| Autor: |
Jeong, Jaehak, Williams, Jimmy R., Rossi, Colleen G., Taylor, Robin A., Wang, Xiuying, Fox, William E. |
| Předmět: |
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| Zdroj: |
Journal of the American Water Resources Association; Feb2015, Vol. 51 Issue 1, p154-167, 14p |
| Abstrakt: |
Accurate spatial representation of climatic patterns is often a challenge in modeling biophysical processes at the watershed scale, especially where the representation of a spatial gradient in rainfall is not sufficiently captured by the number of weather stations. The spatial rainfall generator ( SRGEN) is developed as an extension of the 'weather generator' ( WXGEN), a component of the Agricultural Policy/Environmental eXtender ( APEX) model. SRGEN generates spatially distributed daily rainfall using monthly weather statistics available at multiple locations in a watershed. The spatial rainfall generator as incorporated in APEX is tested on the Cowhouse watershed (1,178 km2) in central Texas. The watershed presented a significant spatial rainfall gradient of 2.9 mm/km in the lateral (north-south) directions based on four rainfall gages. A comparative analysis between SRGEN and WXGEN indicates that SRGEN performs well (PBIAS = 2.40%). Good results were obtained from APEX for streamflow (NSE = 0.99, PBIAS = 8.34%) and NO3-N and soluble P loads (PBIAS ≈ 6.00% for each, respectively). However, APEX underpredicted sediment yield and organic N and P loads (PBIAS: 24.75-27.90%) with SRGEN, although its uncertainty in output was lower than WXGEN results (PBIAS: −13.02 to −46.13%). The overall improvement achieved in rainfall generation by SRGEN is demonstrated to be effective in the improving model performance on flow and water quality output. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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