Exam Notes

Question 1

  • Importance of water flow determination (societal perspective):
    • Water resource management.
    • Flood control.
  • Discharge Curve:
    • Shows the relationship between water level and discharge.
    • Used to estimate flow rates based on water level measurements.
  • Flow measurement method (broad, deep, particle-rich watercourses):
    • Acoustic Doppler Current Profiler (ADCP).
    • Measures water velocity at different depths using sound waves to calculate the overall flow.

Question 2

  • Methods for treating stormwater from roads:
    • Sedimentation ponds: Remove particles through settling.
    • Bioretention systems/Rain gardens: Use soil and plants to filter pollutants.
  • Sedimentation ponds processes and influencing factors:
    • Process: Gravity settling of particles.
    • Factors: Residence time, particle size.
  • Bioretention systems processes and influencing factors:
    • Process: Filtration, adsorption, biological uptake.
    • Factors: Soil composition, vegetation type.

Question 3

  • Nash-Sutcliffe Efficiency (NSE) data requirements: Need observed and modeled flow data.
  • Using SWAT to describe the impact of exploitation: Calibrate the SWAT model with local data (land use, soil, weather) and simulate the hydrological changes due to exploitation.

Question 4

  • SWAT model input vs. Processes:
    • Input: Rectangular boxes representing data like precipitation, temperature, land use etc.
    • Processes: Boxes that represent the calculations of various components of the water cycle.
  • Type of distributed model (SWAT): Spatially semi-distributed model.

Question 5

  • Differences between natural and urban hydrological cycle:
    • Increased impervious surfaces.
    • Increased surface runoff.
    • Reduced infiltration.
  • Limitations and weaknesses of climate change modeling:
    • Uncertainties in future emission scenarios.
    • Model resolution limitations.
    • Difficulty in representing complex feedback mechanisms.
      d) Precipitation pattern changes in Sweden. Increased precipitation and intensity.
  • Hydrological model validation: Compare model outputs with observed data using statistical measures.

Question 6

  • Calculations and graph: Requires calculation and plotting of flow changes based on provided unit hydrograph and rainfall event h.
    b) The maximum flow change Q for the rainfall event h is calculated from the resulting graph.
    c) The time it take for the flow change to return to zero can be read from the graph.

Question 7

  • Rational Method Formula: q<em>dag dim=A⋅i(t)⋅k</em>fq<em>{dag \, dim} = A \cdot i(t) \cdot k</em>f
  • AA = catchment area [ha]
  • i(t)i(t) = rainfall intensity [l/(s \cdot ha)]
  • kfk_f = climate factor

Question 8

  • Log Pearson III vs. Normal Distribution (Gringorten): Log Pearson III is preferred because it can handle skewed data, which is common in hydrological variables.