Hydrogeology Journal (1998) 6 : 233–242 Q Springer-Verlag Laboratory simulation of water-resources conservation by means of the layout of a series of ponds along a streambank Jiin-Shuh Jean 7 Chao-Chi Hung Received, May 1996 Revised, July 1997, March 1998 Accepted, October 1997 Jiin-Shuh Jean (Y) 7 Chao-Chi Hung Department of Earth Sciences, National Cheng Kung University, Tainan, 70101, Taiwan Fax: c886-6-274-0285 e-mail: jiinshuh6sparc4.cc.ncku.edu.tw Abstract The purpose of this research is to describe a water-storage method that is more reliable than reser- voirs, and to study the efficacy of interception and stor- age of surface runoff in ponds. In this method, a series of ponds is laid out along a streambank so that inter- ception of surface runoff can be increased and more water can be stored in the wet season for use in the dry season. The simulated results show that the structure of a pond, vegetation and the extent of land development, topographic slope, and the degree to which a pond pen- etrates an aquifer affect the efficacy of interception and storage of surface runoff in ponds. Résumé Le but de ce travail est de décrire une métho- de de stockage d’eau qui soit plus sure que les réser- voirs, et d’étudier l’efficacité de l’interception et du stockage d’eau de ruissellement dans des bassins. Dans cette méthode, une série de bassins est disposée le long d’une berge de rivière de façon à ce que l’interception de l’écoulement de surface puisse être accrue et que plus d’eau puisse être stockée pendant la saison humide pour être utilisée en saison sèche. Les résultats de la simulation montrent que l’efficacité de l’interception et du stockage du ruissellement dans les bassins sont dé- terminés par la structure du bassin, la végétation et l’importance du développement agricole, la pente des versants et le degré de pénétration du bassin dans la nappe. Resumen El objetivo de este trabajo es describir un método de almacenamiento de agua que ofrece mayor garantía que los embalses, así como estudiar la eficacia de la intercepción y almacenamiento de la escorrentía superficial en pequen ˜ as lagunas artificiales. Este méto- do consiste en crear una serie de lagunas a lo largo de las riberas de un torrente, de manera que intercepción de la escorrentía superficial se pueda incrementar y se almacene más agua en la época húmeda para su utiliza- ción en la época seca. Los resultados simulados mues- tran que la estructura de las lagunas, la vegetación, el grado de desarrollo del terreno, la pendiente topográfi- ca y el grado de penetración de la laguna en el acuífero afectan la eficacia del método. Key words Equipment/field techniques 7 groundwater/surface-water relations 7 laboratory experiments/measurements 7 Taiwan 7 water-resources conservation Introduction Since late 1993, a serious shortage of water resources has been widespread throughout Taiwan, despite abun- dant rainfall during this time. Only 27% of rainfall is intercepted and stored in reservoirs, ponds, lakes, and subsurface media; most of the rainfall in the wet season discharges directly into the rivers and the sea. Further- more, rainfall usually occurs seasonally (generally from April to September) and is subject to geographical var- iations. The typhoon season is usually in July, August, and September and can produce abundant rainfall. However, no typhoons struck Taiwan in 1993, and a se- rious shortage of water resources has existed since then. Two reasons might explain why only 27% of rain- fall is intercepted and stored in surface and subsurface reservoirs: (1) most rivers and streams in Taiwan are steep and short, thus resulting in reduction of infiltra- tion into the subsurface media and a rapid flow to the sea; and (2) poor conservation of water and soil. Rapid land development on the more impervious areas fur- ther reduces infiltration and increases surface runoff. Reservoirs can store water in the wet season for use in the dry season and thus can increase available water resources. However, the problems that are encountered in Taiwan and that usually cause opposition from resi- dents are: (1) difficulty in site selection based on geo- logical and hydrological suitability; (2) safety consider- ations; (3) hydrological effects; and (4) damage to the environment. To overcome such problems, this re-