**Acknowledgements**

conventional based on the topography of the watershed with very high risk (0.63%), high risk (32.00%), moderate risk (32.40%), low risk (31.21%) and very low risk (3.76%) as shown in **Figure 5**. The clusters of very high risk were consistent with the northern, central, eastern regions of the watershed as also presented in **Figure 5**. They were mainly located in mountainsides or hillsides, which are usually steep slope and boundaries between forests and

In general, most areas of the Khlong Kui watershed had high potential risk of soil erosion due to the combination of mountainous topography and agricultural activities. High rainfall in high mountain area generated more areas of higher risk while low rainfall in low and flat area

This study used remote sensing and GIS techniques to assess land use and land cover (LULC) and its dynamics of change with identify the potential risk areas of soil erosion in the Khlong Kui watershed in 1991, 2005 and 2014. The Khlong Kui watershed was selected as the study area because this watershed has been experiencing deforestation and soil degradation due to the development of agricultural lands and urban areas. Moreover, the topography of the watershed, which includes mountains, hills and slopping lands, makes the Khlong Kui watershed an interesting region to examine potential risk areas of soil erosion. The key findings of

The major LULC of the Khlong Kui watershed are forests and agricultural lands. The study monitored an increase in orchards, croplands, evergreen forests, rice field and urban areas while a decrease in deciduous forests and wetlands in the watershed in 1991, 2005 and 2014. The overall accuracy assessment of the image classification was satisfactory in all three differ-

Deciduous forest, evergreen forest and orchards types were major drivers of land use and land cover changes. An increase of range land, croplands and evergreen forests were mainly derived from deciduous forests. The development of range land, barren land and crop land was related to an increase in infrastructure of the Khlong Kui watershed. There is a high probability of change from deciduous forests, wetlands and orchards to rice fields and croplands in 2014.

High-risk areas of soil erosion were primarily located in the northern and eastern regions of the watershed which are also with mountain ranges and hilly areas. High rainfall in high mountain area generated more areas of very high risk at 0.63% of the watershed. The change

highland crops.

**4. Conclusions**

generated areas of lower risk.

178 Land Use - Assessing the Past, Envisioning the Future

the research are as follows:

**4.1. Image classification and analysis**

ent years of satellite data acquisition.

**4.3. Potential risk areas of soil erosion**

**4.2. LULC changes and dynamics**

The ASTER L1B data product was obtained through the online Data Pool at the National Aeronautics and Space Administration (NASA) Land Processes Distributed Active Archive Center (LP DAAC), USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota (https://lpdaac.usgs.gov/data\_access).

The data used in this study were acquired as part of the Tropical Rainfall Measuring Mission (TRMM). The algorithms were developed by the TRMM Science Team. The data were processed by the TRMM Science Data and Information System (TSDIS) and the TRMM office; they are archived and distributed by the Goddard Distributed Active Archive Center. TRMM is an international project jointly sponsored by the Japan National Space Development Agency (NASDA) and the US-NASA Office of Earth Sciences.

This research was supported by the Department of Civil Engineering, Faculty of Engineering, Rajamangala University of Technology Rattanakosin, WangKlaiKangWon Campus, Prachuab Khirikhan, Donor. We would like to thank Rajamangala University of Technology Rattanakosin, WangKlaiKangWon Campus for its financial support and providing facilities to make this research possible. We would also like to thank the National Aeronautics and Space Administration (NASA), Land Processes Distributed Active Archive Center (LP DAAC), USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota (https://lpdaac.usgs. gov/ data\_access) for providing the ASTER L1B data product. We would also express our gratitude to the Goddard Distributed Active Archive Center that delivers TRMM for this research. TRMM is an international project jointly sponsored by the Japan National Space Development Agency (NASDA) and the US-NASA Office of Earth Sciences.
