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Determining wildland fire impacts on streamflow can be problematic as the hydrology in burned watersheds is influenced by post‐fire weather conditions. This study presents a quantile‐based analytical framework for assessing fire impacts on low and peak daily flow magnitudes, while accounting for post‐fire weather influences. This framework entails (a) the bootstrap method to compute the relative change in the post‐fire annual flow and weather statistics, (b) double mass analysis to detect if post‐fire baseflow and quick‐flow yield ratios are significantly altered, and (c) a quantile regression method to parse fire effects on flow at a specific quantile. We illustrate the applicability of this analytical framework using 44 western US streams with at least 5% of their watershed area burned. Results indicate that large, high‐severity burns in upland watersheds can raise the streamflow magnitude at the 0.05th and 0.95th quantiles for at least the five post‐fire years. Quantile regression results show that the median fire‐related increase in flow for the five post‐fire years can be up to 5,000% (Standard Error; S.E.< 2%) at the 0.05th quantile and 161% (S.E.< 10%) at the 0.95th quantile. The fire‐related increase in flow was often pronounced at the 0.05th quantile for streams in the Pacific Northwest and California regions. The difference in fire effects on flow (at both quantiles) across streams was related to post‐fire weather, pyrology, physiography, and land cover. The proposed analytical framework can be useful for detecting and quantifying fire effects on the low and peak stream flows in burned watersheds without overlapping disturbances. Key Points: Evaluating the impact of watershed burning on streamflow can be problematic due to the confounding effect of post‐fire weather influencesA quantile‐based analytical framework is presented for assessing fire effect on low & peak flow while accounting for weather influencesThis analytical framework can be useful for inferring fire effect on low & peak flows in burned watersheds without overlapping disturbances [ABSTRACT FROM AUTHOR]

As one of the fastest developing regions in China, the middle-lower Yangtze River (MLYR) is vulnerable to floods and droughts. With obtained time series of annual highest water level (HWL), annual lowest water level (LWL) and the corresponding river discharges from three gauging stations in MLYR that covering the period 1987-2011, the current study evaluated the change characteristics of annual extreme water levels and the correlation with river discharges by using the methods of trend test, Mann-Whitney-Pettitt (MWP) test and double mass analysis. Major result indicated a decreasing/increasing trend for annual HWL/LWL of all stations in MLYR during the study period. A change point in 1999 was identified for annual HWL at the Hankou and Datong stations. The year 2006 was found to be the critical year that the relationship between annual extreme water levels and river discharges changed in the MLYR. With contrast to annual LWL in MLYR, further investigation revealed that the change characteristics of annual HWL were highly consistent with regional precipitation in the Yangtze River Basin, while the linkage with Three Gorges Dam (TGD) operation is not strong. Our observation also pointed out that the effect of serious down cutting of the riverbed and the enlargement of the cross-section area during the initial period of TGD operation caused the downward trend of the relationship between annual LWL and river discharge. Whereas, the relatively raised river water level before the flood season due to TGD regulation since 2006 explained for the changing upward trend of the relationship between annual HWL and river discharge. [ABSTRACT FROM AUTHOR]