URBAN HYDROGEOLOGY IN KARST REGIONS OF CHINA

1. URBAN HYDROGEOLOGY IN KARST REGIONS OF CHINA Yuan Daoxian Karst Dynamics Laboratory, MLR,Guilin China University of Geosciences,Wuhan

2. Contents * Introduction:Urbanization in China * Functions of Cities in Karsts of China * Urban Hydrogeological & Environmental Problems * Concluding Remarks

3. I, INTRODUCTION: URBANIZATION IN CHINA *1980s: medium size cities: from 180 to 400 *2000: 666, 32 having population more than a million *Urbanization as a strategic measure : for economic development; to reduce the differences between developed and poor regions

4. II, FUNCTIONS OF CITIES IN THE KARST OF CHINA • Karst in China(including buried and covered karst): 3,463,000 km2 , i.e, 1/3 of its territory • Exposed karst: 907,000 km2

5. Fig.1, Exposed karst in China

6. Provincial Capitals: • Jinan,Shandong province • Taiyuan, Shanxi province • Kunming, Yunnan province • Coal Industrial Cities: • Jiaozuo, Henan province • Zibo,Shandong province

7. Fig2, Big Karst Springs in North China

8. Industrial centers • Zunyi, Guizhou province • Liuzhou, Guangxi province • Agriculture • Most of the medium and small size cities are based on local agriculture,but some of them enjoy special products, such as: • Sugar cane: Guigang,Guangxi  • Tobacco : Menzi,Yunnan province

9. Fig.3, Exposed Karst in Southwest China

10. Fig.4, Menzi Basin • Chile pepper: Qiubei,Yunnan province

11. Fig.5, green house nursery of chile pepper • Grape & Wine: Mile,Yunnan

12. Fig.6,Grape yard in Mile county,Yunnan • Herb Medicines:Wenshan,Yunnan

13. Fig.7, Nursery for Panax pseudo-ginseng var. notoginseng

14. Mineral Deposits • Cassiterite: Gejiu,Yunnan • Dachang,Guangxi • Lead-Zinc: Siding,Guangxi

15. Fig.8, Surface collapses around Siding City, induced by dewatering in the underlying lead-zinc mining tunnels

16. Tourisms • Fig.9,Stone Forest, Lunan,Yunnan • Fig.10, Tropical Karst, Guilin, Guangxi • Fig.11,Jinci Karst Springs,Taiyuan, Shanxi

17. Fig.9,Stone Forest, Lunan,Yunnan

18. Fig.10, Tropical Karst, Guilin, Guangxi

19. Fig.11,Jinci Karst Springs,Taiyuan,Shanxi ,North China

20. III, URBAN HYDROGEOLOGICAL &ENVIRONMENTAL PROBLEMS • The exploitation of natural resources (water,land,mineral deposits, coal, and touristic attractions) benefits the urbanization of karst regions. But hydrogeological and environmental problems,even geological hazards may happen when there is an ignorance of scientific management, which need a good understanding on the karst hydrological system.

21. Coastal Cities • Sea water intrusion in coastal regions of Dalian city,Liaoning province,NE China • Fig.12,Karst geological section across Dalian city

22. 1,caves; 2,coastal erosion cavities; 3,coastal erosion columns; 4,through cave; 5,coastal erosion platform;6,coastal springs; 7,submarine karst springs; 8,S, S1, S2, coastal terraces • Fig.12,Karst geological section across Dalian city

23. Fig.13, A view on the eastern coast of Dalian,Liaoning,NE China

24. Cities in the Karst Lowland of Eastern China • Over extraction of groundwater brings about drying of karst springs with touristic attraction:e.g,Jinan, Shandong province • Fig.14, Karst hydrogeological cross section of Jinan city • Fig.15,Karst hydrological variation in Jinan city during the past 40 years

25. Fig.14, Karst hydrogeological cross section of Jinan city

26. Fig.15,Karst hydrological variation in Jinan city during the past 40 years (Xi Deyin,1988) • 1,precipitation; 2,spring flow;3,water table;4,amount of extraction in urban area;5,sum of extraction and spring flow

27. The Baotu Spring and more than 70 other karst springs which used to flow out around downtown Jinan city,with a total discharge of 300,000 to 350,000 m3/day before 1970s. • Stopped flowing when the extraction from the Ordovician karst aquifer underlain the city was more than 270,000 m3/day.

28. *A karst collapse happened in Tai’an city,January,1979,right below the major railway between Beijing and Shanghai. • Fig.16, karst collapses in Guizhou and Guangxi

29. Fig.16, karst collapses in Guizhou and Guangxi

30. Cities on the plateau karst, middle of China • Shanxi province,North China • Permo-Carboniferous coal measures, the most important energy source of China,are overlying the major karst aquifer (Cambrian-Ordovician) • Fig.17,Schematic hydrological profiles showing the general relationship between karst aquifer and coal measures in North China

31. Fig.17,Schematic hydrological profiles showing the general relationship between karst aquifer and coal measures in North China (Han Xingrui,1994)

32. The development of coal industry brings about pollution to the underlying karst aquifers, the major source of urban water supply.

33. Southwest China Karst Plateau • Cenozoic uplift,and development of underground karst drainage systems bring about:-- • Fig.18,Hydrological profile of Menzi Basin, a typical example to show the relationship between land , cities and underground streams

34. Fig.18,Hydrological profile of Menzi Basin, a typical example to show the relationship between land , cities and underground streams

35. *WATER SOURCE PROBLEM • Land and cities are usually distributed on the denudation surfaces of different altitude, but underground streams are dozens to hundreds meters below land and cities. How to find enough water to support the city development is always a challenge.

36. *FLOOD PROBLEMS • When underground streams are not able to drain away excess storm water, flood happens on the surface • Fig.19, Hydrogeological section of Gejiu city,flooded in 1954 • Fig.20, Flood in Sanshi polyje, Donglan County, Guangxi

37. 1.Metamorphic rock; 2.Granite; 3.Karstified limestone; 4.Argillaceous rock • Fig.19, Hydrogeological section of Gejiu city,flooded in 1954

38. Fig.20, Flood in Sanshi polyje,Donglan County,Guangxi

39. *POLLUTION • Fig.21,Shuicheng city,Guizhou,1800m asl,polluted waste water from coal mining,and steel manufactory draining into underground streams

40. 位置 COD BOD5 Phenol CN- As Cd Cr6+ Pb NO3- 水钢出口 1.68 1.54 22.4 0.22 0.68 0.9 0.15 1.26 1.26 落水洞(1983年) 0.66 0.37 4.1 0.06 0.14 0.24 0.90 0.30 0.12 落水洞(1990年) 1.91 0.51 14.1 2.79 0.14 1.14 3771 0.50 0.48 窑上水库 0.2 0.45 0 0 0 0 0.18 0.04 0.1 • Fig.21,Shuicheng city, Guizhou, 1800m asl, polluted waste water from coal mining, and steel manufactory draining into underground streams • (Yao Chenghong,2002)

41. IV, CONCLUDING REMARKS • For sustainable development of water resources in urban areas of karst in China,it is necessary:-- • 1, to get a better understanding on karst hydrological systems with respects to coastal, lowland and plateau areas of China;

42. 2,to take into account protecting scenic attractions and ground stability while exploiting resources. • Fig.22, The relationship between Boyue Cave system,Hunan and the coal measures underlain

43. 1,Middle-Lower Carboniferous limestone; 2,Lower Carboniferous coal measures; 3,Lower Carboniferous Limestone • Fig.22, The relationship between Boyue Cave system and the coal measures underlain

44. 3, to address properly the relationship between landuse planning/management and karst aquifer protection • Fig.23, Landuse along the Baiyandong underground stream,Baojing,Hunan

45. Fig.23, Landuse along the Baiyandong Underground stream,Baojing,Hunan

46. 4,to carry out vulnerability assessment and mapping for karst aquifers • Fig.24,Vulnerability map of karst water in Houzai underground stream,Puding, Guizhou

47. Fig.24,Vulnerability map of karst water in Houzai underground stream, Puding,Guizhou

48. Thank you for your attention!