Paper No. J05149 of the Journal of the American Water Resources Association (JAWRA).
Effects of Rainfall and Ground-Water Pumping on Streamflow in Mākaha, O’ahu, Hawai’i1
Article first published online: 26 JAN 2007
© 2007 American Water Resources Association
JAWRA Journal of the American Water Resources Association
Volume 43, Issue 1, pages 148–159, February 2007
How to Cite
Mair, A., Fares, A. and El-Kadi, A. (2007), Effects of Rainfall and Ground-Water Pumping on Streamflow in Mākaha, O’ahu, Hawai’i. JAWRA Journal of the American Water Resources Association, 43: 148–159. doi: 10.1111/j.1752-1688.2007.00012.x
- Issue published online: 26 JAN 2007
- Article first published online: 26 JAN 2007
- Received April 22, 2005; accepted January 16, 2006.
- ground-water pumping;
- hydrologic cycle;
Abstract: Land-use/land-cover changes in Mākaha valley have included the development of agriculture, residential dwellings, golf courses, potable water supply facilities, and the introduction of alien species. The impact of these changes on surface water and ground water resources in the valley is of concern. In this study, streamflow, rainfall, and ground-water pumping data for the upper part of the Mākaha valley watershed were evaluated to identify corresponding trends and relationships. The results of this study indicate that streamflow declined during the ground-water pumping period. Mean and median annual streamflow have declined by 42% (135 mm) and 56% (175 mm), respectively, and the mean number of dry stream days per year has increased from 8 to 125. Rainfall across the study area appears to have also declined though it is not clear whether the reduction in rainfall is responsible for all or part of the observed streamflow decline. Mean annual rainfall at one location in the study area declined by 14% (179 mm) and increased by 2% (48 mm) at a second location. Further study is needed to assess the effect of ground-water pumping and to characterize the hydrologic cycle with respect to rainfall, infiltration, ground-water recharge and flow in the study area, and stream base flow and storm flow.