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
                                            Starks, Patrickitem
                                            Heathman, Garyitem
                                            Jackson, Thomasitem
                                            Cosh, Michael
  Submitted to: Journal of Hydrology
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 9/30/2005
                                    Publication  Date: 6/1/2006
                                    Citation: Starks, P.J., Heathman, G.C., Jackson, T.J., Cosh, M.H. 2006. Temporal stability of profile soil moisture. Journal of Hydrology. 324:400-411.Interpretive Summary: Validation of satellite estimates of surface soil water content and verification of model simulations of sub-surface soil water content over large land areas cannot be accomplished in a timely, cost-effective manner using traditional manual sampling techniques.  This study analyzes the consistency, both in space and time, of profile soil moisture content obtained from time-domain reflectometry (TDR) probes deployed across the 610 km2 Little Washita River Experimental Watershed (LWREW) located in southwestern Oklahoma.  Analyses were performed to determine if a smaller number of the TDR sites could be used to represent watershed averages of soil water content at various levels in the soil profile, as well as in the total profile.  TDR data were routinely collected during the months of June and July in 1997 and in July 2003, coincident with large-scale hydrological remote sensing experiments.  The results show that two of the sites were stable, as evidenced by their small standard deviations.  One site consistently underestimated and the other consistently overestimated watershed average soil water content at all levels in the soil profile.  Because the offset between these under- and over-estimates and the watershed mean are consistent and known, these sites can be used to determine the watershed mean values of soil water content at all levels in the profile, as well as providing ranges of soil water content within the watershed.  Identification of these temporally stable sites within the LWERW will assist in the validation of coarse spatial resolution surface soil moisture products derived from new generation passive microwave satellites, as well as providing validation data sets for watershed hydrologic modeling of subsurface soil water contents.
                                Technical Abstract: Validation of satellite estimates of surface soil water content and verification of model simulations of sub-surface soil water content over large land areas cannot be accomplished in a timely, cost-effective manner using traditional manual sampling techniques.  This study analyzes the temporal stability of profile soil moisture content obtained from time-domain reflectometry (TDR) probes deployed across the 610 km2 Little Washita River Experimental Watershed (LWREW) located in southwestern Oklahoma.  Analyses were performed to determine if a subset of the TDR sites could be used to represent watershed averages of soil water content at various levels in the soil profile, as well as in the total profile.  TDR data were routinely collected at eight locations during the months of June and July in 1997 and in July 2003, coincident with large-scale hydrological remote sensing experiments.  The results show that two of the eight TDR sites were found to be temporally stable, as evidenced by their small standard deviations.  One site consistently underestimated and the other consistently overestimated watershed average soil water content at all levels in the soil profile.  Because the offset between these under- and over-estimates and the watershed mean are known, these sites can be used to determine the watershed mean values of soil water content at all levels in the profile, as well as providing ranges of soil water content within the watershed.  Identification of these temporally stable sites within the LWERW will assist in the validation of coarse spatial resolution surface soil moisture products derived from new generation passive microwave satellites, as well as providing validation data sets for watershed hydrologic modeling of subsurface soil water contents.


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