22강 환경, 자원, 재활용
Gateway 소프트 패스 하천 공학
What ____ soft-path river engineering?
One way to visualize its spirit is to liken it to a footpath in the ____
Suppose a tree falls across a ____
A soft-path response would be simply ____ redirect the trail around the fallen tree.
A more interventionist response would ____ to remove the tree and restore the original route.
A ____ more interventionist response might be to straighten and pave the path to insert it more permanently in the landscape.
The true high-modernist step would, of course, be to create a ____ that removes the landscape and bulldozes straight through all obstacles in the topography.
Soft-path engineering has the unique advantage of intellectual modesty with respect to ____ we actually know about river movement and its environmental effects.
In contrast to hard-path engineering, soft-path engineering accepts variability in the river's movement as significant ____ proven otherwise.
Backwaters, short-lived wetlands, braids and channels, swamps ― all undesirable to ____ engineering ― are presumed by soft-path engineers to be ecologically important.
Exercise 1 동식물종 이동을 위한 경관 연결성
Connectivity, the capacity of a landscape to support ____ by any given species across the landscape, is of increasing concern for conservation biologists.
As the ____ of a landscape increases from the human perspective (generally through increases in road networks), connectivity decreases for many other species.
Although we may see many species of animals moving across human ____ (e.g. deer, wolves, and turtles crossing roads or wandering through our backyards), landscapes substantially altered for human use act as barriers to movement of both animal and plant species.
In some ____ these barriers are incomplete ― many turtles die on roads, but some make it across.
In other cases, passage is essentially impossible ― cities along landscape corridors such as river valleys can effectively eliminate genetic exchange between previously connected plant and animal populations; ____ can permanently halt spawning of fish by blocking travel to their breeding grounds.
Thus, lack of connectivity can decrease the conservation value of remaining habitat below what its mapped area ____ suggest, increasing the impact of fragmentation.
Exercise 2 바이오 발전
By enhancing energy efficiency and putting waste products to use, biopower helps ____ utilities and industries in a sustainable direction.
The U.S. ____ products industry now obtains half its energy by combusting woody waste and liquid waste from pulp mill processing.
____ helps alleviate climate change as well by reducing carbon dioxide emissions, and capturing landfill gas reduces emissions of methane, a potent greenhouse gas.
Biopower also benefits human health as it cuts down on pollution; by replacing coal in co-firing and direct combustion, biopower ____ emissions of sulfur dioxide because plant matter, unlike coal, contains no appreciable sulfur content.
In addition, ____ resources tend to be geographically spread out, so using them can help support rural economies and reduce many nations' dependence on imported fuels.
Exercise 3 사바나의 특성을 바꾸는 인간 개입
One example of human interventions modifying the character of savannas is through their effects ____ savanna-dwelling mammals such as elephants.
They are what is known ____ a 'keystone species' because they have a strong effect on many aspects of the environment in which they live.
They diversify the ecosystems which ____ occupy and create a mosaic of habitats by browsing, trampling, and knocking over bushes and trees.
They ____ spread seeds through their eating and defecating habits and maintain or create water holes by wallowing.
All these roles are beneficial ____ other species.
Conversely, where human interference prevents elephants from ____ freely within their habitats and leads to their numbers exceeding the carrying capacity of the savanna, their effect can be environmentally disastrous.
Equally, if humans reduce elephant numbers in ____ particular piece of savanna, the savanna may become less diverse and less open, and its water holes may fill with mud.
____ will be harmful to other species.