2020（CREST- Joint call） FY 2020 Application CREST Research ...
A Calibration Procedure Applied To The Surface Runoff...
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Abstract GOES-PRWEB is an algorithm which computes the daily components of the water and energy balance for Puerto Rico. The algorithm uses the United States Dept. of Agriculture Natural Resource Conservation Service Curve Number (CN) method for estimating surface runoff in each of the 1-km model pixels. In this method, the input parameters are the CN and rainfall. CN is derived from information about soil hydrologic characteristics, land use and antecedent soil moisture conditions, and rainfall is obtained from NOAA's Advanced Hydrologic Prediction Service (AHPS) website. In this poster we present the results of ongoing work related to calibration and validation of the runoff component of the model. Introduction GOES-PRWEB is an algorithm which computes the daily water and energy balance for Puerto Rico (Harmsen et al., 2010). Daily data are available at the web site: http://pragwater.com. The algorithm starts by estimating the latent heat from a surface energy balance to obtain evapotranspiration (ET). Surface runoff (RO) is estimated by the United States Dept. of Agriculture (USDA) Natural Resource Conservation Service (NRCS) Curve Number (CN) method (Fangmeier et al., 2005). Surface runoff and ET are subtracted from rainfall to obtain the volume of water which infiltrates into the soil. If the volume plus the initial soil moisture volume exceeds the soil field capacity, then the excess volume is considered to be aquifer recharge. Each component of the water and energy balance needs to be calibrated and validated to provide an accurate product for the public. By producing 25 hydro-climate variables on a daily basis, GOES-PRWEB has the potential of providing valuable information for the management of water and natural resources, and agriculture in the island. This project aims to support NOAA’s goal of becoming a Weather-Ready Nation, and supports two of NOAA’s specific objectives: 1) Improved water resource management and 2) development of a secure, reliable infrastructure for energy, communications, and agriculture through timely and accurate environmental information. A Calibration Procedure Applied To The Surface Runoff Component of the GOES-PRWEB Operational Algorithm Objectives 1) Compute a correction factor (X) between estimated runoff (GOES-PRWEB) and the observed runoff from the United States Geological Survey (USGS) gauge data. 2) Calibrate the pixel-scale CN values for all gauged watersheds within Puerto Rico. 3) Extrapolate calibrated CN values to un-gauged catchments where possible. 4) In operational mode, calibrate the daily rainfall obtained from NOAA’s Advanced Hydrologic Prediction Service (AHPS) website. Technical Approach The NRCS Curve Number method equation is shown below (Fangmeier et al., 2005): Where : RO is the surface runoff (mm). P is the rainfall obtained from NOAA’s Advanced Hydrologic Prediction Service (AHPS) website (mm) . S is the potential maximum soil moisture retention after runoff begins (mm). S is given by the following equation: where : CN is the Curve Number which is derived from information about soil hydrologic characteristics, land use and antecedent soil moisture conditions. Values of CN range between approximately 30 and 100. A value of 30 indicates a low potential for runoff and 100 indicates that all the rainfall is converted into surface runoff. Various steps are required in the process of calibrating and validating the surface runoff component of GOES-PRWEB. These steps are given below: 1) Obtain USGS gauge data for all gauged watersheds in Puerto Rico. Stream flow data is accessed at http://pr.water.usgs.gov/ website. 2) Delineate gauged watersheds in ArcGIS map (Figure 1.). This allows the identification of pixels of estimated runoff within each of the drainage area. Figure 1. USGS gauges catchment areas in the island of Puerto Rico. 3) Select a prototype watershed: • Select a prototype gauged watershed. The prototype gauged watershed selected was Rio Guanajibo Basin, located in western part of the island of Puerto Rico (Figure 2). This watershed has two USGS gauges: 50136400 Rio Rosario NR Hormigueros, PR. 50138000 Rio Guanajibo NR Hormigueros , PR. Figure 2. Guanajibo Watershed located in western Puerto Rico. Red symbols indicated stream gauges. To conduct the analysis with the prototype watershed, the gauged areas inside this watershed were divided in three areas: the drainage areas of the two gauged stations and a new third area, in which stream flow data is obtained by subtracting the flow from Area 2 from the flow of Area 1 (Figure 3). • Compare gauge data and GOES-PRWEB for 2010, 2011 and 2012 for the prototype gauged watersheds. Comparisons will include surface runoff, base flow (aquifer recharge) and total flow (surface runoff + base flow). ACKNOWLEDGEMENTS This research received partial funding from the following sources: NOAA-CREST (grant NA06OAR4810162) and USDA Hatch Project (Hatch-402). Preliminary Results Of the calibration/validation steps given above, numbers 1-3 have been completed. The preliminary results, shown in Figure 4, indicate that in catchment areas 1 and 3, the model produced reliable values of RO for each month except October. Base flow, which is sometimes assumed to be equal to aquifer recharge, was in reasonable agreement, but the model was higher in July. It should be noted that stream base flow may underestimate aquifer recharge, owing to, for example, losses to evapotranspiration where the water table is close to the surface or where there are losses to deep aquifers. Because the total stream flow was underestimated by the model in October, this may suggest that the rainfall used in the model (NEXRAD radar) was lower than the actual rainfall. Catchment area 2 indicates overestimation by the model for RO and underestimation of base flow. By adjusting the CN values and lowering the RO in the model, this will result in an increase in aquifer recharge (≈base flow). The overestimate in the total stream flow (RO+BF) in May, may be an indication of inaccurate rainfall input. Conclusion In this poster, the methodology and preliminary results for calibrating the runoff component of the GOES-PRWEB algorithm were presented (steps 1-3). In addition to preliminary surface runoff results, aquifer recharge (approximately equal to base flow) and total stream flow results were presented. For catchment 2, for example, runoff was significantly overestimated during some months. In the month of May the gauge runoff was 62.6 mm and estimated runoff by GOES- PRWEB was 134.0 mm. Deviations from the gauge data were attributed to incorrect CN values in some cases and incorrect rainfall in others. Steps 4 to 8 of the "Technical Approach" need to be completed to obtain a final model calibration for Puerto Rico. Christie Adorno Garcia and Eric W. Harmsen* *Respectively: Graduate Research Assistant, Dept. of Civil Engineering and Professor, Dept. of Agricultural and Biosystems Engineering , University of Puerto Rico – Mayagüez Campus, P.O. Box 9030, Mayagüez, PR 00681. [email protected] , [email protected] S P S P RO 8 . 0 2 . 0 2 254 25400 CN S Figure 3. Three areas to analyze in the selected prototype watershed (Rio Guanajibo Watershed). Area 1 Area 2 Area 3 4) Calibrate the surface runoff component estimated by the GOES-PRWEB algorithm. A method similar to Balazs et al. (2002) is employed. Preliminary CN values are adjusted (pixel-by-pixel) by a multiplication factor X = RO obs /RO est , where RO obs is the observed runoff, equal to the total stream flow minus the stream base flow, and RO est is the estimated surface runoff from GOES-PRWEB. 5) Apply methodology to all gauged stations. 6) Extrapolate results to ungauged areas of the island. 7) Validate the results with data from 2009. 8) Apply radar-rainfall correction in operational mode. Figure 4. Surface runoff (RO), base flow (BF) and total stream flow (RO+BF) for three catchment areas in southwest PR for each month of 2010. The numbers in the legend (1, 2 or 3) indicate the catchment area. References • Balazs M. Fekete and Charles J. Vorosmarty, 2002. High-resolution fields of global runoff combining observed river discharge and simulated water balances. Global Biochemical Cycles , 16, 15-1 to 15-9. • Harmsen, E. W., J. Mecikalski, A. Mercado and P. Tosado Cruz, 2010. Estimating evapotranspiration in the Caribbean Region using satellite remote sensing. Proceedings of the AWRA Summer Specialty Conference, Tropical Hydrology and Sustainable Water Resources in a Changing Climate. San Juan, Puerto Rico. August 30-September 1, 2010. • Harmsen, E.W., 2012. GOES-Puerto Rico Water and Energy Balance (GOES-WEB) Algorithm. Retrieved from PRAGWATER: http://pragwater.com/. • Fangmeier, D. D., W. J. Elliot, S. R. Workman, R. L. Huffman, and G. O. Schwab, 2005. Soil and Water Conservation Engineering, Fifth Edition. pp. 528. • NOAA AHPS Website : National Oceanic and Atmospheric Administration . Retrieved March 2012, from http://water.weather.gov/precip/ • USGS. USGS Caribbean and Water Sciences. Retrieved March 2012, from http://pr.water.usgs.gov/ • SCS. (1986). Urban Hydrology for Small Watershed (TR-55). USDA.
Transcript of A Calibration Procedure Applied To The Surface Runoff...
Abstract GOES-PRWEB is an algorithm which computes the daily components of the water and energy balance for Puerto Rico. The algorithm uses the United States Dept. of Agriculture Natural Resource Conservation Service Curve Number (CN) method for estimating surface runoff in each of the 1-km model pixels. In this method, the input parameters are the CN and rainfall. CN is derived from information about soil hydrologic characteristics, land use and antecedent soil moisture conditions, and rainfall is obtained from NOAA's Advanced Hydrologic Prediction Service (AHPS) website. In this poster we present the results of ongoing work related to calibration and validation of the runoff component of the model.
Introduction GOES-PRWEB is an algorithm which computes the daily water and energy balance for Puerto Rico (Harmsen et al., 2010). Daily data are available at the web site: http://pragwater.com. The algorithm starts by estimating the latent heat from a surface energy balance to obtain evapotranspiration (ET). Surface runoff (RO) is estimated by the United States Dept. of Agriculture (USDA) Natural Resource Conservation Service (NRCS) Curve Number (CN) method (Fangmeier et al., 2005). Surface runoff and ET are subtracted from rainfall to obtain the volume of water which infiltrates into the soil. If the volume plus the initial soil moisture volume exceeds the soil field capacity, then the excess volume is considered to be aquifer recharge. Each component of the water and energy balance needs to be calibrated and validated to provide an accurate product for the public. By producing 25 hydro-climate variables on a daily basis, GOES-PRWEB has the potential of providing valuable information for the management of water and natural resources, and agriculture in the island. This project aims to support NOAA’s goal of becoming a Weather-Ready Nation, and supports two of NOAA’s specific objectives: 1) Improved water resource management and 2) development of a secure, reliable infrastructure for energy, communications, and agriculture through timely and accurate environmental information.
A Calibration Procedure Applied To The Surface Runoff Component of the GOES-PRWEB Operational Algorithm
Objectives 1) Compute a correction factor (X) between estimated runoff (GOES-PRWEB) and the
observed runoff from the United States Geological Survey (USGS) gauge data.
2) Calibrate the pixel-scale CN values for all gauged watersheds within Puerto Rico.
3) Extrapolate calibrated CN values to un-gauged catchments where possible.
4) In operational mode, calibrate the daily rainfall obtained from NOAA’s Advanced Hydrologic Prediction Service (AHPS) website.
Technical Approach The NRCS Curve Number method equation is shown below (Fangmeier et al., 2005): Where :
RO is the surface runoff (mm). P is the rainfall obtained from NOAA’s Advanced Hydrologic Prediction Service
(AHPS) website (mm) . S is the potential maximum soil moisture retention after runoff begins (mm). S is given by the following equation:
where : CN is the Curve Number which is derived from information about soil
hydrologic characteristics, land use and antecedent soil moisture conditions. Values of CN range between approximately 30 and 100. A value of 30 indicates a low potential for runoff and 100 indicates that all the rainfall is converted into surface runoff.
Various steps are required in the process of calibrating and validating the surface runoff component of GOES-PRWEB. These steps are given below: 1) Obtain USGS gauge data for all gauged watersheds in Puerto Rico. Stream flow data
is accessed at http://pr.water.usgs.gov/ website. 2) Delineate gauged watersheds in ArcGIS map (Figure 1.). This allows the
identification of pixels of estimated runoff within each of the drainage area.
Figure 1. USGS gauges catchment areas in the island of Puerto Rico. 3) Select a prototype watershed:
• Select a prototype gauged watershed. The prototype gauged watershed selected was Rio Guanajibo Basin, located in western part of the island of Puerto Rico (Figure 2). This watershed has two USGS gauges:
50136400 Rio Rosario NR Hormigueros, PR. 50138000 Rio Guanajibo NR Hormigueros , PR.
Figure 2. Guanajibo Watershed located in western Puerto Rico. Red symbols indicated stream gauges.
To conduct the analysis with the prototype watershed, the gauged areas inside this watershed were divided in three areas: the drainage areas of the two gauged stations and a new third area, in which stream flow data is obtained by subtracting the flow from Area 2 from the flow of Area 1 (Figure 3).
• Compare gauge data and GOES-PRWEB for 2010, 2011 and 2012 for the prototype gauged watersheds. Comparisons will include surface runoff, base flow (aquifer recharge) and total flow (surface runoff + base flow).
ACKNOWLEDGEMENTS This research received partial funding from the following sources: NOAA-CREST (grant NA06OAR4810162) and USDA Hatch Project (Hatch-402).
Preliminary Results Of the calibration/validation steps given above, numbers 1-3 have been completed. The preliminary results, shown in Figure 4, indicate that in catchment areas 1 and 3, the model produced reliable values of RO for each month except October. Base flow, which is sometimes assumed to be equal to aquifer recharge, was in reasonable agreement, but the model was higher in July. It should be noted that stream base flow may underestimate aquifer recharge, owing to, for example, losses to evapotranspiration where the water table is close to the surface or where there are losses to deep aquifers. Because the total stream flow was underestimated by the model in October, this may suggest that the rainfall used in the model (NEXRAD radar) was lower than the actual rainfall. Catchment area 2 indicates overestimation by the model for RO and underestimation of base flow. By adjusting the CN values and lowering the RO in the model, this will result in an increase in aquifer recharge (≈base flow). The overestimate in the total stream flow (RO+BF) in May, may be an indication of inaccurate rainfall input.
Conclusion In this poster, the methodology and preliminary results for calibrating the runoff component of the GOES-PRWEB algorithm were presented (steps 1-3). In addition to preliminary surface runoff results, aquifer recharge (approximately equal to base flow) and total stream flow results were presented. For catchment 2, for example, runoff was significantly overestimated during some months. In the month of May the gauge runoff was 62.6 mm and estimated runoff by GOES-PRWEB was 134.0 mm. Deviations from the gauge data were attributed to incorrect CN values in some cases and incorrect rainfall in others. Steps 4 to 8 of the "Technical Approach" need to be completed to obtain a final model calibration for Puerto Rico.
Christie Adorno Garcia and Eric W. Harmsen* *Respectively: Graduate Research Assistant, Dept. of Civil Engineering and Professor, Dept. of Agricultural and Biosystems Engineering ,
University of Puerto Rico – Mayagüez Campus, P.O. Box 9030, Mayagüez, PR 00681. [email protected] , [email protected]
SP
SPRO
8.0
2.02
25425400
CN
S
Figure 3. Three areas to analyze in the selected prototype watershed (Rio Guanajibo Watershed).
Area 1
Area 2
Area 3
4) Calibrate the surface runoff component estimated by the GOES-PRWEB algorithm. A method similar to Balazs et al. (2002) is employed. Preliminary CN values are adjusted (pixel-by-pixel) by a multiplication factor X = ROobs/ROest, where ROobs is the observed runoff, equal to the total stream flow minus the stream base flow, and ROest is the estimated surface runoff from GOES-PRWEB.
5) Apply methodology to all gauged stations. 6) Extrapolate results to ungauged areas of the island. 7) Validate the results with data from 2009. 8) Apply radar-rainfall correction in operational mode.
Figure 4. Surface runoff (RO), base flow (BF) and total stream flow (RO+BF) for three catchment areas in southwest PR for each month of 2010. The numbers in the legend (1, 2 or 3) indicate the catchment area.
References • Balazs M. Fekete and Charles J. Vorosmarty, 2002. High-resolution fields of global runoff combining
observed river discharge and simulated water balances. Global Biochemical Cycles , 16, 15-1 to 15-9. • Harmsen, E. W., J. Mecikalski, A. Mercado and P. Tosado Cruz, 2010. Estimating evapotranspiration in
the Caribbean Region using satellite remote sensing. Proceedings of the AWRA Summer Specialty Conference, Tropical Hydrology and Sustainable Water Resources in a Changing Climate. San Juan, Puerto Rico. August 30-September 1, 2010.
• Harmsen, E.W., 2012. GOES-Puerto Rico Water and Energy Balance (GOES-WEB) Algorithm. Retrieved
from PRAGWATER: http://pragwater.com/.
• Fangmeier, D. D., W. J. Elliot, S. R. Workman, R. L. Huffman, and G. O. Schwab, 2005. Soil and Water Conservation Engineering, Fifth Edition. pp. 528.
• NOAA AHPS Website : National Oceanic and Atmospheric Administration . Retrieved March 2012, from http://water.weather.gov/precip/
• USGS. USGS Caribbean and Water Sciences. Retrieved March 2012, from http://pr.water.usgs.gov/ • SCS. (1986). Urban Hydrology for Small Watershed (TR-55). USDA.
