The technique presented in the paper is very interesting. In fact it is part of a group of new me... more The technique presented in the paper is very interesting. In fact it is part of a group of new methodologies for evaluating surface velocities through image analysis, with the characteristic of using fluorescent seeds. It is applied for measuring surface velocity along a hillslope, which is an important issue. However I have concerns on its reliability in real situations and about the magnitude of the measurement errors. In the following, a more detailed description of the specific aspects that need to be clarified is reported. In conclusion, I believe that the paper is very interesting and well written, so I suggest that I could be published after a moderate revision.
We thank the reviewer, DSc, PhD Chertkov, for his extensive comments on our manuscript. The thoro... more We thank the reviewer, DSc, PhD Chertkov, for his extensive comments on our manuscript. The thorough review will help us to improve the quality of the work. Below we reply on the comments from the reviewer. For readability, the major parts of the reviewer’s comments most relevant for discussion are quoted (indicated by GC or SC for general or specific comments), followed by the author’s response (AR). In some cases the response to multiple comments is combined.
The paper investigates how different methods for estimating the field capacity impact the results... more The paper investigates how different methods for estimating the field capacity impact the results of a bucket model for long-term soil moisture dynamics. The performances of the soil moisture bucket model are evaluated in terms of the difference with a more detailed model based on the Richards equation (the SWAP model). In particular, the work considers two alternative methods to estimate the value of the soil moisture at field capacity: fix and drain method. The different methods are compared for two different soils (loamy-sand and clay) and two different seasons (dry and wet). In the case of a clay soil, fix and drain methods give very similar results for the value of soil moisture at field capacity; consequently the bucket model outputs in term of soil
2. Using the semivariogram of original rainfall data instead of residuals for KED is certainly a ... more 2. Using the semivariogram of original rainfall data instead of residuals for KED is certainly a simplification. The difficulty lies in the simultaneously unknown trend and residuals. To overcome this problem, the trend component could be computed with a slightly modified KED system (Deutsch and Journel, 1992), while calculating the residuals and the residual semivariogram afterwards. However, this iterative process would be very demanding. Another simpler approach could be to infer the semivariogram only from data pairs, that are unaffected by the trend. Investigations of Haberlandt (2007) have shown though, that there were no differences in interpolation performance, which was the reason, why we applied the simplified approach in our study as well.
Cokriging is certainly one of the options for interpolation. Those parameters may be correlated. ... more Cokriging is certainly one of the options for interpolation. Those parameters may be correlated. However, it will be very difficult and time-consuming to decide which parameter(s) will be used for secondary variable(s) as there are at least four parameters in each approach leading to a total of 24 possible combinations. The number of parameters used is nine for the NP approach (IF approach in the revised manuscript). In this sense, although we can do some arbitrary combinations of parameters, using parameters as the secondary variable in cokriging is not practically feasible, unless some prior knowledge is available on which parameters are correlated well with which other parameters. If cokriging is used, then the secondary variable should be the one obtained independently, such as in-situ water contents, so that this information can be used as a
Rendiconti Online della Società Geologica Italiana, 2016
The knowledge of the mechanisms regulating the concentration of nutrients in rivers is of fundame... more The knowledge of the mechanisms regulating the concentration of nutrients in rivers is of fundamental importance in maintaining the ecological functioning of streams. In particular, in the riverbed sediments, where the biogeochemical activity is enhanced, the study of retention mechanisms becomes crucial in order to determine the restoring capacity of a watercourse. In case of groundwater inflow, hot-spots in the recycling of nutrients within the riparian and hyporheic zones can be observed, influencing the nutrient load transported into the stream depending on retention mechanisms. Hence, the study of biotic and abiotic factors affecting retention and transport of nutrients in a riverine ecosystem at different spatial scales (from reach to catchment) becomes fundamental to understand the mechanisms regulating the concentration of nutrients, and in particular nitrates, in streams. The present work is developed within the framework of the IAEA Coordinated Research Project (CRP) Environmental Isotopes and Age Dating Methods to Assess Nitrogen Pollution and Other Quality Issues in Rivers. The main scope is to find a reliable methodology to, spatially and temporally, quantify groundwater inflows to a river in order to study nitrates contamination of a groundwater dependent river ecosystem. In particular, the overall objectives of the proposed project are: i) the identification and quantification of spatio-temporal variation of the connectivity between groundwater and surface water; ii) the identification of the nitrate contamination sources of shallow groundwater; iii) the study of the nitrates retention and recycling mechanisms in riverbed sediments in critical effluent river reaches (key sites) in order to determine the importance of hyporheic and riparian zones. Here, the preliminary results of the hydrogeological, chemical and isotopic (222Rn, δ18O, δD) monitoring are presented and discussed.
The Science of the total environment, Jan 22, 2016
The boreal forest of the northern hemisphere represents one of the world's largest ecozones a... more The boreal forest of the northern hemisphere represents one of the world's largest ecozones and contains nearly one third of the world's intact forests and terrestrially stored carbon. Long-term variations in temperature and precipitation have been implied in altering carbon cycling in forest soils, including increased fluxes to receiving waters. In this study, we use a simple hydrologic model and a 40-year dataset (1971-2010) of dissolved organic carbon (DOC) from two pristine boreal lakes (ELA, Canada) to examine the interactions between precipitation and landscape-scale controls of DOC production and export from forest catchments to surface waters. Our results indicate that a simplified hydrologically-based conceptual model can enable the long-term temporal patterns of DOC fluxes to be captured within boreal landscapes. Reconstructed DOC exports from forested catchments in the period 1901-2012 follow largely a sinusoidal pattern, with a period of about 37years and are tig...
Changes in the spatial and temporal patterns of extreme rainfall may have important effects on th... more Changes in the spatial and temporal patterns of extreme rainfall may have important effects on the magnitude and timing of rainfall erosivity, which in turn lead to even severe soil degradation phenomena. The Mediterranean belt is characterized by strong climatic variability and specific seasonal features, where dry periods are often interrupted by pulsing storms. Identifying the thresholds associated with extreme rainfall events is among the most important challenges for this region. To discern the spatial patterns of rainfall erosivity hazard in the Rhone region (eastern France), this study establishes thresholds in the power of rainstorms. An indicator Kriging approach was employed for computing probability maps of the annual rainfall erosivity exceeding the threshold of 1800 MJ mm ha−1 h−1, the latter being twice greater than the standard deviation. The interdecadal spatial patterns of hazard were assessed for recent decades (1991–2010) and the precedents ones (1961–1990). Clima...
INTRODUCTION This poster presents the preliminary results of the Italian project in the framework... more INTRODUCTION This poster presents the preliminary results of the Italian project in the framework of the CRP project " Environmental isotopes and age dating methods to assess nitrogen pollution and other quality issues in rivers " at the end of the first year of activities. The motivation of the proposed research was to find a reliable methodology for water resources management in alluvial plains heavily impacted by nutrient supplies, particularly nitrates, to groundwater and surface waters focusing on the identification of contamination sources and the recycling and retention capacity of the transition zones of the riverine ecosystem (i.e. hyporheic and riparian zones).
Summary Soil moisture refers to the water present in the uppermost part of a field soil and is a ... more Summary Soil moisture refers to the water present in the uppermost part of a field soil and is a state variable controlling a wide array of ecological, hydrological, geotechnical, and meteorological processes. The literature on soil moisture is very extensive and is developing so rapidly that it might be considered ambitious to seek to present the state of the art concerning research into this key variable. Even when covering investigations about only one aspect of the problem, there is a risk of some inevitable omission. A specific feature of the present essay, which may make this overview if not comprehensive at least of particular interest, is that the reader is guided through the various traditional and more up-to-date methods by the central thread of techniques developed to measure soil moisture interwoven with applications of modeling tools that exploit the observed datasets. This paper restricts its analysis to the evolution of soil moisture at the local (spatial) scale. Though a somewhat loosely defined term, it is linked here to a characteristic length of the soil volume investigated by the soil moisture sensing probe. After presenting the most common concepts and definitions about the amount of water stored in a certain volume of soil close to the land surface, this paper proceeds to review ground-based methods for monitoring soil moisture and evaluates modeling tools for the analysis of the gathered information in various applications. Concluding remarks address questions of monitoring and modeling of soil moisture at scales larger than the local scale with the related issue of data aggregation. An extensive, but not exhaustive, list of references is provided, enabling the reader to gain further insights into this subject.
The technique presented in the paper is very interesting. In fact it is part of a group of new me... more The technique presented in the paper is very interesting. In fact it is part of a group of new methodologies for evaluating surface velocities through image analysis, with the characteristic of using fluorescent seeds. It is applied for measuring surface velocity along a hillslope, which is an important issue. However I have concerns on its reliability in real situations and about the magnitude of the measurement errors. In the following, a more detailed description of the specific aspects that need to be clarified is reported. In conclusion, I believe that the paper is very interesting and well written, so I suggest that I could be published after a moderate revision.
We thank the reviewer, DSc, PhD Chertkov, for his extensive comments on our manuscript. The thoro... more We thank the reviewer, DSc, PhD Chertkov, for his extensive comments on our manuscript. The thorough review will help us to improve the quality of the work. Below we reply on the comments from the reviewer. For readability, the major parts of the reviewer’s comments most relevant for discussion are quoted (indicated by GC or SC for general or specific comments), followed by the author’s response (AR). In some cases the response to multiple comments is combined.
The paper investigates how different methods for estimating the field capacity impact the results... more The paper investigates how different methods for estimating the field capacity impact the results of a bucket model for long-term soil moisture dynamics. The performances of the soil moisture bucket model are evaluated in terms of the difference with a more detailed model based on the Richards equation (the SWAP model). In particular, the work considers two alternative methods to estimate the value of the soil moisture at field capacity: fix and drain method. The different methods are compared for two different soils (loamy-sand and clay) and two different seasons (dry and wet). In the case of a clay soil, fix and drain methods give very similar results for the value of soil moisture at field capacity; consequently the bucket model outputs in term of soil
2. Using the semivariogram of original rainfall data instead of residuals for KED is certainly a ... more 2. Using the semivariogram of original rainfall data instead of residuals for KED is certainly a simplification. The difficulty lies in the simultaneously unknown trend and residuals. To overcome this problem, the trend component could be computed with a slightly modified KED system (Deutsch and Journel, 1992), while calculating the residuals and the residual semivariogram afterwards. However, this iterative process would be very demanding. Another simpler approach could be to infer the semivariogram only from data pairs, that are unaffected by the trend. Investigations of Haberlandt (2007) have shown though, that there were no differences in interpolation performance, which was the reason, why we applied the simplified approach in our study as well.
Cokriging is certainly one of the options for interpolation. Those parameters may be correlated. ... more Cokriging is certainly one of the options for interpolation. Those parameters may be correlated. However, it will be very difficult and time-consuming to decide which parameter(s) will be used for secondary variable(s) as there are at least four parameters in each approach leading to a total of 24 possible combinations. The number of parameters used is nine for the NP approach (IF approach in the revised manuscript). In this sense, although we can do some arbitrary combinations of parameters, using parameters as the secondary variable in cokriging is not practically feasible, unless some prior knowledge is available on which parameters are correlated well with which other parameters. If cokriging is used, then the secondary variable should be the one obtained independently, such as in-situ water contents, so that this information can be used as a
Rendiconti Online della Società Geologica Italiana, 2016
The knowledge of the mechanisms regulating the concentration of nutrients in rivers is of fundame... more The knowledge of the mechanisms regulating the concentration of nutrients in rivers is of fundamental importance in maintaining the ecological functioning of streams. In particular, in the riverbed sediments, where the biogeochemical activity is enhanced, the study of retention mechanisms becomes crucial in order to determine the restoring capacity of a watercourse. In case of groundwater inflow, hot-spots in the recycling of nutrients within the riparian and hyporheic zones can be observed, influencing the nutrient load transported into the stream depending on retention mechanisms. Hence, the study of biotic and abiotic factors affecting retention and transport of nutrients in a riverine ecosystem at different spatial scales (from reach to catchment) becomes fundamental to understand the mechanisms regulating the concentration of nutrients, and in particular nitrates, in streams. The present work is developed within the framework of the IAEA Coordinated Research Project (CRP) Environmental Isotopes and Age Dating Methods to Assess Nitrogen Pollution and Other Quality Issues in Rivers. The main scope is to find a reliable methodology to, spatially and temporally, quantify groundwater inflows to a river in order to study nitrates contamination of a groundwater dependent river ecosystem. In particular, the overall objectives of the proposed project are: i) the identification and quantification of spatio-temporal variation of the connectivity between groundwater and surface water; ii) the identification of the nitrate contamination sources of shallow groundwater; iii) the study of the nitrates retention and recycling mechanisms in riverbed sediments in critical effluent river reaches (key sites) in order to determine the importance of hyporheic and riparian zones. Here, the preliminary results of the hydrogeological, chemical and isotopic (222Rn, δ18O, δD) monitoring are presented and discussed.
The Science of the total environment, Jan 22, 2016
The boreal forest of the northern hemisphere represents one of the world's largest ecozones a... more The boreal forest of the northern hemisphere represents one of the world's largest ecozones and contains nearly one third of the world's intact forests and terrestrially stored carbon. Long-term variations in temperature and precipitation have been implied in altering carbon cycling in forest soils, including increased fluxes to receiving waters. In this study, we use a simple hydrologic model and a 40-year dataset (1971-2010) of dissolved organic carbon (DOC) from two pristine boreal lakes (ELA, Canada) to examine the interactions between precipitation and landscape-scale controls of DOC production and export from forest catchments to surface waters. Our results indicate that a simplified hydrologically-based conceptual model can enable the long-term temporal patterns of DOC fluxes to be captured within boreal landscapes. Reconstructed DOC exports from forested catchments in the period 1901-2012 follow largely a sinusoidal pattern, with a period of about 37years and are tig...
Changes in the spatial and temporal patterns of extreme rainfall may have important effects on th... more Changes in the spatial and temporal patterns of extreme rainfall may have important effects on the magnitude and timing of rainfall erosivity, which in turn lead to even severe soil degradation phenomena. The Mediterranean belt is characterized by strong climatic variability and specific seasonal features, where dry periods are often interrupted by pulsing storms. Identifying the thresholds associated with extreme rainfall events is among the most important challenges for this region. To discern the spatial patterns of rainfall erosivity hazard in the Rhone region (eastern France), this study establishes thresholds in the power of rainstorms. An indicator Kriging approach was employed for computing probability maps of the annual rainfall erosivity exceeding the threshold of 1800 MJ mm ha−1 h−1, the latter being twice greater than the standard deviation. The interdecadal spatial patterns of hazard were assessed for recent decades (1991–2010) and the precedents ones (1961–1990). Clima...
INTRODUCTION This poster presents the preliminary results of the Italian project in the framework... more INTRODUCTION This poster presents the preliminary results of the Italian project in the framework of the CRP project " Environmental isotopes and age dating methods to assess nitrogen pollution and other quality issues in rivers " at the end of the first year of activities. The motivation of the proposed research was to find a reliable methodology for water resources management in alluvial plains heavily impacted by nutrient supplies, particularly nitrates, to groundwater and surface waters focusing on the identification of contamination sources and the recycling and retention capacity of the transition zones of the riverine ecosystem (i.e. hyporheic and riparian zones).
Summary Soil moisture refers to the water present in the uppermost part of a field soil and is a ... more Summary Soil moisture refers to the water present in the uppermost part of a field soil and is a state variable controlling a wide array of ecological, hydrological, geotechnical, and meteorological processes. The literature on soil moisture is very extensive and is developing so rapidly that it might be considered ambitious to seek to present the state of the art concerning research into this key variable. Even when covering investigations about only one aspect of the problem, there is a risk of some inevitable omission. A specific feature of the present essay, which may make this overview if not comprehensive at least of particular interest, is that the reader is guided through the various traditional and more up-to-date methods by the central thread of techniques developed to measure soil moisture interwoven with applications of modeling tools that exploit the observed datasets. This paper restricts its analysis to the evolution of soil moisture at the local (spatial) scale. Though a somewhat loosely defined term, it is linked here to a characteristic length of the soil volume investigated by the soil moisture sensing probe. After presenting the most common concepts and definitions about the amount of water stored in a certain volume of soil close to the land surface, this paper proceeds to review ground-based methods for monitoring soil moisture and evaluates modeling tools for the analysis of the gathered information in various applications. Concluding remarks address questions of monitoring and modeling of soil moisture at scales larger than the local scale with the related issue of data aggregation. An extensive, but not exhaustive, list of references is provided, enabling the reader to gain further insights into this subject.
3. Results 4.Conclusions 1. Project context and motivations Assessing the impact of farmland aban... more 3. Results 4.Conclusions 1. Project context and motivations Assessing the impact of farmland abandonment on ecosystem services of a catchment in Southern Italy In mountainous areas of Mediterranean Europe farming systems have been subjected to progressive abandonment and subsequent expansion of forest during the second half of the 20th century. Therefore, an in-depth knowledge of the influence of afforestation on catchment-scale budget helps define proper trade-offs in regulating and provisioning Hydrologic Ecosystem Services (HES). While it is common evidence that afforestation increases the amount of water consumption and reduces downstream water availability at local or catchment scales (demand-side view), on the other hand, forest might be envisioned as a source of water that contributes in the intensification of the hydrologic cycle at regional or even continental scales (supply-side view). In a demand-side context, our major objective is to compute absolute and relative changes in the average annual and monthly water and sediment budgets by using available historical land-use/land-cover (LULC) maps built in 1955, 1998 and 2015. In contrast, in a supply-side point of view, a second target of this study encompasses the analysis of the relationship between monthly rainfall characteristics and simulated water yield.
SOMMARIO Le applicazioni di modelli idrologici distribuiti a situazioni di pratico interesse rich... more SOMMARIO Le applicazioni di modelli idrologici distribuiti a situazioni di pratico interesse richie-dono un'idonea caratterizzazione della risposta idrologica del suolo e la rappresenta-zione di fenomeni ad una scala maggiore di quella in cui sono state eseguite le misure. Tali problematiche chiamano in gioco questioni legate alla particolare scala di interesse del modello e alla variabilità spaziale delle proprietà del sistema. Alcuni esempi evi-denziano come le proprietà idrauliche dei suoli ottenute con prove di laboratorio o svolte in piccole parcelle di campo possano essere proficuamente impiegate per descrivere l'evoluzione di processi idrologici nel suolo alle maggiori scale spaziali.
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