| ABSTRACT | 第7-9页 |
| 摘要 | 第10-24页 |
| Chapter 1. Introduction | 第24-36页 |
| 1.1 Background to the study | 第24-25页 |
| 1.2 Drought characteristics | 第25-26页 |
| 1.3 Classification of drought | 第26-28页 |
| 1.4 Drought index and drought identification | 第28-31页 |
| 1.5 Probabilistic Characterization of Drought | 第31页 |
| 1.6 Copula and Drought Frequency Analysis | 第31-34页 |
| 1.7 Research Gap | 第34-35页 |
| 1.8 General Aims and Objectives | 第35-36页 |
| Chapter 2. Study Area and Data | 第36-41页 |
| 2.1 Study Area | 第36-37页 |
| 2.2 Study sites and data | 第37-38页 |
| 2.3 Drought Coverage Area | 第38-39页 |
| 2.4 Structure of the research | 第39-41页 |
| Chapter 3. Drought Indices and Univariate Analysis | 第41-72页 |
| 3.1 Drought Index and Univariate Analysis | 第41页 |
| 3.2 Methodology | 第41-50页 |
| 3.2.1 Descriptive statistics | 第41-42页 |
| 3.2.2 Potential evapotranspiration | 第42-43页 |
| 3.2.3 Computation of Drought Indices | 第43-46页 |
| 3.2.3.1 Standardized Precipitation Index | 第43-44页 |
| 3.2.3.2 Standardized Precipitation Evapotranspiration Index | 第44页 |
| 3.2.3.3 Composite Index | 第44-45页 |
| 3.2.3.4 Effective Drought Index | 第45-46页 |
| 3.2.4 Drought event identification and characterization | 第46-47页 |
| 3.2.5 Selection of appropriate marginal distributions | 第47-48页 |
| 3.2.6 Evaluation criteria | 第48-49页 |
| 3.2.7 Estimation of Univariate Drought Return Period | 第49-50页 |
| 3.2.8 Spatial interpolation | 第50页 |
| 3.3 Results and Discussion | 第50-71页 |
| 3.3.1 Spatiotemporal variations of climatic variables | 第50-51页 |
| 3.3.2 Drought indices and their frequency distribution | 第51-54页 |
| 3.3.3 Drought Characteristics | 第54页 |
| 3.3.4 The Spatial and Temporal extent of Drought Characteristics | 第54-59页 |
| 3.3.4.1 Spatial extent of Drought Characteristics | 第54-56页 |
| 3.3.4.2 Temporal extent of Severe Drought events | 第56-59页 |
| 3.3.5 Correlation of Drought Characteristics | 第59-61页 |
| 3.3.6 Estimation of Effective drought index | 第61-64页 |
| 3.3.7 Marginal distribution fit of drought variables | 第64-66页 |
| 3.3.8 Univariate Return Period Analyses | 第66-67页 |
| 3.3.9 Relative performance of drought indices | 第67-71页 |
| 3.4 Brief summary | 第71-72页 |
| Chapter 4. Frequency analysis using Two-Variate Archimedean Copula | 第72-99页 |
| 4.1 Background of two-variate joint copula | 第72页 |
| 4.2 Methodology | 第72-79页 |
| 4.2.1 Theoretical aspects of copula functions | 第72-73页 |
| 4.2.2 Bivariate Archimedean copulas | 第73-74页 |
| 4.2.3 Copulas Parameter Estimation | 第74-76页 |
| 4.2.4 Selecting the Best Copula Family | 第76-77页 |
| 4.2.5 Probabilities of Drought Events | 第77-78页 |
| 4.2.5.1 Bivariate joint occurrence probability | 第77-78页 |
| 4.2.5.2 Bivariate joint Conditional probability | 第78页 |
| 4.2.6 Return Periods of Drought Events | 第78-79页 |
| 4.2.6.1 Bivariate joint return period | 第78-79页 |
| 4.2.6.2 Conditional joint return period | 第79页 |
| 4.3 Results and Discussion | 第79-98页 |
| 4.3.1 Analysis of drought climatology | 第79页 |
| 4.3.2 Drought Event Characterization | 第79-80页 |
| 4.3.3 Analyzing trivariate dependence between drought variables | 第80-83页 |
| 4.3.4 Estimation of bivariate joint distributions | 第83-85页 |
| 4.3.5 Regional Characteristics of drought events | 第85-95页 |
| 4.3.5.1 Regional joint probability of drought events | 第85-88页 |
| 4.3.5.2 Regional bivariate return period of drought events | 第88-95页 |
| 4.3.6 Spatial Characteristics of drought events | 第95-98页 |
| 4.3.6.1 Spatial distribution of drought probabilities | 第95-96页 |
| 4.3.6.2 Spatial pattern of bivariate drought return period | 第96-98页 |
| 4.4 Brief Conclusion | 第98-99页 |
| Chapter 5. Frequency analysis using Three-Variate Archimedean Copula | 第99-118页 |
| 5.1 Background of Three-Variate Copula | 第99页 |
| 5.2 Methodology | 第99-103页 |
| 5.2.1 Empirical trivariate distribution of drought variables | 第99-100页 |
| 5.2.2 Trivariate cumulative probability distribution of drought variables | 第100页 |
| 5.2.3 Trivariate dependence modeling of droughts using Archimedean copula | 第100-102页 |
| 5.2.4 Selection of appropriate Trivariate copula family | 第102页 |
| 5.2.5 Trivariate frequency analysis of droughts | 第102-103页 |
| 5.2.5.1 Trivariate joint occurrence probability of drought events | 第102-103页 |
| 5.2.5.2 Trivariate return period of drought events | 第103页 |
| 5.3 Results and Discussions | 第103-117页 |
| 5.3.1 Copula-based joint dependence modeling of drought variables | 第103-107页 |
| 5.3.2 Comparison of multivariate probability of drought events | 第107-113页 |
| 5.3.2.1 Regional trivariate joint probability of drought events | 第107-109页 |
| 5.3.2.2 Spatial pattern of multivariate drought probabilities | 第109-113页 |
| 5.3.3 Comparison of multivariate return periods of drought events | 第113-117页 |
| 5.3.3.1 Regional trivariate return period of drought events | 第113-115页 |
| 5.3.3.2 Spatial pattern of multivariate drought return period | 第115-117页 |
| 5.4 Brief Conclusion | 第117-118页 |
| Chapter 6. Frequency analysis using Four-Variate Archimedean Copula | 第118-135页 |
| 6.1 Background of Four-variate dimensional Copula | 第118页 |
| 6.2 Methodology | 第118-122页 |
| 6.2.1Empirical four-variate distribution of drought variables | 第118-119页 |
| 6.2.2 Joint cumulative probability distribution of drought variables | 第119页 |
| 6.2.3 Modeling four-variate drought variables using copulas | 第119-120页 |
| 6.2.4 Selection of appropriate copula function | 第120-121页 |
| 6.2.5 Four-variate joint drought frequency analysis | 第121-122页 |
| 6.3 Results and Discussions | 第122-134页 |
| 6.3.1 Drought variable and four-variate dependence | 第122-123页 |
| 6.3.2 Marginal Distribution for Inter-arrival time | 第123-127页 |
| 6.3.3 Copula-based four-variate joint distributions | 第127-130页 |
| 6.3.4 Four-variate joint drought frequency analysis | 第130-134页 |
| 6.3.4.1 Regional four-variate probabilities of drought events | 第130-131页 |
| 6.3.4.2 Regional four-variate return period of drought events | 第131-132页 |
| 6.3.4.3 Spatial distribution of four-variate probability and return periods | 第132-134页 |
| 6.4 Brief Summary | 第134-135页 |
| Chapter 7. Conclusions and suggestions | 第135-139页 |
| 7.1 General Conclusions | 第135-137页 |
| 7.2 Future work | 第137-139页 |
| References | 第139-147页 |
| Acknowledgements | 第147-149页 |
| Author’s Introduction | 第149-150页 |
