Land use change effects

Definition

Land use change effects refer to the impacts that alterations in land use, such as urbanization, agricultural expansion, or deforestation, have on environmental processes, including hydrology. These changes can significantly influence flow duration curves and low flow characteristics by altering the natural water cycle, affecting infiltration rates, and modifying surface runoff patterns.

5 Must Know Facts For Your Next Test

1. Land use changes can significantly increase surface runoff, reducing infiltration and leading to altered streamflow patterns.
2. Urbanization typically results in the creation of impervious surfaces that exacerbate flooding and reduce low flows during dry periods.
3. Agricultural practices can change soil properties and vegetation cover, impacting evapotranspiration rates and influencing flow duration curves.
4. Deforestation can lead to increased sedimentation in water bodies and affect the timing and magnitude of flows in rivers.
5. Effective watershed management strategies can mitigate some adverse effects of land use change by enhancing natural hydrological processes.

Review Questions

• How does urbanization influence flow duration curves and what implications does this have for low flow analysis?
  • Urbanization alters flow duration curves primarily by increasing impervious surfaces which leads to higher peak flows and decreased low flows. This means that during dry periods, urbanized areas may experience lower streamflow levels than natural landscapes would. The increased runoff from urban areas can also result in flash flooding, affecting the overall hydrological balance within the watershed.
• Discuss the relationship between agricultural land use changes and their effects on hydrological responses in river systems.
  • Agricultural land use changes can significantly impact hydrological responses by altering soil moisture conditions, vegetation cover, and evapotranspiration rates. For instance, converting forests to farmland typically reduces water retention in the soil and increases runoff due to less vegetation cover. This leads to alterations in flow duration curves, where peak flows may rise while base flows decrease during dry seasons, ultimately affecting water availability for ecosystems and human use.
• Evaluate how effective watershed management practices can address the negative effects of land use change on hydrology.
  • Effective watershed management practices, such as reforestation, wetland restoration, and sustainable agricultural techniques, can significantly mitigate the adverse impacts of land use change on hydrology. By enhancing natural landscapes and improving soil health, these practices can increase infiltration rates and promote better water retention. Furthermore, implementing green infrastructure in urban areas helps reduce runoff and maintain more stable low flow conditions, ultimately supporting a healthier watershed that balances human needs with ecosystem health.

Related terms

Hydrological Cycle: The continuous movement of water on, above, and below the surface of the Earth, which is affected by land use changes.

Impervious Surfaces: Surfaces that do not allow water to penetrate, such as roads and buildings, leading to increased runoff and altered flow patterns.

Watershed Management: The process of managing land and water resources within a watershed to sustain ecosystems and minimize adverse effects from land use changes.