Land Resources & Pollution ENVIRONMENTAL SCIENCE

Human Land Use Urban  Area covered with buildings and roads  Land with more than 2800 people  Presence of a governing body, such as town council Rural  Land contains relatively few people  Large areas of open space  Undeveloped land

Urbanizatio n Most rapid urbanization took place from By 1960, 70% of the U.S. population lived in urban areas Infrastructure– all of the support systems a society builds (roads, sewers, railroads, bridges, hospitals, fire & police, schools, libraries, water mains, power lines) Urban growth that takes place too quickly causes urban crisis– an overwhelmed infrastructure  Traffic jams  Sub-standard housing  Pollution  Health problems

Urban Sprawl— rapid growth of the city into the surrounding countryside Effects  Destruction of wilderness  Destruction of agricultural land  Collapsing infrastructure  Increased pollution & problems with commuting  Heat islands in urban areas– can alter weather patterns “suburbanization”

Urban planning“land-use planning”  Deciding in advance how land will be used. Residential/agricultural/industrial???????  Shopping malls, sewers, hospitals, other infrastructure  Planning for transportation  Planning for open spaces/greenbelts

Why are open spaces & greenbelts important for urban development?  Provide parks, recreation, gardens, hiking, and bicycling  Plants absorb carbon dioxide & produce oxygen  Plants filter pollutants from air & water  Help with drainage  Help reduce city’s temperature

Agricultural Land Use  Farmland  Rangeland  Timber  Protected Areas– parks & preserves

Arable Land– soil suitable for agriculture

Problems with Farming  Farmlands threatened by urban development  Improper farming techniques increase erosion & soil degradation  Agricultural misuse of land can lead to desertification

Responsible Farming  No-till farming  Terrace or contour farming  Use windbreaks  Plant buffer strips

Problems with Rangelands  Overgrazing  Allowing less desirable plants to take over  Improper range management can lead to desertification

Problems with Timber  Humans use huge amounts of trees Lumber & plywood for homes, paper, furniture, syrup, turpentine  Trees (large growth forests) are responsible for removing CO 2 from the atmosphere  Clear-cutting– causes widespread erosion & ecosystem destruction  Selective-cutting– removes only middle- aged or older trees. Less destructive but more expensive for farmers  Deforestation– causes erosion, landslides, and flooding

Protected areas– wilderness, parks, preserves  Unspoiled forests, deserts, & prairies  Protect species that would otherwise be endangered or extinct  Serve as recreation areas  Serve as outdoor classrooms

Mining Land Use Uses for Mining  Coal, oil, natural gas for fuel  Metals (copper, silver, gold, titanium, lead, iron, zinc)  Non-metals (sulfur, silicon, gypsum)  Gemstones

Environmental Impacts of Mining  Air & noise pollution  Water contamination/pollution  Wildlife displacement  Erosion & sedimentation  Acid mine drainage  Soil Degradation  Subsidence (sink holes)  Fires

Reclamation Because of a variety of regulations (Clean Water Act, Safe Drinking Water Act, SuperFund, and Endangered Species Act), mining companies are required to return mined land to its original or better condition.