Wind Erosion in Western Queensland Australia

More documents

Recommendations

Info

Chapter 7 – Land Erodibility Dynamics 1980-2006Country and Mitchell Grass Downs, but there is no correlation between the PDO and erodibleland cover in the Simpson-Strzelecki Dunefields.Table 7.1 Correlation (r 2 ) between mean annual rainfall, Troup SOI, PDO and modelled landerodibility for the four study area bioregions, based on the 27 year simulation. Significant correlations(p < 0.05) are boldfacedBioregion Rainfall SOI PDOChannel Country -0.19 -0.05 0.28Mitchell Grass Downs -0.23 0.09 0.36Mulga Lands -0.48 -0.38 0.56Simpson-Strzelecki Dunefields -0.09 0.02 -0.16Figure 7.6 presents a plot of mean annual rainfall and the Troup SOI for the four study areabioregions. The data are used to interpret mechanisms driving the temporal patterns andcorrelations between land erodibility, rainfall and the climate indices (Table 7.1).Figure 7.6 Graph of the Troup SOI and mean annual rainfall for the four study area bioregions:Channel Country (CC); Mitchel Grass Downs (MGD); Mulga Lands (ML); and Simpson-StrzeleckiDundefields (SSD). *Years are classified into ENSO phases after McKeon et al. (2004)In the Mulga Lands peaks in land erodibility coincide with negative SOI phases in 1982,1986, 1992-94 and from 2002-06 (Figure 7.6). The peaks are consistent with those yearsreceiving low annual rainfall (
Chapter 7 – Land Erodibility Dynamics 1980-2006are consistent with those years receiving annual rainfall >400 mm. However, the correlationsbetween rainfall, SOI and land erodibility in the Mulga Lands are affected by a lag responsein land erodibility change relative to shifts in the SOI phase (positive to negative). This isevident in the transition from the wet La Niña conditions from 1988-90 to the dry El Niñoevent from 1991-94. A mechanism behind the lag is the steady rather than rapid increase inannual rainfall from 1988-90, and sustained vegetation cover over the bioregion until thedrought in 1992. Short (~1 year) El Niño events, for example in 1997, do not necessarilycause a reduction in rainfall. Land erodibility may therefore continue to increase or decreasethrough these periods in line with trends determined by antecedent rainfall conditions.The Mitchell Grass Downs, Channel Country and Simpson-Strzelecki Desert bioregions areless sensitive than the Mulga Lands to inter-annual rainfall and ENSO variability (Table 7.1).These bioregions appear to be more sensitive to intense and persistent (multi-year) drought.This explains the stronger positive correlations of land erodibility with the PDO in theChannel Country and Mitchell Grass Downs. The lower sensitivity of these bioregions tointer-annual climate variability stems from the nature of climate variability in these regions,and their vegetation and soil characteristics.While the Mitchell Grass Downs experiences high inter-annual rainfall variability (Figure7.6), rainfall across this bioregion is adequate to sustain regionally high vegetation coverlevels and low land erodibility (Figures 7.2 and 7.5). Peaks in land erodibility in the MitchellGrass Downs occur in the north-western half of the bioregion. This area, between Boulia andUrandangie, receives lower annual rainfall than the eastern half of the bioregion and issubsequently more sensitive to drought (e.g. 1986-1989). While rainfall has a strongassociation with El Niño events in the Mitchell Grass Downs (McKeon et al., 2004),variability over the eastern half of the bioregion is not sufficient to induce regular regionalscale (10 4 km 2 ) changes in land erodibility that would provide strong correlations with eitherrainfall or the SOI.Like the Mitchell Grass Downs, land erodibility dynamics in the Channel Country reflectrainfall variability and the PDO more than ENSO phase changes (Table 7.1). The gradualincrease in land erodibility in the Channel Country between 1982 and 1988 is consistent withthe sustained ‘neutral’ ENSO conditions and intensification of the PDO (cooling of SeaSurface Temperatures in the tropical West Pacific). The bioregion received
Page 1:
Modelling Land Susceptibility toWin
Page 4:
AUSLEM was developed as a Geographi
Page 8 and 9:
who joined me on many trips, shared
Page 10 and 11:
Conference Presentations by the Aut
Page 12 and 13:
2.2.5 Soil Moisture Effects........
Page 14 and 15:
Chapter 6: Assessing Land Susceptib
Page 16 and 17:
List of FiguresChapter 1: Introduct
Page 18 and 19:
Figure 2.11 Conceptual model of lan
Page 20 and 21:
hand column) presents trajectories
Page 22 and 23:
List of TablesChapter 1: Introducti
Page 24 and 25:
xxii
Page 26 and 27:
Chapter 1 - Introduction• The abi
Page 28 and 29:
Chapter 1 - Introductionchapter the
Page 30 and 31:
Chapter 1 - Introductionevents yr -
Page 32 and 33:
Chapter 1 - IntroductionFigure 1.2
Page 34 and 35:
Chapter 1 - Introductionsusceptibil
Page 36 and 37:
Chapter 1 - Introductiontemporal pa
Page 38 and 39:
Chapter 1 - Introduction1.5 Researc
Page 40 and 41:
Chapter 1 - IntroductionFigure 1.3
Page 42 and 43:
Chapter 1 - IntroductionMitchell Gr
Page 44 and 45:
Chapter 1 - IntroductionSimpson-Str
Page 46 and 47:
Chapter 1 - IntroductionDowns. Wind
Page 48 and 49:
Chapter 1 - IntroductionChapter 2 p
Page 50 and 51:
Chapter 2 - Land Erodibility Contro
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 93 and 94:
Chapter 3 - Modelling Land Erodibil
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121:
Page 124 and 125:
Chapter 4 -Modelling Soil Erodibili
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155: Chapter 5 - Land Erodibility Model
Page 182 and 183: Chapter 6 - Field Assessments and M
Page 192 and 193: Chapter 7 - Land Erodibility Dynami
Page 214 and 215: Chapter 8 - Conclusions• There is
Page 216 and 217: Chapter 8 - ConclusionsThe third ai
Page 218 and 219: Chapter 8 - Conclusionswas shown to
Page 220 and 221: Chapter 8 - Conclusionsland use cha
Page 222 and 223: Chapter 8 - Conclusionsmodels are n
Page 224 and 225: Chapter 8 - Conclusionsmultiple ass
Page 226 and 227: Chapter 8 - Conclusionsthe opportun
Page 228 and 229: Beadle, N.C.W., 1945. Dust storms.
Page 230 and 231: Bryan, R.B., Govers, G., Poesen, J.
Page 232 and 233: Chepil, W.S., 1965. Transport of so
Page 234 and 235: Fryrear, D.W., Sutherland, P.L., Da
Page 236 and 237: Gregory, J.M., 1984. Prediction of
Page 238 and 239: Hugenholtz, C.H., Wolfe, S.A., 2005
Page 240 and 241: Littleboy, M., McKeon, G.M., 1997.
Page 242 and 243: Marshall, J.K., 1973. Drought, land
Page 244 and 245: Assessment Report of the Intergover
Page 246 and 247: Penner, J.E., et al. , 2001. Climat
Page 248 and 249: Rickert, K.G., McKeon, G.M., 1982.
Page 250 and 251: Stokes, C., J., McAllister, R.R.J.,
Page 252 and 253: Williams, W.J., Eldridge, D.J., Alc
show all

Wind Erosion in Western Queensland Australia

Create successful ePaper yourself

Delete template?

Save as template?