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Global Climate Change and Its Impacts

drying up, affecting local residents’ domestic water supply and agricultural production. For
example, the drought from 2022 to 2023 causedEast Africa nearly20 million people to face a
food crisis, forcing many families to rely on external aid for basic living necessities.
2.Frequent Flood Disasters
The South Asian subcontinent experiences severe floods annually during monsoon
seasons, submerging vast farmlands, damaging irrigation systems, and causing large-scale
casualties and property losses. Additionally, accelerated urbanization processes,reducedper-
meable surfaces have further intensified surface runoff speed, increasing flood risks. For in-
stance, the 2023 floods in India and Bangladesh affected over 40 million people and caused
billions of dollars in economic losses.
3.Seasonal Variations
Agricultural regions traditionally reliant on stable seasonal precipitation now face more
uncertain rainfall patterns. For instance, in Mediterranean coastal countries, prolonged sum-
mer droughts and reduced winter rainfall pose severe challenges to local agricultural produc-
tion and water resource management.
(II) Trend of Water Quality Deterioration
Climate change has not only affected water resource quantity but also negatively im-
pacted water quality. Factors including rising temperatures, frequent extreme weather events,
and sea level rise have collectively caused a series of water quality issues:
【1】 Increased Eutrophication
Higher temperatures promote algal blooms, particularly in lakes and reservoirs, exac-
erbating water eutrophication. This not only compromises aquatic ecosystem health but also
degrades drinking water quality and increases treatment costs.
【2】 Pollution Dispersion
Heavy rainfall and flood events can wash pollutants from soil into water bodies, such
as pesticides, fertilizer residues, and heavy metals, contaminating surface water and ground-
water. Additionally, untreated urban sewage discharged directly into natural water bodies
further threatens water quality.
3.Saltwater Intrusion
Sea level rise-induced saltwater intrusion threatens freshwater resource supplies in
coastal areas. Particularly in island nations and estuarine delta regions reliant on underground
water sources, the risk of seawater backflow affects agricultural irrigation and residential
drinking water safety.
（3）Adaptation Requirements for Water Infrastructure
Facing new challenges in water resource management and quality protection caused by
climate change, existing water infrastructure urgently requires adaptive upgrades to enhance
its response capacity and efficiency:
1.Aging Facility Upgrades
Water conservancy infrastructure in many developing countries was constructed de-

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