Methods to assess sustainability of water resources system in Korea Sung Kim SWRRC, KICT

Transcription

1 Methods to assess sustainability of water resources system in Korea Sung Kim SWRRC, KICT

2 Contents Backgrounds Definition of Sustainable Development Natural Variability - Trends of precipitation, runoff, low flow, evaporation, etc. Simple Indicators - Groundwater level, Withdrawal ratio, etc. System Performances - Reliability, Resilience, Vulnerability, System sustainability Conclusions

3 Backgrounds For the sustainable development of national economy and society, stable water supply is essential. Water-related Problems: Water shortage, Water pollution, Flood control, Conflicts among water users Annual precipitation of Korea is varied with large range but the amount of water use is increased over time. Therefore, it is necessary to analyze the states of water management and to announce proper information to secure socioeconomic sustainable developm ents. It is essential to develop an index properly representing the present states. And the index should be easily understandable. Objective of developing the index: Cooperation to solve water-related problems

4 Definition of Sustainable Development To meet the needs of present generation without compromising those of future generations. If we quantify the sustainability, then It is possible to compare alternative plans and policies with traditional ones. It can be considered one of the targets in system design and operation. Generally, Triple Bottom Lines (TBL) consist of environmental soundness, social equity, economic development. One tries to find out the trade-off region. In water resources management, the TBL can consist of water use, flood management, environmental conservation. In this study, we tried to assess the sustainability of water resources management focusing on water use.

5 International comparison Environmental Sustainability Index (ESI) Consists of 5 themes, 21 indicators, 76 variables Korea: 35.9 (2002), 43.0 (2005) Water Poverty Index (WPI) Relationship between water and economic capacity Korea: WPI=62, ranking: 43/147 Virtual Water Trade Total runoff: 70 BCM, Internal Water Footprint: 21 BCM, External WF (Imported): 34 BCM Water Dependency of agriculture sector : about 81%

6 Natural Variability (1): Precipitation The trends of precipitation and runoff is increasing at Soyanggang Dam basin. Problems: The rainy days are decreasing but the storm days ( over 80 mm/day ) are increasing annual runoff annual precipitation depth(mm) ' year

7 Natural Variability (2): Low flow 7-day and 10-day low flows doesn t show any typical trends at Soyanggang Dam basin Q 7 Q 10 Q 15 Q depth(mm) year

8 Natural Variability (3): Volume of standing trees Chang of the volume of standing trees: in 2006, 7 times increased compare to 1973 Forests help to infiltrate rainfall, but also they are one of the water users. 임목축적량 ( 입방미터 ) 600,000, ,000, ,000, ,000, ,000, ,000,000 0 임목축적량변화 506,380, ,830,000 56,440,000 74,470, 년 1973년 2005년 2006년 연도

9 Natural Variability (4): Evaporation The trend of pan evaporation (small size) is decreasing (Chooncheon) Affecting factors: Trend of temperature is increasing, but that of Sunshine duration (hours/day) is decreasing 00 Pan Evaporation(mm) Pan Ev aporation Y ear

10 Simple Indicator (1): Groudwater levels ( The number of National groundwater measurement sites: 320 points (in 2005) Use of groundwater Seoul, Gyounggi Province: over 50% Change of Groundwater levels(112 sites) Decreasing (56 sites), Increasing(37 sites)

11 Simple Indicator (2): Annual withdrawal ratio(paldang) 연취수율 ( ) Annual Water Withdrawal Rati o Year

12 Simple Indicator (3): Water supply available days 년소양강댐 + 충주댐용수공급가능일수 ( 저수용량기준 ) 용수공급가능일수

13 Simple Indicator (4): Efficiency of reservoir operation Indicates the degree of utilizing reservoir storage in a specified period. Soyanggang Dam(Total storage: 2.9 BCM, Effective storage: 1.9 BCM) Max: 1.16, Min: 0.42 Chungju Dam(Total storage: 2.75 BCM, Effective storage: BCM) Max: 2.74, Min: 0.85

14 Comparison of system performances National Water Resources Planning Period ( 66~ 98, 32 years) ( 66~ 03, 37 years) Moving Severe Drought Period (1884~1910) Data Source: 1777~1907 Seoul, Cheukwoogi, quasi-hourly (G-H Lim) 1908~2003 Seoul, Modern equipment (KMA)

15 System performance (1) Significant difference of 43.2% for reliability between National Water Resources Plan s period and the period of including severe drought period

16 System performance (2) Due to the extended droughts for the period B, its resilience was very small

17 System performance (3) The severe drought period has 7.64 times higher water shortage generally than National Water Resources Plan s period.

18 System performance (4) Very stable water supply if the precipitation of National Water Resources Plan period and the expected demand of 2011 is generated.

19 Conclusions To decrease withdrawal ratio or to balance groundwater levels, water resources securing technologies such as conjunctive use of surface water with groundwater, desalination, and water reuse should be applied. Also, Impaired hydrologic cycle owing to rapid urbanization needs to be restored for sustainable water use. It is necessary to develop an integrated index of sustainability. A simple measure may be useful in the aspects of intuitional assessment, but a holistic picture can be obtained by an integrated measure. Model considering Triple Bottom Lines can be adopted to assess the sustainability of water resources management in Korea. When the assessment is accomplished, an adaptation strategy should be established using the results.

20 Specific activities-proposal Document and disseminate the methodology used for the assessment in Russia 1) Review methodologies used for the assessment in RA II and develop a guidelines 2) Organize a workshop for reviewing and applications in RA II Collect information in water use in countries in the region Provide information on shifts in water resources Assessment of sedimentation rates in major reservoirs Collect information about assessment and sedimentation data in major reservoirs

21 Thank you.