A comprehensive evaluation of input data-induced uncertainty in nonpoint source pollution modeling
L. Chen1, Y. Gong2, and Z. Shen11State Key Laboratory of Water Environment, School of Environment, Beijing Normal University, Beijing 100875, China 2Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
Received: 01 Sep 2015 – Accepted for review: 05 Oct 2015 – Discussion started: 03 Nov 2015
Abstract. Watershed models have been used extensively for quantifying nonpoint source (NPS) pollution, but few studies have been conducted on the error-transitivity from different input data sets to NPS modeling. In this paper, the effects of four input data, including rainfall, digital elevation models (DEMs), land use maps, and the amount of fertilizer, on NPS simulation were quantified and compared. A systematic input-induced uncertainty was investigated using watershed model for phosphorus load prediction. Based on the results, the rain gauge density resulted in the largest model uncertainty, followed by DEMs, whereas land use and fertilizer amount exhibited limited impacts. The mean coefficient of variation for errors in single rain gauges-, multiple gauges-, ASTER GDEM-, NFGIS DEM-, land use-, and fertilizer amount information was 0.390, 0.274, 0.186, 0.073, 0.033 and 0.005, respectively. The use of specific input information, such as key gauges, is also highlighted to achieve the required model accuracy. In this sense, these results provide valuable information to other model-based studies for the control of prediction uncertainty.
Chen, L., Gong, Y., and Shen, Z.: A comprehensive evaluation of input data-induced uncertainty in nonpoint source pollution modeling, Hydrol. Earth Syst. Sci. Discuss., 12, 11421-11447, doi:10.5194/hessd-12-11421-2015, 2015.