Quantifying the relative contribution of the climate and direct human impacts on mean annual streamflow in the contiguous United States
Tóm tắt
Both climate change and human activities are known to have induced changes to hydrology. Consequently, quantifying the net impact of human contribution to the streamflow change is a challenge. In this paper, a decomposition method based on the Budyko hypothesis is used to quantify the climate (i.e., precipitation and potential evaporation change) and direct human impact on mean annual streamflow (MAS) for 413 watersheds in the contiguous United States. The data for annual precipitation, runoff, and potential evaporation are obtained from the international Model Parameter Estimation Experiment (MOPEX), which is often assumed to only include gauges unaffected by human interferences. The data are split into two periods (1948–1970 and 1971–2003) to quantify the change over time. Although climate is found to affect MAS more than direct human impact, the results show that assuming the MOPEX data set to be unaffected by human activities is far from realistic. Climate change causes increasing MAS in most watersheds, while the direct human‐induced change is spatially heterogeneous in the contiguous United States, with strong regional patterns, e.g., human activities causing increased MAS in the Midwest and significantly decreased MAS in the High Plains. The climate‐ and human‐induced changes are found to be more severe in arid regions, where water is limited. Comparing the results to a collection of independent data sets indicates that the estimated direct human impacts on MAS in this largely nonurban set of watersheds might be attributed to several human activities, such as cropland expansion, irrigation, and the construction of reservoirs.
Từ khóa
Tài liệu tham khảo
Budyko M. I., 1958, The Heat Balance of the Earth's Surface
Budyko M. I., 1974, Climate and Life
Fu B. P., 1981, On the calculation of the evaporation from land surface [in Chinese], Sci. Atmos. Sin., 5, 23
National Atlas of the United States (2006) Major dams of the United States inNational Atlas of the United States Reston Va.[Available athttp://nationalatlas.gov/atlasftp.html?openChapters=chpwater#chpwater.]
2002, Estimating Water Use in the United States—A New Paradigm for the National Water Use Information Program
Ol'dekop E. M.(1911) On evaporation from the surface of river basins Transactions on Meteorological Observations Lur‐evskogo Univ. of Tartu Tartu Estonia.
Schreiber P., 1904, Über die Beziehungen zwischen dem Niederschlag und der Wasserführung der Flüsse in Mitteleuropa, Z. Meteorol., 21, 441
S. Siebert P. Döll S. Feick J. Hoogeveen K. Frenken 2007 Johann Wolfgang Goethe Univ. Frankfurt am Main Germany
Slack J. R., 1993, Hydroclimatic data network (HCDN): A U.S. Geological Survey streamflow data set for the United States for the study of climate variation, 1874–1988, U.S. Geol. Surv. Open File Rep., 92
Turc L., 1954, Le bilan d'eau des sols. Relation entre la précipitation, l'évaporation et l'écoulement, Ann. Agron., 5, 491
2001, National Atlas of the United States
2010, National Atlas of the United States