การเขียนเชิงบูรณาการ TOEFL

📖 เนื้อเรื่อง

The expansion of urban areas into adjacent natural habitats is often justified by economic growth, but this practice has profound ecological consequences that are frequently underestimated. One major concern is the loss of biodiversity. When forests or wetlands are converted into residential or commercial developments, the native flora and fauna are displaced or destroyed, leading to a sharp decline in species richness. For example, a study in the Pacific Northwest found that suburban sprawl reduced bird species diversity by up to 40% within a decade. A second issue is the disruption of natural water cycles. Urbanization replaces permeable soil with impermeable surfaces like concrete and asphalt, which prevents rainwater from infiltrating the ground. This increases surface runoff, causing more frequent and severe flooding downstream, while also reducing groundwater recharge that sustains streams and wetlands during dry periods. Third, urban expansion contributes to the urban heat island effect. The dark surfaces of roads and rooftops absorb solar radiation, and the lack of vegetation reduces evaporative cooling. As a result, cities can be several degrees warmer than surrounding rural areas, which increases energy consumption for air conditioning and exacerbates heat-related health risks. Given these ecological, hydrological, and climatic impacts, the costs of urban sprawl may far outweigh its short-term economic benefits.

🎧 การบรรยาย

While the reading raises valid concerns, it overlooks critical counterpoints that undermine its claims. First, regarding biodiversity, the reading assumes that urbanization inevitably destroys habitats, but many modern developments incorporate green infrastructure, such as parks, green roofs, and wildlife corridors. These features can actually support a diverse array of species, sometimes even increasing urban biodiversity compared to monotonous agricultural landscapes that the development may replace. For instance, a study in Berlin found that urban gardens hosted more bee species than surrounding farmland. Second, the claim about water cycle disruption is exaggerated because new urban planning often includes sustainable drainage systems, like permeable pavements and retention basins, which mimic natural infiltration. These technologies can mitigate flooding and even enhance groundwater recharge compared to the compacted soils of intensive agriculture. Third, the urban heat island effect is not inevitable; cities can adopt reflective materials and expand tree cover. In fact, well-designed green spaces can create cooler microclimates, and the heat generated by dense urban cores is often offset by reduced energy use from shared infrastructure like district heating. Thus, the reading’s pessimistic view ignores the potential for thoughtful urban design to reconcile growth with environmental health.