地理漫步·世界地理英语30篇（1）

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恒河三角洲洪泛农业与淤泥富集

The Ganges Delta spans Bangladesh and eastern India, forming the world's largest active delta.
Annual monsoon floods deposit nutrient-rich silt across vast low-lying farmlands each year.
Farmers time rice planting to coincide with receding floodwaters and fresh sediment layers.
This natural fertilization reduces dependence on synthetic inputs while sustaining high yields.
However, embankments and upstream dams increasingly disrupt the flood pulse and sediment supply.
Salinity intrusion during dry seasons also threatens soil fertility in southern delta zones.
Floating gardens, built on water hyacinth rafts, offer adaptive cultivation where land is seasonally submerged.
Tidal channels and mangrove belts buffer storm surges but shrink under aquaculture pressure.
Delta subsidence and sea-level rise compound flood risks for over 150 million residents.
Sustainable management must balance rice production, fisheries, and wetland conservation.