Indian Drainage System:
Divided into Himalayan and the Peninsular rivers.
Evolution of the current drainage system ‐interplay of factors,
like change of relief, precipitation etc.
Himalayan Rivers –
• Miocene period the Himalayas ‐drained by the river Shiwalik or Indo‐Brahma.
• dismembered due to: western Himalayas upheaval In the Pleistocene period.
• uplift of the Potawar Plateau (Delhi Ridge), dismemberment river system by acting as a water divide.
• the crustal down thrusting in area between Rajmahal hills and Meghalaya Plateau.
• dismemberment of the Ganga and Brahmaputra river system. Diversion towards the Bay of Bengal.
Peninsular Rivers –
• Western Ghats ‐ the main water divide. It is the outcome of following 3 major Events:
• In the early Tertiary period, the western flank of the peninsula subsided‐submergence below the sea. Consequently, the direction of the river on either side of the original watershed got disturbed.
• Pleistocene period‐ upheaval of Himalayas the northern flank of the peninsula subsided beneath the Eurasian plate thereby resulting into trough faulting. The Narmada and Tapi flow through these trough
faults.
• Subsidence of northern flank ‐slight tilting of the peninsular block from the northeast to the southeastern. orientation of major peninsular rivers towards the Bay of Bengal.
Thus, the interplay between three major physiographic units and the nature and characteristics of precipitation finally shaped the current drainage system in the Indian subcontinent.
The reason why the Peninsular Rivers are not navigable:
• flow across hills‐a number of waterfalls and rapidsdifficult to develop waterways transport.
• Seasonal‐flow is dependent on rainfall. During the dry season, even the large rivers like Kaveri have limited flow of water in their channels.
• short and shallow courses.
• Hard igneous and metamorphic rock composition of peninsular India makes it difficult to modify the topography for navigation.
Hydroelectric power generation in Deccan Rivers:
Absence of coal
industrialization ‐a
• in South India and rapid
push factor for development of
hydroelectricity in South India. Hydroelectric plant at Shivanasamudram falls on river Kaveri is among the earliest in Asia.
• Western Ghat‐heavy rainfall and abundant water supply during monsoon. opportunity for hydroelectric potential.
• The steep courses of the west flowing rivers like Sharavathi, Idukki, Periyar and the east‐flowing rivers like Bhira, Bhivpuri, and Koyna etc. offer high opportunities for hydel power development.
The total basin area of the Indus, the Ganga and the Brahmaputra is 11.78, 8.61 and 5.8 lakh square kilometres respectively.
The Godavari has the largest basin area of 3.12 lakh square kilometres only which is less than one‐third the basin area of the Indus.
Meanders The highly tortuous upper reaches of the Himalayan rivers. When they enter the plains, there is a sudden reduction in the speed of flow of water. rivers form meanders often
shifting their beds.
Peninsular Plateau
• The hard rock surface and non‐ alluvial character ‐ little scope for the formation of meanders. Rivers
follow straight courses.
Deltas and Estuaries
• The Himalayan rivers‐ big deltas @ mouths. The Ganga‐Brahmaputra delta largest in the world.
• Some Peninsular rivers eg: the Narmada and Tapi form estuaries.
• Other rivers such as the Mahanadi, the Godavari, the Krishna and the Cauvery form deltas.
• small streams from the Western Ghats towards the west enter Arabian Sea without any delta.
Deltas ‐formed by the accumulation of sediments brought down by the river. The West flowing rivers do not form Delta whereas they form Estuaries because,
• Deccan plateau is eastward sloping i.e Western coast is elevated compared to eastern coast. Hence, there is less ground for delta formation at Western Ghats.
• The west flowing rivers travel lesser distance than east flowing rivers before getting into the sea.
• The west flowing rivers travel through the hard rocks and over higher gradient, so they couldn't collect large amount of Slit, widen themselves and flow with very high speed.
(Draw Indian River Map)
Interlinking of rivers
• not new.
• Every irrigation project involves such transfer at some scale.
• Originally mooted by the Britishers, the scheme revisited by irrigation engineer KL Rao in 1972.
• Supreme Court‐issuing orders to the government to implement interlinking of rivers.
Current interlinking of river programme
• is based on the National Perspective Plan (NPP) comprising 30 river links.
• more than 3000 storages to distribute 174 billion cubic meters of water through a canal network of
14900 kms.
• The estimated cost of 30 projects under National Perspective Plan was around Rs. 5,60,000 crore.
• Livelihood issues ‐ o shifting and rehabilitation of around 3.5‐5.5 million people mostly tribals and farmers.
• tensions with neighboring countries like Bangladesh,
Bhutan and Pakistan lower riparian states on the Himalayan rivers.
• Distributing pollution ‐ Rivers like Ganga & Yamuna‐ highly polluted and interlinking a way of distributing pollution to less polluted rivers.
• Ecological dimension‐interfering with natural cycle of river waters flowing into the seas and oceans.
Potential in addressing water related challenges
• uneven distribution of India’s water resources.
• best solution to repeated flooding of Himalayan rivers and erratic water availability in peninsular rvers.
• Improving inland navigation with the help of canals.
• flood control, irrigation, limiting droughts, and boosting farm output can be sorted out by
interlinking rivers.
However, the assumption on which potential is itself has been questioned.
‐ no river basin is water
every drop performs some
surplu s. because
ecological service.
• Environmentalists opine
• The fact is when one river is in spate so is next river and transferring water would require huge storage facilities. Construction of large reservoirs has massive environmental impacts not considered in the scheme. Many irrigation projects are stalled on this count.
Therefore, concerns and challenges remain in realising the true potential of this project. Detailed feasibility reports should be prepared along with Social and Environment Impact Assessment Reports. These challenges need effective solutions before this project can be implemented on such large scale.
B N Navalavala expert committee on river interlinking
Watershed Management
• Geographically, a watershed ‐an area where all water flowing into it goes to a common outlet.
• not merely a hydrological unit but also a sociopolitical‐ecological entity as both the natural as well as human resources constitute an integral part. Watershed management refers to efficient management, conservation, regeneration and judicious use of all resources – natural (like land, water, plants and animals) and human, within a watershed.
It is a comprehensive approach towards sustainable development of land and water resources in order to meet multiple objectives like poverty reduction, ecological conservation, land productivity enhancement, etc. The activities involved in WM are:
• Entry point activities (EPAs): Knowledge based intervention to build rapport with the community.
• Land and Water conservation practices:
In‐situ ‐ i.e. in field activities that prevent improve soil health, protect against land degradation, help in groundwater recharge. E.g. contour bunding,
terracing etc.
iEx‐situ ‐ off field activities that harvest substantial run‐off, improve irrigation potential, etc. E.g. check dams, gully control, etc.
• Pest and Nutrient Management
• Crop diversification and Intensification
• Capacity building of the community
Importance of Watershed Management
About 60% of the total arable area in the country is rainfed. These areas are hotspots of poverty, malnutrition, food insecurity, are prone to severe land degradation, water stress and have poor social and institutional infrastructure.
Watershed development is considered as an effective tool for addressing many of these problems and is recognized as potential engine for agriculture growth and development in fragile and marginal rain‐fed areas. Management of natural resources at watershed scale produces multiple benefits in terms of increasing food production, improving livelihoods and protecting environment.
• Improvement and conservation of land and water resources in a watershed for more efficient and sustained production.
Checks soil erosion and reduce
yield on the watershed.
Increases infiltration of rainwater
• the effect of sediment
• and enhances the ground water recharge
• Builds resilience to floods as well as droughts.
• Enhances alternative livelihood sources like livestock production and dairy farming.
• Supplements household income.
Kothapally Watershed in Andhra Pradesh, of the Krishna basin, is an example of successful watershed management. Groundwater recharge increased more than 4 times and crop yields increased 2‐5 times in monsoon season. There has also been substantial improvement in household income and employment opportunities as well as reduction in poverty. Challenges/limitations in Watershed Management programmes in India
• Equitable sharing of benefits: The area development programs offer benefits primarily to landowners, with landless and marginal farmers often benefit only marginally or not at all.
• Common lands do not get adequately treated.
• Gains from recharge of groundwater are rapidly dissipated through increased withdrawal. Domestic, livestock and ecosystem water needs often do not get adequately addressed.
• Downstream impacts of intensive upstream water conservation are not being considered.
• Costs at which the gains are achieved are considered to be high.
• People’s participation is limited to the watershed project implementation stage.
• No/little building of institutions for long‐term collective management of resources.
Integrated Resources Water Management:
IWRM is a process which promotes the coordinated development & management of water, land & related
resources, in order to maximize the resultant economic & social welfare in an equitable and sustaniable manner.
Principles of IWRM:
• economic efficiency
• environmental sustainability
• social equity, including poverty reduction
Components of IWRM:
• National Water Policy, 2012 tries to promote IWRM in the following ways:
• Common integrated perspective for water resource planning
• Departments at Centre/State Governments levels should be restructured & made multi‐disciplinary to fulfil the needs of IWRM.
• Promotes principles of IWRM.
• Inter‐state coordination: legislation for the optimum development of inter‐ State rivers.
• River basin approach: scientific planning of land & water resources taking basin/sub‐basin.
• Efficient utilization of water: It highlights the need to plan, manage & regulate water
• Information system: All water related data, should be integrated.
• Managing water resource as a community resource. IWRM is the philosophy that needs to be followed both in letter & spirit.
Divided into Himalayan and the Peninsular rivers.
|
Himalayan Drainage
System
|
Peninsular Drainage System
|
|
originate in Himalayan ranges.
|
originate in the Peninsular
Plateau.
|
|
large basins and
catchment
Areas.Ganga
‐ 8.6 lakh square km (after indus)
|
small basins and catchment
Areas. Godavri ‐ 3.2 lsk (highest
)
|
|
Young,
active and
deepening the valleys. Deep V – shaped valleys
called gorges.
|
Old
rivers with graded profile Shallow
& graded valleys. little erosional activity to perform.
|
|
antecedent
drainage.
|
consequent drainage.
|
|
Long course
with meanders, river capturing and shifting
|
Fixed and small course
|
|
Perennial:
from glacier
|
Seasonal: monsoon rainfall
|
Evolution of the current drainage system ‐interplay of factors,
like change of relief, precipitation etc.
Himalayan Rivers –
• Miocene period the Himalayas ‐drained by the river Shiwalik or Indo‐Brahma.
• dismembered due to: western Himalayas upheaval In the Pleistocene period.
• uplift of the Potawar Plateau (Delhi Ridge), dismemberment river system by acting as a water divide.
• the crustal down thrusting in area between Rajmahal hills and Meghalaya Plateau.
• dismemberment of the Ganga and Brahmaputra river system. Diversion towards the Bay of Bengal.
Peninsular Rivers –
• Western Ghats ‐ the main water divide. It is the outcome of following 3 major Events:
• In the early Tertiary period, the western flank of the peninsula subsided‐submergence below the sea. Consequently, the direction of the river on either side of the original watershed got disturbed.
• Pleistocene period‐ upheaval of Himalayas the northern flank of the peninsula subsided beneath the Eurasian plate thereby resulting into trough faulting. The Narmada and Tapi flow through these trough
faults.
• Subsidence of northern flank ‐slight tilting of the peninsular block from the northeast to the southeastern. orientation of major peninsular rivers towards the Bay of Bengal.
Thus, the interplay between three major physiographic units and the nature and characteristics of precipitation finally shaped the current drainage system in the Indian subcontinent.
The reason why the Peninsular Rivers are not navigable:
• flow across hills‐a number of waterfalls and rapidsdifficult to develop waterways transport.
• Seasonal‐flow is dependent on rainfall. During the dry season, even the large rivers like Kaveri have limited flow of water in their channels.
• short and shallow courses.
• Hard igneous and metamorphic rock composition of peninsular India makes it difficult to modify the topography for navigation.
Hydroelectric power generation in Deccan Rivers:
Absence of coal
industrialization ‐a
• in South India and rapid
push factor for development of
hydroelectricity in South India. Hydroelectric plant at Shivanasamudram falls on river Kaveri is among the earliest in Asia.
• Western Ghat‐heavy rainfall and abundant water supply during monsoon. opportunity for hydroelectric potential.
• The steep courses of the west flowing rivers like Sharavathi, Idukki, Periyar and the east‐flowing rivers like Bhira, Bhivpuri, and Koyna etc. offer high opportunities for hydel power development.
The total basin area of the Indus, the Ganga and the Brahmaputra is 11.78, 8.61 and 5.8 lakh square kilometres respectively.
The Godavari has the largest basin area of 3.12 lakh square kilometres only which is less than one‐third the basin area of the Indus.
Meanders The highly tortuous upper reaches of the Himalayan rivers. When they enter the plains, there is a sudden reduction in the speed of flow of water. rivers form meanders often
shifting their beds.
Peninsular Plateau
• The hard rock surface and non‐ alluvial character ‐ little scope for the formation of meanders. Rivers
follow straight courses.
Deltas and Estuaries
• The Himalayan rivers‐ big deltas @ mouths. The Ganga‐Brahmaputra delta largest in the world.
• Some Peninsular rivers eg: the Narmada and Tapi form estuaries.
• Other rivers such as the Mahanadi, the Godavari, the Krishna and the Cauvery form deltas.
• small streams from the Western Ghats towards the west enter Arabian Sea without any delta.
Deltas ‐formed by the accumulation of sediments brought down by the river. The West flowing rivers do not form Delta whereas they form Estuaries because,
• Deccan plateau is eastward sloping i.e Western coast is elevated compared to eastern coast. Hence, there is less ground for delta formation at Western Ghats.
• The west flowing rivers travel lesser distance than east flowing rivers before getting into the sea.
• The west flowing rivers travel through the hard rocks and over higher gradient, so they couldn't collect large amount of Slit, widen themselves and flow with very high speed.
(Draw Indian River Map)
Interlinking of rivers
• not new.
• Every irrigation project involves such transfer at some scale.
• Originally mooted by the Britishers, the scheme revisited by irrigation engineer KL Rao in 1972.
• Supreme Court‐issuing orders to the government to implement interlinking of rivers.
Current interlinking of river programme
• is based on the National Perspective Plan (NPP) comprising 30 river links.
• more than 3000 storages to distribute 174 billion cubic meters of water through a canal network of
14900 kms.
• The estimated cost of 30 projects under National Perspective Plan was around Rs. 5,60,000 crore.
• Livelihood issues ‐ o shifting and rehabilitation of around 3.5‐5.5 million people mostly tribals and farmers.
• tensions with neighboring countries like Bangladesh,
Bhutan and Pakistan lower riparian states on the Himalayan rivers.
• Distributing pollution ‐ Rivers like Ganga & Yamuna‐ highly polluted and interlinking a way of distributing pollution to less polluted rivers.
• Ecological dimension‐interfering with natural cycle of river waters flowing into the seas and oceans.
Potential in addressing water related challenges
• uneven distribution of India’s water resources.
• best solution to repeated flooding of Himalayan rivers and erratic water availability in peninsular rvers.
• Improving inland navigation with the help of canals.
• flood control, irrigation, limiting droughts, and boosting farm output can be sorted out by
interlinking rivers.
However, the assumption on which potential is itself has been questioned.
‐ no river basin is water
every drop performs some
surplu s. because
ecological service.
• Environmentalists opine
• The fact is when one river is in spate so is next river and transferring water would require huge storage facilities. Construction of large reservoirs has massive environmental impacts not considered in the scheme. Many irrigation projects are stalled on this count.
Therefore, concerns and challenges remain in realising the true potential of this project. Detailed feasibility reports should be prepared along with Social and Environment Impact Assessment Reports. These challenges need effective solutions before this project can be implemented on such large scale.
B N Navalavala expert committee on river interlinking
Watershed Management
• Geographically, a watershed ‐an area where all water flowing into it goes to a common outlet.
• not merely a hydrological unit but also a sociopolitical‐ecological entity as both the natural as well as human resources constitute an integral part. Watershed management refers to efficient management, conservation, regeneration and judicious use of all resources – natural (like land, water, plants and animals) and human, within a watershed.
It is a comprehensive approach towards sustainable development of land and water resources in order to meet multiple objectives like poverty reduction, ecological conservation, land productivity enhancement, etc. The activities involved in WM are:
• Entry point activities (EPAs): Knowledge based intervention to build rapport with the community.
• Land and Water conservation practices:
In‐situ ‐ i.e. in field activities that prevent improve soil health, protect against land degradation, help in groundwater recharge. E.g. contour bunding,
terracing etc.
iEx‐situ ‐ off field activities that harvest substantial run‐off, improve irrigation potential, etc. E.g. check dams, gully control, etc.
• Pest and Nutrient Management
• Crop diversification and Intensification
• Capacity building of the community
Importance of Watershed Management
About 60% of the total arable area in the country is rainfed. These areas are hotspots of poverty, malnutrition, food insecurity, are prone to severe land degradation, water stress and have poor social and institutional infrastructure.
Watershed development is considered as an effective tool for addressing many of these problems and is recognized as potential engine for agriculture growth and development in fragile and marginal rain‐fed areas. Management of natural resources at watershed scale produces multiple benefits in terms of increasing food production, improving livelihoods and protecting environment.
• Improvement and conservation of land and water resources in a watershed for more efficient and sustained production.
Checks soil erosion and reduce
yield on the watershed.
Increases infiltration of rainwater
• the effect of sediment
• and enhances the ground water recharge
• Builds resilience to floods as well as droughts.
• Enhances alternative livelihood sources like livestock production and dairy farming.
• Supplements household income.
Kothapally Watershed in Andhra Pradesh, of the Krishna basin, is an example of successful watershed management. Groundwater recharge increased more than 4 times and crop yields increased 2‐5 times in monsoon season. There has also been substantial improvement in household income and employment opportunities as well as reduction in poverty. Challenges/limitations in Watershed Management programmes in India
• Equitable sharing of benefits: The area development programs offer benefits primarily to landowners, with landless and marginal farmers often benefit only marginally or not at all.
• Common lands do not get adequately treated.
• Gains from recharge of groundwater are rapidly dissipated through increased withdrawal. Domestic, livestock and ecosystem water needs often do not get adequately addressed.
• Downstream impacts of intensive upstream water conservation are not being considered.
• Costs at which the gains are achieved are considered to be high.
• People’s participation is limited to the watershed project implementation stage.
• No/little building of institutions for long‐term collective management of resources.
Integrated Resources Water Management:
IWRM is a process which promotes the coordinated development & management of water, land & related
resources, in order to maximize the resultant economic & social welfare in an equitable and sustaniable manner.
Principles of IWRM:
• economic efficiency
• environmental sustainability
• social equity, including poverty reduction
Components of IWRM:
• National Water Policy, 2012 tries to promote IWRM in the following ways:
• Common integrated perspective for water resource planning
• Departments at Centre/State Governments levels should be restructured & made multi‐disciplinary to fulfil the needs of IWRM.
• Promotes principles of IWRM.
• Inter‐state coordination: legislation for the optimum development of inter‐ State rivers.
• River basin approach: scientific planning of land & water resources taking basin/sub‐basin.
• Efficient utilization of water: It highlights the need to plan, manage & regulate water
• Information system: All water related data, should be integrated.
• Managing water resource as a community resource. IWRM is the philosophy that needs to be followed both in letter & spirit.
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