AA decisiondecision supportsupport frameworkframework forfor thethe riskrisk assessmentassessment ofof coastalcoastal erosionerosion inin thethe YangtzeYangtze DeltaDelta
Li Xing, Zhou Yunxuan, Shen Fang, Kuang Runyuan, Wu Wen, Zheng zongsheng
State Key Laboratory of Estuarine and Coastal Research (SKLEC)
East China Normal University (ECNU)
May 28, 2010| 1 OutlineOutline
1. Objectives 2. Why not Decision Support System (DSS)? 3. Decision Support Framework (DSF) 4. GIS-based risk assessment model 5. Results and summary 6. Challenges & future works
May 28, 2010| 2 ObjectivesObjectives
to develop a 121°E 122°E 02040km
Decision Support N ® or Jiangsu th Ji China ang su 32°N Ya co 32°N Framework (DSF) n ast gt ze R iv er C for coastal erosion ho ngm ing Isl and management in ! !
!
! Changxing ! Yangtze Delta !
! ! Jiuduansha
! Shanghai
! !
31°N ! 31°N to develop a risk !
! ! ! assessment model ! Zhejiang ! East ChinaSea of coastal erosion in Hangzhou Bay East ChinaSea Yangtze Delta 121°E 122°E
May 28, 2010| 3 WhyWhy notnot DSS?DSS?
DSS maintain a popular but obvious antiquated label. The technological and administrative base is still absent for the Yangtze Delta to develop a sophisticated DSS for coastal erosion management. a tool or platform is needed to facilitate the understanding the natural and human-induced coastal behaviors. DSS, as a technical artifact, would not be equal to the task.
May 28, 2010| 4 DecisionDecision SupportSupport FrameworkFramework (DSF)(DSF)
Computer system
Visualization Scenario Application Person toolkit generator
GIS-based Coastal erosion Manager, specialist, risk management plan other stakeholders assessment model
Integrated database
Decision-making output
to provide reference data to promote the effectiveness of decision making to provide analysis models to promote the efficiency of decision making to bridge the gap between scientists and policy-makers and eventually facilitate “coevolution” of human and computer
May 28, 2010| 5 DecisionDecision SupportSupport FrameworkFramework (DSF)(DSF)
Computer system
Visualization Scenario Application Person toolkit generator
GIS-based Coastal erosion Manager, specialist, risk management plan other stakeholders assessment model
Integrated database
Decision-making output
to provide reference data to promote the effectiveness of decision making to provide analysis models to promote the efficiency of decision making to bridge the gap between scientists and policy-makers and eventually facilitate “coevolution” of human and computer
May 28, 2010| 6 GISGIS--basedbased riskrisk assessmentassessment modelmodel
May 28, 2010| 7 DPSIRDPSIR frameworkframework
Driving forces and Pressure Integrated database Extreme climate condition Sea level rise Administrative boundary Coastal topography Coastal topography River damming & water Geomorphology & geology diversion Sediment grain size Land reclamation Surface sediment type Intertidal vegetation clear Indicator system Shoreline change rate Coastal urbanization Tidal range, wave climate Vulnerability and sea level rise State and Impact indicators Riverine sediment Shoreline change trend Impact indicators Historical catastrophic events Development patterns of Coastal protection, Subaqueous delta reclamation Population at risk Infrastructure Infrastructure at risk Land Use/Land Cover Nature reserve at risk Ecological hotspot Coastal flood area Urbanization, demography Leisure and recreation Response Coastal protection measures
The definition of indicator system by DPSIR framework
May 28, 2010| 8 RiskRisk assessmentassessment flowchartflowchart
IndicatorIndicator systemsystem
May 28, 2010| 9 RiskRisk assessmentassessment flowchartflowchart
May 28, 2010| 10 ShorelineShoreline segmentationsegmentation
121°30'E 122°E 32°N 32°N Haimen 1 6 Qidong ® Administrative 25 Unit 1 Unit 2 7 5 boundary 24 4 26 23 3 27 2 Surface 8 Chongming Class 1 Class 2 Class 3 22 sediment type 9 28 Taicang 21
29 31°30'N 31°30'N 33 Coastal 10 31 Type 1 Type 2 Type 3 Changxing 30 characteristics Baoshan 32 11 34 36 Hengsha 3537 Homogeneous 12 38 Pudong 39 units 13 40Jiuduansha 123456 14
15 Sketch map of Shoreline segmentation Nanhui 31°N 31°N
（taken from McFadden et al., 2007） Fengxian 16
17 Jinshan 18
19 0210 040km 20
121°30'E 122°E
May 28, 2010| 11 DefinitionsDefinitions andand datadata sourcessources
Vulnerability indicators Definition Data sources Area Z The percentage of the total area with elevation less than 1:50,000 scale topographic map; Shuttle Radar 2.4m (Z) above the mean sea level in a 5km wide buffer Topographic Mission (SRTM) data with 90m zone landwards from the assessment baseline resolution Coastal slope Average topographic slope (in degrees) in a 2km wide 1:50,000 scale topographic map; Shuttle Radar buffer zone that 1km landwards and seawards, Topographic Mission (SRTM) data with 90m respectively, from the assessment baseline resolution; Digitized nautical chart Average annual deposit Average annual deposit volume in a 2km wide buffer zone Digitized nautical chart volume seawards the assessment baseline Shoreline change rates Average shoreline change rates from 1990 to 2008 Landsat TM images Tidal range Average annual tidal range Key Programs for Science and Technology Development of STCSM (04DZ1209) Significant wave height Average annual significant wave height in a 5km wide Simulated by SWAN wave model based on 11- buffer zone seawards from the assessment baseline year (1995-2005) monthly climatological data set from NOAA/NESDIS/National Climatic Data Center website Relative sea level rise Average relative sea level rise in a 5km wide buffer zone AVISO website seawards from the assessment baseline Intertidal width Average intertidal width from assessment baseline to 2m Digitized nautical chart isobaths Intertidal vegetation type Main vegetation type outside seawalls Landsat TM images Intertidal vegetation zone Average width of intertidal vegetation zone outside Landsat TM images width seawalls
May 28, 2010| 12 RankingRanking ofof thethe vulnerabilityvulnerability indicatorsindicators
Vulnerability indicators (variable) Vulnerability rank Vulnerability indicators (variable) Vulnerability rank ： ：＜ Area Z (X1) 1 0—20 Significant wave height (X6) 1 0.12 Unit: % 2：20—40 Unit: m 2：0.12—0.14 3：40—60 3：0.14—0.16 4：60—80 4：0.16—0.18 5：80—100 5：＞0.18 ： ： Coastal slope (X2) 1 0—0.1 Relative sea level rise (X7) 1 0—3 Unit: degree 2：0.1—0.2 Unit: mm/a 2：3—5 3：0.2—0.3 3：5—7 4：0.3—0.45 4：7—8 5：＞0.45 5：8—10 ：＞ ：＞ Average annual deposit volume (X3) 1 400 Intertidal width (X8) 1 3000 Unit: m3/a 2：100—400 Unit: m 2：1500—3000 3：-100—100 3：500—1500 4：-300—-100 4：350—500 5：＜-300 5：0—350 ：＞ ： Shoreline change rates (X4) 1 150 Intertidal vegetation type (X9) 1 woodland Unit: m/a 2：80—150 2：Spartina alterniflora 3：50—80 3：Phragmites australis 4：20—50 4：Scirpus mariqueter 5：＜20 5：no vegetation ：＜ ：＞ Tidal range (X5) 1 2.5 Intertidal vegetation zone width (X10) 1 400 Unit: m 2：2.5—3.0 Unit: m 2：300—400 3：3.0—3.5 3：150—300 4：3.5—4.0 4：10—150 5：＞4.0 5：0—10 1: minimum vulnerability, 5: maximum vulnerability
May 28, 2010| 13 RankingRanking ofof thethe impactimpact indicatorsindicators
Impact indicators (variable) Impact rank ： Population density (Y1) 1 0—500 Unit: people/km2 2：500—800 3：800—1000 4：1000—1500 5：＞1500 ： Main land use type (Y2) 1 reclaimed intertidal and other unused land 2：green area (e.g. forest, park, etc.） 3：village, agricultural land (incl. farm, aquafarm, etc.） 4：town, industrial land, warehouse land 5：public land (incl. airport, port, reservoir etc.) ： Ecological hotspots (Y3) 1 no ecological hotspots 2：general wetlands 3：important wetlands (e.g. Hengsha shoal) 4：wetland park, science experiment station 5：national nature reserve
1: minimum impact, 5: maximum impact
May 28, 2010| 14 AssignAssign weightsweights
Pairwise comparison matrix and weights for the vulnerability indicators (above) and impact indicators (below) derived by Analytic Hierarchy Process (AHP)
X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 Weight
X1 11 1/2 4528773 0.182
X2 11 1/2 4528773 0.182
X3 5739884122 0.264
X4 1/3 1/3 1/4 7661 1/2 55 0.104
X5 1/7 1/7 1/8 1/6 211 1/5 1/2 1/3 0.023
X6 1/7 1/7 1/8 1/6 211 1/5 1/2 1/3 0.023
X7 1/8 1/8 1/9 1/7 1/2 1/2 1 1/7 1/3 1/5 0.016
X8 1/2 1/2 1/3 3417552 0.119
X9 1/5 1/5 1/7 1/5 322 1/4 1 1/2 0.035
X10 1/4 1/4 1/5 1/5 533 1/3 12 0.051
Y1 Y2 Y3 Weight
Y1 1 5 9 0.751
Y2 1/5 1 3 0.178
Y3 1/9 1/3 1 0.070
May 28, 2010| 15 CalculationCalculation ofof IndexIndex
The Vulnerability Index (VI) was built by calculating the weighted sum of the 10 variables:
n VIjiij w f,1,2,, j m i1
VIj — the VI for the jth homogeneous unit; wi — the weight for the ith vulnerability indicator; fij — the scale for the ith vulnerability indicator in the jth homogeneous unit; m, n — the number of the homogeneous units and the vulnerability indicators, respectively.
May 28, 2010| 16 ResultsResults
121°E 121°30'E 122°E 121°E 121°30'E 122°E
lüsi Port lüsi Port ! !
32°N Haimen ® 32°N 32°N Haimen ® 32°N
Qinglong Port Qidong Qinglong Port Qidong ! ! Qidong Port Qidong Port ! ! Sanhe Port Sanhe Port ! !
Lianxing Port Lianxing Port Chongming ! Chongming !
Nanmengang Nanmengang Qiyakou ! Qiyakou ! ! Beibayao ! Beibayao ! !
Tai cang Baozhen Port Tai cang Baozhen Port Liuhe River mouth ! Liuhe River mouth ! ! ! Xijiagang Xijiagang ! ! 31°30'N 31°30'N 31°30'N 31°30'N
Wusongkou Changxing Wusongkou Changxing Baoshan ! Baoshan ! Wuhaogou Wuhaogou ! Hengsha ! Hengsha Vulnerability level Hazard level Sanjia Port Sanjia Port Very hi gh Pudong ! Very hi gh Pudong ! Jiuduansha Jiuduansha High High Moderate Moderate Low Low Nanhui Dazhi River mouth Nanhui Dazhi River mouth Very low ! Very low ! 31°N 31°N 31°N 31°N
Fengxian Nanhuizui Fengxian Nanhuizui ! ! Luchao Port Luchao Port ! ! Jinshan Jinhui Port Jinshan Jinhui Port Caojing ! Caojing ! ! !
Jinshanzui 0210 040km Jinshanzui 0210 040km ! !
121°E 121°30'E 122°E 121°E 121°30'E 122°E
May 28, 2010| 17 ResultsResults
121°E 121°30'E 122°E
lüsi Port Very high High Moderate Low Very low Total !
32°N 32°N Qidong 10 10 16 100 6 84 84 16 Haimen ®
Qinglong Port Qidong Haimen 100 63100 37 5 ! Qidong Port ! Sanhe Port ! Taicang 100 100 100 4
Lianxing Port Chongming ! Baoshan 100 100 100 3
Nanmengang Qiyakou ! ! Beibayao ! Pudong 100 28 69 72 31 6
Ta i ca ng Baozhen Port Liuhe River mouth ! ! Nanhui 100 23 66 43 34 34 8 Xijiagang ! 31°30'N 31°30'N
Wusongkou Changxing ! Fengxian 100 100 100 5 Baoshan Wuhaogou ! Hengsha Jinshan 49 49 100 51 51 3 Risk level Sanjia Port Very hi gh Pudong ! Chongming 4 4 44 36 24 100 32 28 28 29 Jiuduansha High Moderate Changxing 9 91 9 91 100 10 Low Nanhui Dazhi River mouth Very lo w ! Hengsha 67 39 28 3333 100 5 31°N 31°N Jiuduansha 100 100 100 5 Fengxian Nanhuizui ! Luchao Port ! Jinshan Jinhui Port Caojing ! Total 9 9 7 2116 16 23 21 31 26 33 30 21 20 15 100 ! Jinshanzui 0210 040km ! Distribution in length of vulnerability level (1st column), hazard level (2nd column) and risk level (3rd column) (Unit: %, blanks indicate zero) 121°E 121°30'E 122°E
May 28, 2010| 18 SummarySummary
The results show that the mean of RIs is 45.5%. The values over 50% of RI appear in 17 shoreline segments, amounts to over 35% of the total length of all shorelines in study area. The shoreline segments with RIs being over 60% are mainly distributed in the four districts of Baoshan, Pudong, Fengxian and Jinshan. Moderate values of RI appear in the southern part of Qidong and Chongming Island, most parts of Changxing Island, and the southern part of Nanhui district. And the low values appear in Chongming Dongtan, Jiuduansha, and the North Branch.
15% 7% 16% Very high (>80%) High (60-80%) Risk level Moderate (40-60%) Low (20-40%) 30% Very low (<20%) 32%
May 28, 2010| 19 ChallengesChallenges && furtherfurther worksworks
To develop some models for predicting coastal erosion, especially for muddy coasts, and coastal risk assessment method based on prediction models… To seek public participation by means of Internet-based technologies… To develop On-line Real-time Assessment (ORA) technology and web-based decision making…
May 28, 2010| 20 Thanks!Thanks!
May 28, 2010| 21