Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → États-Unis → 1987 → AN ASSESSMENT OF EROSION PROCESSES AS SIMULATED USING ARTIFICIAL RAINFALL SOUTHWEST CONDITIONS

New Mexico State University (1987)

AN ASSESSMENT OF EROSION PROCESSES AS SIMULATED USING ARTIFICIAL RAINFALL SOUTHWEST CONDITIONS

SERRAG, SALAHEDDIN ALI

Titre : AN ASSESSMENT OF EROSION PROCESSES AS SIMULATED USING ARTIFICIAL RAINFALL SOUTHWEST CONDITIONS

Auteur  : SERRAG, SALAHEDDIN ALI

Université de soutenance : New Mexico State University

Grade : Doctor of Philosophy (PhD) 1987

Résumé
A data base of 522 small plot rainfall simulations from fourteen different sites was compiled. These data were used to assess the types and quality of information that could be gained from using simulated rainfall to produce soil erosion on small plots. Various statistical tests were applied to investigate differences, and functional relationships between and among the different sites. Results revealed that initial soil moisture content was one of the most significant variables in studying soil erosion on small plots. Site characteristics had significant effects on the variations between the measured variables. Various nondimensional variables were selected to develop multiple regression models to predict sediment concentration. Three different models were developed. Identification of detachment processes was approached by two different techniques : statistical analysis and physical process modeling. Results of the statistical analysis showed a strong correlation between sediment yield and flow detachment-related variables for wet initial moisture conditions but not for dry conditions. No dependence between sediment yield and rainfall detachment related-variables was found. Results of the physical process modeling indicated that the active detachment process on the plot was rainfall rather than flow as the correlation analysis indicated. An experiment was conducted to investigate the time variation of sediment concentration on small plots. Results showed a concentration decay with time, followed by an increase towards the end of the simulation. In general, results of this study demonstrated the applicability of rainfall simulation techniques on small plots as a valuable tool to collect data and use it to characterize rainfall-runoff-erosion processes. Data collected from small plots can be used to evaluate empirical parameters required by the physical process models.

Présentation

Page publiée le 12 avril 2015, mise à jour le 20 décembre 2019