Title Page
Contents
ABSTRACT 15
1. INTRODUCTION 19
1.1. General remarks 19
1.2. Objective of the research 24
1.3. Literature review 28
1.3.1. Prediction of hydrological phenomena 28
1.3.2. Reservoir operation for coping with a drought 37
1.3.3. Drought index 42
1.4. Thesis outline 48
2. DROUGHT RECORDS IN KOREA 49
2.1. Drought from the Three Kingdoms to the Joseon Dynasty 50
2.2. Drought damage and response since the 1900s 52
2.3. Drought Damage and Response in 2014-2015 56
2.4. Deduction of Implications 63
3. THEORIES AND METHODOLOGY 64
3.1. Statistical method for hydrology 64
3.1.1. Parametric approach 64
3.1.2. Nonparametric approach 70
3.2. Reservoir operation rule for coping with water shortage 76
3.2.1. Hedging rule 76
3.2.2. Evaluation for reservoir operation 81
3.3. Drought index 84
3.3.1. Meteorologic drought index 84
3.3.2. Hydrologic drought index 93
4. DEVELOPMENT AND APPLICATION OF PROBABILISTIC STORAGE PREDICTION MODEL 98
4.1. Development of Probability Storage Prediction Model (PSPM) 99
4.2. Applicability of the PSPM 103
4.3. Application of the PSPM 112
4.3.1. Probabilistic prediction of reservoir storage 112
4.3.2. Application to reservoir operation rule 117
5. DEVELOPMENT AND APPLICATION OF HEDGING RULE USING PSPM 122
5.1. Study area 122
5.2. Water supply adjustment criterion of K-water 127
5.3. Simulation of the dam operation using the rev-PSPM 134
5.3.1. Comparison between Case A and Case B 135
5.3.2. Change in the achievement probability in the monsoon season 147
5.4. Development and assessment of hedging rule using rev-PSPM 152
5.4.1. Development of hedging rule for Chungju Dam 152
5.4.2. Assessment of hedging rule using rev-PSPM 164
6. DEVELOPMENT OF DAM INFLOW DROUGHT INDEX 169
6.1. Method 169
6.2. Application of the DIDI 174
6.3. Comparison with typical drought indices 180
6.3.1. Comparison with SWSI 181
6.3.2. Comparison with PDSI 182
6.3.3. Comparison with SPI 183
6.4. Provision of seamless drought information 188
7. SUMMARY AND CONCLUSIONS 189
REFERENCES 192
Appendix 220
[Appendix-A] Monthly inflow of Chungju Dam 220
[Appendix-B] Change in CDF according to the target storage 226
[Appendix-C] Drought indices 238
논문요약 250
[Table 2.1] Drought record of ancient county 50
[Table 2.2] Major drought in Korea 55
[Table 2.3] Rainfall in 2014 and 2015 58
[Table 2.4] Drought response of K-water in 2015 60
[Table 2.5] Recent drought damages in Korea 61
[Table 3.1] Probability density function commonly used in hydrology 68
[Table 3.2] Typical kernel functions 72
[Table 3.3] Drought severity classification of PSDI 88
[Table 3.4] Drought severity classification of SPI (and SPEI) 92
[Table 3.5] Drought severity classification of SWSI 94
[Table 3.6] Drought severity classification of SDI 97
[Table 4.1] Results of K-S test (significance level: 0.05, critical value: 0.2525) 111
[Table 4.2] Probabilities that reservoir storage is less than the 30-year average storage... 115
[Table 4.3] Summary of reservoir operation simulation for achieving target storage on... 120
[Table 5.1] Dimensions of Chungju Dam 124
[Table 5.2] Statistics of dam inflow of Chungju Dam (106 m³)(이미지참조) 125
[Table 5.3] Water supply plan of Chungju Dam (106 m³)(이미지참조) 125
[Table 5.4] Strategies for water reduction 128
[Table 5.5] Storages of each response stage for coping with the water shortage of... 129
[Table 5.6] The amount of the reduction in water supply of Chungju Dam 131
[Table 5.7] Results of evaluation for dam operation of WSAC 132
[Table 5.8] Correlation coefficient between statistical performance indices, the target... 138
[Table 5.9] Correlation coefficients among indices of Case A 140
[Table 5.10] Correlation coefficient between statistical performance indices, the target... 142
[Table 5.11] Correlation coefficients among indices of Case B 144
[Table 5.12] Correlation coefficients among indices of Case C 149
[Table 5.13] Total number of simulations and the number of cases for the trigger... 151
[Table 5.14] Total number of the simulation and the number of cases for the trigger... 153
[Table 5.15] Result of the vulnerability in descending order 154
[Table 5.16] Trigger volume of the WSAC and the fist ranking result of the rev-PSPM... 160
[Table 5.17] Comparison of the evaluation index between WSAC and rev-PSPM 165
[Table 5.18] Comparison of the evaluation index between SOP and rev-PSPM 167
[Table 6.1] ROC classification 172
[Table 6.2] Volumes of WSAC's attention stage 175
[Table 6.3] Comparison of ROC scores 187
[Figure 1.1] Digital elevation model 21
[Figure 1.2] Characteristic of seasonal rainfall 21
[Figure 1.3] Waterworks service rate 22
[Figure 1.4] The amount of the water supply from the dam 22
[Figure 1.5] Waterworks service rate of each basin 23
[Figure 1.6] Diagram for hydrologic forecasting approaches (Yuan et al., 2015) 32
[Figure 1.7] Possible ensemble streamflow prediction traces (Faber and Stedinger, 2001) 32
[Figure 2.1] Drought record of ancient country 52
[Figure 2.2] Drought occurrence in the 1900s 54
[Figure 2.3] Rainfall rate in 2014 and 2015 compared to normal year 58
[Figure 2.4] Temporal and spatial changes in SPI(6) during the 2014-2015 drought 59
[Figure 2.5] Water storage rate compared to normal years (2015.12) 60
[Figure 2.6] Water supply restricted area and emergency alert area during the 2014-2015... 62
[Figure 3.1] Comparison of probability distributions 69
[Figure 3.2] Shape of kernel functions 72
[Figure 3.3] Kernel density functions with kinds of various kernels. Bandwidth: 10 73
[Figure 3.4] Gaussian kernel density function with various bandwidths 73
[Figure 3.5] Differences between kdf and bounded kdf 75
[Figure 3.6] Hedging rule compared with SOP (Lund, 1996) 77
[Figure 3.7] Trigger volume hedging (Lund, 1996) 79
[Figure 3.8] Zone-based hedging (Lund, 1996) 80
[Figure 4.1] Change in storages that apply the observed inflow and the planned water... 104
[Figure 4.2] Comparison of theoretical and empirical CDF (1) 105
[Figure 4.3] Comparison of theoretical and empirical CDF (2) 106
[Figure 4.4] Comparison of theoretical and empirical CDF (3) 107
[Figure 4.5] P-P plot on PSPM (theoretical CDF) versus dam simulation result... 108
[Figure 4.6] P-P plot on PSPM (theoretical CDF) versus dam simulation result... 109
[Figure 4.7] P-P plot on PSPM (theoretical CDF) versus dam simulation result... 110
[Figure 4.8] Cumulative distribution function for reservoir storage for various... 114
[Figure 4.9] Change of reservoir storage for various supply reduction scenarios 115
[Figure 4.10] Comparison of reduced water supply 116
[Figure 4.11] CDF of current reservoir storage for achieving target storage... 119
[Figure 4.12] Temporal change of storage (a) and supply reduction simulated for various... 121
[Figure 5.1] Chungju Dam basin 123
[Figure 5.2] Time series of monthly inflow of Cungju Dam 124
[Figure 5.3] Mean inflow and water supply of Chungju Dam 126
[Figure 5.4] Boxplot of monthly inflow of Chungju Dam 126
[Figure 5.5] Storages of each response stage for coping with the water shortage of... 130
[Figure 5.6] The amount of the reduction in water supply of Chungju Dam 130
[Figure 5.7] Simulated reservoir storages by WSAC 133
[Figure 5.8] The amount of reduction in water supply by WSAC 133
[Figure 5.9] Change in the reliability of Case A 137
[Figure 5.10] Change in the resiliency of Case A 137
[Figure 5.11] Change in the vulnerability of Case A 138
[Figure 5.12] Relation between the reliability and the resiliency in Case A 139
[Figure 5.13] Relation between the reliability and the vulnerability in Case A 139
[Figure 5.14] Relation between the resiliency and the vulnerability in Case A 140
[Figure 5.15] Change in the reliability of Case B 141
[Figure 5.16] Change in the resiliency of Case B 141
[Figure 5.17] Change in the vulnerability of Case B 142
[Figure 5.18] Relation between the reliability and the resiliency of Case B 143
[Figure 5.19] Relation between the reliability and the vulnerability of Case B 143
[Figure 5.20] Relation between the resiliency and the vulnerability in Case B 144
[Figure 5.21] Comparison of the reliability between Case A and Case B 145
[Figure 5.22] Comparison of the resiliency between Case A and Case B 145
[Figure 5.23] Comparison of the vulnerability between Case A and Case B 146
[Figure 5.24] Relation between the reliability and the resiliency of Case C 148
[Figure 5.25] Relation between the reliability and the vulnerability of Case C 148
[Figure 5.26] Relation between the resiliency and the vulnerability of Case C 149
[Figure 5.27] Probability histogram of the reliability of Case B and Case C 150
[Figure 5.28] Probability histogram of the resiliency of Case B and Case C 150
[Figure 5.29] Probability histogram of the vulnerability of Case B and Case C 151
[Figure 5.30] Trigger volume for the target storage 700 x 106 m³, AP(1) 0.50 and...(이미지참조) 155
[Figure 5.31] Trigger volume for the target storage 700 x 106 m³, AP(1) 0.50 and...(이미지참조) 155
[Figure 5.32] Trigger volume for the target storage 750 x 106 m³, AP(1) 0.46 and...(이미지참조) 156
[Figure 5.33] Trigger volume for the target storage 750 x 106 m³, AP(1) 0.44 and...(이미지참조) 156
[Figure 5.34] Trigger volume for the target storage 750 x 106 m³, AP(1) 0.42 and...(이미지참조) 157
[Figure 5.35] Trigger volume for the target storage 700 x 106 m³, AP(1) 0.48 and...(이미지참조) 157
[Figure 5.36] Trigger volume for the target storage 700 x 106 m³, AP(1) 0.46 and...(이미지참조) 158
[Figure 5.37] Trigger volume for the target storage 710 x 106 m³, AP(1) 0.46 and...(이미지참조) 158
[Figure 5.38] Trigger volume for the target storage 740 x 106 m³, AP(1) 0.42 and...(이미지참조) 159
[Figure 5.39] Trigger volume for the target storage 740 x 106 m³, AP(1) 0.44 and...(이미지참조) 159
[Figure 5.40] Comparison of hedging rule of WSAC with rev-PSPM (1) 161
[Figure 5.41] Comparison of hedging rule of WSAC with rev-PSPM (2) 162
[Figure 5.42] Comparison of hedging rule of WSAC with rev-PSPM (3) 163
[Figure 5.43] Comparison of the simulation results with WSAC and rev-PSPM 165
[Figure 5.44] Deviation of the reduction amount between WSAC and rev-PSPM 166
[Figure 5.45] Comparison of the simulation results with SOP and rev-PSPM 167
[Figure 5.46] Deviation of the reduction amount between SOP and rev-PSPM 168
[Figure 6.1] ROC curve and ROC score 172
[Figure 6.2] The description of ROC score. 173
[Figure 6.3] Critical inflows of Chungju Dam 175
[Figure 6.4] Observed monthly inflows of Chungju Dam 176
[Figure 6.5] Difference between the observed inflow and critical inflow 176
[Figure 6.6] The point at which water supply is reduced and the amount of reduction in... 177
[Figure 6.7] ROC scores according to the threshold change 178
[Figure 6.8] Cumulative difference between the observed inflow and the critical inflow... 178
[Figure 6.9] DIDI and reduction in water supply 179
[Figure 6.10] Chungju weather station and dam basin 180
[Figure 6.11] Comparison between DIDI and SWSI 181
[Figure 6.12] Comparison between DIDI and PDSI 182
[Figure 6.13] Comparison between DIDI and SPI 184
[Figure 6.14] Monthly observed inflow, critical inflow, and DIDI during 1991-1993 185
[Figure 6.15] Monthly observed rainfall, average rainfall, and 12-month rainfall during... 185
[Figure 6.16] Monthly observed inflow, critical inflow, and DIDI during 2006-2007 186
[Figure 6.17] Monthly observed rainfall, average rainfall, and 12-month rainfall during... 186
[Figure 6.18] Results of ROC analysis 187
[Figure 6.19] Provision of drought information with a seamless from past to present and... 188