| Volumes and Issues Contents of Issue 6 Special Issue |
www.biogeosciences-discuss.net/6/11401/2009/
doi:10.5194/bgd-6-11401-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Partitioning of catchment water budget and its implications for ecosystem carbon exchange
1Dept. of Atmospheric Sciences, Yonsei Univ., Seoul, 120-749, Korea
2Korea Basic Science Institute, Daejon, 305-333, Korea
3Korea Institute of Construction Technology (Sustainable Water Resource Research Center), Goyang, 411-712, Korea
Abstract. Spatially averaged annual carbon budget is one of the key information to understand ecosystem response and feedback to climate change. Water availability is a primary constraint of carbon uptake in many ecosystems and therefore the estimation of transpiration (T) may serve as an alternative to quantify carbon budget. To apply this concept, we estimated long-term steady state water budget for the Han River basin (~26 000 km2) in Korea and examined its implication for catchment scale carbon exchange. For this, the catchment scale evapotranspiration (ET) was derived from the long term precipitation (P) and discharge (Q) data. Then, using stable isotope data of P and Q along with hydrometeorological information, ET was partitioned into evaporation from soil and water surfaces (ES), evaporation from intercepted rainfall (El), and transpiration. ES was identified as a minor component of ET in the study areas regardless of the catchment scales. T was estimated from ET after accounting for El and ES. For the Han River basin, the estimated annual T from 1966 to 2007 was 22–31% of annual P and the proportion decreased with increasing P. Assuming that T further constrains catchment scale carbon uptake in terms of water use efficiency (WUE), we examined the possibility of using T as a relative measure for the strength and temporal changes of carbon uptake capacity. The proposed relations provide a simple and practical way to assess the distribution and strength of carbon sink.
Discussion Paper (PDF, 682 KB) Interactive Discussion (Closed, 6 Comments) Final Revised Paper (BG)
Citation: Lee, D., Kim, J., Lee, K.-S., and Kim, S.: Partitioning of catchment water budget and its implications for ecosystem carbon exchange, Biogeosciences Discuss., 6, 11401-11433, doi:10.5194/bgd-6-11401-2009, 2009. Bibtex EndNote Reference Manager XML
