U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            CHEN, FAN - SSAIitem
                                            Crow, Wade
  Submitted to: Meeting Abstract
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 3/10/2009
                                    Publication  Date: 4/15/2009
                                    Citation: Chen, F., Crow, W.T. 2009. Multi-objective calibration of hydrologic model using satellite data [abstract]. Abs. 10, BARC Poster Day.Interpretive Summary:
                                Technical Abstract: Hydrologic modeling often involves a large number of parameters, some of which cannot be measured directly and may vary with land cover, soil or even seasons. Therefore parameter estimation is a critical step in applying a hydrologic model to any study area. Parameter estimation is typically done by a manual or automated calibration of the model in order to identify the parameter values that produce the best fit between model predicts and observations. While observed stream flow records are often the only available data for calibration, the emergence of remote sensing provides an independent data source for the calibration task, which implies tremendous potential for data-sparse or ungaged basins. We used thermal remote sensing-based surface evapotranspiration (ET) data as well as observed stream flow data to carry out a series of single- or multi- objective calibrations of the USDA-ARS developed watershed model Soil and Water Analysis Tool (SWAT). A sensitivity analysis was performed first to identify the parameters that both stream flow and ET are sensitivity to. Then the model was calibrated, using an automated global search algorithm, under different scenarios designed to reveal the effects of integrating remote sensing data on improving the hydrologic simulations: calibration against stream flow alone, ET alone and both variables at the same time with equal weights. Preliminary results suggested that (1) multi-objective calibration converges faster than single-objective calibration and result in comparable improvements of stream flow prediction as to the calibration of stream flow alone, i.e. integrating remote sensing ET data led to higher optimization efficiency; (2) calibration of evapotranspiration alone also resulted in improved runoff estimation, especially in the monthly time step. Although it did not produce as good hydrograph as direct calibration of stream flow, the annual water balance was more realistic. The results of this work can help enhance watershed or regional scale conservation practice assessment through improved simulation of hydrologic processes as well as nutrient and sediment loads.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov