An expression for land surface water storage monitoring using a two-formation geological weighing lysimeter

Field studies have demonstrated that ground surface rainfall accumulation can be detected at depth by synchronous increases in static confined groundwater pore pressures. This opens the way for “geological weighing lysimeters” providing disturbance-free water storage monitoring of the surface environment, in effect by weighing a significant land area in real time. Such systems require specific hydrogeological conditions, which are not easily verified by field observations and replicated observations from multiple geological formations are a prerequisite for quality control. Given replication over two monitored formations, we introduce an expression which utilises the respective formation piezometric water levels to give an improved combined estimate of the ground surface water budget. The expression utilises raw piezometric levels and has the advantage of direct correction for Earth tide noise, which may sometimes be influenced by local effects in addition to the pure solar/lunar tidal potential. The expression is particularly simple, if the two formations have similar (but possibly unknown) undrained Poisson ratios and porosities. Surface water budgets can then be estimated using only the respective formation barometric coefficients and piezometric levels. An example application to two vertically separated confined aquifers at a New Zealand site indicate an improved accuracy over single-formation observations. The two-formation expression for surface storage could find use as an accurate water budget tool with particular application to monitoring diffuse hydrological systems such as wetlands, arid regions, and heavily forested localities

Preliminary soilwater conductivity analysis to date clandestine burials of homicide victims

This study reports on a new geoscientific method to estimate the post-burial interval (PBI) and potential post-mortem interval (PMI) date of homicide victims in clandestine graves by measuring decomposition fluid conductivities. Establishing PBI/PMI dates may be critical for forensic investigators to establish time-lines to link or indeed rule out suspects to a crime. Regular in situ soilwater analysis from a simulated clandestine grave (which contained a domestic buried pig carcass) in a semi-rural environment had significantly elevated conductivity measurements when compared to background values. A temporal rapid increase of the conductivity of burial fluids was observed until one-year post-burial, after this values slowly increased until two years (end of the current study period). Conversion of x-axis from post-burial days to 'accumulated degree days' (ADDs) corrected for both local temperature variations and associated depth of burial and resulted in an improved fit for multiple linear regression analyses. ADD correction also allowed comparison with a previous conductivity grave study on a different site with a different soil type and environment; this showed comparable results with a similar trend observed. A separate simulated discovered burial had a conductivity estimated PBI date that showed 12% error from its actual burial date. Research is also applicable in examining illegal animal burials; time of burial and waste deposition. Further research is required to extend the monitoring period, to use human cadavers and to repeat this with other soil types and depositional environments

Illuminating hydrological processes at the soil-vegetation-atmosphere interface with water stable isotopes

Funded by DFG research project “From Catchments as Organised Systems to Models based on Functional Units” (FOR 1Peer reviewedPublisher PDFPublisher PD

Assessment of groundwater extraction in the Tadla irrigated perimeter (Morocco) using the SSEBI remote sensing algorithm

In the Tadla irrigation perimeter, farmers supplement their irrigation supplies with groundwater, leading to water table depletion in the area. An additional concern is the deteriorating water quality in the area. There is no regulation to control withdrawals of groundwater, and no data are available to quantify groundwater use. The paper demonstrates a method based on remote sensing techniques and field observation data to estimate the ground water use for the 2006 hydrological year. Calculations show that for Tadla, average groundwater use amounts to around 55% of the surface irrigation water use. This is substantial, and requires immediate attention. Policy recommendations are needed to control the use of groundwater and to reach an integral management with the canal water. For exact calculations, data on groundwater levels are needed

Modelling evapotranspiration of soilless cut roses "Red Naomi" based on climatic and crop predictors

Original PaperThis study aimed to estimate the daily crop evapotranspiration (ETc) of soilless cut ‘Red Naomi’ roses, cultivated in a commercial glass greenhouse, using climatic and crop predictors. A multiple stepwise regression technique was applied for estimating ETc using the daily relative humidity, stem leaf area and number of leaves of the bended stems. The model explained 90% of the daily ETc variability (R2 = 0.90, n = 33, P < 0.0001) measured by weighing lysimeters. The mean relative difference between the observed and the estimated daily ETc was 9.1%. The methodology revealed a high accuracy and precision in the estimation of daily ETcinfo:eu-repo/semantics/publishedVersio

Estimation of Regional Evapotranspiration Using Remotely Sensed Land Surface Temperature. Part 2: Application of Equilibrium Evaporation Model to Estimate Evapotranspiration by Remote Sensing Technique

In a humid region like Japan, it seems that the radiation term in the energy balance equation plays a more important role for evapotranspiration then does the vapor pressure difference between the surface and lower atmospheric boundary layer. A Priestley-Taylor type equation (equilibrium evaporation model) is used to estimate evapotranspiration. Net radiation, soil heat flux, and surface temperature data are obtained. Only temperature data obtained by remotely sensed techniques are used

Impacts of the Species Elaeagnus umbellate on the Soil and Water Quality of the Pierce Cedar Creek Institute Ecosystem

The species Elaeagnus umbellate, more commonly known as autumn olive, is a shrub that is invasive to the United States and indigenous to East Asia. Even though the autumn olive is not native to North America, it was able to thrive and adapt to the new environment by using its ability to fix nitrogen. Nitrogen-fixing is a process where plants intake molecular nitrogen from the atmosphere and convert it into other forms of nitrogen that can be used by the plants. One of the nitrogen-fixing by-products is nitrate. Excessive amounts of nitrate can easily leach from the plant’s root region into underlying aquifer systems. Relatively small amounts (\u3e10mg/L) of nitrate in the environment are known to be toxic to humans and aquatic life. This study was conducted to assess the impact of Elaeagnus umbellate on nitrate concentrations in its surrounding soil and groundwater. Thirty plots were selected for collecting groundwater and soil samples. Fifteen of those plots were dominated by mature E. umbellate. The other fifteen plots were dominated by native grass species. Water and soil samples were collected two feet below the ground surface (root zones of the autumn olive plants). Samples were collected during the growing season, in ten day intervals during the summer of 2010, and analyzed for the respective concentrations of nitrate, ammonia, total nitrogen, potassium, calcium, and magnesium. The data obtained from these analyses was statistically analyzed. The results of the samples collected from the autumn olive dominated plots showed an increase in the concentrations of nitrates and other nitrogen forms. However, statistical t-tests showed that this increase is not significantly different compared to results of the control plots dominated by native grass species

Estimation of Regional Evapotranspiration Using Remotely Sensed Land Surface Temperature. Part 1: Measurement of Evapotranspiration at the Environmental Research Center and Determination of Priestley-taylor Parameter

In order to study the distribution of evapotranspiration in the humid region using remote sensing technology, the parameter (alpha) in the Priestley-Taylor model was determined. The daily means of the parameter alpha = 1.14 can be available from summer to autumn and alpha = to approximately 2.0 in winter. The results of the satellite and the airborne sensing done on 21st and 22nd January, 1983, are described. Using the vegetation distribution in the Tsukuba Academic New Town, as well as the radiation temperature obtained by remote sensing and the radiation data observed at the ground surface, the evapotranspiration was calculated for each vegetation type by the Priestley-Taylor method. The daily mean evapotranspiration on 22nd January, 1983, was approximately 0.4 mm/day. The differences in evapotranspiration between the vegetation types were not detectable, because the magnitude of evapotranspiration is very little in winter

Dairy wintering systems in southern New Zealand : quantification and modelling of nutrient transfers and losses from contrasting wintering systems : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Soil Science at Massey University, Palmerston North, New Zealand

Traditional dairy wintering practice in the lower South Island of New Zealand has been to graze brassica crops in situ. This practice has been under increasing scrutiny from local Regional Councils due to the relatively high nitrogen (N) leaching losses from this component of the whole farm system. Alternative wintering options to reduce N leaching losses that are currently available to farmers (such as barns and permanent wintering pads) are high cost and involve a large capital investment. In this work a new wintering system (termed a ‘portable pad’) was developed for use on support blocks (which can be located many kilometres from the milking platform) as an interim measure for reducing N leaching losses that is low cost and low input. This system is designed as a mitigation strategy that is available for use immediately while research investigates more permanent solutions. This system is a hybrid of the traditional crop grazing system and an off-paddock system, where effluent is captured. It makes use of the advantages of each of the original systems utilising the low cost feed source of the brassica crops, grazed in situ, while also utilising the benefits of duration controlled grazing with its associated effluent capture and irrigation at low rates. The aim of the research was to generate whole system N leaching loss values for each of the three farm systems investigated (crop wintering, deep-litter wintering barn, and portable pad). Field and laboratory research was conducted to fill identified knowledge gaps such that system N loss values could be estimated. OVERSEER Nutrient Budget software tool was used in conjunction with measured and modelled (APSIM) data to simulate whole farm N leaching loss values for the three farm systems investigated. Nitrogen leaching losses from the portable pad and barn systems were between 5 and 26 % and between 13 and 26 % lower, respectively, than the crop wintering system

A rainfall loading response recorded at 300 meters depth: implications for geological weighing lysimeters

Static pore water pressures in confined aquifers vary in response to ground surface loading changes, including precipitation and evaporation. Under certain hydrogeological conditions such aquifers can function as giant natural weighing lysimeters, referenced here as ‘geological weighing lysimeters’. The extent of the land area ‘weighed’ increases with aquifer depth and it is of interest to establish at what depth it is still possible to monitor surface water budgets. An 86 mm rainfall event produced a clear loading signal in a well in western Kansas at 300 m depth. The loading effect is quantitatively consistent with elastic deformation induced by the rainfall mass and suggests that geological weighing lysimeters could operate at considerably greater depths, thereby monitoring water budgets over a significant land area