Water is life. Kunitoshi Sakurai, Ph.D Professor Okinawa University

Transcription

1 Water is life Kunitoshi Sakurai, Ph.D Professor Okinawa University

2 Millennium Development Goals Millennium Development Goals (MDGs) To reduce by two thirds child mortality by To reduce by half world population without access to safe drinking water and basic sanitation by Benchmark year = 1990 Target year =

3 Definition of Access Access means that. 20 liter/capita/day of safe drinking water is available within 1 km distance from people s residence. Basic Indicators Life Expectancy MDG Child Mortality MDG Population with (years) (per 1000 live Improved Access to 2005 births) Drinking Water (%) Japan Samoa Tonga Fiji Solomon Islands Vanuatu PNG Source: Human Development Report 2007/2008

4 Impacts of Climate Change 20 years have passed after Rio s Earth Summit where UNFCCC was adopted. Global warming will make pacific island countries very vulnerable to natural disasters such as hurricanes and tsunami. THREE FACTORS Sea level rise is taking place. Coral reef, our natural breakwater system, is now severely damaged. The size of hurricanes/typhoons is increasing.

5 Big Question; Is it possible for us to hand over this pristine sea unspoiled to next generation? Experts predict that beaches in Okinawa will completely disappear if 59cm sea level rise (maximum under IPCC s A1FI scenario) happens. What can we do in Okinawa if white sand beaches disappear? Tourism, the main industry of Okinawa, will be severely hit. Change of Average Sea Level in Naha, Okinawa (m) 11.8 約 40 cm 年間に rise in 11.8cm 40 years 上昇 (year)

6 Asahi Shimbun September 10, 2008 High seawater temperature is causing bleaching of coral system. Brown algae escapes from coral when sea water temperature is higher than 28. This is the cause of bleaching. In Sekisei Coral Sea, 70% of coral disappeared in 5 years. Round table coral is falling apart in Sekisei Coral Sea, Aragusuku Island, Okinawa.

7 0% ~ 5% Change of percentage Aragusuku Island of live coral in Sekisei Coral Sea Source: National Institute of Environment Ministry of Environment Over sizing of typhoons

8 Large scale typhoons are forecasted. Hurricane Katrina in 2005 had minimum barometric pressure 902hPa, and maximum wind speed 78m/s. It caused a serious disaster in Louisiana with more than 1,700 deaths and more than one million refugees. (%) Percentage of typhoons/cyclones/hurricanes in each category Strong typhoons are increasing. years

9 Case of Tongatapu Vulnerability Assessment: Tonga A sea level rise of 1 m could affect 10 km2 of land and 9,000 people. Nuku alofa could be isolated as a small island.

10 Temperature Rise : / 10 years Y = X deg C Change of Average Temperature in Tongatapu (1949~2005) Sea Level Rise at the pace of 8.8mm/year Mean Sea Level (m) Change of Sea Level in Tongatapu (1993~2007)

11 Y = X mm Change of Annual Precipitation in Tongatapu (1945~2005) Average ~ 1,700mm El Niño (1983) 832mm La Niña (1999) 2,540mm mm Relationship between El Niño Phenomenon and Precipitation in Tongatapu (1945~2005)

12 Number of Cyclones 60/69 70/79 80/89 90/99 00/08 Number of Cyclones in Each Decade in Tongatapu Source Domestic Water Sources in Tongatapu Water Supply Facilities Urban Water Supply No. of Households % Village Water Supply No. of Households % Groundwater Piped Water 4, , Rainwater Storage Tanks 2, , Others Personal Wells and Others

13 Mataki Eua Group Wells Developed Fresh Water Lens Fresh Water Lens Seawater Intrusion Area Max 20m Limestone 130~250 m Fragmented Volcanic Rock Fresh Water Lens in Tongatapu Island Impacts of Climate Change on Water Resources Most coral island countries depend on rainwater as water resources. As geologic stratum of these countries is formed by limestone with high penetrability, precipitation does not flow into rivers but forms a freshwater lens under the ground. The rise of water levels due to sea level rise will make this lens thinner and reduce the available amount of fresh water. In addition to this phenomenon, these countries will experience great impacts on their water resources if precipitation decreases as a result of climate change.

14 Scale down of Fresh Water Lens will take place due to: Decrease of Recharge Sea Level Rise Sea Level Rise Decrease of Land Area Decrease of Recharge 1 m Sea Level Rise Submersion under Water 21.3 km2 (30.3 km2 in Case of Cyclones) Scale down of Fresh Water Lens Prediction for 2050 Decrease of Precipitation by 10% Decrease of Groundwater Recharge by 30% Prediction for 2010 Decrease of Precipitation by 17.5% Decrease of Groundwater Recharge by 32%

15 Chlorine Ion (mg/l) Average Change of Groundwater Salinity in Tongatapu (26 wells) Increasing Salinity in Tngatapu Village Waters (1966~1999)

16 Adaptation Measures to Climate Change in the Field of Water Resource Management (National Communication, 2005) Measures Water Resource Management Contents Control of Leakage Awareness Raising about Water Saving Increase in Water Rates Introduction of Water Saving Instruments Development of Alternative Water Sources Pollution Control of Groundwater Desalination of Seawater Prevent Salinity Increase Caused by Excessive Pumping Introduce Land Use Control to Prevent Groundwater Pollution Caused by Soil Pollution Familiarize Compost Toilets Familiarize Waterless Toilets Protect Fresh Water Lens by Controlling Seawater Intrusion through Coastal Erosion Prevention Measures Because of High Operation Cost, Only in Case When the Use of Fresh Water Lens or Rainwater is Impossible Migration of People Transportation of Fresh Water Last Resort of Adaptation Measures Only in Case of Emergency because of High Cost Fresh water lens in Tonga was polluted by pesticides through squash cultivation.

17 Water Resource Problem in Okinawa Water resource is scarce in Okinawa. Fukuchi Reservoir (Okinawa Times, May 8, 2002)

18 Okinawa tight water supply island Rainfall in Okinawa Rainfall in Mainland Japan 2000mm/year > 1600mm/year However, Okinawa is the prefecture that suffers the severest water shortage in Japan. Why????? Short and steep rivers, and high population density Rooftop Rainwater Pond Okinawa Univ. is very active in the use of rainwater.

19 Okinawa Univ. s Wastewater Treatment Plant Wastewater is treated for re use purpose although discharge into Naha City s sewer is possible. Rainwater and effluent from the treatment plant are used to flush toilets.

20 Notice in toilets on the use of rainwater and treated wastewater This notice is to promote environmental education in Okinawa Univ. The late Prof. emeritus Jun Ui, the designer of the plant, gave lecture on water resource problem in Okinawa.

21 Protection of Groundwater in Miyako Island 南西諸島の分類 - 高島 と 低島 の別 高島 の地質は比較的濃い色 低島 は薄い色で示される Let s study a little about Miyako Island s groundwater problem. 西表島 石垣島伊良部島多良間島 久米島 伊是名島 伊平屋島 沖永良部島 徳之島 奄美大島 宮古島 沖縄島 与論島 喜界島 Miyako Island Okinawa Island

22 Miyako Island Area:158.9km 2 Population:47 thousands Rainfall:2,000mm/year Av. Temperature:23.4 Maximum Height:115m Sugar cane field:58km 2 Cattle:14 thousands Irabu Town Groundwater in Miyako Island Ryukyu Limestone About 40% of rainwater goes to groundwater. Shimajiri Mudstone

23 Underground Dam Ryukyu Limestone Shimajiri Mudstone Groundwater Fault Geology and groundwater supply mechanism in Miyako Island Rainfall Mountai 山岳 森林 n Forest 湖沼 ダム Lake/Dam Groundwater 地下水 River 河川 後背山地のある地域 Area with mountainous : 集水域 生活空間 hinterland : Catchment Area 生 Living 活 Space 空間 Living Space Rainfall Living Space Groundwater 地下水 低平な島嶼地域 : 集水域 Catchment Flat Island : = 生活空間 = Area Living Space

24 Heavy Rain High Temperature Intensive Agriculture Organic N Inorganizatio n NH + 4 Inorganic N Nitrification NO - 2 NO 3 - NO Flat Topo Shallow and Aerobic Soil Highly Porous Geology Eluviation 図 These ( conditions 高透水性地質 + observed 低平な地形 + 浅薄土壌 in Miyako + 集約的農業 Island + 高温多雨 is quite ) likely 条件は硝酸態窒素による地下水汚染を引き起こし易い to cause groundwater pollution by nitrate N.. Nitrate Nitrogen mgl -1 Drinking Water Standard 4 2 y=-0.106x R 2 = Change of Nitrate N Concentration in Miyako s Groundwater 図宮古島の地下水硝酸態窒素濃度の推移 1966 年の値は琉球政府の調べた 21 地点の分析結果を示した.1989 年以降 (1993 年を除く ) は宮古 島全域の 13 地点から毎月採水された地下水中の硝酸態窒素濃度の年度別平均値を示した. たて棒は 13 地点中の最大 最小平均値. 1966: Average of 21 points. 1989~2003 : Average of 13 points.

25 14 mgl Drinking Water Standard 図伊良部町における地下水中硝酸態窒素濃度の推移 フナハ井戸 井 5 井 8 井 7 伊良部浄水 伊良部北区 BG 海洋センター 浄水場施設内 伊良部着水井 Change of Nitrate N Concentration in Irabu s Groundwater Land Use in Miyako Farmland Urban Area Forest

26 Human Origin 生活系 Natural 自然系 159t(8.3%) Origin 228t(11.8%) 畜産系 Livestock 684t(35.5%) 耕種系 Farm 855t(44.4%) Total N 総窒素量 :1,926t 宮古島に投入された年窒素量 年度 Total Nitrogen Input into Miyako Island (1998) Human 生活系 Origin 157t(16.4%) Natural Origin 自然系 159t(16.6%) 畜産系 Livestock 302t(31.4%) 耕種系 Farm 342t(35.6%) 総窒素量 Total N :960t 宮古島の地下水に負荷された年窒素量 - Total Nitrogen Loading to 1998 Groundwater 年度 of Miyako Island (1998)

27 In Miyako, where the rain goes? Ultimately almost all rain goes to sea. Ryukyu Limestone Shimajiri Mudstone Coral For Local Socio economy Tourism Seafood Recreation Coral Ecosystem System adapted to oligotrophic sea area Impact of eutrophic groundwater (high nitrate N)?

28 Seashore Affected by High Nitrate N Groundwater Southern part of Okinawa Island Stockholm Junior Water Prize In 2004, 3 high school students from Miyako were awarded Stockholm Junior Water Prize.

29 When three high school students at Japan s Okinawa Prefectual Miyako Agriculture and Forestry High School started a water related research project, their goal was to find a way to recover and protect groundwater which has been made nearly unusable because of chemical fertilizer used to grow sugarcane. They developed an environmentally friendly, organic fertilizer as an alternative to commercial fertilizers. Combined with proper management, the organic fertilizer not only gives Miyako island s farmers the ability to reduce the nitrate contamination, it even recycles phosphorus accumulated in the soils. Appropriate Technology Water & Wastewater

30 Inappropriate Management of Grey Water in Nicaragua Conditiones of Appropriate Technology Technical Aspects e.g., Compatibility with natural conditions Financial Aspects e.g., Affordability of service users Economic Aspects e.g., Desalination vs. wastewater treatment Socio Cultual Aspects e.g., Who collects water in the community?

31 Attention!!! Advanced technologies and/or large scale technologies are not necessarily appropriate! Technologies appropriate for Japan may not be appropriate for other countries!!!! Example of Appropriate Technology In water scarce area, water used for bathing is reused for animals (cows and goats) drinking purpose. Cascade Use In Rural Area of Myanmar by M. Araishi

32 Don t forget!!! If we use water, we generate wastewater! If we do not treat wastewater properly, it will pollute our valuable water resources. If we avoid water over consumption, we can reduce the amount of wastewater to be treated and the cost for its treatment. We can shoot two birds with proper wastewater treatment!!! The first bird is the protection of water resources from pollution. The second bird is the acquisition of stable water resources for miscellaneous purposes. Wastewater is a stable water resource even in the case of drought.

33 Okinawa Univ. s Wastewater Treatment Plant Wastewater is treated for re use purpose although discharge into Naha City s sewer is possible. Rainwater and effluent from the treatment plant are used to flush toilets.

34 Notice in toilets on the use of rainwater and treated wastewater This notice is to promote environmental education in Okinawa Univ. University s contribution to local economy and environment Prof. Ui was observing low cost piggery wastewater treatment plant designed by him. Pig farming is one of the main industries in Okinawa.

35 Okinawa Type Batch Oxidation Ditch Inlet for wastewater Outlet for supernatant Wate rwhe el Wate rwhe el Pond Partition Wall Outlet for sludge Designed by Prof. Jun Ui. Operation of Okinawa Type Batch Oxidation Ditch Intake of wastewater Aeration by water wheel Discharge of supernatant Stopping of water wheel and settling

36 Leveling the ground first Kinjo family in Okinawa built a batch type oxidation ditch themselves. Construction of a pond by blocks and concrete Finished ditch Effluent and sludge are used in nearby vegetable farms as liquid and solid fertilizers with good production increase. Oxidation Ditch Hotel Kitano, Apia Samoa Feb. 2000

37 Compost Toilet in Robert Stevenson Park Apia, Samoa Compost Toilet in Samoana Resort

38 Let s achieve the goal of Healthy Islands through joint efforts! Thank you for your attention. fin