjunctive & multiple river projects Flood defence / control Integrated use river projects River Conservation management River basin planning Structural & bioengineering revetments Mitigation, enhancement & restoration techniques 21st Century Conservation management Re-management of rivers Sustainable use of river project Integrated river basin planning Flow mitigation, enhancement & restoration techniques

GNR 639

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 624 : River basin management

0.05

Meet growing demands from:

• Intercepting, diverting, storing and transferring water
• Rainwater harvesting
• Water diversions
• Storing water in reservoirs
• Transferring water among basins
• Water re-use
• Desalination

Single purpose- Early efforts were mainly single-purpose: flood control, hydroelectric generation, irrigation supply, etc. Dual purpose - Combining two development goals can be done by making simple, easily monitored trade offs, a dam can supply power and control floods. Multi-purpose - RBDPM seeks to, more-or-less simultaneously, pursue a number of goals. Holistic approach to improve its performance and support sustainable development

GNR 639

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 624 : River basin management

0.05

Source courtesy: slideshare.net

GNR 639

• Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 624 : River basin management

2.06

Source courtesy: linkedin.com

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