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 EROSION ASSESSMENT BY DIFFERENT MODELS From the results of MSc researches it appeared that 2 erosion models namely RUSLE and RMMF, seem to be the most appropriate for Thailand. They can be applied without major constrains. RMMF can be made applicable to watershed level by incorporating flow accumulation derived from digital elevation data. But this must be validated using field data. Then only we can say which model is the most suitable one for Thailand situation since the results from the two models vary considerably. Even using one erosion model results can vary by changing some parameters. Main problem is due to unavailability of field data for validating model results. Without soil loss data it is difficult to say which model gives results which are close to the real situation. In September 2003 Dhruba Shrestha, together with Ms. Suda Swutanakoon and Mr. Sunton Ratchadawong (LDD staff, regional office in Phitsanulok) visited erosion plots in Nam Nao, which is close to Namchun Watershed. Soil loss data from these plots would be very much useful in calibrating and validating model results. Shrestha suggested to improve the existing erosion plots and also suggested to add some more plots to cater for measuring soil losses under maize cultivation, the main crop in the area. Since the erosion plots were not in good condition suggestions were made to improve them during project meetings in Bangkok. Soil loss data still needs to be collected. Figure 1 : Results of two erosion models applied in Lomsak–Lomkao area, Thailand (Shrestha et al., 2004) Development of Methodologies for Land Degradation Assessment Applied to Land Use Planning in Thailand ^go to top