1.2 Objectives in Water Resources Management The general objective of water resources management is to maximize the benefits obtained from the utilization and control of water resources Evaluation of the benefits The amount of water to be supplied or controlled The need for protection or improvement of its quality The cost of providing the potential benefits to the various users
1.2 Objectives in Water Resources 1.2 Objectives in Water Resources Management Management The general objective The general objective of water resources management is to maximize the benefits obtained from the utilization and control of water resources Evaluation of the benefits: Evaluation of the benefits: ¾ The amount of water to be supplied or controlled ¾ The need for protection or improvement of its quality ¾ The cost of providing the potential benefits to the various users
1.3 Options for Meeting Water Demands Two major approaches (1)Implementation of large engineering projects to obtain more water from various freshwater systems- Supply-type (2) Increase of water recycling, using both constructed and natural purification systems- Reuse-type
Two major approaches: Two major approaches: (1) Implementation of large engineering projects to obtain more water from various freshwater systems – Supply-type (2) Increase of water recycling, using both constructed and natural purification systems – Reuse-type 1.3 Options for Meeting Water 1.3 Options for Meeting Water Demands Demands
Supply options: (1) Dam and reservoirs Benefits: equalization and control of stream flow, power generation, flood and drought control. recreation Problems: silting up of reservoirs over time, great evaporation losses (2) Large-scale water diversions Benefit: supplying abundant water for regional development Problems: high cost, evaporative loses, salt buildup and soil deterioration
Supply options: Supply options: (1) Dam and reservoirs (1) Dam and reservoirs ¾ Benefits: equalization and control of stream flow, power generation, flood and drought control, recreation ¾ Problems: silting up of reservoirs over time, great evaporation losses (2) Large (2) Large -scale water diversions scale water diversions ¾ Benefit: supplying abundant water for regional development ¾ Problems: high cost, evaporative loses, salt buildup and soil deterioration
(3) Groundwater Benefits: higher quality, decentralized water supply Problems: lowering groundwater table (4)Desalination Benefits: using salty water or sea water as the resource for water suppl Problems: high construction cost(e.g RO), high energy consumption (5) Relocation of water users Benefits: mitigation of regional water shortage Problems: high cost, social impact
(3) Groundwater (3) Groundwater ¾ Benefits: higher quality, decentralized water supply ¾ Problems: lowering groundwater table (4) Desalination (4) Desalination ¾ Benefits: using salty water or sea water as the resource for water supply ¾ Problems: high construction cost (e.g. RO), high energy consumption (5) Relocation of water users (5) Relocation of water users ¾ Benefits: mitigation of regional water shortage ¾ Problems: high cost, social impact
Reuse options (1 Reuse and recycling of wastewater Increasing the number of times that water can be reused before its return to the hydrologic cycle efficient way to meet water demand in the long term (2) Reducing evaporation from water surfaces Especially in the case of agricultural irrigation, the largest single user of water resources (3)Water conservation techniques Installation of water-saving faucet or shower fittings, water-saving industrial equipment, leakage prevention etc
Reuse options: Reuse options: (1) Reuse and recycling of wastewater (1) Reuse and recycling of wastewater ¾ Increasing the number of times that water can be reused before its return to the hydrologic cycle – efficient way to meet water demand in the long term (2) Reducing evaporation from water surfaces (2) Reducing evaporation from water surfaces ¾ Especially in the case of agricultural irrigation, the largest single user of water resources (3) Water conservation techniques (3) Water conservation techniques ¾ Installation of water-saving faucet or shower fittings, water-saving industrial equipment, leakage prevention etc