Regionalization of landscape characteristics to map hydrologic variables

By integrating groundwater, surface water and vadose zone systems, the terrestrial hydrologic system can be used to spatially map water balance characteristics spanning local to global scales, even when long-term stream gauge data are unavailable. The Watershed Characteristics Approach (WCA) is a hydrologic estimation model developed using a system-based approach focused on the regionalization of landscape characteristics to define unique hierarchical hydrogeological units (HHUs) and establish their link to hydrologic characteristics. Although the WCA can be used to map any hydrologic variable, its validity is demonstrated by summarizing results generated by applying the methodology to quantify the renewable groundwater flux at a spatial scale lacking long-term stream gauge monitoring data. Landscape components for 97 East-Central Minnesota (ECM) watersheds were summarized and used to identify which unique combinations of characteristics statistically influenced mean annual minimum groundwater recharge. These resulting combinations of landscape characteristics defined each HHU; as additional characteristics were applied, units were refined to create a hierarchical organization. Results were mapped to spatially represent the renewable groundwater flux for ECM, demonstrating how hydrologic regionalization can address knowledge gaps in multi-scale processes and aid in quantifying water balance components, an essential key to sustainable water resources management.

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Variations of global and continental water balance components as impacted by climate forcing uncertainty and human water use

Hydrology and Earth System Sciences ◽

10.5194/hess-20-2877-2016 ◽

2016 ◽

Vol 20 (7) ◽

pp. 2877-2898 ◽

Cited By ~ 73

Author(s):

Hannes Müller Schmied ◽

Linda Adam ◽

Stephanie Eisner ◽

Gabriel Fink ◽

Martina Flörke ◽

...

Keyword(s):

Water Resources ◽

Water Balance ◽

Water Use ◽

Climate Forcing ◽

Land Area ◽

Water Balance Components ◽

Climate Forcings ◽

The Impact ◽

Global Water

Abstract. When assessing global water resources with hydrological models, it is essential to know about methodological uncertainties. The values of simulated water balance components may vary due to different spatial and temporal aggregations, reference periods, and applied climate forcings, as well as due to the consideration of human water use, or the lack thereof. We analyzed these variations over the period 1901–2010 by forcing the global hydrological model WaterGAP 2.2 (ISIMIP2a) with five state-of-the-art climate data sets, including a homogenized version of the concatenated WFD/WFDEI data set. Absolute values and temporal variations of global water balance components are strongly affected by the uncertainty in the climate forcing, and no temporal trends of the global water balance components are detected for the four homogeneous climate forcings considered (except for human water abstractions). The calibration of WaterGAP against observed long-term average river discharge Q significantly reduces the impact of climate forcing uncertainty on estimated Q and renewable water resources. For the homogeneous forcings, Q of the calibrated and non-calibrated regions of the globe varies by 1.6 and 18.5 %, respectively, for 1971–2000. On the continental scale, most differences for long-term average precipitation P and Q estimates occur in Africa and, due to snow undercatch of rain gauges, also in the data-rich continents Europe and North America. Variations of Q at the grid-cell scale are large, except in a few grid cells upstream and downstream of calibration stations, with an average variation of 37 and 74 % among the four homogeneous forcings in calibrated and non-calibrated regions, respectively. Considering only the forcings GSWP3 and WFDEI_hom, i.e., excluding the forcing without undercatch correction (PGFv2.1) and the one with a much lower shortwave downward radiation SWD than the others (WFD), Q variations are reduced to 16 and 31 % in calibrated and non-calibrated regions, respectively. These simulation results support the need for extended Q measurements and data sharing for better constraining global water balance assessments. Over the 20th century, the human footprint on natural water resources has become larger. For 11–18% of the global land area, the change of Q between 1941–1970 and 1971–2000 was driven more strongly by change of human water use including dam construction than by change in precipitation, while this was true for only 9–13 % of the land area from 1911–1940 to 1941–1970.

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Linking Climate, Basin Morphology and Vegetation Characteristics to Fu’s Parameter in Data Poor Conditions

Water ◽

10.3390/w11112333 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2333 ◽

Cited By ~ 1

Author(s):

Dario Ruggiu ◽

Francesco Viola

Keyword(s):

Water Balance ◽

Potential Evapotranspiration ◽

Seasonal Pattern ◽

Computational Effort ◽

Model Parameters ◽

Large Set ◽

Regression Equations ◽

Water Balance Components ◽

Water Partitioning

The prediction of long term water balance components is not a trivial issue, even when empirical Budyko’s type approaches are used, because parameter estimation is often hampered by missing or poor hydrological data. In order to overcome this issue, we provided regression equations that link climate, morphological, and vegetation parameters to Fu’s parameter. Climate is here defined as a specific seasonal pattern of potential evapotranspiration and rain: five climatic scenarios have been considered to mimic different conditions worldwide. A weather generator has been used to create stochastic time series for the related climatic scenario, which in turn has been used as an input to a conceptual hydrological model to obtain long-term water balance components with low computational effort, while preserving fundamental process descriptions. The morphology and vegetation’s role in determining water partitioning process has been epitomized in four parameters of the conceptual model. Numerical simulations explored a large set of basins in the five climates. Results show that climate superimposes partitioning rules for a given basin; morphological and vegetation watershed properties, as conceptualized by model parameters, determine the Fu’s parameter within a given climate. A sensitive analysis confirmed that vegetation has the most influencing role in determining water partitioning rules, followed by soil permeability. Finally, linear regressions relating basin characteristics to Fu’s parameter have been obtained in the five climates and tested in a basin for each case, obtaining encouraging results. The small amount of data required and the very low computational effort of the method make this approach ideal for practitioners and hydrologists involved in annual runoff assessment.

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Applications of Hydrological Model Simulated Long Term Water Balance Components for India

10.22541/au.159423230.01524040 ◽

2020 ◽

Author(s):

Saksham Joshi ◽

Venkat Raju Pokkuluri ◽

Annie Issac ◽

Venkateshwar Rao ◽

Pamaraju Venkata Rao ◽

...

Keyword(s):

Water Balance ◽

Hydrological Model ◽

Water Balance Components

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Trends and variability of water balance components over a tropical savanna and Eucalyptus forest in Australia

Journal of Water and Climate Change ◽

10.2166/wcc.2021.374 ◽

2021 ◽

Author(s):

Yinhong Kang ◽

Lu Zhang ◽

Warrick Dawes

Keyword(s):

Climate Change ◽

Water Balance ◽

Water Content ◽

Soil Water Content ◽

Potential Evapotranspiration ◽

Annual Runoff ◽

Water Balance Components ◽

Eucalyptus Forest ◽

The Waves

Abstract In this paper, the long-term dynamics of water balance components in two different contrasting ecosystems in Australia were simulated with an ecohydrological model (WAter Vegetation Energy and Solute modelling (WAVES)) over the period 1950–2015. The selected two ecosystems are woodland savanna in Daly River and Eucalyptus forest in Tumbarumba. The WAVES model was first manually calibrated and validated against soil water content measured by cosmic-ray probe and evapotranspiration measured with eddy flux techniques. The calibrated model was then used to simulate long-term water balance components with observed climate data at two sites. Analyzing the trends and variabilities of potential evapotranspiration and precipitation is used to interpret the climate change impacts on ecosystem water balance. The results showed that the WAVES model can accurately simulate soil water content and evapotranspiration at two study sites. Over the period of 1950–2015, annual evapotranspiration at both sites showed decreasing trends (−1.988 mm year−1 in Daly and −0.381 mm year−1 in Tumbarumba), whereas annual runoff in Daly increased significantly (5.870 mm year−1) and decreased in Tumbarumba (–0.886 mm year−1). It can be concluded that the annual runoff trends are consistent with the rainfall trends, whereas trends in annual evapotranspiration are influenced by both rainfall and potential evapotranspiration. The results can provide evidence for controlling the impacting factors for different ecosystems under climate change.

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On the difficulties in estimating water balance components from remote sensing in an anthropogenically modified catchment in southern India

10.5194/egusphere-egu2020-2197 ◽

2020 ◽

Author(s):

Tejas Kulkarni ◽

Mathias Gassmann ◽

Sanaz Vajedian

Keyword(s):

Remote Sensing ◽

Water Balance ◽

Cloud Cover ◽

Water Levels ◽

State Variables ◽

Water Balance Components ◽

Supply Source ◽

Groundwater Exploitation

The Arkavathy river was once a major water supply source to the city of Bangalore, India, till 1970s but has completely dried up post the 1990s. The study re-invigorates on the socio-hydro dynamics in the Upper Arkavathy Catchment (UAC), covering 1432 km2, through the combination of latest remote sensing products (namely Gravity Recovery and Climate Experiment (GRACE), Global Land Data Assimilation System (GLDAS), Landsat derived NDVI). The parameters of remotely sensed long-term precipitation and temperature from corresponded well with in-situ data. Seasonal trend analysis helped re-instate no evidence of climatic driven drought to explain the decline of flows in the river. To investigate the anthropogenic proximate drivers of change - mainly groundwater exploitation and increase in water intensive cropping in the catchment - a spatio-temporal assimilation of GRACE TWS, GLDAS state variables and LandSAT-NDVI with in-situ well observations is incorporated into the water balance equation. While, studies have shown high correlation in quantifying groundwater storage changes (GWSC) and attempted downscaling with this GRACE-GLDAS-GWL-NDVI assimilation in natural catchments, this did not seem to be very skilful in human-altered fractured rock aquifers of south India for the following reasons. Firstly, the GRACE-TWS (RL-06) for the grid showed a meagre declining trend of -.033mm/year (2002-2018) and did not seem to capture the deeper groundwater extraction as compared to the social narrative in shift of hundreds of metres decline in static water levels. Secondly, the disaggregation through the GLDAS-NOAH soil moisture which corresponded well with rainfall patterns, assigns inclusion of only the shallow storage fluxes in the sub-surficial aquifer showing -5.3mm/year, which explains no overland flows in the river, but neglects the modelling of the GW aquifer and showed a faulty +47.4mm/year (2002-2018). Thirdly, the simple addition of groundwater observation well trends showed a decrease of -106.6mm/year in GWSC (2001-2017) as compared to the -656.6mm/year (1970-2000) of field scale models by Srinivasan et.al (2015). This is attributed to the fact that data used in such studies from the governmental groundwater authority boards are generally of shallower wells (up to 70m below surface) and cannot be representative of the on-ground reality of shift to deeper exploitation of GW (up to 350m) by privatised borewells. Finally, cloud-cover and scan line error corrected NDVI pixels showed an increase of irrigated area in the UAC by 31% (1972-2018). However, we observed long term data gaps (1998-2003) in images and higher uncertainties during the crucial cropping season due to monsoonal cloud cover (JJASO months) in the images to effectively understand the agricultural dynamics. Hence, it is concluded that this &#160;procedure coupled with this period receiving higher rainfall with an average of1000mm/year (2001-2019) as compared to 800mm/year (1901-2000) makes it an unreliable method to disassociate the human interventions in modifying hydro-geologic fluxes or patterns accurately in the UAC.

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Estimation of Soil Water Balance Components Based on Continuous Soil Moisture Measurement and Inversed Richards Method in an Irrigated Agricultural Field of a Desert Oasis

10.5194/egusphere-egu2020-6274 ◽

2020 ◽

Author(s):

Hu Liu ◽

Yang Yu ◽

Zhongkai Li ◽

Wenzhi Zhao ◽

Qiyue Yang ◽

...

Keyword(s):

Soil Moisture ◽

Water Balance ◽

Soil Water ◽

Estimation Method ◽

Growing Season ◽

Soil Water Balance ◽

Richards Equation ◽

Water Balance Components ◽

Sustainable Water Resources Management ◽

Irrigation Drainage

An accurate assessment of soil water balance components (SWBCs) is necessary for improving irrigation strategies in any water-limited environment. However, quantitative information of SWBCs is usually challenging to obtain, because none of the components (i.e., irrigation, drainage, and evapotranspiration) can be easily measured under actual conditions. Soil moisture is a variable that integrates the water balance components of land surface hydrology, and the evolution of soil moisture is assumed to contain the memory of antecedent hydrologic fluxes, and thus can be used to determine SWBCs from a hydrologic balance. A database of&#160;soil&#160;moisture&#160;measurements from six experimental plots with different treatments in the middle Heihe River Basin of China was used to test the potential of a soil moisture database in estimating the SWBCs. We first compared the hydrophysical properties of the soils in these plots, such as vertical saturated hydraulic conductivity (Ks) and soil water retention features, for supporting the SWBC estimations. Then we determined evapotranspiration and other SWBCs through a method that combined the soil water balance method and the inverse Richards equation (a model of unsaturated soil water flow based on the Richards equation). To test the accuracy of our estimation, we used both indirect methods (such as power consumption of the pumping irrigation well, and published SWBCs values at nearby sites), and the water balance equation technique to verify the estimated SWBCs values, all of which showed a good reliability of our estimation method. Finally, the uncertainties of the proposed methods were analyzed to evaluate the systematic error of the SWBC estimation and any restrictions on its application. The results showed significant variances among the film-mulched plots in both the cumulative irrigation volumes (652.1~ 867.3 mm) and deep drainages (170.7~364.7 mm). Moreover, the unmulched plot had remarkably higher values in both cumulative irrigation volumes (1186.5 mm) and deep drainages (651.8 mm) compared with the mulched plots. Obvious correlation existed between the volume of irrigation and that of drained water. However, the ET demands for all the plots behaved pretty much the same, with the cumulative ET values ranging between 489.1 and 561.9 mm for the different treatments in 2016, suggesting that the superfluous irrigation amounts had limited influence on the accumulated ET throughout the growing season because of the poor water-holding capacity of the sandy soil. This work confirmed that relatively reasonable estimations of the SWBCs in coarse-textured sandy soils can be derived by using soil moisture measurements; the proposed methods provided a reliable solution over the entire growing season and showed a great potential for identifying appropriate irrigation amounts and frequencies, and thus a move toward sustainable water resources management, even under traditional surface irrigation conditions.

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Sensitivity of Model-Based Water Balance to Low Impact Development Parameters

Water ◽

10.3390/w10121838 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1838 ◽

Cited By ~ 5

Author(s):

Johannes Leimgruber ◽

Gerald Krebs ◽

David Camhy ◽

Dirk Muschalla

Keyword(s):

Water Balance ◽

Environmental Protection Agency ◽

Planning Process ◽

Low Impact Development ◽

Sensitivity Analyses ◽

Storm Event ◽

Water Balance Components ◽

Soil Thickness ◽

Model Based

Low impact development (LID) strategies aim to mitigate the adverse impacts of urbanization, like the increase of runoff and the decrease of evapotranspiration. Hydrological simulation is a reasonable option to evaluate the LID performance with respect to the complete water balance. The sensitivity of water balance components to LID parameters is important for the modeling and planning process of LIDs. This contribution presents the results of a global sensitivity analysis of model-based water balance components (runoff volume, evapotranspiration, groundwater recharge/storage change) using the US Environmental Protection Agency Storm Water Management Model to the parameters (e.g., soil thickness, porosity) of a green roof, an infiltration trench, and a bio-retention cell. All results are based on long-term simulations. The water balance and sensitivity analyses are evaluated for the long-term as well as single storm events. The identification of non-influential and most influential LID parameters for the water balance components is the main outcome of this work. Additionally, the influence of the storm event characteristics precipitation depth and antecedent dry period on the sensitivity of water balance components to LID parameters is shown.

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The Water-Balance Components of the Aral Sea and their Impact on Long-Term Level Fluctuations

Soviet Geography ◽

10.1080/00385417.1974.10770689 ◽

1974 ◽

Vol 15 (7) ◽

pp. 408-421 ◽

Cited By ~ 1

Author(s):

A. Ye. Asarin

Keyword(s):

Water Balance ◽

Aral Sea ◽

Water Balance Components

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Quantification of soil water balance components based on continuous soil moisture measurement and the Richards equation in an irrigated agricultural field of a desert oasis

Hydrology and Earth System Sciences ◽

10.5194/hess-23-4685-2019 ◽

2019 ◽

Vol 23 (11) ◽

pp. 4685-4706 ◽

Cited By ~ 2

Author(s):

Zhongkai Li ◽

Hu Liu ◽

Wenzhi Zhao ◽

Qiyue Yang ◽

Rong Yang ◽

...

Keyword(s):

Soil Moisture ◽

Water Balance ◽

Soil Water ◽

Estimation Method ◽

Growing Season ◽

Soil Water Balance ◽

Richards Equation ◽

Water Balance Components ◽

Sustainable Water Resources Management ◽

Irrigation Drainage

Abstract. An accurate assessment of soil water balance components (SWBCs) is necessary for improving irrigation strategies in any water-limited environment. However, quantitative information on SWBCs is usually challenging to obtain, because none of the components (i.e., irrigation, drainage, and evapotranspiration) can be easily measured under actual conditions. Soil moisture is a variable that integrates the water balance components of land surface hydrology, and the evolution of soil moisture is assumed to contain the memory of antecedent hydrologic fluxes, and can thus be used to determine SWBCs from a hydrologic balance. A database of soil moisture measurements from six experimental plots with different treatments in the middle Heihe River basin of China was used to test the potential of a such a database for estimating SWBCs. We first compared the hydrophysical properties of the soils in these plots, such as vertical saturated hydraulic conductivity (Ks) and soil water retention features, for supporting SWBC estimations. We then determined evapotranspiration and other SWBCs using a method that combined the soil water balance method and the inverse Richards equation (a model of unsaturated soil water flow based on the Richards equation). To test the accuracy of our estimation, we used both indirect methods (such as power consumption of the pumping irrigation well and published SWBCs values at nearby sites) and the water balance equation technique to verify the estimated SWBCs values, all of which showed good reliability with respect to our estimation method. Finally, the uncertainties of the proposed methods were analyzed to evaluate the systematic error of the SWBC estimation and any restrictions regarding its application. The results showed significant variances among the film-mulched plots in both the cumulative irrigation volumes (652.1–867.3 mm) and deep drainages (170.7–364.7 mm). Moreover, the un-mulched plot had remarkably higher values in both cumulative irrigation volumes (1186.5 mm) and deep drainages (651.8 mm) compared with the mulched plots. Obvious correlation existed between the volume of irrigation and that of drained water. However, the ET demands for all of the plots behaved pretty much the same, with the cumulative ET values ranging between 489.1 and 561.9 mm for the different treatments in 2016, suggesting that the superfluous irrigation amounts had limited influence on the accumulated ET throughout the growing season due to the poor water-holding capacity of the sandy soil. This work confirmed that relatively reasonable estimations of the SWBCs in coarse-textured sandy soils can be derived by using soil moisture measurements; the proposed methods provided a reliable solution over the entire growing season and showed a great potential for identifying appropriate irrigation amounts and frequencies, and thus a move toward sustainable water resources management, even under traditional surface irrigation conditions.

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Long-term variations in water balance components for Croatia

Theoretical and Applied Climatology ◽

10.1007/s00704-007-0366-5 ◽

2008 ◽

Vol 95 (1-2) ◽

pp. 39-51 ◽

Cited By ~ 9

Author(s):

K. Pandžić ◽

D. Trninić ◽

T. Likso ◽

T. Bošnjak

Keyword(s):

Water Balance ◽

Water Balance Components ◽

Long Term Variations

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