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

2.03

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. 10.1

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. 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. 10.1 Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 639 GNR 624 : River basin management 9.03 Prof. R. Nagarajan, CSRE , IIT Bombay

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 or 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 GNR 624 : River basin management water-short regions Most 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. 0.05 Prof. R. Nagarajan, CSRE , IIT Bombay

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

GNR 624 : River basin management 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) 10.1 Prof. R. Nagarajan, CSRE , IIT Bombay

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 10.1

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 GNR 624 : River basin management Chronological phase Characteristic development Management methods Hydraulic civilization River flow regulation Dam construction Irrigation River diversion Land reclamation Land drainage Pre-industrial revolution Flow regulation In-channel structure Drainage scheme Canal construction Water mills Dredging Navigation & timber transport Local channelization Industrial revolution Industrial mills Dam building Cooling water Canal construction Power generation Dredging Irrigation & water supply Local channelization Nineteenth century River flow regulation River basin planning Conjunctive & multiple river projects Structural & bioengineering Flood defence / control revetments Integrated use river projects Mitigation, enhancement & restoration River Conservation management techniques 21 st Century Conservation management Integrated river basin planning Re-management of rivers Flow mitigation, enhancement & Sustainable use of river project restoration techniques 0.05 Prof. R. Nagarajan, CSRE , IIT Bombay

GNR 639 GNR 624 : River basin management 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 0.05 Prof. R. Nagarajan, CSRE , IIT Bombay