Land and Water Use
What you must know
Examine agriculture: subsistence vs. commercial, slash-and-burn, monocropping, CAFOs, and integrated pest management. Know irrigation types (drip, flood, furrow, center-pivot) and their water-use efficiency and salinization risks. Understand forestry (clear-cutting vs. selective logging, sustainable yield), rangeland management and overgrazing/desertification, and urban land use (urban sprawl, smart growth, zoning). Study fisheries and the tragedy of the commons. Distinguish renewable from nonrenewable land/water resources and the concept of maximum sustainable yield. Know mining impacts (surface vs. subsurface, acid mine drainage) and water use in agriculture, industry, and homes.
Traps
- Assuming all irrigation is equally efficient - drip is most efficient; flood is least.
- Confusing sustainable yield (harvest at regeneration rate) with maximum exploitation.
- Overlooking salinization and waterlogging from over-irrigation.
- Treating the tragedy of the commons as inevitable - it is a governance failure, not a resource property.
Worked example / rule of thumb
A fishery with a sustainable yield of 100 tons/year should be harvested at ≤100 tons. Rule: harvest at or below the regeneration rate; exceeding it depletes the stock.