Developing a New Deconvolution Technique to Model Rainfall-Runoff in Arid Environments
Affiliation
Department of Hydrology and Water ResourcesWater Resources Research Center
Water Resources Research Center
Department of Hydrology and Water Resources
Issue Date
1982-09Keywords
Rain and rainfall -- Mathematical models.Runoff -- Mathematical models.
Arid regions -- Water-supply -- Mathematical models.
Hydrologic models.
Metadata
Show full item recordDescription
Project Completion Report, OWRT Project No. A-086-ARIZ / Agreement No. 14-34-0001-8003, Project Dates: 10/01/77-9/30/78 / Acknowledgement: The work upon which this report is based was supported by funds provided by the State of Arizona and the United States Department of Interior, Office of Water Research and Technology as authorized under the Water Resources Act of 1964. / From the Introduction: "The research work under this contract has been conducted by graduate student David B. Dunbar and summarized in his M.S. thesis entitled "Analysis of a Parameter Estimation Technique for Linear Hydrologic Systems Using Monte Carlo Simulation" submitted to the Department of Hydrology and Water Resources, University of Arizona, Tucson, in 1981. The present report is a brief summary of Mr. Dunbar's thesis." David Dunbar's thesis is available at: http://arizona.openrepository.com/arizona/handle/10150/191728Additional Links
http://arizona.openrepository.com/arizona/handle/10150/191728Abstract
The primary accomplishment of this research has been demonstrating the power of the deconvolution technique developed by Neuman and de Marsily (1976) in dealing with noisy rainfall- runoff records of short duration. Such records are encountered in arid environments where rainfall often occurs in short isolated bursts and the data are measured with a considerable margin of error. Our research work consisted of superimposing known noise on synthetic rainfall- runoff data and examining the ability of the Neuman -de Marsily deconvolution method to estimate the correct impulse response of the system when the data include only a single storm event. Approximately 50 Monte Carlo simulation runs were performed for each of three different noise models considered in our work. The results clearly demonstrated that the deconvolution model leads to reliable estimates and can be used with confidence in the presence of realistic noise levels. In addition to the Monte Carlo simulation tests and their analysis, certain improvements were introduced into the original deconvolution technique. In particular, the original version of the technique required that the hydrologist exercise subjective judgement in choosing the "best" solution for the deconvolution problem from a large number of admissible solutions. Our new method of selecting the "best" result is based on a comparative analysis of residuals and is more reliable than the earlier subjective approach. The improved method has been applied to real as well as synthetic rainfall -runoff data.Language
en_USCollections
Related items
Showing items related by title, author, creator and subject.
-
Modeling System Reliability For Digital Preservation: Model Modification and Four-Copy Model StudyResearch has been studied to evaluate the reliability of storage media and the reliability of a computer backup system. In this paper, we use the Continuous Time Markov Chain to model and analyze the reliability of a computer backup system. We propose a modified model from that of the Constantopoulos, Doerr and Petraki [1]. We analyze the difference, show computational results, and propose new input parameters (e.g. time to repair) for the model from our experience. Further we developed a four-copy data model to test if it fulfills the sample reliability rate set by the RLG-NARA. The modeling process can be applied to construct models for computer preservation systems using different storage media. The reliability of constructed models can be calculated so that preservation institutions can have quantitative data to decide their preservation strategies.
-
Dendroclimatic Analysis Using Thornwaite-Mather-Type Evapotranspiration Models: A Bridge Between Dendroevology and Forest Simulation ModelsThe objective of this study was to document correlations between radial growth of white oak (Quercus alba L.) at 128 sites in the eastern US and variables related to early growing season site water balance, including the ratio of actual to potential evapotranspiration (AE/PE) computed based on the procedure described by Thornthwaite and Mather (1957). White oak radial growth was strongly correlated with all measures of early growing season water balance, but was most consistently and strongly correlated with Palmer Drought Severity Index (PDI) and AE /PE ratio computed using a modified Thornthwaite-Mather model. We propose that dendroecological analyses of tree growth responses to climate based on AE /PE variables could provide empirical data useful for improving climate response algorithms in forest simulation models. This change of standard practice could also improve biological interpretations derived from such dendroecological analyses.
-
The effects of surface roughness and stress on lattice gas models using kinetic Monte Carlo modelingThis thesis reports kinetic Monte Carlo computer simulations using a lattice gas model conducted on a variety of systems. These studies may be divided into two main categories: rod eutectics and related surface roughening, and surface morphology changes due to local stresses. The first grouping is a study of irregular rod eutectic systems. Simulations of directional solidification of rod eutectic systems were conducted using a model similar to the spin one Ising model. Growth of the rods was initiated from columns of pure A atoms embedded in a matrix of B atoms. The growth characteristics of the eutectic depend on the location of the surface roughening transition for the two phases. The surface roughening transition was determined using fluctuation dissipation theory, where the kinetic behavior of the interface is related to a characteristic time of fluctuations about an equilibrium position. These times were determined by time correlations. Results show a sharp transition in the kinetic behavior of the interface as a function of Jackson's alpha factor. This is the first time this method has been used to locate the surface roughening transition. An applied temperature gradient supplied the restoring force for the interface. The roughening behavior of binary alloys was also examined and compared to pure component systems. The second set of simulations reported here examine the effects of local stress on surface morphology. The weakening of bonds due to the dislocation stress field was studied as the origin of the formation of etch-pits at dislocations. Atoms from a diamond cubic lattice were irreversibly removed with a probability which depends on an local surface configuration as well as on the local stress developed from its physical location with respect to a dislocation in the lattice. In accordance with experimental observations, both faceted and non-faceted dislocation etch-pits have been observed. Simulations of crystal surfaces near equilibrium have reproduced direct experimental results using atomic force microscopy (AFM). The probe tip interacts with the shape and the motion of step edges, and the motion of a step is retarded in the vicinity of the tip.
