In situ measurement of soil hydraulic properties may be achieved by analyzing the unconfined efflux from disc tension infiltrometers, once consistent infiltration equations can derived. this paper an analytical, three‐dimensional equation is developed, based on use parameters with sound physical meaning and adjustable for varying initial boundary conditions. The valid over entire time range. For practical purposes, a simplified solution also full give excellent agreement published...

Wireless sensor network technology has the potential to reveal finegrained, dynamic changes in monitored variables of an outdoor landscape. But there are significant problems be overcome order realize this vision working systems. This paper describes design and implementation a reactive, event driven for environmental monitoring soil moisture evaluates its effectiveness. A novel feature our solution is reactivity environment: when rain falls changing rapidly, measurements collected...

SUMMARY A new field method of obtaining, with minimal disturbance, the unsaturated hydraulic conductivity ( K 0 ) and sorptivity S from unconfined disc permeameter measurements is introduced. Conventionally, obtained initial square‐root‐of‐time behaviour discharge permeameter. In some cases this can be difficult to measure, in part because multi‐dimensional flows approach quasi‐steady state very rapidly. As an alternative we extend ponded twin‐ring discs several radii. This has advantage...

Understanding the spatiotemporal patterns of vegetative cover in relation to climate and land uses is essential for effective management ecology environment. In this study, spatial temporal changes normalized difference vegetation index (NDVI) potential influencing factors were analyzed different elevations across southwest China. Results showed: (1) there was a critical elevation 3400 m, with NDVI responses human interventions above below m. Below mean each use area whole region did not...

Simple functions do not adequately describe the hydraulic properties of many field soils, particularly those with substantial macroporosity. By considering soil pore-size distribution f(ψ) = ΣNi 1 ψi fi (ψ) corresponding to effective saturation S(ψ) Si(ψ), where ψ is matric pressure head, are fractions porosity, Si(ψ) simple water retention in common use, and fi(ψ) S'i(ψ), we show that relative conductivity according Mualem model Kr(ψ) Sp[ΣΣNi gi(ψ)/ΣNi gi(0)]2, gi(ψ) εψ-xψ−1 dψ p a pore...

AbstractA quantitative investigation was undertaken to ascertain the relationships between radiometrics and surface soil properties within a 77 km2 survey area, on Elashgin Creek catchment, Wyalkatchem, Western Australia. A high-resolution airborne gamma-ray survey, with measurement 'footprint' width of approximately 40 m length 80 m, provided measurements radionuclide distributions across study area. Ground-based gamma-spectrometry measurements, much smaller one metre diameter, were also...

The hydraulic properties of an unsaturated homogenous and isotropic soil can be obtained from the unconfined flux out a disc infiltrometer into over depth wetting. is becoming increasingly popular, but methods analysis have generally relied on restrictive assumptions one‐dimensional flow at early times or quasi‐steady state large times. We provide approximate analytical expression for three‐dimensional unsteady, infiltrometer, this includes geometric effect circular source ignores gravity....

Wireless sensor network technology promises to reveal fine-grained, dynamic changes in monitored variables of an outdoor landscape. But there are significant problems be overcome translating this vision working systems. This paper describes the design and implementation a reactive, event driven for environmental monitoring soil moisture evaluates effectiveness solution. A novel feature our solution is its reactivity environment: when rain falls changing rapidly, measurements collected...

Over the next 30 years, it is anticipated that world will need to source 70% more food provide for growing population, and likely a significant amount of this have come from irrigated land. However, quality irrigation water also important, measuring allow management decisions be made. Soil salinity an important parameter in crop yield, paper, we describe chloride sensor system based on low-cost robust screen-printed ion sensor, suitable use distributed networks. Previously, has been used...

In situ field measurements and laboratory determinations are presented of the saturated unsaturated flow properties two contrasting soils. Field were obtained with ponded rings or disc permeameters different radii. A pressure-transient outflow technique was used in on undisturbed cores. The soil water diffusivity function from this, when integrated, provides a good rendition growth field-measured sorptivity as surface potential, ψo, approaches zero. wetting hydraulic conductivity K(ψ) cores...

The effects of two rotation and tillage systems on earthworm populations have been studied in a red-brown earth under wheat. At the time sampling, population direct drill was nearly double that conventional cultivation. total number worms not affected by crop with pasture or lupins, but following there were significantly more large worms. It is suggested at this site may be responding rapidly to alterations food supply water stress different agricultural systems.

Summary Two fluorescent dyes, sulpho‐rhodamine B and lissamine yellow FF, three non‐fluorescent chlorantine fast green, sirius red Chicago blue are compared for use in the identification of water transmission routes structured soils. Subsequent to flow labelled water, a microsampling extraction technique is employed identify dye distribution relation structural features. The desirable properties dyes tested include stability over wide pH range, anionic character high molecular weight, latter...

There is increasing concern that widespread forest decline could occur in regions of the world where droughts are predicted to increase frequency and severity as a result climate change. The average annual leaf area index (LAI) an indicator canopy cover difference between maximum minimum LAI turnover. In this study, we analyzed satellite-derived estimates monthly across forested coastal catchments southwest Western Australia over 12 year period (2000-2011) included driest on record for last...

Water flow in soils with sufficiently large aggregate size or pore‐class heterogeneity may exhibit a nonequilibrium between the actual water content and that given by retention curve. The result is deeper penetration of infiltrating than predicted using classical infiltration theory. Models this process usually divide soil into two more exchanging regions. A simpler treatment possible combining Richards' equation dynamic description approach to equilibrium. We present first‐order time...