scholarly journals Effects of drainage treatment and stand growth on changes in runoff components from a forested watershed

2010 ◽  
Vol 56 (No. 7) ◽  
pp. 307-313
Author(s):  
V. Černohous ◽  
F. Šach ◽  
D. Kacálek
Keyword(s):  
Land Surface ◽  
Overland Flow ◽  
Source Area ◽  
Base Flow ◽  
Forested Watershed ◽  
Runoff Generation ◽  
Forest Environment ◽  
Variable Source ◽  
Positive Ratio ◽  
Long Time

Runoff generation under various natural conditions has often been studied in forested watersheds for a long time. In 1967, Hewlett designed a variable source area model. The model is based on the expansion and shrinkage of variable source areas and consequent changes in a drainage network during a discharge event. The runoff investigation was carried out in a forested watershed situated in the summit area of the Orlické hory Mts. The watershed has a drainage area of 32.6 ha with the land-surface elevation ranging from 880 to 940 m a.s.l. Runoff components, their amounts and ratios were calculated using a simple graphical-mathematical method of the hydrograph recession limb analysis according to a reservoir model representing the particular components (base flow, subsurface flow and overland flow, in other words slow, accelerated and rapid flows). Comparing the amount of slow and rapid runoff constituents (89.5–99.4% and 0.6–10.5%, respectively), the greater amount of slowly moving water confirmed that overland flow was absent under conditions of forest environment. Not even the drainage treatment altered this positive ratio of the runoff constituents. During the third period, under stabilized hydrology and stand conditions, the accelerated and rapid runoff increased again, however maximally by 10% and 4%, respectively, not reaching the initial size of the calibration period.

scholarly journals A simple topography-driven and calibration-free runoff generation module

2019 ◽  
Vol 23 (2) ◽  
pp. 787-809 ◽  
Author(s):  
Hongkai Gao ◽  
Christian Birkel ◽  
Markus Hrachowitz ◽  
Doerthe Tetzlaff ◽  
Chris Soulsby ◽  
...  
Keyword(s):  
Land Surface ◽  
Forest Cover ◽  
Storage Capacity ◽  
Root Zone ◽  
Global Scale ◽  
Runoff Generation ◽  
The Us ◽  
Long Time ◽  
Calibration Free ◽  
Rainfall Runoff Model

Abstract. Reading landscapes and developing calibration-free runoff generation models that adequately reflect land surface heterogeneities remains the focus of much hydrological research. In this study, we report a novel and simple topography-driven runoff generation parameterization – the HAND-based Storage Capacity curve (HSC), which uses a topographic index (HAND, Height Above the Nearest Drainage) to identify hydrological similarity and the extent of saturated areas in catchments. The HSC can be used as a module in any conceptual rainfall–runoff model. Further, coupling the HSC parameterization with the mass curve technique (MCT) to estimate root zone storage capacity (SuMax), we developed a calibration-free runoff generation module, HSC-MCT. The runoff generation modules of HBV and TOPMODEL were used for comparison purposes. The performance of these two modules (HSC and HSC-MCT) was first checked against the data-rich Bruntland Burn (BB) catchment in Scotland, which has a long time series of field-mapped saturation area extent. We found that HSC, HBV and TOPMODEL all perform well to reproduce the hydrograph, but the HSC module performs better in reproducing saturated area variation, in terms of correlation coefficient and spatial pattern. The HSC and HSC-MCT modules were subsequently tested for 323 MOPEX catchments in the US, with diverse climate, soil, vegetation and geological characteristics. In comparison with HBV and TOPMODEL, the HSC performs better in both calibration and validation, particularly in the catchments with gentle topography, less forest cover, and arid climate. Despite having no calibrated parameters, the HSC-MCT module performed comparably well with calibrated modules, highlighting the robustness of the HSC parameterization to describe the spatial distribution of the root zone storage capacity and the efficiency of the MCT method to estimate SuMax. This novel and calibration-free runoff generation module helps to improve the prediction in ungauged basins and has great potential to be generalized at the global scale.

scholarly journals Development and calibration of a global hydrological model for integrated assessment modeling

2017 ◽  
Author(s):  
Tingju Zhu ◽  
Petra Döll ◽  
Hannes Müller Schmied ◽  
Claudia Ringler ◽  
Mark W. Rosegrant
Keyword(s):  
Land Surface ◽  
Crop Production ◽  
Hydrological Model ◽  
Computational Cost ◽  
Base Flow ◽  
Grid Cells ◽  
Runoff Generation ◽  
Runoff Series ◽  
The Impact

Abstract. This paper describes the IMPACT Global Hydrological Model (IGHM), a component of the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) integrated modeling system. IMPACT has been developed in the early 1990s to identify and analyze long-term challenges and opportunities for food, agriculture, and natural resources at global and regional scales and builds on a series of previous food demand and supply projections models developed at the International Food Policy Research Institute since the early 1980s. The IGHM has been developed to assess water availability and variability as drivers of water use and irrigated crop production in IMPACT. It adopts a saturation runoff generation scheme and uses a linear groundwater reservoir to simulate base flow in 0.5º latitude by 0.5º longitude grid cells over the global land surface excluding Antarctica. The IGHM has four cell-specific calibration parameters, which are determined through maximizing the Kling–Gupta efficiency (KGE) with a genetic algorithm at the grid cell level, using gridded natural runoff series generated by the WaterGAP Global Hydrological Model (WGHM). During the calibration and validation periods, globally, the majority of grid cells attain KGE values greater than 0.50. As a meta-model of the more computationally expensive WGHM, IGHM transfers the climate-hydrology dynamics provided by WGHM into the integrated IMPACT model at a lower computational cost and enables coupling hydrology and other related processes considered in IMPACT which are important for analyzing long-term water and food security under a range of environmental and socioeconomic changes.

scholarly journals A simple topography-driven and calibration-free runoff generation module

2018 ◽  
Author(s):  
Hongkai Gao ◽  
Christian Birkel ◽  
Markus Hrachowitz ◽  
Doerthe Tetzlaff ◽  
Chris Soulsby ◽  
...  
Keyword(s):  
Land Surface ◽  
Storage Capacity ◽  
Root Zone ◽  
Runoff Generation ◽  
The Us ◽  
Long Time ◽  
Calibration Free ◽  
Spatio Temporal ◽  
Rainfall Runoff Model ◽  
Effective Visualization

Abstract. Reading landscapes and developing calibration-free runoff generation models that adequately reflect land surface heterogeneities remains the focus of much hydrological research. In this study, we report a novel and simple topography-driven runoff generation parameterization – the HAND-based Storage Capacity curve (HSC), that uses a topographic index (HAND, Height Above the Nearest Drainage) to identify hydrological similarity and the extent of saturated areas in catchments. The HSC can be used as a module in any conceptual rainfall-runoff model. Further, coupling the HSC parameterization with the Mass Curve Technique (MCT) to estimate root zone storage capacity (SuMax), we developed a calibration-free runoff generation module HSC-MCT. The runoff generation modules of HBV and TOPMODEL were used for comparison purposes. The performance of these two modules (HSC and HSC-MCT) was first checked against the data-rich Bruntland Burn (BB) catchment in Scotland, which has a long time series of field-mapped saturation area extent. We found that the HSC performed better in reproducing the spatio-temporal pattern of the observed saturated areas in the BB compared to TOPMODEL. The HSC and HSC-MCT modules were subsequently tested for 323 MOPEX catchments in the US, with diverse climate, soil, vegetation and geological characteristics. Comparing with HBV and TOPMODEL, the HSC performs better in both calibration and validation. Despite having no calibrated parameters, the HSC-MCT module performed comparably well with calibrated modules, highlighting the robustness of the HSC parameterization to describe the spatial distribution of the root zone storage capacity and the efficiency of the MCT method to estimate SuMax. Moreover, the HSC-MCT module facilitated effective visualization of the saturated area, which has the potential to be used for broader hydrological, ecological, climatological, geomorphological, and biogeochemical studies.

scholarly journals Hillslope-scale experiment demonstrates the role of convergence during two-step saturation

2014 ◽  
Vol 18 (9) ◽  
pp. 3681-3692 ◽  
Author(s):  
A. I. Gevaert ◽  
A. J. Teuling ◽  
R. Uijlenhoet ◽  
S. B. DeLong ◽  
T. E. Huxman ◽  
...  
Keyword(s):  
Land Surface ◽  
Overland Flow ◽  
Subsurface Flow ◽  
Water Dynamics ◽  
Natural Environments ◽  
Wetting Front ◽  
Runoff Generation ◽  
Hillslope Scale ◽  
Saturation Excess

Abstract. Subsurface flow and storage dynamics at hillslope scale are difficult to ascertain, often in part due to a lack of sufficient high-resolution measurements and an incomplete understanding of boundary conditions, soil properties, and other environmental aspects. A continuous and extreme rainfall experiment on an artificial hillslope at Biosphere 2's Landscape Evolution Observatory (LEO) resulted in saturation excess overland flow and gully erosion in the convergent hillslope area. An array of 496 soil moisture sensors revealed a two-step saturation process. First, the downward movement of the wetting front brought soils to a relatively constant but still unsaturated moisture content. Second, soils were brought to saturated conditions from below in response to rising water tables. Convergent areas responded faster than upslope areas, due to contributions from lateral subsurface flow driven by the topography of the bottom boundary, which is comparable to impermeable bedrock in natural environments. This led to the formation of a groundwater ridge in the convergent area, triggering saturation excess runoff generation. This unique experiment demonstrates, at very high spatial and temporal resolution, the role of convergence on subsurface storage and flow dynamics. The results bring into question the representation of saturation excess overland flow in conceptual rainfall-runoff models and land-surface models, since flow is gravity-driven in many of these models and upper layers cannot become saturated from below. The results also provide a baseline to study the role of the co-evolution of ecological and hydrological processes in determining landscape water dynamics during future experiments in LEO.

scholarly journals A Modified Distributed CN-VSA Method for Mapping of the Seasonally Variable Source Areas

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1270
Author(s):  
Kishore Panjabi ◽  
Ramesh Rudra ◽  
Pradeep Goel ◽  
Syed Ahmed ◽  
Bahram Gharabaghi
Keyword(s):  
Source Area ◽  
Moisture Distribution ◽  
Runoff Generation ◽  
Topographic Wetness Index ◽  
Runoff Simulation ◽  
Variable Source ◽  
Study Results ◽  
Potential Maximum ◽  
Scs Cn ◽  
Maximum Retention

Many watershed models employ the Soil Conservation Service Curve Number (SCS-CN) approach for runoff simulation based on soil and land use information. These models implicitly assume that runoff is generated by the Hortonian process and; therefore, cannot correctly account for the effects of topography, variable source area (VSA) and/or soil moisture distribution in a watershed. This paper presents a new distributed CN-VSA method that is based on the SCS-CN approach to estimate runoff amount and uses the topographic wetness index (TWI) to distribute the runoff-generating areas within the watershed spatially. The size of the saturated-watershed areas and their spatial locations are simulated by assuming an average annual value of potential maximum retention. However, the literature indicates significant seasonal variation in potential maximum retention which can considerably effect water balance and amount of nonpoint source pollution. This paper focuses on developing a modified distributed CN-VSA method that accounts for the seasonal changes in the potential maximum retention. The results indicate that the modified distributed CN-VSA approach is better than distributed CN-VSA to simulate runoff amount and spatial distribution of runoff-generating areas. Overall, the study results are significant for improved understanding of hydrological response of watershed where seasonal factors describe the potential maximum retention, and, thus, saturation excess runoff generation in the watershed.

scholarly journals Hillslope experiment demonstrates role of convergence during two-step saturation

2014 ◽  
Vol 11 (2) ◽  
pp. 2211-2232 ◽  
Author(s):  
A. I. Gevaert ◽  
A. J. Teuling ◽  
R. Uijlenhoet ◽  
P. A. Troch
Keyword(s):  
Land Surface ◽  
Overland Flow ◽  
Wetting Front ◽  
Runoff Generation ◽  
Biosphere 2 ◽  
Soil Moisture Sensors ◽  
Water Tables ◽  
Gravity Driven ◽  
Saturation Excess

Abstract. A continuous and intense rainfall experiment on an artificial hillslope at the Landscape Evolution Observatory in Biosphere 2 resulted in saturation excess overland flow and gully erosion in the convergent hillslope area. An array of 496 soil moisture sensors revealed a two-step saturation process. First, the downward movement of the wetting front brought soils to a relatively constant but still unsaturated moisture content. Second, soils were brought to saturated conditions from below in response to rising water tables. Convergent areas responded faster than upslope areas, due to contributions from lateral subsurface flow. This led to the formation of a groundwater ridge in the convergent area, triggering saturation excess runoff generation. This unique experiment demonstrates, at very high spatial and temporal resolution, the role of convergence on subsurface storage and flow dynamics. The results bring into question the representation of saturation excess overland flow in conceptual rainfall-runoff models and land-surface models, since flow is gravity-driven in many of these models and upper layers cannot become saturated from below.

scholarly journals On the value of combined event runoff and tracer analysis to improve understanding of catchment functioning in a data-scarce semi-arid area

2011 ◽  
Vol 15 (6) ◽  
pp. 2007-2024 ◽  
Author(s):  
M. Hrachowitz ◽  
R. Bohte ◽  
M. L. Mul ◽  
T. A. Bogaard ◽  
H. H. G. Savenije ◽  
...  
Keyword(s):  
Water Resources ◽  
Water Resources Management ◽  
Overland Flow ◽  
Base Flow ◽  
High Yield ◽  
Runoff Generation ◽  
Direct Flow ◽  
Resources Management ◽  
Sustainable Water Resources Management ◽  
Semi Arid

Abstract. Hydrological processes in small catchments are not quite understood yet, which is true in particular for catchments in data scarce, semi-arid regions. This is in contrast with the need for a better understanding of water fluxes and the interactions between surface- and groundwater in order to facilitate sustainable water resources management in such environments, where both floods and droughts can result in severe crop loss. In this study, event runoff coefficient analysis and limited tracer data of four small, nested sub-catchments (0.4–25.3 km2) in a data scarce, semi-arid region of Tanzania helped to characterize the distinct response of the study catchments and to gain insights into the dominant runoff processes. The estimated event runoff coefficients were very low and did not exceed 0.09. They were found to be significantly related to the 5-day antecedent precipitation totals as well as to base flow, indicating a close relation to changes in soil moisture and thus potential switches in runoff generation processes. The time scales of the "direct flow" reservoirs, used to compute the event runoff coefficients, were up to one order of magnitude reduced for extreme events, compared to "average" events, suggesting the activation of at least a third flow component, besides base- and direct flow, assumed to be infiltration overland flow. Analysis of multiple tracers highlighted the importance of pre-event water to total runoff, even during intense and high yield precipitation events. It further illustrated the distinct nature of the catchments, in particular with respect to the available water storage, which was suggested by different degrees of tracer damping in the individual streams. The use of multiple tracers subsequently allowed estimating uncertainties in hydrograph separations arising from the use of different tracers. The results highlight the presence of considerable uncertainties, emphasizing the need for multiple tracers in order to avoid misleading results. This study shows the value of hydrological data collection over one whole wet season using multi-tracers to improve the understanding of hydrological functioning and thus for water resources management in data scarce, semi-arid environments.

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