People and Floods - Geol 116 People and Floods Fall 2009...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Geol 116 Fall 2009 People and Floods Development Effects on Floodplains Early towns established along rivers for access to water and transportation Severe alterations of landscape through urbanization, logging, grazing, forest fires Added sediment load to rivers Increased size and damaging nature of floods Urbanization Increasing urbanization promotes increasing numbers of flash floods and higher flood levels Wherever roads and buildings cover landscape, water forced to run off rapidly into nearby streams, sometimes through concrete channels Fires, Logging, and Overgrazing Watershed deforestation by fire, clear-cut logging, overgrazing increased sediment load Streams choked with sediment, braided, steeper Forest soil soaks up water Fire removes soil protection, decreases soil permeability Clear-cut logging methods remove brush, form skid trails and logging roads that focus downslope drainage and add sediment to streams Grazing removes surface vegetation, increasing soil erosion Mining Mining can change sediment load, disrupt equilibrium of river Large amounts of sand and gravel for construction use come from streambed mining Reduced sediment supply in stream increases stream’s erosive energy Bridges Raise roadway above 100-year flood level Partial dam across floodplain, with narrow open channel under roadway bridge Deep water under bridge flows faster, causes erosion
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/21/2010 for the course GEOL 116 taught by Professor Kruger during the Spring '09 term at Binghamton University.

Page1 / 3

People and Floods - Geol 116 People and Floods Fall 2009...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online