Mohid SWAT

Introduction

Two modified versions of SWAT were developed, based on the two SWAT releases (SWAT2000 and SWAT2005). The functionalities described herein are equal in both versions. So we refer to this modified versions has SWAT-MOHID.

Outputs

This modified version maily produce new outputs of SWAT in MOHID format. The aim of these developments is not to replace the use of SWAT graphical user interfaces for input or output, but to complement it. This also means that the developed outputs do not include all the SWAT variables but instead, they were developed on a need basis either for easier exploring, results analysis, model coupling, etc. This development benefits from many current developments and improvements of MOHID tools made by its users and will continue to benefit in the future.

Time series output

A first modification was the implementation of time series outputs. The modified SWAT source code enables the user to output time series for two geometric entities found in SWAT: (i) hydrological response units (HRU) and (ii) or sub-basins/reaches. The output of the time series is done with a frequency which is independent of the “normal” SWAT output and the format of the time series is done in MOHID format. Time series written for selected HRU’s are organized in four categoiries: (i) meteorological information, (ii) plant growth, (iii) nutrient concentration and (iv) erosion. Time series written fro selected sub-basins/reaches are nutrient concentration, sediments concentrations and the water flows into the reaches. Time series generated by SWAT-MOHID:

Results per sub-basin

• RCH – results from the SWAT river – Flows, properties concentrations, temperature, etc
• DIS – results per sub-basin – contribution of each sub-basin to the reach) – This files were created for coupling SWAT with Mohid River Network. Units are in m3/s and mg/l

Results per HRU

• PLT – results related with plant growth – LAI, Biomass, Growth Stress, etc
• MTO – results related with climatic model variables
• USL – results at HRU level related with erosion
• NIT – results related with the nitrogen cycle in the soil – plant uptake of N, N remove by
• PHS - results related with the phosphorus cycle in the soil

Global results

• LDU – average results related per land use of all watershed
• GLB – results related with overall watershed
  • GlobalWater.glb - results related with the global water
  • GlobalNutrient.glb – Results related with global sediment budgets
  • Average_Basin_kg_ha.glb – Results related with global model pathways

Animated map results (HDF)

MOHID’s HDF class is a class on the top of the Hierarchical Data Format (HDF library). HDF is a general purpose library and file format for storing scientific data, developed and maintained by the United States National Center for Supercomputing Applications. The main functionality of this library is to store matrix data in a structured way. The inclusion of output result files in HDF5 format is currently under development. This allows the visualization of watershed properties (modeled by SWAT) in animated maps using MOHID animation tools like MOHID-GIS. These tools allow the production of animated graphic files showing the spatial and time evolution of the modeled properties. The user decides on the time step output. For each output a vector with the values of soil water content of each sub-basin is stored.

• How to create a new simulation and runs
• Mohid gis.JPG

  Figure 1: SWAT Soil Water content results and visualization in MOHID-GIS using the HDF result files produced by SWAT-MOHID