China Working Group Annual Report of IGCP513
“ Karst Aquifers and Water Resources ” in 2005
(Institute of Karst Geology, CAGS, Karst Dynamics Laboratory, Guilin 541004)
1. Major results of Project
Progresses of project IGCP513 achieved in the year 2005 in China could be summarized in line with the 4 objectives of the Project.
1) Relation of hydrology to the function and health of karst ecosystems;
To probe an indicator to reflect restoration and reconstruction success for kart ecosystem, epikarst springs under different ecological successional stages in Guangxi and Guizhou provinces were chosen to carry out vegetation investigation and automatic monitoring of water chemistry (Xie yunqiu, Jiang Zhongcheng et al. 2005) . The contents of Ca2+ , HCO3- ,etc., at shrub cluster stage in Guilin, Guangxi have been increasing as years. Spring Landiantang at secondary forest stage has stabler low, shorter time without water and higher contents of Ca2+ , Mg2+ , HCO3- ,etc.,compared with Spring Dongwang at shrub cluster about 1 km away. No.1 spring under summit stage at Laqiao, Maolan National Nature Reserve in Guizhou, the member of Man and Biosphere Protection Network, has been flowing from the start to the end of a year, but No.2 spring at shrub stage has small flow and often stops flowing in dry seasons or in rainy seasons without rain for a long time. From karst shrub cluster to karst secondary forest and up to karst primary forest, dissoluble organic carbon in epikarst spring adds continually, which just reflects the vegetation recovery. With the method of space substituting for time, as karst ecosystem's texture restores, epikarst spring has long, short time without water and finally always flows with continued increase of soluble ions. So, epikarst spring can indicates the situation of karst ecosystem, and has great importance in drinking and irrigating.
For understanding soil nutrient loss characteristics under different precipitation at karst area in Southwest China, the Nongla karst dynamic system monitoring site, situated at E 108o19' N 23o29', was studied(Li Qiang, etal. 2005). Because of the double-layered surface and subsurface structure at karst area, rainfall rapidly penetrates into ground and forms spring or underground water. Therefore, by monitoring the hydrochemical variation of local spring, the soil nutrient loss characteristics can be known under different precipitation. In accordance with the reason, high-resolution measurements of rainfall, K+ and NO3- variation of Landiantang spring were recorded by using data logger with time interval of fifteen minutes from Aug. 5 to Aug. 7 in 2003 at Nongla, Mashan county in Guangxi Province, China, which is scarcely disturbed by man.
From the result, it can be seen that the contents of K+ and NO3- in Landiantang spring rapidly increased under different precipitation and the content of K+ and NO3- in the spring had the positive correlation with the rainfall. According to the result, it can be known that the precipitation is the main factor that leads to the soil nutrient loss at karst area. Moreover, the content of NO3- in the spring had the different rule from K+ and continued increase for a long time. The reason is that because of nitrogen mainly existing as NO3- -N in the soil at karst area, the NO3- still can be lost for a long time undergoing eluviation, even when it stops raining.
Therefore, it can be concluded from the result that precipitation not only will bring the problem of nutrient loss at karst area, which will accelerate the process of soil erosion and rock desertification, but also can produce some environmental problems, if presents cultivate at the replenishment region of spring or underground water.
2) Water supply in karst regions;
Jiang Guanghui and Guo Fang(2005) discussed the different effects of rainfall recharge for epikarst in karst forest. Rainfall less than 5mm in dry season don't result in the recharge for epikarst; rainfall less than 5mm only results in weak recharge when it rains in 24 hours before this rainfall; rainfall greater than 5mm or continuous rainfall can make obviously recharge for epikarst. The hinder for rainfall recharge is the protection layer of epikarst: vegetation layer and soil layer. The protection layer take an important part in the condition of dry season or little rainfall. We can estimate the recharge effect by monitoring and analyzing the lag time of water level, water temperature, EC(Electric conductivity ) and their variation.
Corrosional hill region mainly distributed in central part of Hunan Province, China, and also scattered thinly in mountainous Fengcong (peakcluster) area in Hunan, Guizhou, Guangxi and Sichuan Provinces, etc.. Each stratum from middle Proterozoic Erathem to Quaternary has its outcrops in the area. Karst is well- developed in carbonate rocks from Devonian System to middle Triassic System, abounds with karst water which has a considerable exploiting prospects. Karst water system in the area featured multi-massive and multi-layer structure(Pei Jianguo, 2005). Fissure-cave type is the major water-bearing media. Karst water hydraulic field is characterized by high non-sequence flow, whereas it doesn't have a unified flow. Karst water regime, which has a short time lag, is very sensitive to precipitation and changes almost synchronously. The key premise to shaking off poverty and sustainable development for karst stone-hill area is the solution of water problem. Karst water exploitation and utilization should be carried out with local condition, in conjunction with varied exploiting methods, such as reservoir, draw and channel, pumping, pounding, drainage, etc., and mid-small scale projects should be considered with scatting distribution, artesian running-way.
3) Water-related environmental problems in karst regions;
Subterranean river is an important reservation and movement location for karst water resources in Southwest China, and important water source for the local people. The water quality of subterranean river not only affected the people's health, but also an important factor affected the water sustainable development of karst area in Southwest China. Long-term auto-monitor for subterranean river, measuring the index which sensitivity to environment change such as pH, EC, water temperature, HCO3- and Ca2+ in the scene, observation once a month and in flood process, especially in fertilization season adding density observation are approaches to explore the water quality change discipline in southwest karst area.
Guo Fang, Jiang Guanghui(2005) studied the change disciplinarian and trend of major ions concentrations in Guancun subterranean river, Rongan County, Guangxi, China. Bases on the pre-study, They found NO3- 、 SO42- 、 Cl- 、 K+ are the most important observation objects. According to study for about a year in Guangcun subterranean river, it shows that except for the precipitation, the agriculture activity is also a major factor affected water quality. K+ 、 NO3- 、 SO42- 、 Cl- are affected by fertilization obviously. In the past two decades, NO3- concentration increase heavily; the variety of SO42- is very complex, it need longer time observation to explore it's discipline; Cl - rises a little; the contents of K+, Na+ have no obviously change; Mg2+ is likely to rise; HCO3- and Ca2+ have no change. They suggest that strengthen the protection of karst aquifer, use the fertilizer in reasonable, at the same time we should enhance the mechanism study of water quality of subterranean rive by human activity.
He Shiyi and Zhou Jinzhong(2005) gave a comparative analysis on the resources characters of karst underground rivers systems in both of Dalongdong, Xiangxi, Hunan and Poxin, Fengshan County, Guangxi. The elementary project or suggestion to the development of the resources are discussed according to the hydrogeological condition, main society demands and regional predominance of resources. The survey indicates that the predominant hydrogeological condition and high social and economical benefits in Dalongdong system is suitable to construct a reservoir. Relatively, the study and reasoning emphasizes particularly on to ascertain the drainage boundary, main karst seepage, water quality and quantity and so on.
Drought in karst mountain area and inner flooding in the boundary polijies is the main environmental problems in Poxin karst underground system, where the underground water table is more than 100m below the surface and the hydraulic gradient of the underground river is 0.3~0.4%. The input of sand and mud from shale areas surrounding has induced the filling up in the drainage passages of the underground system, as a result, the inner flooding takes place frequently during the raining seasons in the meet areas of limestone and shale. Therefore, the main engineering measures to manage to resolve the flooding problem in Poxin area is to find and dredge the “bottle neck” drainage passage on the base of cave exploration. Moreover, some aspects, such as the reasonable development to epikarst springs in mountain areas for drinking water, small barrages building in the valleys up streams in the shale area to farthest hold up the movement of sand and mud , monitoring to the water and soil lose, and emphasis on the management of mining, are important measures to synthetically renovate environment in this area.
4)The impact of land use change on groundwater quality
Jiang Yong-jun(2005) studied the impact of land use change on groundwater quality in a typical karst agricultural region of Xiaojiang watershed, Yunnan . They analyzed the land use changes from 1982 to 2003, and assessed the effects of land use changes on groundwater quality of Xiaojing watershed, a typical karst agricultural region, of Yunan province, southwest China . The results indicates: (1) The total land use transform covers 610.12 km 2 , of which 134.29Km 2 of forestland were transformed into cultivated land, and 210Km 2 of unused land was transformed into cultivated land during the past 20 years in Xiaojiang watershed. (2) The rapid growth of population and the economic development were the main driving forces of cultivated land change, and the comparative economic benefit and the macro-policies such as ecological and environmental protection were important driving forces of forestland change in Xiaojiang watershed during the past 20 years. (3) There was a dynamic relation between the groundwater quality change and the land use change.The groundwater quality change is related to the non-point pollution of using fertilizer and pesticide brought by the increasing of cultivated land and the degeneration of eco-environment bought by the worsening of forestland quality. As forestland and unused land transformed into cultivated land, the total hardness, total alkalinity, pH, and the concentration of NH 4 + ,SO 4 2- , NO 3 - , NO 2 - ,Cl - in the groundwater increased obviously, but the concentration of Ca 2+ and HCO 3 - in the groundwater declined obviously.
Therefore, based on the watershed served as research unit, the research of land use change and its effects of hydrogeology environment are very important to protect the resources and environment of karst region.
5)Research on evolution of karst water system and global changes
Ma Teng et al.(2005) studyed the evolution rule of karst water systems of Shanxi Province.From the 20th century, the global environment deteriorated rapidly, and the global change study whose major content is the research on environmental change has become the hottest topics for geosciences and environmental science studies. Several international programs such as IGBP, WCRP, IHDP, and DIVERSITAS had been set up to investigate the rule of environmental evolution in different timescales, discover the cause of environmental change, discern the natural evolution process of environment and the effect of human activity on it, evaluate accurately the effect of environmental change, and forecast the environmental state of this century and the future.
In the light of the deficiency of global water resource, the research on the response of water resource to global change, especially to global environment change has come to extensive attention. Groundwater is not only the important water supply for human being, but also the essential support to ecological system. Thus, the studies on groundwater and global change are both urgent and significant. There is a population of about 1000,000,000 in the karst regions where are the important living environment for human being. But the ecological systems in karst regions are very vulnerable, the effect of climate change and human activity on it being very markedly and the damage in different degrees of karst water systems being detectable. In view of above situations, the research on karst water system evolution and global change is very necessary.
In this book, the indication and response of karst water system to global change have been elaborated based on the research on karst water system evolution and global change. The study basis of this book is that karst waters are both the information carrier and receiver of global
change. The indication of karst water to global change, especially climate change comes from the flowability of groundwater and the water-rock interaction. In view of its function of “palaeoclimate record”, karst water has been the new information carrier of climate change after
ice cores, loess, marine sediment, sporopollen, and treering, which changes the view of groundwater studies significantly, namely groundwater had been regarded as the information reservoir, instead of fluid. The existent study results were summarized in this book, which show
that physical indexes (such as groundwater level and spring discharge) and chemical indexes (such as the storage of 14C、4He, 39Ar, 81Kr,226Ra, the disequilibrium of 234U/238U, and 36Cl, 87Sr/86Sr, noble gas, 13C, Mg/Ca, Sr/Ca, Na/Cl and some trace elements) of groundwater and karst sediments (such as stagmalite, travertinee, and calcite vein) can indicate the environmental changes in different timescales effectively.
In this book, the evolution rule of karst water systems of Shanxi Province in geological, historical, and instrumental record timescale were studied in the case of Niangziguan spring and Shentou spring that are the famous big karst springs in northern China using karst sediment
analytical method, historical literature analytical method, comparison analysis method and time series analysis method, which can discover the driving mechanism of geological, climate and human activity factor to karst water evolution in above timescales, discern the natural evolution
and human activity affecting process of karst water system, and forecast future climate change and evolution trend of karst water system under the effect of human activity. The study results of this book have significant sense for improving the living environment in karst regions of northern
China, heightening the adaptability of human being to environmental change, and realizing the sustainable development of regional economies.
6) Aqueous geochemistry of karst aquifer/landscape systems.
Zhang Cheng and Yuan Daoxian(2005) analysed the environmental sensitivity of typical epikarst system of Nongla, Mashan County, Guangxi Zhuang Autonomous Region. The data from Greenspan CTDP300 multichannel data logger indicates that the karst dynamic system of Nongla is highly sensitive to environmental change. The response time scale may be hours, evenminutes. Multi-day and diurnal physico-chemical composition of epikarst spring water is quite different under the different climatic condition. In normal day(no rainfall), water temperature and air temperature have about the same variation. Conductivity has a good positive correlativity with pH value and water temperature. During rain storm, physico-chemical variation of spring is mainly controlled by dilution effect in the beginning, pH and electric conductivity drop rapidly. But 0.15~1 hour later, CO 2 effect will occupy the dominant position due to the high fissure rate and permeability in epikarst zone, electric conductivity rises again. Dilution effect can last for the entire rain storm process, whereas, it only acts on the earliest period of light rain.
Moreover, high resolution measurements at two locations within the vertical zoned climate region of the Jinfo Mountain Nature Reserve, Chongqing, China, were made using data loggers recording with 15 minutes resolution. While Bitan spring 700m a.s.l. represents subtropic climate, Shuifang spring 2000m a.s.l. represents plateau temperate climate. The results showed that hydrochemistry parameters of epikarst springs at different altitudes are very sensitive to environmental change and mainly controlled by two factors: air temperature and soil CO2 concentration(Zhang Cheng, 2005). Lower altitude means higher air temperature and CO2 concentration, thus more active karst processes. Water temperature, pH of Bitan spring has a remarkable diurnal variation with high value in the day and low value at night. During flood pulse, at least there are two effects impacted on hydrochemistry of groundwater: one is dilution effect, the other is CO2 effect, the pH of Bitan spring drops while the conductivity falls. Inversely, and at the same time, the pH of Shuifang spring rises, while conductivity falls. It may indicate that Bitan spring represents conduit-fissure flow and Shuifang spring fissure media.
Epikarst dynamic system is characterized by instability and heterogeneity, and its regulation capacity is limited. Yu Liu, Daoxian Yuan analysed the rainfall sensitivity and hydrochemical variations in epikarst system and its comparison with phreatic system. Automatic measurement of rainfall, water table, temperature, pH, conductivity of ground water of two adjacent springs within the peak cluster karst of the Guilin Karst Experimental Site in Guangxi Province, China, were made using data loggers recording with 15 minutes resolution. The epikarst spring responded to small rainfall, 9.5mm/d, 6 hours earlier than the phreatic spring which almost had no change in hydrochemical parameters except its discharge. In addition, at the beginning of discharge response, hydrodynamic effect, CO2 effect and dilution effect were increasing synchronizely, until 4 hours later dilution effect began to dominate. As to medium rainfall, e.g., 35mm/d, the duration of the integration of hydrodynamic and CO2 effect as well as dilution effect, was much shorter as for the epikarst spring, whereas, phreatic system still had no obvious change in hydrochemistry. Under the condition of rainstorm, 92.5mm/d, the spring of the epikarst system responded only 1 hour earlier and dilution effect dominated from the beginning of response, whereas for the phreatic spring there was still 3 hours duration of integration of hydrodynamic, dilution and CO2 effects before replaced by merely dilution effect. In conclusion, shallow karst dynamic system is sensitive to the environment and it acts differently both physically and chemically in different parts. Therefore, the further study of regulation capacity of karst dynamic system and its response to rainfall have great significance for the study of karst development including the forming of cave in south of China with complicated climate which enjoys frequent rainstorm and various types of rainfall.
So it is necessary to take water-rock-CO2 as a whole(system) for explanation of hydrochemical behavior of epikarst processes.
2. Scientific activities
In conjunction with the symposium on underground water resources and environment (December 5-10, 2005) which sponsored by Geology Survey of China and National Natural Science Foundation of China. First meeting of China Working Group of IGCP513 was held on 7 December, 2005 in Haikou, Hainan Province, China. 23 participants from 15 institutions, including Najing University; China Geosciences University; Institute of Karst Geology, CAGS; Institute of Hydrogeology and Environmental Geology, CAGS, attended the meeting. Group leader Prof. Yuan Daoxian made a work report, and introduced the bachground, objectives and major areas of emphasis for the project, and progresses achieved in yaer 2005 in China. 18 papers related to the objectives of IGCP513 were presented in different sessions of the Symposium. Tentative work schedule for next four years was discussed. The second group meeting will be held during the 34th IAH Congerss(Beijing, October 9-13, 2006). Two post-congress excursions related to IGCP513 were designed: T2 — Eco-geology and environmental geology of Huanglong-Jiuzgaigou, Sichuan Province (2006.10.14 –10.19); T5 — Karst hydrogeology of Guangxi Province(2006.10.14 –10.20, Beijing- Guilin- Liuzhou-Nanning)
Several members of working group also attended the 14 th International Congerss of Speleology(Athens, 21-28 August 2005) and the international conference and field seminars on water resources and environmental problems in karst(Belgrade, 13-19 September 2005).
1,Meeting in Belgrade, Serbia and Montenegro
The international conference and field seminars on water resources and environmental problems in karst were held in Belgrade, Serbia and Montenegro(13-19 September 2005). The themes included Vulnerability of karst environment and ecological problems, management and sustainable use of karstic resources, hydrogeology and multidisciplinary research of karst, impact of man-made structures on karst ecosystem, vulnerability of geo-and bio-diversities in karst and their protection, legal aspects and environment education. 133 papers were presented during the conference. Pre-conference excursion was arranged during 11-12 September, Carpatho-Balkanides karst in eastern part of Serbia was visited, including general geology and hydrogeology of Carpatho-Balkanides karst, karstification intensity, karst aquifer recharge and direction, drainage of karst aquifer, karst groundwater use, karst groundwater quality and environmental problems, some examples of chemical and bacteriological pollution of karst waters.
Yuan Daoxian, Lu Yaoru, Xie Yunqiu and Zhang feng'e from China working group attended the meeting, and gave oral presentations respecttivily: “Global study of karst aquifers and water resources”(IGCP513): Objectives and implementation plan. Karst water resources and geo-ecology in typical regions of China. On the causes of vulnerability of karst environment in Southwest China. The role of bacteria in the development of sulfate karst.
Moreover, During the meeting 513 members discussed the proposal for compiling global karst hydrogeological map. As scheduled, Asian karst hydrogeological map will be finished by China Working Group of IGCP513.
2,Meeting in Athens, Greece
The 14 th International Congerss of Speleology and the annual meeting of IGCP513 were held in Athens, Greece during 21-28 August 2005). About 400 people from 42 countries took part in the meeting. 311 papers were presented. Topics included speleogenesis and evolution of karst aquifers including geology, hydrogeology and geomorphology; physical chemistry and geochemistry; archaeology and palaeontology in caves including art and anthropology; biospeleology; protection and management of show caves and associated karst paleokarst and speleochronology; speleo-education; and speleology and tourist development et al. Liu Yu from China Southwest University attended the 513 annual meeting, and gave a oral presentation: Study on the rainfall sensitivity and hydrochemical variations in epikarst system and its comparison with phreatic system. Moreover, several Union International Speleology (UIS) departments and commissions meetings were also helded, such as Physical Chemistry & Hydrogeology of Karst Commission, Archaeology & Paleontogy in Caves Commission, Volcanic caves Commission.
3. Work plan of year 2006
• Compiling Asian karst hydrogeological map;
• To attend Annual Meeting of Project IGCP 513 Global study of karstic aquifers and water resources, in conjunction with International Congress on GROUNDWATER IN THE MEDITERRANEAN COUNTRIES(Malaga, Spain, 24-28 April 2006)
• To attend International Field Meeting on Sub-aerially exposed continental shelves since the Middle Pleistocene climatic transition (August 13-18, 2006. Exmouth and Ningaloo Reef, Western Australia)
• Organizing the second group meeting in conjunction with the 34th IAH Congerss(Beijing, October 9-13, 2006), and two post-congress excursions related to IGCP513: T2 — Eco-geology and environmental geology of Huanglong-Jiuzgaigou, Sichuan Province (2006.10.14 –10.19); T5 — Karst hydrogeology of Guangxi Province(2006.10.14 –10.20, Beijing- Guilin- Liuzhou-Nanning)
4. List of important publications
• Zhang Cheng, Yuan Daoxian, Cao Jianhua. Analysis on the environmental sensitivities of typical dynamic epikarst system at the Nongla monitoring site, Guangxi, China. Environmental Geology. 2005,47(5): 615 – 619
• Lu YR. Karst water resources and geo-ecology in typical regions of China. In: Water Resources and Environmental Problems in Karst—Proceedings of the international conference and field seminars. Belgrade&Kotor/Serbia & Montenegro / 13-19 September 2005. Zoran Stevanovic & Petar Milanovic(Eds). Belgrade, 2005, 19-26
• Xie Y. On the causes of vulnerability of karst environment in Southwest China. In: Water Resources and Environmental Problems in Karst—Proceedings of the international conference and field seminars. Belgrade&Kotor/Serbia & Montenegro / 13-19 September 2005. Zoran Stevanovic & Petar Milanovic(Eds). Belgrade, 2005, 103-108
• Daoxian Y. “Global study of karst aquifers and water resources”(IGCP513): Objectives and implementation plan. In: Water Resources and Environmental Problems in Karst—Proceedings of the international conference and field seminars. Belgrade&Kotor/Serbia & Montenegro / 13-19 September 2005. Zoran Stevanovic & Petar Milanovic(Eds). Belgrade, 2005, 227-230
• Zhang FE, Lu YR et al. The role of bacteria in the development of sulfate karst. In: Water Resources and Environmental Problems in Karst—Proceedings of the international conference and field seminars. Belgrade&Kotor/Serbia & Montenegro / 13-19 September 2005. Zoran Stevanovic & Petar Milanovic(Eds). Belgrade, 2005, 485-492
• Zhang Cheng, Yuan Daoxian et al. Analysis on the environmental sensitivities of typical dynamic epikarst system. Hydrogeology and Engineering Geology, 2005, 32(1):78-80(in Chinese with English abstract)
• Li Xiangquan,Hou Xinwei. Study on transfer and renew properties of groundwater systems in Taiyuan basin, Shanxi Province, China. Proceeding of symposium of National Groundwater Resources and Environment. Sponsor: China Geology Survey and China National Natural Science Foundation. Haikou, Hainan Province. 2005.12.5-10. pp 57-63 (in Chinese with English abstract)
• Wu Aiming, Zhou Zhiming, Liang Yongcheng. Exploitation excitation effect of Shuangcun karst water system in Shandong Province. Proceeding of symposium of National Groundwater Resources and Environment. Sponsor: China Geology Survey and China National Natural Science Foundation. Haikou, Hainan Province. 2005.12.5-10. pp 658-663(in Chinese with English abstract)
• Liang Yongping. Cause of environmental problem in Karst Big Spring watershed of Shanxi Province and the definition of protect area. Proceeding of symposium of National Groundwater Resources and Environment. Sponsor: China Geology Survey and China National Natural Science Foundation. Haikou, Hainan Province. 2005.12.5-10. pp 664(in Chinese with English abstract)
• Guolin, Chen Zhihua. Problem and prospect of evaluation of underground river system in karst area. Proceeding of symposium of National Groundwater Resources and Environment. Sponsor: China Geology Survey and China National Natural Science Foundation. Haikou, Hainan Province. 2005.12.5-10. pp 670-675(in Chinese with English abstract)
• Y. Liu, D.Yuan. Study on the rainfall sensitivity and hydrochemical variations in epikarst system and its comparison with phreatic system.Final Programme & Abstract Book. 14 th International Congress of Speleology. 21-28 August, 2005. Athens, Greece. pp 99(abstract)