Human-Modified Landscapes

Abstract

Although eastern Canada is perceived as dominated by natural landscapes, human modification to geomorphology in many areas is extensive. Agricultural activity has resulted in drainage of wetlands, alteration of stream courses, erosion and sedimentation in coastal areas, and modification of aeolian dunes. Forest clearance, both for initial agricultural expansion and modern forestry, has resulted in erosion and local accentuation of karst topography. Mining, quarrying, dam construction, and canal building have also created geomorphic impacts. Increased tourism has added stresses to several geomorphologically interesting landscapes. Development of urban centres has resulted in significant alterations to drainage systems, with storm-induced flooding of river systems. Construction of cities on glacilacustrine and glacimarine terrains has resulted in relatively few geomorphic hazards. Geotechnical problems include slope stability in ravines, karst dissolution, construction issues on glacilacustrine sand and clay, slope failures in thixotrophic Champlain Sea clays, failures associated with glacifluvial channels, difficulties encountered during subway tunnelling, and glacitectonic-induced fracturing of bedrock. Human impacts on northern and arctic geomorphology, in addition to permafrost ablation resulting from warming climate, focus on modification of coastal landscapes.