Deriving RUSLE cover factor from time-series fractional vegetation cover for hillslope erosion modelling in New South Wales

Soil Research ◽  
2014 ◽  
Vol 52 (3) ◽  
pp. 253 ◽  
Author(s):  
Xihua Yang
Keyword(s):  
Time Series ◽  
Vegetation Cover ◽  
Soil Loss ◽  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Erosion Hazard ◽  
Fractional Vegetation Cover ◽  
South Wales ◽  
Factor C

Soil loss due to water erosion, in particular hillslope erosion, can be estimated using predictive models such as the Revised Universal Soil Loss Equation (RUSLE). One of the important and dynamic elements in the RUSLE model is the cover and management factor (C-factor), which represents effects of vegetation canopy and ground cover in reducing soil loss. This study explores the potential for using fractional vegetation cover, rather than traditional green vegetation indices (e.g. NDVI), to estimate C-factor and consequently hillslope erosion hazard across New South Wales (NSW), Australia. Values of the C-factor were estimated from the emerging time-series fractional cover products derived from Moderate Resolution Imaging Spectroradiometer (MODIS). Time-series C-factor and hillslope erosion maps were produced for NSW on monthly and annual bases for a 13-year period from 2000 to 2012 using automated scripts in a geographic information system. The estimated C-factor time-series values were compared with previous study and field measurements in NSW revealing good consistency in both spatial and temporal contexts. Using these time-series maps, the relationship was analysed between ground cover and hillslope erosion and their temporal variation across NSW. Outcomes from this time-series study are being used to assess hillslope erosion hazard, sediment and water quality (particularly after severe bushfires) across NSW at local, catchment and regional scales.

Effects of logging and fire on small mammals in Mumbulla State Forest, near Bega, New South Wales

1987 ◽  
Vol 14 (2) ◽  
pp. 163 ◽  
Author(s):  
D. Lunney ◽  
B. Cullis ◽  
P. Eby
Keyword(s):  
Small Mammals ◽  
New South ◽  
New South Wales ◽  
Canopy Cover ◽  
Ground Cover ◽  
First Year ◽  
Severe Effect ◽  
South Wales ◽  
Antechinus Stuartii ◽  
Rattus Fuscipes

This study of the effects of logging on small mammals in Mumbulla State Forest on the south coast of New South Wales included the effects of a fire in November 1980 and a drought throughout the study period from June 1980 to June 1983. Rattus fuscipes was sensitive to change: logging had a significant impact on its numbers, response to ground cover, and recapture rate; fire had a more severe effect, and drought retarded the post-fire recovery of the population. The three species of dasyurid marsupials differed markedly in their response to ground cover, canopy cover, logging and fire. Antechinus stuartii was distributed evenly through all habitats and was not affected by logging, but fire had an immediate and adverse effect which was sustained by the intense drought. A. swainsonii markedly preferred the regenerating forest, and was not seen again after the fire, the failure of the population being attributed to its dependence on dense ground cover. Sminthopsis leucopus was found in low numbers, appeared to prefer forest with sparse ground cover, and showed no immediate response to logging or fire; its disappearance by the third year post-fire suggests that regenerating forest is inimical to the survival of this species. Mus musculus showed no response to logging. In the first year following the fire its numbers were still very low, but in the next year there was a short-lived plague which coincided with the only respite in the 3-year drought and, importantly, occurred in the intensely burnt parts of the forest. The options for managing this forest for the conservation of small mammals include minimising fire, retaining unlogged forest, extending the time over which alternate coupes are logged and minimising disturbance from heavy machinery.

Establishing surface-sown pastures in a Poa labillardieri-Themeda australis association

1986 ◽  
Vol 26 (3) ◽  
pp. 331 ◽  
Author(s):  
MH Campbell ◽  
MJ Keys ◽  
RD Murison ◽  
JJ Dellow
Keyword(s):  
Festuca Arundinacea ◽  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Cost Effective ◽  
Phalaris Aquatica ◽  
South Wales ◽  
Before And After

The effects of time and rate of application of glyphosate, 2,2-DPA and tetrapion on Poa labillardieri and Themeda australis were measured in seven experiments carried out 55 km south of Braidwood, on the southern tablelands of New South Wales between 1980 and 1982. In an eighth experiment (1981) and in a 35-ha demonstration (1983), at the same site, the effects of applying herbicides (before and after the autumn break) and surface-sowing Phalaris aquatica, Festuca arundinacea and Trifiolium repens with fertiliser on the control of P. labillardieri were ascertained. All three herbicides proved effective in reducing the ground cover of P. labillardieri from applications at any time of the year. For T. australis, tetrapion proved effective when applied at any time of the year, while glyphosate and 2,2-DPA were effective in all seasons except winter. Glyphosate at rates between 0.72 and 1.44 kg/ha a.i. was more cost effective than 2,2-DPA (11.1 kg/ha a.i.) and tetrapion (3.75 kg/ha a.i.). Best establishment and development of sown grasses and legumes was attained by applying herbicides after the autumn break but before heavy frosts, and then surface-sowing 1-3 months later. Control of P. labillardieri was best where P. aquatica and F. arundinacea established most densely.

Temporal and spatial variability of the sediments budget of the subaerial beach at Warilla, New South Wales

1982 ◽  
Vol 33 (6) ◽  
pp. 945 ◽  
Author(s):  
IG Eliot ◽  
DJ Clarke
Keyword(s):  
Time Series ◽  
Least Squares ◽  
New South ◽  
New South Wales ◽  
Eof Analysis ◽  
Sediment Volume ◽  
South Wales ◽  
Periodic Fluctuations ◽  
Temporal And Spatial ◽  
Phase Differences

A 5-year set of profile data from Warilla Beach, N.S.W., measured fortnightly, has been statistically analysed by using Fourier transform, least-squares, and empirical orthogonal function (eigenfunction or EOF) techniques to identify characteristic patterns of temporal and spatial variation in the sediment volume of the subaerial beach. Least-squares analysis enabled separation of the variation in the subaerial beach at Warilla into a 5-year trend, periodic fluctuations and aperiodic events. The periodic fluctuations are dominated by biennial and annual components. The biennial component accounts for 40% of the sediment budget of the subaerial beach, the annual component 30%, 13% is due to the long-term trend over the 5 years, and about 20% is estimated as aperiodic fluctuations mainly related to changes in the wave regime. Phase differences were identified for periodic oscillations on adjacent beach segments and a chronology of change in sediment volume deduced from the phase differences. The results show that variation in the sediment volume of the subaerial beach is determined by interaction between the biennial and seasonal exchanges although the resulting pattern of exchange may be obscured by higher-frequency beach changes. In alternate years the focus of onshore-offshore sediment exchange shifts from the centre of the beach to the exposed, northern sector. The major depositional zone associated with this exchange is located on the southern+entral sector of the beach and the major erosion zone is on the northern part of the beach. The pattern of alongshore sediment exchange was more closely investigated by EOF analysis. The method facilitated separation of onshore-offshore and alongshore modes of sediment transfer and identification of the patterns of alongshore sediment exchange. The first four EOF's for the data on the subaerial beach at Warilla contain 95.3% of the total variance. The fundamental pattern of sediment movement identified in the EOF analysis involves an onshore-offshore transfer of sediment in biennial, seasonal and 6-monthly cycles. The transfer accounts for 61.7% of the variance for the sediment store of the subaerial beach. The amplitude spectrum of the associated time series for this eigenfunction mode shows that the biennial component is dominant. This result supports the results from the least-squares analysis. It could not have been anticipated from previous studies of beach change from New South Wales or elsewhere and is the subject of ongoing investigation. Subsequent eigenfunction modes identify alongshore movements, with three patterns accounting for a further 33.8% of the remaining variance. They are associated with the prevailing system of inshore water circulation and identify major, recurrent rip and bar locations. Time series associated with the eigenfunction modes confirm the dominance of biennial, annual, and biannual sediment transfers occurring on Warilla Beach.

Humid to Arid to Subhumid Vegetation Shift on Pilliga Sandstone, Ulungra Springs, New South Wales

1989 ◽  
Vol 32 (2) ◽  
pp. 182-192 ◽  
Author(s):  
J.R. Dodson ◽  
R.V.S. Wright
Keyword(s):  
Vegetation Cover ◽  
Vegetation History ◽  
Arid Zone ◽  
New South ◽  
New South Wales ◽  
Vegetation Shift ◽  
South Wales ◽  
Shrub Steppe ◽  
Pollen Rain ◽  
Open Forests

AbstractThe Pilliga Sandstone region of the northwest slope of New South Wales has a natural vegetation cover of sclerophyllous relatively closed to open forests with a largely heathy understorey, and a warm, subhumid and continental climate. Pollen analysis of spring-fed deposits gives a vegetation history extending from at least 30,000 yr B.P. to the late Holocene. Tree pollen became scarce after about 25,000 yr B.P. and an assemblage dominated by Chenopodiaceae, Liguliflorae, Tubuliflorae, and probably Poaceae developed. No similar assemblage is known from present pollen rain studies carried out in Australia. However, it clearly represents a treeless open shrub-steppe formation and therefore an arid or semiarid environment. The site thus provides evidence of an eastward late Pleistocene extension of the arid zone in Australia, and is the first full-glacial vegetation record between 20° and 35° latitude in Australia. The present vegetation cover did not become reestablished until the beginning of the Holocene, which raises questions about the form in which Pilliga Sandstone vegetation survived full-glacial conditions.

Digital mapping of RUSLE slope length and steepness factor across New South Wales, Australia

Soil Research ◽  
2015 ◽  
Vol 53 (2) ◽  
pp. 216 ◽  
Author(s):  
Xihua Yang
Keyword(s):  
Land Use Planning ◽  
Soil Loss ◽  
Overland Flow ◽  
New South ◽  
New South Wales ◽  
Slope Angle ◽  
Universal Soil Loss Equation ◽  
Slope Length ◽  
South Wales ◽  
Soil Loss Equation

The Universal Soil Loss Equation (USLE) and its main derivate, the Revised Universal Soil Loss Equation (RUSLE), are widely used in estimating hillslope erosion. The effects of topography on hillslope erosion are estimated through the product of slope length (L) and slope steepness (S) subfactors, or LS factor, which often contains the highest detail and plays the most influential role in RUSLE. However, current LS maps in New South Wales (NSW) are either incomplete (e.g. point-based) or too coarse (e.g. 250 m), limiting RUSLE-based applications. The aim of this study was to develop automated procedures in a geographic information system (GIS) to estimate and map the LS factor across NSW. The method was based on RUSLE specifications and it incorporated a variable cutoff slope angle, which improves the detection of the beginning and end of each slope length. An overland-flow length algorithm for L subfactor calculation was applied through iterative slope-length cumulation and maximum downhill slope angle. Automated GIS scripts have been developed for LS factor calculation so that the only required input data are digital elevation models (DEMs). Hydrologically corrected DEMs were used for LS factor calculation on a catchment basis, then merged to form a seamless LS-factor digital map for NSW with a spatial resolution ~30 m (or 1 s). The modelled LS values were compared with the reference LS values, and the coefficient of efficiency reached 0.97. The high-resolution digital LS map produced is now being used along with other RUSLE factors in hillslope erosion modelling and land-use planning at local and regional scales across NSW.

Sustainable grazing systems for the Central Tablelands of New South Wales. 4. Soil water dynamics and runoff events for differently-managed pasture types

2006 ◽  
Vol 46 (4) ◽  
pp. 483 ◽  
Author(s):  
J. D. Hughes ◽  
I. J. Packer ◽  
D. L. Michalk ◽  
P. M. Dowling ◽  
W. McG. King ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Soil Water ◽  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Environmental Data ◽  
Quality Data ◽  
Water Runoff ◽  
South Wales ◽  
Management Factors

Soil water, runoff amount and quality, pasture production and environmental data were measured for a pastoral prime lamb enterprise in the Central Tablelands of New South Wales from 1998 to 2002. There were 4 pasture treatments: fertilised and sown chicory (CH), fertilised and sown introduced pastures (SP), fertilised naturalised pastures (FN) and unfertilised naturalised pastures (UN). Two grazing management regimes, tactically grazed (TG) and continuously grazed (CG) were imposed on the SP, FN and UN treatments. The CH treatment was rotationally grazed. To compare pasture and grazing system water use, maximum soil water deficit values (SWDMax) were calculated from neutron moisture meter data. SWDMax was influenced by both environmental and management factors. Management factors that influenced SWDMax were herbage mass of perennials, degree of perenniality, and the perennial species present. Environmental factors accounted for >50% of the variation in SWDMax. Inclusion of management factors (perennial herbage mass of C3 and C4 species and percentage perennial herbage mass), accounted for an additional 16% of variation. While the influence of pasture management appears to be relatively small, importantly, management is the only avenue available to land managers for influencing SWDMax. The UNTG and all sown treatments, with greater perennial herbage mass or greater C4 herbage mass consistently produced the highest SWDMax. Runoff amount and quality data are presented for ground cover percentages which generally exceeded 80% for the experimental period. Runoff as a proportion of rain received during the experiment was <3%. Environmental factors explained 47% of variation in runoff, while pasture herbage mass and ground cover percentage explained an additional 2% of variation. Water quality was monitored on 3 treatments (SPTG, FNTG and UNCG) for total nitrogen (N), total phosphorus (P) and total suspended solids (TST) over a 6-month period. The mean values for total N and P were below the acceptable contaminant concentration for agricultural irrigation water. An important outcome of this research is the concept of a practical Targeted Water Management Plan (TWMP) which devises a framework for optimum water usage and productivity at a landscape scale.

Use of herbicides for selective removal of Eragrostis curvula (Schrad.) Nees from a Phalaris aquatica pasture

1985 ◽  
Vol 25 (3) ◽  
pp. 665 ◽  
Author(s):  
MH Campbell ◽  
JJ Dellow ◽  
MJ Keys ◽  
AR Gilmour
Keyword(s):  
Maximum Rate ◽  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Trifolium Subterraneum ◽  
Selective Removal ◽  
Main Experiment ◽  
Phalaris Aquatica ◽  
Eragrostis Curvula ◽  
South Wales

In the main experiment, the effectiveness of tetrapion, glyphosate and 2,2-DPA in selectively removing Eragrostis curvula from a Phalaris aquatica pasture was determined by applying each at three rates in July 1980, September 1980, December 1980 and March 1981 near Braidwood, New South Wales. Auxiliary experiments were conducted from April 1981 to April 1983 to determine the reliability of herbicide effect on E. curvula. Tetrapion (2.25 and 3.375 kg/ha a.i.) was the most effective herbicide in killing E. curvula and promoting P. aquatica and Trifolium subterraneum. It was more selective when applied in September 1980 and December 1980 than when applied in July 1980 or March 198 1. Re-infestation by E. curvula seedlings in the 3 years after spraying with tetrapion amounted to a maximum of 3% of ground cover. In the auxiliary experiments, tetrapion was effective on all nine occasions of application, which demonstrated its reliability and effectiveness at any time of the year. Glyphosate (1.08 and 1.62 kg/ha a.i.) was effective in killing E. curvula in March 1981 but this result could not be repeated in March 1982 or March 1983 or in nine other applications at other times in these years. 2,2-DPA (maximum rate 22.2 kg/ha a.i.) was ineffective in killing E. curvula at four times of application. Recovery of the P. aquatica pasture after treatment declined in the order: tetrapion >2,2-DPA>glyphosate.

Reducing denitrification loss with nitrification inhibitors following presowing applications of urea to a cottonfield

1994 ◽  
Vol 34 (1) ◽  
pp. 75 ◽  
Author(s):  
DL Chen ◽  
JR Freney ◽  
AR Mosier ◽  
PM Chalk
Keyword(s):  
Soil Loss ◽  
New South ◽  
New South Wales ◽  
Calcium Carbide ◽  
Nitrification Inhibitors ◽  
N Loss ◽  
Mineral N ◽  
N Transformations ◽  
South Wales ◽  
Denitrification Loss

The effects of the nitrification inhibitors nitrapyrin, acetylene (provided by wax-coated calcium carbide), and phenylacetylene on nitrogen (N) transformations and denitrification losses following presowing applications of urea were determined in a cottonfield in the Namoi Valley of New South Wales. The study used 0.05-m-diameter microplots to follow the changes in mineral N, and 0.15-m-diameter microplots fertilised with 15N-labelled urea (6 g N/ m2; 5 atom % 15N) to assess losses of applied N. When urea was applied in February (34 weeks before sowing), 84% of applied N was lost from the soil. Loss of applied N was reduced by addition of nitrapyrin and phenylacetylene, to 53 and 57%, respectively. In the absence of nitrification inhibitors, less N was lost (72% of that applied) from an application in May than from the February application. Addition of acetylene, phenylacetylene, and nitrapyrin reduced losses over the 24 weeks to sowing to 57, 52, and 48%, respectively. These experiments show that N loss from presowing applications of urea can be significantly reduced by the use of nitrification inhibitors, but that the losses of N are still substantial.

scholarly journals Digital mapping of soil erodibility for water erosion in New South Wales, Australia

Soil Research ◽  
2018 ◽  
Vol 56 (2) ◽  
pp. 158 ◽  
Author(s):  
Xihua Yang ◽  
Jonathan Gray ◽  
Greg Chapman ◽  
Qinggaozi Zhu ◽  
Mitch Tulau ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Soil Properties ◽  
Soil Loss ◽  
New South ◽  
New South Wales ◽  
Field Measurements ◽  
Soil Erodibility ◽  
South Wales ◽  
Australian Continent ◽  
K Factor

Soil erodibility represents the soil’s response to rainfall and run-off erosivity and is related to soil properties such as organic matter content, texture, structure, permeability and aggregate stability. Soil erodibility is an important factor in soil erosion modelling, such as the Revised Universal Soil Loss Equation (RUSLE), in which it is represented by the soil erodibility factor (K-factor). However, determination of soil erodibility at larger spatial scales is often problematic because of the lack of spatial data on soil properties and field measurements for model validation. Recently, a major national project has resulted in the release of digital soil maps (DSMs) for a wide range of key soil properties over the entire Australian continent at approximately 90-m spatial resolution. In the present study we used the DSMs and New South Wales (NSW) Soil and Land Information System to map and validate soil erodibility for soil depths up to 100 cm. We assessed eight empirical methods or existing maps on erodibility estimation and produced a harmonised high-resolution soil erodibility map for the entire state of NSW with improvements based on studies in NSW. The modelled erodibility values were compared with those from field measurements at soil plots for NSW soils and revealed good agreement. The erodibility map shows similar patterns as that of the parent material lithology classes, but no obvious trend with any single soil property. Most of the modelled erodibility values range from 0.02 to 0.07 t ha h ha–1 MJ–1 mm–1 with a mean (± s.d.) of 0.035 ± 0.007 t ha h ha–1 MJ–1 mm–1. The validated K-factor map was further used along with other RUSLE factors to assess soil loss across NSW for preventing and managing soil erosion.

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