A Assessment of Hydrological Drought using Tree-ring Data

Generally, Long-term data are vital for analysis of hydrological phenomenon, but it also has many constraints. So, 19th century onwards data are mainly used. The objective of the study is, therefore, to reconstruct and evaluate hydrological data using tree-ring, which known as the method to acquire long-term data, and to analyze drought frequency with its result. For this, The tree-ring data in the Sacramento river basin were obtained and about 300 years streamflow data were reconstructed based on the artificial neural network. Also, the drought frequency and its occurrence trend were analyzed with copula method which is widely adopted for drought.