to download report - Geological Survey of Ireland

More documents

Recommendations

Info

Platform / sensor pixel resolution(m) spectral spectral rangeresolutionAVHRR 1100 5 VNIR-TIRSPOT veg 1150 4 VNIR-SWIRTERRA/MODIS 250/500/1000 36 VNIR-SWIR-TIRTERRA/ASTER 15,30,90 16 VNIR-SWIR-TIRTERRA/MSIR 275/1150 4 VNIRLANDSAT /TM 30,120 7 VNIR-SWIR-TIRLANDSAT / ETM 30,60,15 8 PAN +TMSPOT HRV 10,20 4 PAN, VNIRSPOTHRVIR 10,20 5 SWIR-HRVQUICKBIRD 0.61, 2.44 5 PAN, VNIRIKONOS 1, 4 5 PAN, VNIRAVIRIS HYMAP 4,20 168-224 VNIR, SWIRCASI-2 5 48-288 VNIRADAR 5500 0.5 4 VNIRRADARSAT 25 * *ENVISAT/ASAR 30 DUALPOLARIZATIONERS1/2 25LIDAR
Available datasetsThe first task in developing a susceptibility map involves an assessment of the available data. The followingdatasets were available for the case study:Theme Source Scale ExtentSoilAn Foras Taluntais 1:127,560 Western half of MayoEPA Soil & Subsoil 1:50,000-1:100,000 Entire countyMapping Project (Nominal)LandcoverEPA Soil & Subsoil 1 Ha grid cell resolution Entire countyMapping ProjectSlope EPA-Teagasc DEM 20m grid cell resolution Entire countyTable 5.3 Datasets available for Co. Mayo case studyDataset background informationAt the outset of the EPA Soil & Subsoil Mapping Project (initially established as the FIPS-IFS project), lessthan half of the country’s soils had been surveyed and published at a detailed reconnaissance (1:126,720)scale (Fealy et al., 2004). This necessitated the development of soil mapping for the remainder of the countryat a similar scale. Due to the short project time frame, remote sensing and GIS techniques were incorporatedinto the project methodology.The EPA Soil & Subsoil Mapping Project developed a methodology for the creation of a first-approximation soilclassification for those areas not previously surveyed by the National Soil Survey. This also involved the productionof a subsoils map for the entire country using stereo-photogrammetric interpretation supported by field work.The use of stereo-photogrammetric image pairs facilitated viewing of the landscape in a simulated 3-dimensionalenvironment. This technique is well established in soil survey methodology and is widely used internationally.Map units are discriminated using visual signals from the imagery such as texture, tone and appearance alongwith contextual information provided by 3D viewing. Vegetation overlying peat is generally very easilydiscriminated from the imagery, facilitating generally high accuracy levels for the classification of peat.Within the same project, a landcover map of Ireland has been developed using supervised classification ofsatellite imagery acquired by the Thematic Mapper (TM) sensor on board Landsat 5. The resulting land coverthematic map illustrates the distribution of land cover classes. These classes represent groupings of vegetationtypes, developed from aerial photographic training data, and are indicative of vegetation type in a broad sense.The EPA-Teagasc DEM was developed using ANUDEM software and the Ordnance Survey of Ireland 1:50,000data as input. (Preston and Mills, 2002).The National Soil Survey (NSS) was initiated in 1959, shortly after the establishment of An Foras Taluntais(AFT), the precursor organisation to Teagasc. During the period of operation of the NSS, a number of soilsurvey outputs were produced at varying scales. Chief amongst these was the publication of 1:127,560 scalemapping for approximately 44% of the country.The NSS Soil Map of West Mayo was developed using the established methods of soil survey used in othercounties in Ireland. This involved mapping soils in the field and the production of a reduced scale soil map forpublication at 1:127,560 scale. Although available for only half of Co. Mayo, the map provided a very usefuldataset to assess the other datasets used in this case study.Methodology and resultsThe production of the susceptibility map based on the criteria supplied by the geotechnical sub-group isrelatively straightforward in the sense of the GIS methodology used. In simple terms, it requires the input of aslope map, a peat map, and the application of the criteria thresholds.The development of a slope map for Co. Mayo for this case study was straightforward. The slope map wasproduced in ESRI Grid format using ESRI ArcView software. Conceptually, the slope request fits a plane to a3x3 cell neighbourhood of height values from the DEM around the processing or centre cell. The slope for thecell is calculated from the 3x3 neighbourhood using an average maximum technique.The development of a peat map suitable for use in mapping susceptibility, although theoretically straightforward,is a somewhat more difficult task. This is illustrated by the results of the first run of the susceptibility model.39
Page 1 and 2:
Landslides in IrelandGeological Sur
Page 3 and 4: LANDSLIDESinIRELANDEditorRonnie Cre
Page 5 and 6: CONTENTSPreface ...................
Page 7 and 8: Fig. 4.3 Forces caused by water in
Page 9 and 10: PREFACEUntil recently Ireland has b
Page 11 and 12: een very important in populating th
Page 13 and 14: involves a report on the current st
Page 15 and 16: Main Objectives• Increase public/
Page 17 and 18: 1. INTRODUCTIONRonnie Creighton1.1
Page 19: 1.3 The Landslides PublicationThis
Page 22 and 23: Peat flows are not nearly so well d
Page 24 and 25: In Ireland the Quaternary or uncons
Page 26 and 27: Journal - published papersLetter -
Page 28 and 29: Fig. 3.1 Two images showing the use
Page 30 and 31: Table 3.1 Landslide Events Per Coun
Page 32 and 33: Fig. 3.3 Location map of the Pollat
Page 34 and 35: 3.7.4 Quaternary GeologyQuaternary
Page 36 and 37: 3.8 The Derrybrien Landslide - 2003
Page 38 and 39: • The classification scheme shoul
Page 40 and 41: The force causing the block to slid
Page 42 and 43: Plate 4.1 Herringbone drainage syst
Page 44 and 45: 1210Number of events864Raised bogBl
Page 46 and 47: It is well known by research at Uni
Page 48 and 49: 5. LANDSLIDE SUSCEPTIBILITY MAPPING
Page 50 and 51: Two simplified hypothetical example
Page 52 and 53: 5.1.4 Mapping and GISBy definition,
Page 56 and 57: For this initial run, the criteria
Page 58 and 59: 42Fig. 5.5 Peat and peaty podzols f
Page 60 and 61: for susceptibility mapping purposes
Page 62 and 63: elationships between developed susc
Page 64 and 65: The methodology used to derive the
Page 66 and 67: 50Fig. 5.12. Landslide susceptibili
Page 68 and 69: 52Table 5.6. Landslide classificati
Page 70 and 71: The percentage of events occurring
Page 72 and 73: with slope, overall 20-25% of all e
Page 74 and 75: As the dataset was not available at
Page 79 and 80: CHAPTER 5.2 - TABLE APPENDIXBedrock
Page 81 and 82: 6. LANDSLIDES AND PLANNINGAileen Do
Page 83 and 84: 6.2.4 Development ManagementThe phy
Page 85 and 86: 6.5 Current Practice on Landslides
Page 88 and 89: 7. LANDSLIDES IN NORTHERN IRELANDTe
Page 90 and 91: 2. MudflowsPlate 7.1 Rotational Lan
Page 92 and 93: 7.2 Carboniferous Cliff Lines (Co F
Page 95 and 96: 8. RESEARCH ON IRISH LANDSLIDESKoen
Page 97 and 98: 8.4 Research. Post-2003 AbstractsTa
Page 99 and 100: Identifying, recognizing, and predi
Page 101 and 102: In the case of vulnerability mappin
Page 103 and 104: Steep slopes in glacial tillMichael
Page 105 and 106:
9. RECOMMENDATIONS FOR FUTURE WORK9
Page 107 and 108:
Priority 1 Peat slides and peat str
Page 109 and 110:
TEXT REFERENCESAcreman, M., 1991. T
Page 111 and 112:
Skipper, J., Follett, B., Menkiti,
Page 113 and 114:
APPENDIX 2Glossary of TermsBlanket
Page 115 and 116:
APPENDIX 3Nomenclature for Landslid
Page 117 and 118:
APPENDIX 4101
Page 119 and 120:
103
Page 121 and 122:
105
Page 123 and 124:
Hammond, R. 1979. The Peatlands of
Page 125:
APPENDIX 7Useful Web Linkswww.gsi.i
show all

to download report - Geological Survey of Ireland

Create successful ePaper yourself

Delete template?

Save as template?