Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States

May combine two claims.

For the 5-year reference period, the CEM predicted a streamflow change of -242 mm (-47%), compared with an observed change of -201 mm (-39%).

“The 5 year CEM 0 predicted a -242 mm (-47%) change in annual streamflow vs. a -201 mm (-39%) observed change (Table 3 and Figure”

May combine two claims.

The annual streamflow decrease was -178 mm (-36%) relative to the 10-year reference period and -201 mm (-39%) relative to the 5-year reference period, with lower precipitation dominant in both cases.

“The decrease in annual streamflow was -178 mm (-36%) relative to the 10 year reference period vs. 201 mm (-39%) relative to the 5 year reference period, and lower precipitation was the dominant factor in both cases (Table 3 and Figure 7).”

May combine two claims.

In the South Carolina watershed, annual prescribed burning has occurred since at least the 1940s, and 40% of the watershed burned between 2004 and 2014.

“Annual prescribed burning has been conducted in the Carolina Sandhills National Wildlife Refuge (NWR) in the lower portion of this mixed land use watershed since at least the 1940s, and 40% of the watershed was burned between 2004 and 2014”

May combine two claims.

The model simulated the rapid increase in streamflow in November-December 2004 following the wildfire, while observed streamflow increased even more rapidly, providing minimal additional evidence of a non-climate contribution to streamflow change.

“Nonetheless, the model simulated the dynamic of rapid increase in streamflow in November-December 2004 following the wildfire while the observed streamflow increased even more rapidly than before, providing minimal additional evidence of a non-climate contribution to streamflow change.”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

The May 1999 disturbance in the South Carolina watershed is a break point in the cumulative streamflow-precipitation relationship (p<10^-6), with the runoff coefficient dropping from 0.419 in the five-year reference period to 0.306 afterward.

“The disturbance of May 1999 also represents a break point in the relationship between cumulative streamflow and precipitation (p<10 -6 ) (Figure 6a), with the coefficient of the unrestricted linear model (runoff coefficient) declining from 0.419 (5 year reference) to 0.306 in the post-disturbance period.”

• AssumptionThe authors state this as an assumption: Double-mass analysis assumes an approximately linear relationship between precipitation and streamflow when there are no changes in climate, land cover, or water withdrawals.

May combine two claims.

The runoff coefficient had not recovered to its pre-disturbance value 5 years after the fire in 2009, nor as late as 2012.

“The runoff coefficient had not recovered to its pre-disturbance value 5 years after the fire in 2009, based on the increasing trend in the residual plot (Figure 6b), nor even as late as 2012 verified with additional analysis.”

May combine two claims.

At a monthly time step, May 1999 had the largest L statistic and was chosen as the disturbance change point for the South Carolina watershed.

“Greater statistical power was obtained at a monthly time step (Figure 5b), which also allowed us to select the month with the greatest L (May 1999) as the disturbance change point to be evaluated.”

• AssumptionThe authors state this as an assumption: An undisturbed continuous streamflow time series follows a single distribution F0.
• AssumptionThe authors state this as an assumption: If a change point exists, the streamflow time series follows distribution F1 before the change point and F2 after, with F1 not equal to F2.

May combine two claims.

In the South Carolina watershed, streamflow changes showed no clear connection to prescribed burning periods but coincided with a very wet winter and reported storm damage.

“Changes in streamflow within a watershed in South Carolina had no apparent link to periods of prescribed burning but matched a very wet winter and reports of storm damage.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The increase in runoff coefficient relative to the 10-year reference period was of the same order of magnitude.

“The increase in runoff coefficient with respect to the 10 year reference period was in the same order of magnitude.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The double-mass curve for the 10-year reference period shows a moment of even greater change corresponding with exceptionally high rainfall of 158 mm and 251 mm in January and February 1998, respectively.

“The DMC for the 10 year reference period (Figure 6c, right panel) shows that there is a moment of even greater change in the DMC corresponding with the exceptionally high rainfall of 158 mm and 251 mm in January and February 1998, respectively.”

May combine two claims.

In the South Carolina watershed, burn severity was usually low, and fire had limited effect on NDVI, with seasonal values peaking at 73-74% and minimums at 54-57%.

“Burn severity was typically low.Fire impact on the interannual variability of vegetative phenology evidenced by the NDVI was limited, with seasonal NDVI values peaking between 73% and 74% and minimum values between 54% and 57%”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The Deer Park wildfire burned 14.1% of the California watershed, with moderate to high severity on chaparral hillslopes and unburned/underburned to low severity near streams.

“The Deer Park wildfire started on July 20, 2003 on a hillslope in the upper part of the watershed and burned 14.1% of its area (Figure 3c), with moderate to high burn severity (3.8% and 1.2%, respectively, of the watershed) on the chaparral covered hillslopes, and unburned/underburned to low burn severity near streams (4.9% and 4.1%, respectively).”

May combine two claims.

The Willow wildfire burned 83.6% of the Arizona watershed, with burn severity distributed as under/unburned 10.7%, low 46.3%, moderate 26.2%, and high 0.5%.

“The Willow wildfire that started on June 24 th , 2004 affected 83.6% of the watershed, with under/unburned to low burn severity (10.7% and 46.3%, respectively, of the watershed) on the more sparsely vegetated south-facing slopes, and moderate burn severity (26.2% of the watershed) on the north-facing slopes (Figure 3b).Approximately 0.5% of the watershed was affected by high severity burning.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the California watershed, NDVI in the severely burned area dropped from about 0.58 at the summer peak to about 0.30 in autumn.

“The NDVI in the severely burned area decreased (Figure 4c) from around 0.58 during the summer peak to around 0.30 in autumn.”

May combine two claims.

In the Arizona watershed, fire lowered NDVI from about 0.60 to 0.26 for moderate and high burn severity, and from 0.41 to 0.29 for low burn severity.

“Fire reduced NDVI from approximately 0.60 to 0.26 (moderate and high burn severity) and from 0.41 to 0.29 (low burn severity).”

May combine two claims.

The hydrological model reproduced observed values correctly until autumn 2000, but was unable to simulate the intermittent character of streamflow after that date.

“The residual plot in Figure 8b (right panel) shows that the hydrological model reproduced the observed values correctly until the autumn of 2000, but was unable to simulate the intermittent character of streamflow after this date.”

May combine two claims.

There was a significant breakpoint in the double-mass curve corresponding with the July 2003 Deer Park wildfire (p<10^-6), and the runoff coefficient increased from 0.04 (4%) to 0.058 (5.8%).

“There was a significant breakpoint in the DMC corresponding with the July 2003 Deer Park wildfire (p<10 -6 ), and runoff coefficient increased from 0.04 (4%) to 0.058 (5.8%) (Figure 6c, left panel).”

May combine two claims.

In the third case study, the South Carolina watershed, the change in streamflow could not be linked to prescribed fire but was chiefly attributed to a declining trend in precipitation.

“In the third case study (SC watershed) change in streamflow could not be linked to prescribed fire, but was chiefly attributed to a declining trend in precipitation.”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

Prescribed burnings followed a regular pattern of small, low-severity fires, no wildfires were reported, and bark beetle activity was very low.

“Prescribed burnings followed a regular pattern (small fires with low burn severity; Carolina Sandhills NWR, 1998;1999), no wildfires were reported, and bark beetle activity was very low (Carolina Sandhills NWR, 1998;1999;South Carolina Forestry Commission, 1999).”

• cites Carolina Sandhills NWR, 1998Not checked yet

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• cites Carolina Sandhills NWR, 1999Not checked yet

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• cites South Carolina Forestry Commission, 1999Not checked yet

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May combine two claims.

The 10-year reference period preceding the 2003 wildfire in the California watershed includes both the strong El Niño year 1997-1998 with exceptionally high rainfall and the drier La Niña years 1998-1999 and 1999-2000, whereas the 5-year reference period included only the La Niña years.

“For example, the 10-year reference period preceding the 2003 wildfire in the CA watershed includes both the strong El Niño year 1997-1998 with exceptionally high rainfall and the drier La Niña years 1998-1999 and 1999-2000, where the 5-year reference period included only the La Niña years.”

May combine two claims.

The change point analysis detected significant change in streamflow for the extended period between 1998 and 2000 at the annual time step and 1995-2011 at the monthly time step, corresponding with periods of increased interannual and monthly variability in streamflow.

“The change point analysis furthermore detected significant change in streamflow for the extended period between 1998 and 2000 (annual time step; Figure 5a) and 1995-2011 (monthly time step; Figure 5b), corresponding with periods of increased interannual and monthly variability in streamflow, respectively.”

May combine two claims.

As demonstrated in the three case studies, the contribution of fire disturbance to streamflow change varied from negligible in the South Carolina watershed to substantial in the Arizona watershed, and intermediate in the California watershed.

“As demonstrated for the three case studies, the contribution of fire disturbance to streamflow change can vary from negligible (SC) to substantial (AZ) or somewhere in between (CA).”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

The change point model linked the time of maximum streamflow disturbance to May 1999, where the CEM attributed the observed loss in water yield of -39% to a negative climate contribution of -47% attenuated by a positive non-climate contribution of +8% for the 5-year reference period.

“The change point model linked the time of maximum streamflow disturbance (L max ) to May 1999, where the CEM attributed the observed loss in water yield of -39% to a negative (-47%) climate contribution attenuated by a positive (+8%) non-climate contribution (5 year reference period).”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

High flows in the Arizona watershed occurred mostly in winter when mean annual snow water equivalent varied between 8 mm in November and 110 mm in January, and high daily maximum temperatures of 12°C in January allowed immediate snowmelt.

“These high flows occurred mostly in the winter when the mean annual snow water equivalent varied between 8 mm (November) and 110 mm (January) (reference and post-disturbance period combined), and high daily maximum temperatures (12°C during the coldest month of January) allowed for immediate snowmelt.”

May combine two claims.

The mean annual number of precipitation days in the California watershed increased from 54 to 58 days, while the number of days with moderate precipitation did not change substantially.

“The mean annual number of precipitation days increased from 54 days (p{P d ≥ 1 mm} = 0.158) in the reference period to 58 days (p{P d ≥ 1 mm} = 0.148) in the post-disturbance period, while the number of days with moderate precipitation did not change substantially (1.2 days (p{P d ≥ 25.”

May combine two claims.

This is the case for the California watershed, where the double-mass curve has no clear breakpoint for the 2006 Canyon Fire even though it burned an area similar in size to the 2003 Del Puerto Creek Fire.

“This is the case for the CA watershed where there the DMC has no clear breakpoint for the 2006 Canyon Fire even though it burned an area similar in size to the 2003 Del Puerto Creek Fire.”

May combine two claims.

Climate in the South Carolina watershed was variable, with a wet winter in 1998 followed by a period of less precipitation and a lower mean annual number of extreme precipitation days greater than 50.8 mm.

“Climate was quite variable with a wet winter in 1998 (September 1997 to April 1998 were all months with >100 mm) followed by a period of less precipitation and lower mean annual number of extreme precipitation days >50.8 mm (see Appendix).”

May combine two claims.

Case studies showed that the framework can detect delayed hydrological responses to wildfire and establish whether wildfire enhanced or attenuated streamflow regardless of precipitation trends during the evaluation period in the Arizona and California watersheds.

“Case studies showed that the framework can detect delayed hydrological responses to wildfire, and establish whether wildfire enhanced or attenuated streamflow regardless of precipitation trends during the period of evaluation (AZ and CA watersheds).”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

In Del Puerto Creek, the change in precipitation duration and the 75th percentile of streamflow was minor.

“Despite the minor change in precipitation duration and the 75 th percentile of streamflow”

May combine two claims.

Fire effects on streamflow differ by region and depend on pre-fire conditions, fire severity, and post-fire climate.

“these effects vary by geographic region and depend on pre-fire conditions, fire severity and post-fire climate (Neary et al., 2005)”

• cites Neary et al., 2005Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

A climate elasticity model using precipitation and temperature was not significantly better than one using precipitation alone.

“Biederman et al. (2015) found that the CEM with precipitation and temperature parameters was not a significantly better model than the CEM based on precipitation alone.”

• cites Biederman et al., 2015Not checked yet

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May combine two claims.

Although fire disturbance was responsible for a considerable increase in runoff, the effect was amplified by increased precipitation.

“Although fire disturbance is responsible for a considerable increase in runoff, the effect was amplified by increased precipitation (Table 3 and Figure 7a).”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

CEM1 models with a positive fitted beta were rejected because a positive beta would imply that higher PET increases streamflow.

“Each CEM 1 with a positive fitted value of β was rejected because this wrongly implies a scenario where a higher PET leads to more streamflow.”

May combine two claims.

Double-mass analysis needs only local data and has been applied to streamflow changes after fire, forest harvesting, mountain pine beetle outbreaks, and urbanization.

“Double-mass analysis (Merriam, 1937;Searcy and Hardison, 1960) requires only local data and assumes an approximately linear relationship between for example precipitation and streamflow when there are no changes in climate, land cover or water withdrawals”

• Also stated in: § INTRODUCTION · plain

  “has been used to assess streamflow changes after fire (e.g.Anderson et al., 1955), forest harvesting, mountain pine beetle infestations (Wei and Zhang, 2010;Zhang and Wei, 2012), and urbanization (Hao et al., 2015).”

• cites Merriam, 1937Not checked yet

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• cites Searcy and Hardison, 1960Not checked yet

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• cites Anderson et al., 1955Not checked yet

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May combine two claims.

WaSSI water yield simulations provided a climate-variability baseline, and comparing them with observed streamflow allowed estimation of the non-climate or disturbance contribution over time.

“Water yield simulations in WaSSI provided a baseline accounting for climate variability, and a comparison with observed streamflow allowed us to estimate the non-climate or disturbance contribution as a function of time (Eq.6).”

• AssumptionThe authors state this as an assumption: The observed change in streamflow is comprised of a climate-induced change and a component attributed to hydrologic disturbance.

May combine two claims.

Paired watershed analysis has been the standard for multi-year disturbance impacts, but comparable watersheds are often unavailable, restricting analysis to local data.

“Paired watershed analysis has long been the standard for quantifying multi-year disturbance impacts (Bosh and Hewlett, 1982), however a lack of comparable conditions between watersheds often limits the analysis to local data.”

• cites Bosh and Hewlett, 1982Not checked yet

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May combine two claims.

The CEM predicted a much greater reduction of streamflow (-52 mm or -102%) than observed, meaning that fire disturbance itself increased streamflow by +19 mm (+38%).

“however CEM 0 predicted a much greater reduction of streamflow (-52 mm or -102%) than observed, meaning that fire disturbance itself increased the streamflow by +19 mm (+38%).”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

The one-parameter precipitation climate elasticity model was retained over the two-parameter precipitation and PET model for all three watersheds and evaluated periods based on a higher AICc value.

“The one-parameter (precipitation) CEM 0 was retained at the expense of the two-parameter (precipitation and PET) CEM 1 for all three watersheds and evaluated periods (Table 3), based on a higher AIC c value.”

May combine two claims.

The predicted increase fell short of the observed increase of +134 mm (+266%), with the difference of +110 mm (+219%) representing the effect of the 2004 Willow Fire.

“This predicted increase in streamflow fell short of the observed increase of +134 mm (+266%), with the difference (+110 mm or +219%) representing the effect of the 2004 Willow Fire in this watershed.”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

Lepage-type tests do not require knowledge of the underlying distribution and have greater statistical power than Mann-Whitney, Chi-square, and Student's t-test statistics.

“Lepage-type tests do not require any knowledge of the underlying distribution of observations, and provide greater statistical power than the Mann-Whitney, Chi-square and student's t-test statistics (Hirakawa, 1974;Lloyd et al., 2014).”

• cites Hirakawa, 1974Not checked yet

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• cites Lloyd et al., 2014Not checked yet

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May combine two claims.

The discrepancy was possibly related to low winter precipitation in 2003 and 2008, which made water balance calculations more challenging and led to overestimation of the non-climate contribution to streamflow changes.

“While the dry winters were simulated correctly, the discrepancy was possibly related to low winter precipitation in 2003 and 2008, which represented a greater challenge for calculating water balances and lead to an overestimation of the non-climate contribution to streamflow changes (Figure 8b right panel).”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

Knowledge of fire effects on annual water yields in the United States is incomplete and rests mainly on a few experimental watersheds in the West.

“current knowledge about fire impacts on annual water yields in the United States is fragmentary and based primarily on only a small number of experimental watersheds in the western states.”

May combine two claims.

Fire may create an ash or water-repellent layer that blocks infiltration and decreases lateral soil flow.

“The formation of an ash layer or hydrophobic layer may inhibit infiltration and reduce lateral flow in the soil (DeBano, 2000;Jung et al., 2009)”

• cites DeBano, 2000Not checked yet

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• cites Jung et al., 2009Not checked yet

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May combine two claims.

Fire can affect peak flows, base flows, and yearly water yields for multiple years, with possible consequences for downstream city water supplies.

“fire impacts on peak flows, base flows and annual water yields can last for years and potentially affect downstream municipal water supplies (Shakesby and Doerr, 2006;Silins et al., 2014)”

• cites Shakesby and Doerr, 2006Not checked yet

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• cites Silins et al., 2014Not checked yet

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May combine two claims.

Change point analysis can identify when a time series shifts in location and scale without needing a second variable, unlike double-mass analysis.

“Time series analysis now features methods such as change point analysis (Hawkins et al., 2003;Hawkins and Zamba, 2005;Wang et al., 2016) to identify the timing of significant change in the location and scale of a time series rather than relying on a second variable like the double-mass analysis”

• cites Hawkins et al., 2003Not checked yet

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• cites Hawkins and Zamba, 2005Not checked yet

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• cites Wang et al., 2016Not checked yet

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May combine two claims.

Loss of canopy raises the amount of precipitation reaching the ground, which can increase surface runoff and storm flow.

“Canopy loss increases net precipitation at the surface (Helvey and Patric, 1965;National Research Council, 2008), leading to more surface runoff and accelerated storm flow.”

• cites Helvey and Patric, 1965Not checked yet

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• cites National Research Council, 2008Not checked yet

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Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based). May combine two claims.

Hydrologic response to wildfire is highly non-linear in snow-dominated, arid, or drought-affected systems, and under such conditions the framework would benefit from a more physically based nonlinear CEM.

“Hydrologic response to wildfire is highly non-linear in snowdominated, arid or drought-affected systems and under such conditions the framework would benefit from a more physically based nonlinear CEM.”

May combine two claims.

The change point model was used to detect observed changes in streamflow, while the double-mass curve was used to evaluate changes in water yield efficiency (streamflow expected based on precipitation).

“The CPM was used to detect observed changes in streamflow, while the DMC was used to evaluate changes in water yield efficiency (streamflow expected based on precipitation).”

May combine two claims.

The accuracy of the attribution analysis depends on the performance of models in the framework, and may be considered acceptable for temperate, humid, and Mediterranean climates provided that annual water yield efficiencies are approximately constant during the pre-disturbance and post-disturbance periods.

“The accuracy of the attribution analysis depends on the performance of models in the framework, and may be considered acceptable for temperate, humid and Mediterranean climates provided that annual water yield efficiencies (runoff coefficients) are approximately constant during the pre-disturbance and post-disturbance periods, respectively.”

Probably not a substantial claim: may not pass S3 (load-bearing).

At least 20% of basal area of vegetation must be removed to cause any significant change in streamflow.

“Estimates say that at least 20% of basal area of vegetation must be removed to cause any significant change in streamflow (Bosch and Hewlett, 1982;Stednick, 1996).”

• cites Bosch and Hewlett, 1982Not checked yet

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• cites Stednick, 1996Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims. The quote only partly states this claim.

Therefore, the change in streamflow was possibly the result of a combination of dam failure, beaver activity, major weather events, or water management and water usage.

“Therefore, the change in streamflow was possibly the result of a combination of dam failure (Carolina Sandhills NWR, 1994;1999), beaver activity (Carolina Sandhills NWR, 1999), major weather events (severe thunderstorm on May 6 th , 1999 that killed many trees; National Climatic Data Center Storm Events Database, retrieved February 8, 2016; and an ice and snowstorm on January 24-25, 2000;Carolina”

• cites Carolina Sandhills NWR, 1994Not checked yet

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• cites Carolina Sandhills NWR, 1999Not checked yet

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• cites National Climatic Data Center Storm Events DatabaseNot checked yet

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May combine two claims.

The change point model and double-mass curve were used to evaluate slightly different types of disturbances and are complementary tools in the framework.

“The CPM and DMC were used to evaluate slightly different types of disturbances and are complementary tools in the framework.”

Classified as probably not a substantial claim. May combine two claims.

The framework combines hydrological data and methods into a single procedure for assessing wildland fire impacts on water yields in single watersheds, and is more practical than traditional paired watershed analysis.

“The framework combines hydrological data and methods into a single procedure for the assessment of wildland fire impacts on water yields in single watersheds, and as such presents a more practical assessment tool compared to traditional paired watershed analysis.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Long- and short-term drought is common in regions such as Southern California, Nevada, and other parts of the Southwest, where it contributes to wildfire and affects streamflow.

“Long and short term drought is common in regions like Southern California, Nevada and other parts of the Southwest, where it represents a contributing factor to wildfire and affects streamflow (Littell et al., 2016).”

• cites Littell et al., 2016Not checked yet

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May combine two claims.

The change point model can detect multiple disturbances using the Lepage test, whereas the classic double-mass curve approach evaluates only one disturbance at a time using the F test.

“On the other hand, CPM can detect multiple disturbances (with the Lepage test), where the classic DMC approach evaluates only one disturbance at a time (F test).”

May combine two claims.

Storm flow studies emphasize the importance of the organization of flow paths on the timing of flow delivery at the base of the hillslope and the watershed, but the framework lumps all these effects together.

“Storm flow studies emphasize the importance of the organization of flow paths on the timing of flow delivery at the base of the hillslope (Hallema et al., 2014;2016) and the watershed (Hallema et al., 2013), however the framework lumps all these effects together.”

• cites Hallema et al., 2014Not checked yet

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• cites Hallema et al., 2016Not checked yet

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• cites Hallema et al., 2013Not checked yet

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May combine two claims.

El Niño effects are strong in this part of California, and the high precipitation during the 1997-1998 phase may have caused erosion and alteration of the streambed, producing a breakpoint in the double-mass curve.

“El Niño effects are strong in this part of California (Hoell et al., 2016), and the high precipitation during 1997-1998 phase may have resulted in erosion and alteration of the streambed, causing a breakpoint in the DMC (Figure 6c).”

• cites Hoell et al., 2016Not checked yet

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May combine two claims.

This eliminates the possibility of evaluating wildland fire impacts on individual hydrological processes, but also creates the possibility of evaluating wildland fire effects on a much wider range of watersheds.

“This eliminates the possibility to evaluate wildland fire impacts on individual hydrological processes (e.g., infiltration and storm flow generation) but also creates the possibility to evaluate wildland fire effects on a much wider range of watersheds.”

May combine two claims.

The framework can separate climate effects overlapping with non-climate effects, but multiple overlapping non-climate disturbances are sometimes difficult to disentangle.

“The framework can separate climate effects overlapping with non-climate effects, however multiple overlapping non-climate disturbances are sometimes difficult to disentangle.”

May combine two claims.

Nevertheless, a 10-year CEM does not necessarily improve the accuracy of attribution analysis for individual wildfires, because in the California watershed there was another smaller fire in 1996 within this period.

“Nevertheless, this does not imply that the 10-year CEM improves the accuracy of the attribution analysis for individual wildfires because in the case of the CA watershed there was another, smaller fire (1996) in this period.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

The framework is a step up from traditional analyses because it can be used with long-term streamflow data from a single flow station, and does rely on paired watershed data.

“The framework is a step up from traditional analyses because it can be used with long-term streamflow data from a single flow station, and does rely on paired watershed data.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The corrected Akaike information criterion imposes a greater penalty for extra parameters, thus decreasing the probability of overfitting the climate elasticity model by adding too many parameters.

“The AIC c is based on Akaike's information criterion (Akaike, 1973), and imposes a greater penalty for extra parameters, thus decreasing the probability of overfitting the climate elasticity model as a result of adding too many parameters.”

• cites Akaike, 1973Not checked yet

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May combine two claims.

Furthermore, if there is more than one potential disturbance event, the change point model can indicate the relative impact of each disturbance, making the framework suitable for a wide range of applications including hydrologic impact assessment of wildland fires, erosion modeling, and post-fire management.

“Furthermore, if there is more than one potential disturbance event, the change point model can indicate the relative impact of each disturbance, making the framework suitable for a wide range of applications including hydrologic impact assessment of wildland fires, erosion modeling and post-fire management.”

May combine two claims.

The framework uses change point and double-mass curve methods to detect changes in streamflow, and a climate elasticity model to distinguish the contributions of climate and wildland fire or other non-climate disturbances to that change.

“Yes, the framework uses CPM and DMC to detect changes in streamflow, and subsequently a CEM to distinguish between the respective contributions of climate and wildland fire or other non-climate related disturbances to that streamflow change.”

May combine two claims.

This is necessary because wildfire and precipitation trends can partly cancel each other out, as in the California watershed, in which case streamflow data alone may not be sufficient to find the timing of the disturbance.

“This is necessary because wildfire and precipitation trends can partly cancel each other out (CA watershed) in which case streamflow data alone may not be sufficient to find the timing of the disturbance.”

Probably not a substantial claim: may not pass S3 (load-bearing).

CEM results can be compared to an attribution analysis based on WaSSI hydrologic simulations.

“CEM results can subsequently be compared to an attribution analysis based on WaSSI hydrologic simulations.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

The flow duration curve changes as a result of climate variability and/or watershed characteristics, and for this reason provides an important indicator for watershed disturbance.

“The FDC changes as a result of climate variability and/or watershed characteristics, and for this reason provides an important indicator for watershed disturbance.”

Probably not a substantial claim: may not pass S4 (based).

The disadvantage of the change point model is that the Lepage statistic for intermittent or ephemeral streamflow series will rarely be significant if there are many months with zero flow.

“The disadvantage of CPM is that the Lepage statistic for intermittent or ephemeral streamflow series will rarely be significant (L>h t given α) if there are many months out of the year with zero flow.”

May combine two claims.

The modest contribution of wildfire to streamflow change in the California watershed was consistent with the rapid recovery of NDVI, and conversely, the slow recovery of NDVI in the Arizona watershed agreed with the large contribution of wildfire to streamflow change there.

“The modest contribution of wildfire to streamflow change in the CA watershed was furthermore consistent with the rapid recovery of NDVI and conversely, the slow recovery of NDVI in the AZ watershed agreed with the large contribution of wildfire to streamflow change there.”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

The modest increase in streamflow in the South Carolina watershed attributed to non-climate factors could not be linked with individual prescribed fires, which agrees with earlier observations that low-severity prescribed fires are unlikely to influence water yield, especially compared to high-severity wildfires.

“The modest increase in streamflow in the SC watershed attributed to non-climate factors could not be linked with individual prescribed fires, which agrees with earlier observations by Troendle et al. (2010) that low severity prescribed fires are unlikely to influence water yield, especially compared to the effects of high severity wildfires.”

• cites Troendle et al. (2010)Not checked yet

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• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

The framework's finding of an increase in runoff coefficient in the California watershed from 4% to 5.8% despite a 64% lower yield agrees with the steady baseflow observed throughout most of the winter in the post-fire period.

“The framework found an increase in runoff coefficient of the CA watershed from 4% to 5.8% despite a -64% lower yield agrees with the steady baseflow observed throughout most of the winter in the post-fire period.”

May combine two claims.

High burn severity drastically reduces evapotranspiration, increases net precipitation, and leaves the soil exposed to direct rainfall impact.

“High burn severity reduces evapotranspiration drastically, increases net precipitation, and leaves the soil exposed to direct rainfall impact (Winkler et al., 2010).”

• cites Winkler et al., 2010Not checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

A framework was presented for assessing wildland fire impacts on annual water yields in watersheds.

“A framework was presented for the assessment of wildland fire impacts on annual water yields in watersheds.”

May combine two claims.

Wildfire had an increasing effect on 5-year water yields in the Arizona and California watersheds, but the net amount and direction of streamflow change also depended on climate trends: the response was amplified by a positive precipitation trend in Arizona and attenuated in California where post-wildfire precipitation was lower.

“Wildfire had an increasing effect on 5-year water yields in the AZ and CA watersheds, however the net amount of change in streamflow and the direction of this change also depended on climate trends: an amplified response in conjunction with a positive trend in precipitation in the AZ watershed and an attenuated response in the CA watershed where post-wildfire precipitation was lower.”

• AssumptionThe authors state this as an assumption: The streamflow change not accounted for by climate represents the net positive contribution of watershed disturbance.

May combine two claims.

This is explained by the stable annual water yield of 33% and perennial streamflow resulting from year-round precipitation, which can be accurately represented in a linear CEM.

“This is explained by the stable annual water yield (of 33%) and perennial streamflow resulting from year-round precipitation, which can be accurately represented in a linear CEM.”

May combine two claims.

Snow is the dominant hydrologic input in much of the western United States, and therefore snow processes are important controlling factors of streamflow disturbance in this area.

“Notwithstanding, snow is the dominant hydrologic input in much of the western United States (Rocky Mountains, Sierra Nevada, Cascade Ranges) and therefore snow processes (annual snowfall, snowmelt, sublimation) are important controlling factors of streamflow disturbance in this area (Troendle and King, 1985;Harpold et al., 2014).”

• cites Troendle and King, 1985Not checked yet

  Not checked in the free run.

• cites Harpold et al., 2014Not checked yet

  Not checked in the free run.

May combine two claims.

Each set of climate and watershed characteristics yields a unique flow duration curve, which typically contains a fast flow component and a delayed flow component.

“Each set of climate and watershed characteristics yields a unique FDC, and typically contains a fast flow component and a delayed flow component.”

May combine two claims.

Choosing an appropriate length is very challenging in California watersheds where high fire frequency meets extreme climate and ephemeral runoff, and in this case the true wildfire effect on runoff may lie somewhere between the values attributed using the 5-year and 10-year reference periods.

“Choosing an appropriate length is very challenging in California watersheds where high fire frequency meets extreme climate and ephemeral runoff, and in this case the true wildfire effect on runoff may lie somewhere between the values attributed using the 5-year and 10-year reference periods, respectively.”

May combine two claims.

Post-fire soil surface sealing and heat-induced soil water repellency change the amount of runoff generated along the hillslope, while the spatial sequence of burned areas controls how much of the generated runoff is transported downhill.

“Post-fire soil surface sealing and heat-induced soil water repellency change the amount of runoff generated along the hillslope (Larsen et al., 2009;Ebel et al., 2012), while the spatial sequence of burned areas controls how much of the generated runoff is transported downhill (Moody et al., 2016).”

• cites Larsen et al., 2009Not checked yet

  Not checked in the free run.

• cites Ebel et al., 2012Not checked yet

  Not checked in the free run.

• cites Moody et al., 2016Not checked yet

  Not checked in the free run.

May combine two claims.

The framework uses a change point model to identify and assess multiple disturbances where they exist, and a climate elasticity model to determine the contributions of climate variability and wildland fire to streamflow changes over a multi-year period.

“This framework uses a change point model to identify and assess multiple disturbances where existing, and a climate elasticity model to determine the contributions of climate variability and wildland fire to streamflow changes over a multi-year period.”

May combine two claims.

The 2014 summer peak NDVI of 0.48 in Del Puerto Creek indicates progress in post-disturbance recovery despite low precipitation (<400 mm) in 2006, 2009, 2011, and 2012.

“and demonstrated progress in post-disturbance recovery despite a low precipitation of <400 mm in 2006, 2009, 2011 and 2012.”

Classified as probably not a substantial claim.

Model selection for the climate elasticity models was based on the lowest small-sample AIC.

“Model selection was based on the lowest small-sample AIC (Sugiura, 1978; Hurvich and Tsai, 1991).”

• cites Sugiura, 1978Not checked yet

  Not checked in the free run.

• cites Hurvich and Tsai, 1991Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

The Wet Bottom Creek watershed in Arizona was affected by the 2004 Willow Fire.

“Wet Bottom Creek watershed (AZ) and the 2004 Willow Fire”

• cites Monitoring Trends in Burn Severity, 2014Not checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

The Del Puerto Creek watershed in California was affected by the 2003 Deer Park Fire.

“Del Puerto Creek watershed (CA) and the 2003 Deer Park Fire”

• cites Monitoring Trends in Burn Severity, 2014Not checked yet

  Not checked in the free run.