Near surface water balance in the Northern Murray-Darling Basin

2003 ◽  
Vol 48 (7) ◽  
pp. 207-214 ◽  
Author(s):  
R.W. Vervoort ◽  
M. Silburn ◽  
M. Kirby
Keyword(s):  
Water Balance ◽  
Hydrological Cycle ◽  
Shallow Groundwater ◽  
Irrigated Agriculture ◽  
Simulation Studies ◽  
Deep Drainage ◽  
Catchment Scale ◽  
Near Surface ◽  
Current State ◽  
Murray Darling Basin

The water balance allows the calculation of deep drainage from other components of the hydrological cycle. Deep drainage has been linked to outbreaks of dryland and irrigated salinity. Until recently, deep drainage was not considered to be an issue on the alluvial plains of the Northern Murray-Darling Basin. Recent simulation studies and calculations using the water balance suggest that substantial deep drainage occurs under irrigated agriculture. However, these estimates have large uncertainties due to possible errors in measurement, calculation and due to spatial variability. On a catchment scale the relative area under a certain land use as well as the connection to local groundwater and the influence of anomalies such as prior streams needs to be considered. This paper discusses the current state of knowledge on the water balance in the Northern Murray-Darling Basin and highlights the need for a concentrated effort to measure all the components of the water balance in this area, as well as the effect on shallow groundwater quality and levels.

Modelling shows that the high rates of deep drainage in parts of the Goondoola Basin in semi-arid Queensland can be reduced with changes to the farming systems

Soil Research ◽  
2010 ◽  
Vol 48 (1) ◽  
pp. 58 ◽  
Author(s):  
J. B. Robinson ◽  
D. M. Silburn ◽  
D. Rattray ◽  
D. M. Freebairn ◽  
A. Biggs ◽  
...  
Keyword(s):  
Water Balance ◽  
Good Condition ◽  
Shallow Groundwater ◽  
Farming Systems ◽  
Field Measurements ◽  
Simulation Modelling ◽  
Soil Types ◽  
Native Vegetation ◽  
Deep Drainage ◽  
Deep Roots

Clearing native vegetation and introducing crops and pastures may increase deep drainage and result in dryland salinity. In south-west Queensland, native vegetation of the Goondoola Basin has been substantially cleared for cropping and pastoral activities, resulting in shallow groundwater and localised salinity. Simulation modelling was used to estimate the water balance of a range of vegetation and soil types. Six soils were studied, with plant-available water capacity (PAWC) of 71 mm (a Kandosol) to 198 mm (a Vertosol) for 1200 mm depth. Vegetation types were annual wheat, opportunity cropping, and perennial pastures in poor and good condition, and high quality perennial pasture with deep roots growing on deep (2400 mm) variants of the 6 soil types. Opportunity cropping did not reduce deep drainage. Substantial differences were found in long-term average deep drainage (mm/year) between wheat crops and pastures for all soil types. The differences in deep drainage between wheat cropping and pasture in good condition were greatest for the 2 Kandosols, which had the lowest PAWC (34 and 21 mm/year less deep drainage, reductions of 53% and 62%, respectively), and a Vertosol with intermediate PAWC (23 mm/year less deep drainage). A Chromosol and a Dermosol with intermediate PAWC had smaller reductions in deep drainage (14 and 11 mm/year, respectively). In the case of a Vertosol with high PAWC (198 mm), deep drainage was negligible with all pastures. Due to increased infiltration and reduced soil evaporation, more deep drainage was simulated with pasture in good condition than pastures in poor condition, especially for 2 Kandosols. Pasture with deep roots (2400 mm) growing on deep variants (2400 mm) of the 6 soils had lower rates of deep drainage than the other pastures. Simulated deep drainage and other components of the water balance were in good agreement with field measurements and expectations. These results indicate that large reductions in deep drainage can be achieved in the Goondoola Basin by replacing cropping with pastoral activities. Kandosol soils used for wheat cropping should be the primary target for land use change.

Water-balance response to climate variability, a small-to-large scale Italian dataset

2021 ◽  
Author(s):  
Giulia Bruno ◽  
Francesco Avanzi ◽  
Simone Gabellani ◽  
Luca Ferraris ◽  
Edoardo Cremonese ◽  
...  
Keyword(s):  
Water Balance ◽  
Water Resource Management ◽  
Large Scale ◽  
Hydrological Cycle ◽  
Climatic Variability ◽  
Remote Sensing Data ◽  
Data Availability ◽  
Catchment Scale ◽  
Wide Range ◽  
Mean Square Errors

<p>Understanding how deficit of precipitation impacts the hydrological cycle is of growing interest and is essential for water resource management. It has been recently observed that the relationship between precipitation and runoff during droughts is subjected to a shift in the sense that the predicted runoff is much less than the one expected due to the deficit in precipitation. Unraveling why this occurs requires an accurate knowledge of all the components of the water balance equation. However, large-scale and consistent samples of precipitation, runoff, evapotranspiration, ET and change in storage have always been challenging to collect. Here, we hypothesized that blending ground-based and remote-sensing data products could fill this gap. We present a countrywide dataset of catchment-scale water balance, covering the last 10 water years in Italy. Italy shows a broad variety of climatic and topographic features and faced several droughts over recent years. We use ground-based daily runoff data, interpolated precipitation maps, and a remote-sensed daily evapotranspiration dataset from the LSASAF ET product. The ET dataset is additionally compared with flux towers data across the country, obtaining root mean square errors on the order of 30 mm/month. Lastly, changes in storage are estimated to close the water balance. More than 100 catchments - including the major Italian basins - are selected, according to data availability and reliability. These catchments cover a wide range of size, morphologic and climatic characteristics. </p><p>This dataset is a strategic source of information to analyze catchment-scale runoff, ET and storage response to climatic variability across climates and landscapes.</p>

Determining water transit times in dynamic environments

2020 ◽  
Author(s):  
Ian Cartwright
Keyword(s):  
Hydrological Cycle ◽  
Shallow Groundwater ◽  
Dynamic Environments ◽  
Near Surface ◽  
Geochemical Tracers ◽  
Headwater Catchments ◽  
Transit Times ◽  
Hydrological Cycles ◽  
Pass Through ◽  
Stream Waters

<p>Determining the time taken for water to pass through catchments from where it is recharged to where it discharges into streams or is sampled from within the soils or aquifers (the transit time) is vital for understanding catchment functioning. Near-surface environments are dynamic and transit times are likely to vary at different stages of the hydrological cycle. Because of the lower input of bomb-pulse tritium in the southern hemisphere it is possible to determine transit times from individual tritium measurements. Additionally, because tritium is radioactive, transit times can be estimated where the catchment is not stationary. While the transit times are subject to uncertainties, this approach allows transit times at different stages of the hydrological cycles in dynamic environments to be determined.</p><p>In several southeast Australian headwater catchments, the mean transit times of stream waters at low flows range from several years to decades. The tritium activities increase at higher flows, implying that there is an input of younger water at that time. However, the tritium activities generally remain below those of recent rainfall implying that simple dilution by recent rainfall is not occurring; that conclusion is consistent with the variation in the concentrations of other geochemical tracers at different streamflows. Rather, the variations in geochemistry are consistent with shallower younger stores of water from the soils and regolith being progressively mobilised as the catchments wet up during winter. These younger water stores typically have mean transit times of at least a few years. The generally long transit times imply that the southeast Australian headwater catchments have large storage capacities, probably due to the catchments being unglaciated and deeply weathered. The observation that the transit times at high flows are still relatively long suggest that, even though they may only be active for part of the year, the shallow water stores also have relatively large volumes.</p><p>Understanding the transit times improves our ability to predict the behaviour and management of these catchments. The large storage capacities result in the catchments being resilient to year-on-year variations in rainfall and many of the headwater streams in southeast Australia have continued to flow through recent droughts. Similarly, the streams are less susceptible to inputs of surface contamination but contaminants stored in the soil water or shallow groundwater may impact the streams over prolonged periods. As the bomb-pulse tritium decays over the next few decades, determining mean transit times from single tritium measurements will become possible in northern hemisphere catchments. This will enable a better global understanding of catchment functioning in a wider range of environments.</p>

scholarly journals Shift of annual water balance in the Budyko space for catchments with groundwater-dependent evapotranspiration

2016 ◽  
Vol 20 (9) ◽  
pp. 3673-3690 ◽  
Author(s):  
Xu-Sheng Wang ◽  
Yangxiao Zhou
Keyword(s):  
Water Balance ◽  
Water Table ◽  
Shallow Groundwater ◽  
Aridity Index ◽  
Catchment Scale ◽  
Shallow Water Table ◽  
Annual Water Balance ◽  
State Water ◽  
Annual Water

Abstract. The Budyko framework represents the general relationship between the evapotranspiration ratio (F) and the aridity index (φ) for the mean annual steady-state water balance at the catchment scale. It is interesting to investigate whether this standard F − φ space can also be applied to capture the shift of annual water balance in catchments with varying dryness. Previous studies have made significant progress in incorporating the storage effect into the Budyko framework for the non-steady conditions, whereas the role of groundwater-dependent evapotranspiration was not investigated. This study investigates how groundwater-dependent evapotranspiration causes the shift of the annual water balance in the standard Budyko space. A widely used monthly hydrological model, the ABCD model, is modified to incorporate groundwater-dependent evapotranspiration into the zone with a shallow water table and delayed groundwater recharge into the zone with a deep water table. This model is applied in six catchments in the Erdos Plateau, China, to estimate the actual annual evapotranspiration. Results show that the variations in the annual F value with the aridity index do not satisfy the standard Budyko formulas. The shift of the annual water balance in the standard Budyko space is a combination of the Budyko-type response in the deep groundwater zone and the quasi-energy limited condition in the shallow groundwater zone. Excess evapotranspiration (F > 1) could occur in dry years, which is contributed by the significant supply of groundwater for evapotranspiration. Use of groundwater for irrigation can increase the frequency of the F > 1 cases.

Simulating the water balance of border-check irrigated pasture on a cracking soil

2004 ◽  
Vol 44 (2) ◽  
pp. 163 ◽  
Author(s):  
M. Bethune ◽  
Q. J. Wang
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Storage ◽  
Dairy Industry ◽  
Soil Water Storage ◽  
Deep Drainage ◽  
Annual Crop ◽  
Murray Darling Basin ◽  
Physically Based ◽  
Soil Cracks

The irrigated dairy industry relies on perennial pasture and is a major user of water in the Murray–Darling Basin of Australia. The sustainability of the irrigated dairy industry is threatened by high watertables and land salinisation. Options to alleviate these problems by reducing deep drainage are required. This paper assesses the potential to use the simulation model 'SWAP' to appraise options for reducing deep drainage. Minor modifications were made to SWAP so that it could simulate border-check irrigated pasture on a cracking soil. The model was tested against lysimeter data describing the water balance of irrigated pasture. Evapotranspiration, runoff, infiltration, soil water storage and deep drainage were well simulated when infiltration through soil cracks was modelled using the physically based approached in SWAP. Large errors in evapotranspiration, infiltration, runoff, soil water storage and deep drainage occurred when the process of infiltration through cracks was not simulated. Slight improvements in model predictions were achieved by specifying monthly crop factors, as opposed to a constant annual crop factor. However, a constant annual crop factor should be sufficiently accurate for most studies of deep drainage under border-check irrigated pastures.

scholarly journals Assessing Annual Actual Evapotranspiration Based on Climate, Topography and Soil in Natural and Agricultural Ecosystems

Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 20
Author(s):  
Kleoniki Demertzi ◽  
Vassilios Pisinaras ◽  
Emanuel Lekakis ◽  
Evangelos Tziritis ◽  
Konstantinos Babakos ◽  
...  
Keyword(s):  
Water Balance ◽  
Large Scale ◽  
Hydrological Model ◽  
Actual Evapotranspiration ◽  
Irrigated Agriculture ◽  
Climate Data ◽  
Natural Ecosystems ◽  
Loading Effects ◽  
Very High ◽  
Of Greece

Simple formulas for estimating annual actual evapotranspiration (AET) based on annual climate data are widely used in large scale applications. Such formulas do not have distinct compartments related to topography, soil and irrigation, and for this reason may be limited in basins with high slopes, where runoff is the dominant water balance component, and in basins where irrigated agriculture is dominant. Thus, a simplistic method for assessing AET in both natural ecosystems and agricultural systems considering the aforementioned elements is proposed in this study. The method solves AET through water balance based on a set of formulas that estimate runoff and percolation. These formulas are calibrated by the results of the deterministic hydrological model GLEAMS (Groundwater Loading Effects of Agricultural Management Systems) for a reference surface. The proposed methodology is applied to the country of Greece and compared with the widely used climate-based methods of Oldekop, Coutagne and Turk. The results show that the proposed methodology agrees very well with the method of Turk for the lowland regions but presents significant differences in places where runoff is expected to be very high (sloppy areas and areas of high rainfall, especially during December–February), suggesting that the proposed method performs better due to its runoff compartment. The method can also be applied in a single application considering irrigation only for the irrigated lands to more accurately estimate AET in basins with a high percentage of irrigated agriculture.

scholarly journals Using a Groundwater Adjusted Water Balance Approach and Copulas to Evaluate Spatial Patterns and Dependence Structures in Remote Sensing Derived Evapotranspiration Products

2021 ◽  
Vol 13 (5) ◽  
pp. 853
Author(s):  
Mohsen Soltani ◽  
Julian Koch ◽  
Simon Stisen
Keyword(s):  
Remote Sensing ◽  
Water Balance ◽  
Spatial Pattern ◽  
Spatial Patterns ◽  
Principal Component ◽  
Small Scale ◽  
Dependence Structure ◽  
Test Case ◽  
Catchment Scale ◽  
Balance Approach

This study aims to improve the standard water balance evapotranspiration (WB ET) estimate, which is typically used as benchmark data for catchment-scale ET estimation, by accounting for net intercatchment groundwater flow in the ET calculation. Using the modified WB ET approach, we examine errors and shortcomings associated with the long-term annual mean (2002–2014) spatial patterns of three remote-sensing (RS) MODIS-based ET products from MODIS16, PML_V2, and TSEB algorithms at 1 km spatial resolution over Denmark, as a test case for small-scale, energy-limited regions. Our results indicate that the novel approach of adding groundwater net in water balance ET calculation results in a more trustworthy ET spatial pattern. This is especially relevant for smaller catchments where groundwater net can be a significant component of the catchment water balance. Nevertheless, large discrepancies are observed both amongst RS ET datasets and compared to modified water balance ET spatial pattern at the national scale; however, catchment-scale analysis highlights that difference in RS ET and WB ET decreases with increasing catchment size and that 90%, 87%, and 93% of all catchments have ∆ET < ±150 mm/year for MODIS16, PML_V2, and TSEB, respectively. In addition, Copula approach captures a nonlinear structure of the joint relationship with multiple densities amongst the RS/WB ET products, showing a complex dependence structure (correlation); however, among the three RS ET datasets, MODIS16 ET shows a closer spatial pattern to the modified WB ET, as identified by a principal component analysis also. This study will help improve the water balance approach by the addition of groundwater net in the ET estimation and contribute to better understand the true correlations amongst RS/WB ET products especially over energy-limited environments.

scholarly journals Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D

2012 ◽  
Vol 16 (8) ◽  
pp. 2485-2497 ◽  
Author(s):  
B. Leterme ◽  
D. Mallants ◽  
D. Jacques
Keyword(s):  
Water Balance ◽  
Groundwater Recharge ◽  
Potential Evapotranspiration ◽  
Future Climate ◽  
Annual Precipitation ◽  
Balance Model ◽  
Subtropical Climate ◽  
Northern Spain ◽  
Near Surface ◽  
Hydrus 1D

Abstract. The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from −42% to +5% and from +8% to +82%, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72% to an increase of 3% for the four different analogue stations. The Gijon analogue station (Northern Spain), considered as the most representative for the near future climate state in the study area, shows an increase of 3% of groundwater recharge for a 5% increase of annual precipitation. Calculations for a colder (tundra) climate showed a change in groundwater recharge ranging from a decrease of 97% to an increase of 32% for four different analogue stations, with an annual precipitation change from −69% to −14% compared to the present-day climate.

Catchment-scale evaluation of pollution potential of urban snow at two residential catchments in southern Finland

2013 ◽  
Vol 68 (10) ◽  
pp. 2164-2170 ◽  
Author(s):  
Nora Sillanpää ◽  
Harri Koivusalo
Keyword(s):  
Snow Water Equivalent ◽  
Hydrological Cycle ◽  
Cold Climate ◽  
Road Maintenance ◽  
Catchment Scale ◽  
Small Surface ◽  
Climate Conditions ◽  
Snow Water ◽  
High Level ◽  
Mass Loads

Despite the crucial role of snow in the hydrological cycle in cold climate conditions, monitoring studies of urban snow quality often lack discussions about the relevance of snow in the catchment-scale runoff management. In this study, measurements of snow quality were conducted at two residential catchments in Espoo, Finland, simultaneously with continuous runoff measurements. The results of the snow quality were used to produce catchment-scale estimates of areal snow mass loads (SML). Based on the results, urbanization reduced areal snow water equivalent but increased pollutant accumulation in snow: SMLs in a medium-density residential catchment were two- to four-fold higher in comparison with a low-density residential catchment. The main sources of pollutants were related to vehicular traffic and road maintenance, but also pet excrement increased concentrations to a high level. Ploughed snow can contain 50% of the areal pollutant mass stored in snow despite its small surface area within a catchment.

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