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[1] The effects of topography resolution on upscaling point-scale processes and parameters on watershed hydrology numerical routing are investigated. Parsimonious continuous simulation was applied to two forested catchments with shallow and sloping soils, one medium-sized (123 km 2 ) and one small-sized (4.5 km 2 ), where saturation excess runoff prevails. The computed discharge showed highest sensitivity to spatial resolution, due to smoothing effects during aggregation of the digital elevation model caused by a coarse grid. The loss of information content of terrain curvature as consequence of the averaging procedure was related to the amplification factor required for the soil hydraulic conductivity to compensate the resulting retardation of the runoff hydrograph. A scaling relation has been developed that links soil hydraulic conductivity measured at the point-scale with that required at the typically much coarser modeling scale. The entropy concept for the measurement of information loss could be a good index for parameter rescaling of other basins where the terrain curvature is similarly scale-dependent.

Core Ideas Soil physical quality (SPQ) of four areas with Mediterranean vegetation was evaluated. BEST procedure was tested to evaluate SPQ and detect signs of soil degradation. Independently measured indicators of SPQ were compared with those derived by BEST. BEST reproduced plausible SPQ evaluation. BEST is a promising technique to simply detect land degradation in natural environments. Conversion of Mediterranean maquis and/or natural forest into agro‐pastoral lands is a cause of soil degradation in many Mediterranean areas. Indicators of soil physical quality (SPQ) quantitatively linked to soil hydraulic properties are a valuable tool to assess the effect of land use changes. In this investigation, the Beerkan Estimation of Soil Transfer parameters (BEST) procedure for soil hydraulic characterization was used to estimate SPQ indicators. Four areas of the Baratz Lake watershed, Sardinia, Italy, characterized by both typical natural vegetation (holm oak [Quercus ilex L.] forest and high maquis) and degraded vegetation (grassland established after fire or clearing of the maquis) were considered. The SPQ was assessed by either independently measured soil physical attributes, like soil bulk density, organic C content, saturated hydraulic conductivity, and sorptivity, and “capacitive” and “dynamic” indicators calculated from the water retention curve estimated by the BEST procedure. Measured and estimated SPQ indicators unanimously showed that clearing of the maquis caused a severe deterioration of SPQ associated with soil compaction, organic matter loss, and decrease of macropore volume and soil aeration capacity as well as reduced water circulation. A different and unexpected result was obtained for the fire‐affected area, where the SPQ was comparable to that of the neighboring oak forest area. We deduced that vegetation restoration after fire passage contributed to maintain a high organic matter content and to mitigate rain compaction effects. We concluded that SPQ indicators derived by applying the BEST procedure are suitable to detect land degradation in the natural environments studied.

Although crop residue management is known to affect near-surface soil physical quality, little is known about the temporal variability of these indicators over short time intervals. This study evaluates the temporal changes of nine indicators of soil physical quality. These are organic carbon content, structural stability index, bulk density, macroporosity, air capacity, relative field capacity, plant available water capacity, Dexter's S-index and saturated hydraulic conductivity. A second set of soil physical indicators, based on the distribution of soil pore volume, was also evaluated. The indicators were determined in three different times during the growing cycle of winter durum wheat cultivated within a long-term field research carrying out in Southern Italy and comparing two types of crop residue management, that is, burning (B) and soil incorporation (I). Only the bulk density changed over time for both treatments, although the air capacity also changed for the incorporation of wheat residues. Residual effects of the autumnal soil tillage and soil compaction were a common source of variability, irrespective of which treatment was used. Based on the existing guidelines for evaluating the physical quality of these agricultural soils, optimal or near-optimal values were detected in about half of the cases under consideration. This suggests that both B and I create sufficiently good conditions for crop growth during the crop cycle. The comparison between observed and optimal soil pore distribution function was always poor. The pore volume distributions showed lower densities of small pores and relatively higher densities of large pores than the proposed optimal distribution. This study also suggests that the considered optimal or references curves probably cannot be applied successfully to a wide range of agricultural soils.

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