home    land degradation    project outcome    Gallery Flooding Flood Hazard Assessment Pilot Area • The Pilot Areas • Climate • Cover factor (C) estimation • Digital terrain analysis • Relationship between soil properties • Relationship of soil properties with different land use/cover types Methodology • Methodologies • LISEM Results • Result Soil Properties and Land Use • Runoff rate for different land cover types • Model calibration and validation • Sensitivity analysis • Land use scenarios • Rainfall size scenarios • Flooding Scenario - 2 years return period • Flooding Scenario - 10 years return period • Flooding Scenario - 20 years return period • Flooding Scenario - 50 years return period • Summary tables for each flood characteristic • Flood hazard mapping • Conclusions and Recommendation Erosion Erosion Assessment Pilot Area • The Pilot Areas • Climate • Cover factor (C) estimation • Digital terrain analysis • Relationship between soil properties • Relationship of soil properties with different land use/cover types Methodology • Methodologies • Erosion Models Result • Results • C-Factor Mapping for erosion assessment • Soil erosion assessment • Assessment of land use/cover change effect on soil erosion • Assessing critical zones for ephemeral gully formation • Erosion Assessment by Different Models • The recommended erosion models • RMMF Landslide Case I • Landslide hazard assessment • The area (Pilot 3) • Landslide Mapping in Wang Chin using digital image analysis Techniques. • Results • Discussions Case II • Doi Ang Khang (Ang Khang) (Pilot area 4) • Landslide mapping in Ang Khang using aerial photos • Landslide Inventory Mapping • Landslide modelling and Susceptibility mapping • Landslide Susceptibility Maps from the three Scenarios (models) • Comparison between Ang Khang and Wang Chin (with respect to weights of evidence modelling using morphometric parameters) Salinization Case I • Pilot area II • Soil salinity • Salinization • Geomorphology • Soils • Geopedologic map • Results Case II • CASE II - The study of Yadav, R.D. (2005), • Methodology • Crop Simulation Model • PS 123 • Results • Mathematical (Regression) Model for Crop Yield Estimation • Conclusion Case III • Case III • Modeling Salinization • Geostatistics and Interpolation (GIS and Kriging) • Model Simulation and Prediction of Salinity • Simulated Depth to water table • Tenth Years Prediction • Twenty Years Prediction • Conclusion Runoff • Surface Runoff • Methodology • Modelling Runoff • Modelling Runoff Using Empirical Approach • Modelling runoff using the Semi-physical approach • Estimation with the Curve Number Method • Results and Discussion • Generation of Scenarios • Comparison of runoff rates with soil loss map • Conclusions • Presentation of papers based on project work at international • Workshop in Lomsak • Hua Hin seminar • Training of LDD staff • GIS and RS based predictive soil mapping • Soil erosion assessment • Landslide hazard assessment • Flood hazard assessment • Soil salinity study • List of completed MSc. theses on project ASSESSING CRITICAL ZONES FOR EPHEMERAL GULLY FORMATION Sensitive areas for ephemeral gully formation were calculated by using slope, catchment area and flow width. The range of sensitive areas was between -0.0550 to 2.4457. These sensitive areas then were classified by using threshold 0.72 into two classes; gully erosion and no gully erosion. According to land use/cover classification map of 2007, most of the critical zones areas were found in agriculture areas which are located in the upper part, central part and bottom right part of study area Field studies also revealed that agriculture areas really have a lot of gully erosion. However in forest areas especially plantation forest were also found gully erosion because of less vegetation cover and distance between the trees quite far. Figure 1 : Sensitive areas (a) and critical zones (b) For validation, critical zone maps were crossed with 20 gully erosion validated. Contingency matrix was done and showed overall accuracy of 65% for predicting gully erosion. This result explained that critical zones with the threshold 0.72 seemed to be acceptable index for prediction the gully erosion formation. However, because of inaccessible areas, the lack of sufficient validation points was a limitation. Table 1 : Contingency matrix between Critical zone and Erosion data from fieldwork Land use class   Reference from fieldwork Gully Erosion Total Critical zone Gully 13 13 No Gully 7 7 Total   20 20 Overall accuracy = (13/20) x 100 = 65% Figure 2 : Gully erosion formation prediction with validated gully erosion points Most of the study area fell on very slight (83.02%). The other areas was classified into slight (6.12%), moderate (7.60%), severe (2.79%) and very severe (0.47%) level. The gully erosion formation area was 5.53% and without gully erosion formation 94.47% of study area. Development of Methodologies for Land Degradation Assessment Applied to Land Use Planning in Thailand ^go to top