地理漫步·世界地理英语30篇（6）

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冰川-河流过渡带中的沉积物连通性

Where retreating glaciers meet meltwater rivers, sediment transport shifts from ice-bound to water-driven.
Sediment connectivity here depends on channel braiding intensity and floodplain storage capacity.
High-sediment loads often bury riparian forests but also build new gravel bars for spawning fish.
Landsat time-series show sediment plumes extending over 50 km downstream during peak melt.
Downstream deltas grow rapidly when sediment supply exceeds coastal wave energy dispersion.
However, dams upstream sever this natural sediment corridor and starve delta coastlines.
Field measurements reveal grain-size sorting creates layered aquifers beneath active channels.
This vertical stratification controls both groundwater recharge rates and contaminant filtration efficiency.
Restoring sediment connectivity requires coordinated dam sediment bypassing and floodplain reconnection.
It is not just water flow—but particle movement—that defines landscape resilience.