H. Zepp et al.: Sino-German symposium on ecosystem services on the River Basin 173

BERICHTE UND MITTEILUNGEN

REPORT ON THE SINO-GERMAN SYMPOSIUM ON WETLAND REGIONALIZATION OF ECOSYSTEM SERVICES IN THE YANGTZE RIVER BASIN

CHANGSHA, PROVINCE, PR , APRIL 10–15, 2005 With 4 figures, 1 table and 3 photos

HARALD ZEPP,VOLKER HEIDT,AXEL THOMAS,WERNER BUCK and GÜNTER MEON

The first task in administering a country is to prevent five disasters: flood; drought; wind; fog and hail; plagues; and fire. Of these, the most serious is flood.1) Guan Zhong, great political figure of Qi, Spring and Autumn Dynasty (770–476 BC)

Zusammenfassung: Bericht über ein Chinesisch-Deutsches Symposium zum Feuchtgebietsschutz und zur Hochwasservor- sorge am Yangtze, China. , Hunan Province, China, 10.–15. April 2005 Das chinesisch-deutsche Symposium diente der gegenseitigen Information und dem Erfahrungsaustausch zwischen Wissenschaftlern, Behörden und Vertretern von Nichtregierungsorgansationen über Hochwasserschutz, nachhaltige Land- nutzung und Feuchtgebietsschutz am Mittellauf des Yangtze. Auf einer Exkursion im Anschluss an die Vortragsveranstaltung wurden den Teilnehmern Demonstrationsprojekte gezeigt, die die Flutung zuvor eingedeichter Polder am Dongting-See um- fassen: Qingshan Polder, Xipanshanzhou Polder and Caishanghu National Nature Reserve. Im vorliegenden Tagungsbericht sind die während der Exkursion mitgeteilten Informationen zusammengefasst. Von den deutschen Teilnehmern wurden die Anstrengungen der chinesischen Wissenschaftler, Behörden und NGOs für den Hochwasserschutz gewürdigt. Während die chinesischen Wissenschaftler vor allem die Bedeutung der Öffnung von Polderflächen hervorgehoben haben, um Hochwas- serscheitelabflüsse zu senken, betonten die deutschen Tagungsteilnehmer die Notwendigkeit integrierter Hochwasseraktions- pläne unter Berücksichtigung der verschiedensten ökonomischen Erfordernisse und ökologischen Belange.

Summary: The symposium brought together Chinese and German experts from various disciplines to exchange ideas and concepts of flood protection, for sustainable land use and on developing wetland ecosystem functions in the middle reaches of the Yangtze River. During a post-conference tour the participants were shown key-areas for wetland restoration in the Dongt- ing Lake area: Qingshan Polder, Xipanshanzhou Polder and Caishanghu National Nature Reserve. Additional data provided during the field trip is compiled in this report. The achievements in mitigating flood hazards by a variety of measures were acknowledged. Chinese scientists strongly promoted the idea that flood peaks can significantly be lowered by opening polders and restoring wetlands, whereas their German counterparts stressed the need for integrated flood action planning taking into account various economic and land use needs as well as ecological functions.

1 Introduction Experts from various disciplines (geography, ecology, economies, water resources management and sociol- The workshop was initiated by Prof. Yu XIAOGAN, ogy) were brought together to exchange ideas and con- Nanjing Institute of Geography and Limnology, Chi- cepts of flood protection, for sustainable land use and nese Academy of Sciences, and Prof. Volker HEIDT, on developing wetland ecosystem functions. The work- Geographisches Institut, Universität Mainz and sup- shop contributions were grouped into five sessions and ported by Sino-German Center for Science Promotion covered a variety of topics from the Yangtze catchment. (NSFC and DFG), . Co-organizers and additional The German contributions focussed on flood protec- sponsors were World Wide Fund for Nature (WWF) and tion and integrated concepts for land use (HEIDT, Hunan Water Resource Department. BUCK,QUAST,ROTHER,MEON) along the rivers Rhine, Elbe and Oder and on sociological aspects of large engineering projects (DOMBROWSKI). In addition, stud- 1) From SEPA/UNEP/UNHABITAT (2004). ies on high resolution climate data modelling in China 174 Erdkunde Band 60/2006

(THOMAS) as well as micro-scale results from hydrolog- the lives of thousands of people. The flood control sys- ical investigations in SE-China (ZEPP) were presented. tem consists of dikes and retention basins. The major The Chinese scientists and officials reported on wet- flood defence along the river consists of the 3,570 km land studies (ZHAO,WANG and ZHU,CHANG,WENG,LI long grand levees north and south of the river, but of and GAO), flood hazards (XU and WANG), ecosystem equal importance are the more than 30,000 km of lev- services (JIANG,YAN, N. and YU,YAN, B., YU), influ- ees along the , riparian lakes and canals, and ences of global change on the upper Yangtze catch- on a local scale, protective walls built by municipalities. ment area (LU and ZHEN), fishery and ichthyology Retention basins also play an important role in the (CHANG and GU), nature protection (YU and ZHANG) flood protection system. Their purpose is to protect the as well as on regional planning (DENG,DUAN,ZHU, grand levees, whose breach would cause damage be- CHEN and MA). cause they protect the 126,000 km2 plain on which 75 During a post-conference tour the participants were million people are dwelling and many industrial hubs shown key-areas for wetland regeneration in the such as Wuhan, Nanjing and are located area. there (WANG a. PLATE 2002). The Dongting and Poyang Lakes play important roles in reducing crest flood discharge of the Yangtze 2 Flood protection in the middle Yangtze region River. Dongting Lake (Fig. 2) used to be China’s largest freshwater lake. During the younger earth’s history The middle reaches of the Yangtze (Changjiang) the lake was dammed by the alluvial sediments of River extend from the Dam near the Yangtze River in the north of the basin area. to Juijiang and cover a catchment area of The Yangtze River supplies the largest portion of the 77,000 km2, including many lakes and rivers total inflow into Dongting Lake through the Songzi, (Fig. 1). The extremely low river gradient and the in- Taiping and Ouchi channels. An additional four rivers flow of numerous tributary rivers contribute to the dan- (Xiangjiang, Zijiang, Yuangjiang and Lishui) contribute ger of flooding. Flood disasters are reported to have to the lake waters entering the lake from the southwest taken place at least from the first century AD. However, and south. The total lake area during summer floods it seems that the floods causing loss of life and consid- was reported to cover an area of 7,000 km2 in the erable damage are now happening more frequently middle of the 20th century, while during winter time the than in the past (cf. Tab. 1 and JIANG et al. 2004). open water surface is restricted to comparably narrow Flood protection of the middle reach has a long tra- channels. dition. The Yangtze River used to inundate many thou- In 1952 the lake was enlarged by a flood retention sands of square kilometres almost every year, claiming basin with 52 sluices at its northern and 32 sluices at its

Fig. 1: The Yangtze River (Jangtsekiang), its tributaries and riparian lakes (source: WANG a. PLATE 2002) Der Yangtze (Jangtsekiang), seine Zuflüsse und Seeflächen (Quelle: WANG a. PLATE 2002) H. Zepp et al.: Sino-German symposium on ecosystem services on the Yangtze River Basin 175

Table 1: Flood disasters in Dongting Lake region (source: HYDRO AND POWER DEPARTMENT OF HUNAN PROVINCIAL GOVERNMENT 1996) Hochwasserkatastrophen im Gebiet des Dongting-Sees (Quelle: HYDRO AND POWER DEPARTMENT OF HUNAN PROVINCIAL GOVERNMENT 1996) Flood disaster Waterlogging disaster year Affected farmland Direct economic Affected farmland Direct economic (104 MU*) losses (108 RMB) (104 MU) losses (108 RMB) 1949 172.4 0.54 325.8 1.40 1952 48.1 0.76 162.6 0.71 1954 385.0 18.17 514.2 2.86 1964 25.1 0.71 355.8 2.93 1965 22.9 2.15 101.0 0.62 1979 19.5 1.72 119.6 0.81 1980 38.6 1.17 307.6 7.61 1983 28.8 1.63 332.5 7.19 1988 22.5 0.99 522 6.79 1991 2.9 0.65 688 2.87 1949–1991 total 971.3 32.13 8054.7 65.09 * 15 Chinese mu equal 1 ha

southern edge. “The mean annual runoff volume of Yichang Luoshan 3 Shashi City JianLi the Dongting Lake is estimated at 301.8 billion m with 78800 the flood waters discharging into the Yangtze River via 71100 The Changjiang River . The mean annual sediment yield into the lake Songzi Notch Chenglinji 3 11030 Songzi River Taiping 1970 Diaoguan is estimated at 129 million m and an average of 100 19610 Ouchi River

3210 Hudu River Ouchi

Notch 57900 million m3 silts up in the lake every year” (HYDRO AND POWER DEPARTMENT OF HUNAN PROVINCIAL Yueyang GOVERNMENT 1996, 1). Figure 2 shows the maxi- mum discharges of Dongting Lake’s major inlets and East outlets. Dongting Lake Wetland reclamation and sedimentation led to a con- stant decrease of the lake’s area: 1825: 6,250 km2, Shimen Jinshi 1935: 4,700 km2,1949: 4,350 km2, 1954: 3,915 km2, 17600 2 2 1958: 3,141 km , 1998: 2,623 km (WWF 2005b, cf. Taoyuan

Fig. 3). Since the 1950s Dongting Lake ranks only sec- 29000 Yuanshui RiverWest Dongting Lake Xiangjiang R. 20300 Changsha ond in size following Poyang Lake in the neighbouring province of . In terms of water volume it is still the largest freshwater body in China. Since 1949 large scale construction (dikes, wetland drainage and recla- Taojiang mation) have led to a total dike length of 5,812 km, 15300 Zishui R. dikes including 3,471 km along the Yangtze and other Fig. 2: Dongting Lake river system: mean annual through- rivers for flood protection and 1,509 km along the flows (m3/s) (source: HYDRO AND POWER DEPART- floodways. The total installed electric irrigation and MENT OF HUNAN PROVINCIAL GOVERNMENT 1996, drainage pumping capacity amounted to 600 MW 4, modified) (HYDRO AND POWER DEPARTMENT OF HUNAN Gewässersystem des Dongting-Sees: mittlere Jahresdurch- PROVINCIAL GOVERNMENT 1996). flüsse (Quelle: HYDRO AND POWER DEPARTMENT In 1998 an extreme flood occurred on the Yangtze OF HUNAN PROVINCIAL GOVERNMENT 1996, 4, ver- River, which resulted in serious flood damage and ändert) 176 Erdkunde Band 60/2006 affected 8 million people. The return period of the reduced the retention capacity for Yangtze floodwater. flood was about 100 years in terms of flood volume. The two lakes retained 65 billion m3 of water and The flood stages in the middle reaches of the river were reduced the peak discharges in the river by 28–56%. even higher than those in 1954 although the flood crest In the middle and lower reaches of the river and in discharge was smaller. the area of the two lakes, dikes of 1,075 polders were The capacity of the Dongting and Poyang Lakes, broken and 321,000 ha of land were inundated, of lakes to reduce the crest flood discharge, was much which 197,000 ha were farmland (WANG a. PLATE smaller than in 1954, and heavy rainfall in the lake 2002). watersheds caused high water levels in the lakes and The main reasons for the high flood levels are the

Fig. 3: Dongting Lake: reduction of lake area between 1825 and 1958 (source: WWF 2005b, modified) Dongting-See: Verkleinerung der Seefläche zwischen 1825 and 1958 (Quelle: WWF 2005b, verändert) H. Zepp et al.: Sino-German symposium on ecosystem services on the Yangtze River Basin 177 much smaller areas available for inundation. In 1954 3 Wetland restoration projects the total diversion of flood volume to detention basins and through levee breaches was 102.3 billion m3.In On a post-conference field trip the participants were 1998 only about 10 billion m3 were retained on flood- shown key localities of wetland restoration projects plains, partly because of fewer levee breaches. Also, the around Dongting Lake. The central Yangtze region is regulating function of the Dongting and Poyang Lakes one of 200 eco-regions worldwide as identified by was much reduced. In the past 40 years sediment WWF. It includes two Ramsar sites (Fig. 4) of wetland deposition and reclamation in the riparian lakes have ecosystems with international significance (WWF 2005a). reduced the lake area, so that in comparison with con- Xipanshanzhou Polder has an area of 110 ha with a ditions in 1954 the volume of the Dongting Lake in population of 580, established in 1972: “Flooding oc- 1998 was reduced by 10.1 billion m3. The flood prob- curred three times between 1996 and 1999 and people lem was aggravated by silting up of the river channel. suffered significant property losses. After the launch of The 1998 flood has given reason to rethink the strat- WWF Yangtze Programme in 1999, Xipanshanzhou egy of flood control of the river. The new strategy rests Polder was chosen as a pilot site for wetland restoration. on the following actions: construction of the Three The farmers moved to higher ground and allow the Gorges reservoir; reinforcing and increasing the height floodwater to flow into the polder. Four years passed, of the levees; conversion of some polders back into and people wasted no time in building dikes and resist- river channels ; increasing the size of Dongting Lake by ing flood. They have learned to breed aquatics” (WWF returning farmland to the lake area to increase its flood 2005b, 2). detention capacity; dredging the main channel of the Qingshan Polder in the Western Dongting Lake cov- river; relocating people from flood detention polders; ers an area of 30,000 ha and is managed by the WWF reclamation and reforestation in the upper reaches as a nature protection area. The former polder had of the catchment area (WANG a. PLATE 2002; SEPA/ been established in 1976 and 5,021 people were settled UNEP/UNHABITAT 2004; ZENG et al. 2002). Follow- thereafter. Repeated floods caused severe damage, and ing the flooding of polder areas wetland reclamation after the disastrous floods in 1996 and 1998 the inhab- programmes have been assisted by WWF China. itants, mostly farmers, were resettled in safer neigh-

Photo 1: Qingshan Polder: Concrete buildings are the remains of the former village. Brick-stone buildings were deconstructed prior to flooding (Photo: BUCK 2005) Qingshan Polder: Die Betonbauten sind die Überreste des ehemaligen Dorfes. Aus Ziegelsteinen errichtete Gebäude wur- den vor der Flutung abgetragen 178 Erdkunde Band 60/2006 bouring areas. The WWF promotes the idea of a land was reached on wetland conservation and a sustainable use concept with different primary functions of the for- use plan by the two sides. In the plan spawning areas mer polder area. 30,000 primarily migratory birds have for fish and water bird habitat were strictly sited, and found their way back to an area where they had not except for the official fish-banning period April 1 – June been sighted for many years. “In 2003 West Dongting 30, an additional fish-banning period for wintering Nature Reserve started to consider co-management birds has been set. From the end of 2003 to the begin- with local communities and dialogue between the two ning of 2004, altogether 180 families participated in parties is focussed on bilateral benefits. An agreement the Co-management Association and a Commission of

Photo 2: Qingshan Polder: Water Bird Habitat (Photo: BUCK 2005) Qingshan Polder: Wasservögel-Habitat

Photo 3: Dwelling mound in the vicinity of Junshan islet (Photo: BUCK 2005) Warft in der Umgebung des Junshan Insel H. Zepp et al.: Sino-German symposium on ecosystem services on the Yangtze River Basin 179

Co-management is formed, composed of 7 members interval of 10 years. Smaller dikes with heights of 34 m including fisherman, NGOs and local Government a.s.l. offer less safety and thus do not fully protect agri- officers” (WWF 2005a, 3). cultural fields and dwellings. Between the Caishanghu In the Eastern Dongting Lake area the Caishanghu National Nature Reserve and the newly built bridge National Nature Reserve was visited. Here a monitoring across the northeastern Dongting Lake to Yueyang, station was set up on the dike to monitor the populations large fields belong to state farms. They stand in contrast of migratory birds. The dike has a height of 36.3 m a.s.l. to the small fields of individual farmers and their fami- and is designed to withstand a flood with a recurrence lies that prevail in the lake region.

Pilot sites: Shasi 1 Xipanshanzhou Polder 2 Quingshan Polder 3 Caishanghu Nature Reserve

ang Y tze R iv e Gongle r

Shishou Jingshi Lixian

er 3 Lixian Riv

East Yueyau Linli Dongting Lake

Datong Lake

Changde 1

Nuping Lake South Dongting Lake Hanshou 2 Yuanyang

Nanpichong River Xiangjin Lake, river Lake, temporary dry Yiyang Polder Yuanjiang Polder for flood defense Taojiang Dyke River Provincial border Highway, road Wangeli

Town, village Changsha

Fig. 4: Dongting Lake: polders, some wetland restoration sites and National Nature Reserve Caishanghu (source: WWF 2005a, modified and supplemented) Dongting-See: Polderflächen, Lage von Feucht- und Naturreservaten (Quelle: WWF 2005a, verändert und ergänzt) 180 Erdkunde Band 60/2006

In the vicinity of the polder the Junshan islet is fa- integrated flood action planning taking into account mous for its green tea. Every year during flood periods various economic and land use needs as well as ecolog- the island (0.96 km2, maximum height 55 m above the ical functions. The complexity of flood protection for lake level) is surrounded by the lake waters covering the sustainable development in the middle reaches of marsh lands. Artificial earth hills rise as safety platforms Yangtze River is so immense that the short visit could within the marsh land in the foreland of the large dikes. not by far illuminate all aspects of the problem. It They are important structures to reduce the risks for is obvious that further research and investigation is human life and properties. As an interesting cross-cul- needed and organizational structures adapted to the tural convergence they resemble the dwelling mounds regional requirements have to be developed. In the on the Friesian coast of northern Germany. future the effects of the and of the river diversion to North China on discharge and mat- ter flux (solid matter and solutes) have to be studied 4 Conclusions thoroughly. The German participants were impressed by the openness of the Chinese colleagues from the The German group was impressed by the huge chal- fields of science and administration to discuss details of lenge the Chinese society has to face in terms of flood water quality issues and the public discussion and con- protection. The achievements of Chinese scientists and troversy concerning large water engineering measures. the administration in mitigating flood hazards by a A complementary workshop in Germany is planned variety of measures was acknowledged. Chinese scien- to introduce the Chinese colleagues to the German tists strongly promoted the idea that flood peaks can be handling of similar challenges and to continue dis- significantly lowered by opening polders and restoring cussions, which are expected to evolve into future co- wetlands. German counterparts stressed the need for operation projects.

References

HYDRO AND POWER DEPARTMENT OF HUNAN PROVIN- China. In: Proc. Institution of Civil Engineers, Water & CIAL GOVERNMENT (1996): Dongting Lake (= informa- Maritime Engineering 154 (3), 177–188. tion brochure). Changsha. WWF CHINA (WORLD WIDE FUND FOR NATURE) (2005a): JIANG, T.; KING, L.; GEMMER,M.a.KUNDZEWICZ,Z.W. Wetland rehabilitation and nature reserve co-management (eds.) (2004): Climate Change and Yangtze Floods. Pro- (= information brochure). S. l. ceedings of a Sino-German Workshop, Nanjing, PR – (2005b): Demonstration Project in Xipanshanzhou Polder. China, April 4–8, 2003. Beijing. (= information brochure). S. l. SEPA/UNEP/UNHABITAT (STATE ENVIRONMENTAL PRO- ZENG, G.; ZHANG, S.; ZHANG, H.; LUO, X.; LU, H.; HUANG, TECTION ADMINISTRATION OF CHINA, UNITED G. a. LI, J. (2002): Research on sustainable strategy for NATIONS ENVIRONMENT PROGRAMME, UNITED flood defence and mitigation of Dongting Lake. In: WU,B.; NATIONS HUMAN SETTLEMENTS PROGRAMME) WANG, Z.-Y.; WANG, G.; HUANG, G. G. H.; FANG,H.a. (2004): Flood Vulnerability Assessment – A Case Study HUANG, J. (eds.): Flood Defence I. Proceedings of the 2nd of Dongting Lake Area. Beijing. International Conference on Flood Defence. Beijing, New WANG, Z.-Y. a. PLATE, E. J. (2002): Recent flood disasters in York.