Evaluation of short-term changes of hydrological response in mountainous basins of the Vitim Plateau (Russia) after forest fires based on data analysis and hydrological modelling

Abstract

Abstract. Twelve mountainous basins of the Vitim Plateau (Eastern Siberia, Russia) with areas ranging from 967 to 18 200 km 2 affected by extensive fires in 2003 (from 13 to 78 % of burnt area) were delineated based on MODIS Burned Area Product. The studied area is characterized by scarcity of hydrometeorological observations and complex hydrological processes. Combined analysis of monthly series of flow and precipitation was conducted to detect short-term fire impact on hydrological response of the basins. The idea of basin-analogues which have significant correlation of flow with "burnt" watersheds in stationary (pre-fire) period with the assumption that fire impact produced an outlier of established dependence was applied. Available data allowed for qualitative detection of fire-induced changes at two basins from twelve studied. Summer flow at the Amalat and Vitimkan Rivers (22 and 78 % proportion of burnt area in 2003, respectively) increased by 40-50 % following the fire.The impact of fire on flow from the other basins was not detectable.The hydrological model Hydrograph was applied to simulate runoff formation processes for stationary pre-fire and non-stationary post-fire conditions. It was assumed that landscape properties changed after the fire suggest a flow increase. These changes were used to assess the model parameters which allowed for better model performance in the post-fire period.

HESS Opinions: Advocating process modeling and de-emphasizing parameter estimation

“…And, an automated model calibration procedure should not be used as a way to justify a poorly formulated model that is then "camouflaged by uncertainty estimation". As has been pointed out before many times (see, e.g., Semenova and Beven, 2015), expert opinion and judgment should matter when evaluating the credibility of model performance and predictions. To this one might add that scientific knowledge and principles of physics should matter even more, as should practical perceptual and observational knowledge about the system being modeled.…”

“…However, the work of Bergstrom with the HBV model, and more recently Semenova and Beven (2015), seems to suggest otherwise (although note that Beven has a different opinion in this regard, as discussed briefly in their paper; see also Beven's equifinality thesis in Beven, 2006b). The work of the St. Petersburg modeling team on a deterministic distributed process-based model of runoff formation processes named the "hydrograph model" is closely in line with what is described for parameter estimation in this opinion paper (Vinogradov, 1990;Vinogradov et al, 2011;Semenova et al, 2013Lebedeva et al, 2014).…”

A Conceptual Model to Quantify the Water Balance Components of a Watershed in a Continuous Permafrost Region

“…Addressing this challenge by integrating the active layer's freeze-thaw process into a physically-based hydrological model involves solving the heat transfer equation in a porous medium with moving boundary conditions. Due to its simplicity, the original Stefan's analytical solution [6,7] and subsequent modifications [8][9][10][11][12][13][14][15] have been incorporated into several models. Although the computational time is short, this modeling approach has limitations that are inherent in the assumptions underlying the derivation of this analytical solution [16].…”