Chuzhou, Anhui Province, China, 1981-

Location and Scale

The Chuzhou Hydrology Laboratory(Chuzhou Hydrology Experimental Base,Chuzhou Experiment Station),is located in the Huashan watershed, the drinking water source protection area of Chuzhou City in Anhui Province, China.

The Chuzhou Hydrology Laboratory has combined natural and artificial facilities for systematic investigations of hydrologic processes across scales. This field laboratory has many components, with a natural forested catchment called Nandadish and an artificial catchment called Hydrohill as major representatives.

1.The Nandadish(A Natural Catchment)

The Nandadish is a forested catchment bounded by surface topographical divides, with a surficial drainage area of 7897 m2, and its subsurface is bounded by natural bedrock at its bottom. The cover during the catchment’s construction in 1979 was natural grass with small shrubs and a few Masson pines (Pinus massoniana Lamb.) aged 5 to 6 yr.

2.The Hydrohill(An Artificial Catchment)

The artificial Hydrohill catchment (Gu, 1988, 1990), with a drainage area of 490 m2 by horizontal projection via plane surveying or 512 m2 including the inclined surface, is situated on a small andesitic hill. The entire hillslope was first excavated to fresh bedrock with an area of ~4700 m2 that was prepared for artificial catchments, of which the Hydrohill was the first.

Dates

The Chuzhou Hydrology Laboratory(Chuzhou Hydrology Experimental Base) was established in April,1981 by the Nanjing Institute of Hydrology with the approval of the former Ministry of Water Resources.

Climate

Chuzhou has a subtropical humid monsoon climate, with four distinct seasons, distinct monsoons, humid climate, and the same season of rain and heat. The city's annual average temperature is 15.4 ℃, and the annual average precipitation is 1000-1100 mm.

Geology and soil

1. The Nandadish: A Natural Catchment

The entire catchment may be viewed as a large soil dish resting on consolidated bedrock of the concordant body of andesitic and tuffaceous facies with a thin weathered layer. The overlying Quaternary regolith consists of brunisolic soil of heavy loam and medium and clay loams with a vadose zone thickness of 1 to 7 m (with an average thickness of 2.5 m). This catchment has deeper soils near the divide but only about 1 m thick near the outlet, making the catchment easy to close via a concrete wall installed to the bedrock at the outlet. Within the vadose zone, horizontal and vertical fissures and cracks have developed in the upper regolith, with prismatic and blocky soil structures.

2. The Hydrohill: An Artificial Catchment

Silt loam soil was filled in above the concrete aquiclude, layer by layer, using soils from an adjacent agricultural field near the Hydrohill. The bulk density of the soil was controlled during the infilling to approximate the natural soil profile nearby. Hence, the final 1-m soil profile approximates the natural soil profile.

Topography

1. The Nandadish: A Natural Catchment

The surficial topography is shown in Fig. 2a, while the bedrock topography is shown in Fig.2b, which was surveyed via 69 drillings. The altitudinal difference inthe watershed approaches 12.9 m, with a surface slope ranging from 6.7 to 17.1%.

2. The Hydrohill: An Artificial Catchment

The artificial Hydrohill catchment(Gu, 1988, 1990), with a drainage area of 490 m2 by horizontal projection via plane surveying or 512 m2 including the inclined surface, is situated on a small andesitic hill.The entire hillslope was first excavated to fresh bedrock with an area of ?4700 m2 that was prepared for artificialcatchments, of which the Hydrohill was the first.

Vegetation / Land Use

1. The Nandadish: A Natural Catchment

The cover during the catchment’s construction in 1979 was natural grass with small shrubs and a few Masson pines (Pinus massoniana Lamb.) aged 5 to 6 yr. Since then, the land cover has shifted to a dense forest with a canopy height of ~8 m.

2. The Hydrohill: An Artificial Catchment

The natural grass cover was kept over the soil surface.

History

The idea for the necessity of an experimental system for watershed hydrology was summarized from the decades working on field basin studies since the operation of the first hydrological experimental station in China, the Bluebrook, which was established in 1953. The dream of a WHES finally came to reality with the establishment of the Chuzhou hydrology laboratory (CHL) in 1978 by the Nanjing Hydraulic Research Institutes of the Chinese Ministry of Water Resources on the basis of the Chengxi Runoff Experimental Station established on 1962 with three experimental watersheds. This Chuzhou WHES was designed including both artificial and natural entities of different scale, within which, most of them have established, few of them are in modified and renewed after an interruption of many years. This WHES is settled in a natural Bloomhill (Hua-Shan) watershed, with surficial drainage area of 82.1 km2 since 1962, 80.0 km2 since 1998 due to a hydraulic engineering.

Hydrological Knowledge Gained

For example: The 1986 data were measured using a neutron moisture gauge,while the 2014 data were measured using FDR sensors (PR2 model from the Delta-T Devices, with a precision of ±0.04 m3m?3 in the temperature range from 0 to 40°C).

Reference Material

Gu, W.-Z. 1987. On the domain and approach of the experimental hydrology. In: Nanjing Hydrology Institute, editor, Treatise on hydrology and water resources. (In Chinese.) Water Resour. Electric Power Press, Beijing. p. 507–515.

Gu, W.-Z. 1988. Field research on surface water and subsurface water relationships in an artificial experimental catchment. In: P. Dahlblom and G. Lindh, editors, Interaction between Groundwater and Surface Water, International Symposium, Ystard, Sweden. 30 May–3 June 1988. Lund Univ., Lund, Sweden. p. 33–41.

Gu, W.-Z. 1990. Experimental and representative basin studies in China. In: J.C. Hooghart et al., editors, Hydrological research basins and the environment: Proceedings of the International Conference, Wageningen, the Netherlands. 24–28 Sept. 1990. TNO, The Hague. p. 24–28.

Gu, W.-Z. 1992. Experimental research on catchment runoff responses traced by environmental isotopes. (In Chinese with English abstract.) Adv. Water Sci. 4:245–254.

Gu, W.-Z. 1993. Basin studies in China over the last four decades. Euromediterranean Network of Experimental and Representative Basins Newsl. 9:12

Gu, W.-Z. 1995. Various patterns of basin runoff generation identified by hydrological experiment and water tracing using environmental isotopes. (In Chinese with English abstract.) J. Hydraul. Eng. 5:9–17.

Gu, W.-Z. 1996a. Unreasonableness of the current two-component isotopic hydrograph separation for natural basins. In: Isotopes in Water Resources Management: Proceedings of an International Conference, Vienna. 20–24 Mar. 1995. IAEA, Vienna. p. 261–264.

Gu, W.-Z. 1996b. On the hydrograph separation traced by environmental isotopes. (In Chinese with English abstract.) Adv. Water Sci. 7:105–111.

Gu, W.-Z., and J. Freer. 1995. Patterns of surface and subsurface runoff generation. IAHS Publ. 229:265–273.

Gu, W.-Z., and S.-L. Liang. 1965. Bluebrook Runoff Experimental Station. (In Chinese.) Water Resour. Hydropower Eng. 43.

Gu, W.-Z., J.-F. Liu, J.-J. Lu, and J. Frentress. 2013. Current challenges in experimental watershed hydrology. In: P.M. Bradley, editor, Contaminant hydrology and water resources sustainability. InTech Publ., Rijeka, Croatia. p. 299–333. doi:10.5772/55087

Gu, W.-Z., C.-M. Liu, X.-F. Song, J.-J. Yu, and J. Xia. 2004. Hydrological experimental system and environmental isotope tracing: A review on the occasion of the 50th Anniversary of Chinese basin studies and the 20th Anniversary of Chuzhou Hydrology Laboratory. In: R.-Z. Xi et al., editors, Proceedings of the International Conference on Research Basins and Hydrological Planning, Hefei, China. March 2004. A.A. Balkema, London. p. 22-31.

Gu, W.-Z., J.-J. Lu, X. Zhao, and N.E. Peters. 2007. Responses of hydrochemical inorganic ions in the rainfall–runoff processes of the experimental catchments and its significance for tracing. (In Chinese with English abstract.) Adv. Water Sci. 1:1–7.

Gu, W.-Z., M.-T. Shang, S.-Y. Zhai, J.-J. Lu, F. Jason, J.J. McDonnell, and C. Kendall. 2010. Rainfall–runoff paradox from a natural experimental catchment. (In Chinese with English abstract.) Adv. Water Sci. 4:471–478.

Kendall, C. & Gu, W. (1992) Development of isotopically heterogeneous infiltration waters in an ar- tificial catchment in Chuzhou, China. Li: Isotope Techniques in Water Resources Development. 61-73, IAEA, Vienna.

Kendall, C., McDonnell, J.J. and Gu, W., 2001. A look inside ‘black box’hydrograph separation models: a study at the Hydrohill catchment. Hydrological Processes, 15(10), pp.1877-1902.

Yang, N., Zhang, J., Liu, J., Liu, G., Liao, A. and Wang, G., 2020. Analysis of event-based hydrological processes at the hydrohill catchment using hydrochemical and isotopic methods. Proceedings of the International Association of Hydrological Sciences, 383, pp.99-110.

Links

Web page in Chinese at http://czjd.nhri.cn/index.html