Superb Earth and Human Activity
第 4 單元，第 1 課

Impact on Land對陸地的影響

這課一眼看
Population and land use人口與土地利用
    How land use affects Earth土地利用對地球的影響
    • deforestation森林砍伐: Cutting of large areas of forest for human activities.
    • desertification沙漠化: Development of desertlike conditions due to human activities and/or climate change.
    • urbanization都市化: Development of land for houses and other buildings near a city.
    • stream discharge河川流量: Volume of water flowing past a point in a stream per unit of time.
    • landfill掩埋場: Area where trash is buried.
    • hazardous waste有害廢棄物: Waste containing substances that can harm living things or the environment.
    • pollution汙染: Contamination of the environment with substances harmful to life.
    Protecting the land保護土地
    • conservation資源保育: Careful use of Earth’s materials to reduce damage to the environment.
    • compost堆肥: Mix of decayed organic material, bacteria, other organisms, and water used to enrich soil.
    • reforestation造林: Planting trees to replace ones that were removed.
    • reclamation土地復育: Restoring land disturbed by mining.
    1Population and land use人口與土地利用

    AA growing population成長中的人口

    1. About 1,000 years ago there were roughly 300 million people on Earth. Today there are more than 7 billion, and there could be over 9 billion by 2050.大約一千年前，地球上只有約 3 億人。現在超過 70 億人，到 2050 年可能超過 90 億人。
    2. As the population grows, people use more natural resources, things from Earth that living things use to meet their needs. Land itself is a resource: people need space for homes, roads, farms, and forests.人口成長時，人們會用掉更多自然資源，也就是生物用來滿足需求的地球物質。土地本身就是一種資源：人們需要空間蓋房子、修路、耕種和保留森林。
    注意
    Only a small slice of Earth can grow food. Three-quarters of the surface is water, and about two-thirds of the land is too hot, too cold, or too mountainous to farm or live on.地球上只有一小部分能種植糧食。四分之三的表面是水，而陸地中約三分之二太熱、太冷或山勢太陡，無法耕種或居住。
    2How land use affects Earth土地利用對地球的影響

    ADeforestation森林砍伐

    1. deforestation is the cutting of large areas of forest for human activities such as grazing, farming, and building. Only a fraction of Earth’s original frontier forest remains; in Central America it is under 10%.森林砍伐是為了放牧、耕種、建築等人類活動而砍伐大片森林。地球原始森林只剩下一部分，中美洲甚至不到 10%。
    2. Deforestation destroys habitats and can endanger species. Tropical rain forests hold about half of all species and take hundreds of years to recover. Fewer trees also means less photosynthesis, so more carbon dioxide stays in the air.森林砍伐破壞棲地，可能讓物種瀕臨滅絕。熱帶雨林擁有約一半的物種，需要數百年才能恢復。樹木減少也代表光合作用變少，更多二氧化碳留在空氣中。

    BAgriculture農業

    1. Fertilizers, herbicides, and pesticides help farmers grow more food per square kilometer, but runoff carrying these chemicals can seep into groundwater and pollute drinking water or flow into streams and harm aquatic life.肥料、除草劑和殺蟲劑幫助農民在每平方公里種出更多糧食，但帶著這些化學物質的逕流可能滲入地下水、汙染飲用水，或流進河川傷害水中生物。
    2. Plowed fields expose soil. With no roots to hold it, wind and water carry soil away. Severe erosion can lead to desertification, the development of desertlike conditions caused by human activities and/or climate change. Desertified land can no longer grow food.翻耕過的田地讓土壤裸露。沒有根抓住土壤，風和水就把它帶走。嚴重的侵蝕可能導致沙漠化，也就是因人類活動和（或）氣候變遷而形成類似沙漠的狀況。沙漠化的土地無法再生產糧食。
    3. About one-fifth of U.S. land grows crops and about one-fourth is used to graze livestock.美國約五分之一的土地用來種植作物，約四分之一用來放牧牲畜。

    CUrbanization都市化

    1. urbanization is the development of land for houses and other buildings near a city. Since 2007, more people worldwide live in urban areas than rural areas.都市化是城市周邊土地被開發成住宅和其他建築。自 2007 年起，全世界住在都市的人口已經多於住在鄉村的人口。
    2. Pavement keeps rain from soaking into the ground, so water runs quickly into streams. This raises stream discharge, the volume of water flowing past a point per unit of time, and increases flooding. Less water soaks in to refill groundwater.鋪面讓雨水無法滲入地面，雨水便快速流入河流。這會增加河川流量（單位時間內流經某一點的水量），提高淹水風險，也讓補充地下水的水變少。
    3. Urbanization also destroys habitats and farmland, and many wetlands have been drained and filled for building. Wetlands provide habitat, filter pollutants, and reduce flood damage.都市化也會破壞棲地和農地，許多溼地被抽乾、填平來蓋房子。溼地能提供棲地、過濾汙染物並減少洪水災害。
    Land use and runoff土地利用與逕流
    Land use土地利用Rainfall that runs off to streams流入溪流的雨水
    Commercial (offices, stores)商業區（辦公室、商店）Highest (mostly paved)最多（大多鋪面）
    Residential (houses)住宅區（房屋）About 40%約 40%
    Natural areas (forest, grassland)自然地區（森林、草原）Lowest最少

    DLandfills and hazardous waste掩埋場與有害廢棄物

    1. About 34% of U.S. trash is recycled or composted, about 11% is burned, and the rest goes to a landfill, an area where trash is buried. Many materials break down slowly or not at all, so landfills fill up and new ones are needed.美國約 34% 的垃圾被回收或堆肥，約 11% 被焚化，其餘送到掩埋場，也就是掩埋垃圾的地方。許多材料分解得很慢甚至不會分解，所以掩埋場會被填滿，需要再建新的。
    2. hazardous waste contains substances that can harm soil, air, water, and living things, such as used needles, motor oil, and batteries. It cannot go into ordinary landfills.有害廢棄物含有會危害土壤、空氣、水和生物的物質，例如用過的針頭、機油和電池。它們不能送到一般掩埋場。
    3. Rainwater that seeps through a landfill becomes leachate, which can carry pollutants into soil and groundwater. pollution is the contamination of the environment with substances that are harmful to life.雨水滲過掩埋場會形成滲出水，可能把汙染物帶進土壤和地下水。汙染是指環境被對生命有害的物質汙染。
    3Protecting the land保護土地

    AConservation資源保育

    1. conservation is the careful use of Earth’s materials to reduce damage to the environment and prevent future shortages.資源保育是謹慎使用地球的物質，以減少對環境的傷害並避免將來短缺。
    2. Reduce means using less in the first place. Reuse means finding another use for an item instead of throwing it away. Recycle means processing used material so it can be made into something new.減量是一開始就少用。重複使用是替物品找到另一種用途，而不是丟掉。回收是把用過的材料處理後做成新東西。
    3. Yard waste and vegetable scraps can become compost, a mix of decayed organic material, bacteria, other organisms, and a little water. Compost enriches soil and reduces the need for synthetic fertilizer.庭院廢棄物和菜渣可以做成堆肥，也就是腐爛的有機物、細菌、其他生物和少量水分的混合物。堆肥能讓土壤更肥沃，減少對化學肥料的需求。

    BManaging land resources管理土地資源

    1. Governments preserve forests and unique ecosystems by banning or limiting logging and development. Loggers may cut selected trees and replant. reforestation is planting trees to replace ones that were removed.政府可以禁止或限制伐木和開發，以保護森林和特殊生態系。伐木業者可以只砍選定的樹並重新種植。造林是種樹來補回被砍掉的樹。
    2. reclamation is restoring land disturbed by mining: reshaping it, covering it with soil, and replanting it, as required by law.復育是依法把被採礦破壞的土地恢復原狀：重新整地、覆土並重新種植。
    3. Farmers can leave crop stalks after harvest to protect soil and use organic methods. Cities can set aside green spaces, such as parks, which give wildlife habitat.農民可以在收成後留下作物殘株保護土壤，並採用有機耕作。城市可以保留綠地（例如公園），提供野生動物棲地。
    自我檢查
    A town wants to build a mall on farmland near a stream. Name two land impacts and one way to reduce each.某個鎮想在溪流附近的農地蓋購物中心。說出兩個對土地的影響，以及各一個減少影響的方法。
    看答案
    More pavement increases runoff and flooding — use permeable pavement or retention ponds. Loss of habitat and farmland — preserve green space or plant trees around the site.鋪面增加使逕流和淹水增加——使用透水鋪面或滯洪池。棲地和農地消失——保留綠地或在周圍種樹。

    這課的重點字

    • deforestation森林砍伐
    • desertification沙漠化
    • urbanization都市化
    • stream discharge河川流量
    • landfill掩埋場
    • hazardous waste有害廢棄物
    • pollution汙染
    • conservation資源保育
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