3. Tài nguyên nước và nhu cầu sử dụng nước

Giới thiệu về tài nguyên nước và nhu cầu sử dụng nước

Questions

What are the relative merits of using surface water vs. groundwater as a water resource?
Why is society facing a crisis involving water supply and how can we solve it?

Giới thiệu chung về tài nguyên nước

Phân bố nước toàn cầu

The World's Water - Distribution of Earth's Water. Source: [Igor Shiklamonov, 1993, Water in Crisis: A Guide to the World's Freshwater Resources / USGS](https://www.usgs.gov/media/images/distribution-water-and-above-earth) — The World’s Water - Distribution of Earth’s Water. Source: Igor Shiklamonov, 1993, Water in Crisis: A Guide to the World’s Freshwater Resources / USGS

Phân bố lượng mưa toàn cầu

World Rainfall Map. Source: [Earth Forum, Houston Museum of Natural Science / USGS](https://www.usgs.gov/media/images/generalized-world-precipitation-map) — World Rainfall Map. Source: Earth Forum, Houston Museum of Natural Science / USGS

Tài nguyên nước ngầm

Các đặc trưng của nước ngầm

Subsurface Water Terminology. Groundwater in pore spaces and fractures of earth materials, saturated zone, unsaturated zone, and water table, which follows land surface but in a more subdued way. Source: [United States Geological Survey](https://www.usgs.gov/media/images/groundwater-saturated-zone-soilrock-below-land-surface) — Subsurface Water Terminology. Groundwater in pore spaces and fractures of earth materials, saturated zone, unsaturated zone, and water table, which follows land surface but in a more subdued way. Source: United States Geological Survey

Dòng chảy nước ngầm

Flowing Groundwater. Blue lines show the direction of groundwater in unconfined aquifers, confined aquifers, and confining beds. Deep groundwater moves very slowly especially through low permeability layers. Source: [United States Geological Survey](https://www.usgs.gov/media/images/conceptual-groundwater-flow-diagram) — Flowing Groundwater. Blue lines show the direction of groundwater in unconfined aquifers, confined aquifers, and confining beds. Deep groundwater moves very slowly especially through low permeability layers. Source: United States Geological Survey

Giếng Artesian

Artesian wells can bring water to the land surface naturally. Source: [United States Geological Survey](https://www.usgs.gov/media/images/artesian-wells-can-bring-water-land-surface-naturally) — Artesian wells can bring water to the land surface naturally. Source: United States Geological Survey

Sự tương tác của nước ngầm và dòng chảy nước mặt

Interaction of Streams and Ground Water. A) Gaining stream where water table slopes toward river and groundwater discharges into river, B) Losing stream where water table slopes away from river and river water discharges into groundwater, C) Losing stream where water table is separated from and below river. Source: [United States Geological Survey](https://pubs.usgs.gov/circ/circ1186/html/gw_effect.html) — Interaction of Streams and Ground Water. A) Gaining stream where water table slopes toward river and groundwater discharges into river, B) Losing stream where water table slopes away from river and river water discharges into groundwater, C) Losing stream where water table is separated from and below river. Source: United States Geological Survey

Các vấn đề về khai thác tài nguyên nước ngầm

Khai thác quá mức nước ngầm dẫn đến hạ thấp mực nước ngầm
Cone of depression: Pumping a well can cause water level lowering. Source: United States Geological Survey
Khai thác quá mức nước ngầm ở ven biển dẫn đến tăng cường xâm nhập mặn
How intensive ground-water pumping can cause salt-water intrusion in coastal aquifers. Source: United States Geological Survey
Khai thác quá mức nước ngầm có thể gây sụt lún (land subsidence) và hố sụt (sinkhole)
Aquifer compaction and land subsidence. Source: United States Geological Survey

Đồng bằng Sông Hồng, Đồng Bằng Sông Cứu Long, và một số đồng bằng ven biển có nguy cơ sụt lún:

Global Subsidence Map, Vietnam. Source: [Herrera-Garcia et. al., 2021](https://www.science.org/doi/10.1126/science.abb8549), [Map](https://info.igme.es/visor/?Configuracion=globalsubsidence&idioma=en) — Global Subsidence Map, Vietnam. Source: Herrera-Garcia et. al., 2021, Map

Nhu cầu sử dụng nước

Nhu cầu sử dụng nước ngày càng tăng

Trends in global water use by sector. Source: [Philippe Rekacewicz, February 2006 / GRID-Arendal](https://www.grida.no/resources/5626) — Trends in global water use by sector. Source: Philippe Rekacewicz, February 2006 / GRID-Arendal

Bản đồ hiện trạng sức ép tài nguyên nước (baseline water stress) theo WRI, 2023. Aqueduct 4.0

Source: WRI, 2023. Aqueduct 4.0 Current and Future Global Maps Data

Description of Baseline water stress

Baseline water stress measures the ratio of total water demand to available renewable surface and groundwater supplies. Water demand include domestic, industrial, irrigation, and livestock uses. Available renewable water supplies include the impact of upstream consumptive water users and large dams on downstream water availability. Higher values indicate more competition among users.

Bản đồ sức ép tài nguyên nước tương ứng với các kịch bản biến đổi khí hậu tương lai theo WRI, 2023. Aqueduct 4.0

Source: WRI, 2023. Aqueduct 4.0 Current and Future Global Maps Data

Description of Water stress - future projections (2030-2050-2080)

Water stress is an indicator of competition for water resources and is defined informally as the ratio of demand for water by human society divided by available water. Future projections are available for 3 long-term trends over a 30 year period (2015-2045, 2035-2065, 2065-2090) and 3 scenarios (Optimistic, Business as usual, Pessimistic).
Optimistic: The “optimistic” scenario (SSP1 RCP2.6) represents a future that limits the rise in average global surface temperatures by 2100 to 1.3°C to 2.4°C compared to preindustrial levels (1850-1900). SSP1 is characterized by sustainable socioeconomic growth: stringent environmental regulations and effective institutions, rapid technological change and improved water use efficiencies, and low population growth.
Business as usual: The “business as usual” scenario (SSP3 RCP7.0) represents a middle-of-the-road future where temperatures increase by 2.8°C to 4.6°C by 2100. SSP3 is a socioeconomic scenario characterized by regional competition and inequality, including slow economic growth, weak governance and institutions, low investment in the environment and technology, and high population growth, especially in developing countries.
Pessimistic: The “pessimistic” scenario (SSP5 RCP8.5) represents a future where temperatures increase up to 3.3°C to 5.7°C by 2100. SSP5 describes fossil-fueled development: rapid economic growth and globalization powered by carbon-intensive energy, strong institutions with high investment in education and technology but a lack of global environmental concern, and the population peaking and declining in the 21st century.

Các giải pháp sử dụng nước bền vững

Hồ chứa nhân tạo và đập thủy điện

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Khử mặn nước biển

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Bảo tồn tài nguyên nước (water conservation)

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