A PARTICIPATORY LAND SUITABILITY ASSESSMENT USING INTEGRATED TOPOSEQUENCE ANALYSIS NAM CHUN SUB-WATERSHED, PETCHABUN PROVINCE, THAILAND Ronald Job Vargas Rojas March, 2004 A PARTICIPATORY LAND SUITABILITY ASSESSMENT USING INTEGRATED TOPOSEQUENCE ANALYSIS NAM CHUN SUB-WATERSHED, PETCHABUN PROVINCE, THAILAND by Ronald Job Vargas Rojas Thesis submitted to the International Institute for Geo-information Science and Earth Observation in partial fulfilment of the requirements for the degree of Master of Science in Geoinformation Science and Earth Observation, with specialization in Soil Information Systems for Sustainable Land Management. Degree Assessment Board Dr. D.G. Rossiter (Chairman/main supervisor) ESA Department, ITC Dr. Ir. S. de Bruin (External Examiner) Wageningen University Dr. K. de Bie (Internal Examiner) NRS Department, ITC Dr. H. Huizing (2nd supervisor) NRS Department, ITC Dr A. Farshad (Study advisor) ESA Department, ITC INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION ENSCHEDE, THE NETHERLANDS Disclaimer This document describes work undertaken as part of a programme of study at the International Institute for Geo-information Science and Earth Observation. All views and opinions expressed therein remain the sole responsibility of the author, and do not necessarily represent those of the institute. A PARTICIPATORY LAND SUITABILITY ASSESSMENT USING INTEGRATED TOPOSEQUENCE ANALYSIS ABSTRACT Conventional land evaluation studies have been critized for their lack of applicability. Improper land uses and/or land management in steep and unstable slopes in the Nam Chun sub-watershed, Petchabum, Thailand has lead to land degradation. A participatory approach for matching the land supply with the land demand is needed. Hence, the aim of this study was to carry out a participatory land suitability assessment based on local and scientific knowledge using integrated toposequence analysis, considering the stakeholder preferences in the generation of land use alternatives. Traditional soil-landscape analysis through remote sensing material was performed for the identification of toposequences. Integrated toposequence analysis was performed to couple the conventional and participatory land resources survey and mapping. Additional PRA techniques were used for identifying the multiple land use alternatives among the stakeholders. Farmers were also asked to complete a land suitability assessment exercise. Finally, a relative ranking exercise was performed to know the farmers‘ LUA preferences. The result was a two complete micro-toposequences with their land resources characterization components: conventional landscape conceptualisation, farmers land units, soil erosion, land use/land cover, slope grade, lithology and soil classification. A striking conclusion is that farmers use soil-landscape relationships to divide their different lands and in this way assign the different land uses and management practices, which are mostly dominated by socio- economical and political aspects. That is the main task of the conventional land evaluation is looking for. Land evaluators sometimes make wrong assumptions that in the prognosis stage results are unrealistic. Farmers understand the microenvironment and crop requirements that can be matched to get realistic results. ITA is a tool that in a short period of time allowed us to combine scientific and local knowledge for the land resources survey, participatory mapping and land evaluation. The participatory land evaluation approach proved to be a very important approach for bridging the distance between the data produced by conventional LE approaches and its use by the stakeholders. Key words: Land degradation; Integrated toposequence analysis; soil-landscape relationship; local knowledge; participatory mapping; land suitability assessment; land use preferences; ranking; Nam Chun Sub-watershed. I A PARTICIPATORY LAND SUITABILITY ASSESSMENT USING INTEGRATED TOPOSEQUENCE ANALYSIS —Money is a stupid measure of achievement but unfortunately it is the only universal measure we have“ C.P. Steinmetz (1865-1923) A las personas que les debo lo que soy: M is increibles, unicos y adorados padres: R igoberto y T eresa II A PARTICIPATORY LAND SUITABILITY ASSESSMENT USING INTEGRATED TOPOSEQUENCE ANALYSIS ACKNOW LEDGM ENTS Every start has an end and with that, time to express our gratitude for people who make this became true, just arrived. First I would like to thank the University of San Simon and the CLAS project for giving me the support for my application. I would like to thank Dr. Carlos Valenzuela for his collaboration and guidance. My gratitude to the Dutch Government through the NUFFIC for granting me with this scholarship that brought me scientific and life knowledge in such a nice country. I‘m indebted to my supervisor Dr. D. Rossiter from whom I learnt a lot in truly research and also for share his knowledge. Dr. Huizing my second supervisor for his valuable contribution and experience in the topic. A lot o thanks for the LDD staff in Thailand that helped me during my fieldwork stage. I‘d to express my thankfulness to ITC especially to the teachers of NRM program and the SISLM specialization (Dr. Abbas Farshad, Dr. Dhruba Shrestha, Ir. Rob Hennemann. Ir. Bart Krol, Dr. W. Siderius and Drs. Emile Dopheide). One of the most beautiful aspects of being in ITC is the worldwide friendship that one can get. I‘m very happy and grateful to get good friends such: Gerlee, Retno, Analia, Budi, Trang, and Brando. To my fieldwork partners Chalermchai and Kunda for the enjoyable moments in Thailand. Especial thanks to my friend Aiman with whom we have discuss a lot of science and life aspects. Muchisimas gracias to my best friend Rafael con quien disfrutamos de nuestra vida en Enschede, incluidas sus violentaciones y quien me ayudo muchisimo. To my dear friend Carlos por su bella amistad y sobretodo sus sabios consejos. Siempre tuve la suerte de tener el apoyo incondicional de mis hermanas y mi cunado que junto a mis padres me brindaron ese afecto y dedicacion aun en la distancia. Gracias por todo. A mi amada Elizabeth, gracias por tu apoyo y amor incondicional. Finally to my source of inspiration —God and my beautiful country: Bolivia“ III A PARTICIPATORY LAND SUITABILITY ASSESSMENT USING INTEGRATED TOPOSEQUENCE ANALYSIS TABLE OF CONTENTS 1. INTRODUCTION..............................................................................................................1 1.1. General background....................................................................................................1 1.2. Overview of land degradation in Thailand.................................................................1 1.3. Actual Nam Chun Sub-watershed overview ..............................................................2 1.4. Research Problem.......................................................................................................2 1.5. Objectives ...................................................................................................................3 1.5.1. General objective................................................................................................3 1.5.2. Specific objectives..............................................................................................3 1.6. Research questions and Hypothesis............................................................................4 2. LITERATURE REVIEW...................................................................................................5 2.1. Integrated Toposequence Analysis.............................................................................5 2.2. Participatory rural appraisal........................................................................................5 2.3. Conventional Land evaluation Approach...................................................................6 2.3.1 Land demand ......................................................................................................6 2.3.2 Land supply........................................................................................................6 2.3.3 Matching the land demand and land supply.......................................................7 2.3.4 Land suitability results........................................................................................7 2.4. New trends in land evaluation ....................................................................................8 2.4.1. Participatory land evaluation..............................................................................9 2.4.2. Demand-driven land evaluation..........................................................................9 3. METHODS AND MATERIALS.....................................................................................11 3.1. Study Area ................................................................................................................11 3.1.1. Location............................................................................................................11 3.1.2. Climate..............................................................................................................11 3.1.3. Geology............................................................................................................11 3.1.4. Land use and land cover ...................................................................................12 3.1.5. Accessibility.....................................................................................................12