Services > Environmental Modeling > Model Development > PRZM > Improvements
Waterborne Improvements to PRZM
Waterborne has continued to update the PRZM model including modifications requested by our clients. Key modifications include the following.
- Nonuniform mixing model (i.e., extraction model) for runoff
- Calculation of peak flow as a function of time of concentration
- Assignment of regional/seasonal storm event distributions to daily precipitation records
- Option to select MUSS, MUST, and MUSLE erosion equations
- Biphase degradation and transformation
- Transformation of metabolites in solid phase
- Transformation of chemical on foliage
- Correction to exponential decay calculation (previously underestimated decay with half-life ‹ 7 days)
- Temperature dependent degradation (PELMO)
- Enhanced/expanded Chemical Application Methods (CAM replaces FAM)
- Surface application to soil (linear decreasing with depth to 4 cm)
- Foliar application (soil interception uses linear crop growth)
- Foliar application (soil interception based on exponential filtration)
- Rototil: uniform residue distribution to user-defined depth
- Furrow: residue distribution linearly increasing with depth to 4 cm
- Incorporation: residue linearly decreasing to user-defined depth
- T-Band: user-defined incorporation depth
- Shank injection: user-defined incorporation depth
- Each application and each chemical can have a different CAM
- User-defined application efficiency
- Farm flag to prevent application on days with precipitation
- Flexibility in temporal changes to CN, USLE C, and Manning N
- Number of compartments allowed increased from 200 to 500
- Number of applications allowed increased from 200 to 800
- Availability of total-, dissolved-, gas-, and sorbed-phase concentrations in time-series output file
- Ability to output averages and totals of time-series output variables over specified depth increments (compare to analytical results of soil cores)
- Availability of depth-weighted average of soil pore-water concentrations (compare to analytical results of suction lysimeter samples)
- Center of mass (CMSS) and maximum depth of incursion
- (INCS) available as time-series output for leaching evaluations
- Metabolite transfer to EXAMSII model (.EXA file)
- Ability to specify drift load as transfer to EXAMSII model (.EXA file)
