Karst conduit flow and its hydrodynamic characteristics — Houzhai River drainage basin in Puding, Guizhou, China as an example

Abstract

Conduit flow is a special geomorphologic and hydrological phenomenon in karst area. Houzhai River drainage basin in Puding, Guizhou Province is a large-scale test field in the main and broad karst area in the southern part of China, where conduit flow is a general reserve and drainage system for groundwater. Based on the great deal of field investigation and indoor research work during the 1970s-1980s, pulse tests were done four times there during 1988-1991 in wet and dry seasons. It shows that water level at each observation site changes from 10 to 1800 mm, with the larger variation in upper stream and at karst windows than in lower reaches and at each exit along subterraneous rivers. The average flow velocity in conduit system is determined within 200 -800 m/h, with the less change from flood to dry seasons, and it is higher in principal conduits and in upper stream area. Also, the reliable divided discharge ratio among each hydrological conduit of sunken system has been got. Thus, combined with detailed field survey in this area, the river system has been exposed finally.

Variability in Groundwater Flow and Chemistry in the Houzhai Karst Basin, Guizhou Province, China

“…They interpret those observations as resulting from evaporative loss during the dry season (Yue et al, 2018). Wang and Zhang (2001) document the results of four "pulse tests", which are analogous to large-scale slug tests, within the Houzhai catchment between 1988 and 1991. They found that water flow velocity ranged from 200-800 m/hr, with higher flow velocities during the wet season and lower flow velocities during the dry season (Wang and Zhang, 2001).…”

“…Wang and Zhang (2001) document the results of four "pulse tests", which are analogous to large-scale slug tests, within the Houzhai catchment between 1988 and 1991. They found that water flow velocity ranged from 200-800 m/hr, with higher flow velocities during the wet season and lower flow velocities during the dry season (Wang and Zhang, 2001). These pulse tests have also been used to identify three different "types of aquifer media" based on their response and flow recession curve (Yang, 2001).…”

“…The Houzhai catchment is classified as a typical mountain karst river basin (Wang and Zhang, 2001) (Figure 2). Elevation ranges from 1552 m above sea level (masl) to 1212 masl at the outlet, with a decreasing slope from southeast to northwest.…”

“…Total annual precipitation in 2018 amounted to 1290 mm, right in the middle of the historical range. Mean annual evaporation is around 920 mm (Wang and Zhang, 2001). Historical annual air temperature is 20.1 °C (typically ranging from 16°C to 22°C), with highest temperatures in July and lowest temperatures in January (Chen et al, 2013;Zhang et al, 2017).…”

“…This study explores groundwater flow by monitoring water parameters at multiple locations with varying temporal and spatial frequencies within the karstic Houzhai catchment. This 73.5 km 2 basin in Guizhou province, China, is located in the center of the largest karst area in the world, the Southeast Asian karst region (Wang and Zhang, 2001;Li et al, 2010) (Figures 1 and 2). Exposed carbonate rocks account for just over 20% of the land surface in China, making this location a key area of karst research (Cao et al, 2015).…”