Developing sustainable land use systems through soil and water conservation in the Sakae Krang Watershed, Central Thailand | |
| Author | Shrestha, Rajendra Prasad |
| Call Number | AIT Diss. no.AC-99-01 |
| Subject(s) | Soil conservation--Thailand--Sakae Krang Watershed Water conservation--Thailand--Sakae Krang Watershed Land use, Rural--Thailand--Sakae Krang Watershed |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Decreasing land productivity due to increasing land degradation and environmental problems is today's main concern of sustainable development. It is especially important in the developing countries, like Thailand where a rapid agricultural growth has been experienced for the last few decades mostly due to land conversion and chemical agriculture. The modified concept of sustainable land management calls for integrating technologies, policies and activities aimed at integrating socioeconomic principles with environmental concerns so as to simultaneously enhance productivity, attain security, protect further degradation of natural resources, gain viable economic return and be acceptable to society. The concerns for sustainability are global but the required actions including development and refinement of the criteria for sustainability evaluation must be local. The area selected for the study is deemed to be representative of those watersheds of Thailand having low watershed productivity due to rapid biophysical degradation as the consequence of land conversion. Location-specific studies demonstrating integrated use of biophysical and socioeconomic information are lacking. This study evaluates the criteria and indicators, in the light of the five objectives of sustainable land management, and identifies the most significant indicators to describe the sustainability levels of land uses using Geographic Information Systems as a centerpiece analytical tool. The population growth is the most obvious driving force of land use change in the area. An annual rate of forest depletion is about two folds of the proportion of population growth. The current estimate of 10 percent of the area under severe erosion hazard is likely to increase to more than one third of the area in the near future with the continuing farming situation of upland agriculture at present. The higher rates of chemical fertilization in the agricultural crops seeking to obtain higher yields not only give an indication of the decreasing trend of soil productivity onsite, hence not sustainable, but also give rise to other environmental impacts due to downstream chemical run-off. Suitability evaluation shows that the majorities of the area are under inappropriate land uses. The differences between the upland and lowland farming systems are significant with relation to socioeconomic settings including problems in farming leading to different levels of significance of factors of production which eventually result into different levels of land use sustainability. Considering that the sustainability is dynamic and should be addressed in the context of specific location, different levels of land use sustainability are defined based on the specific time frames. Only about one fourth of the agricultural area in the watershed meets the sustainability thresholds leaving a substantial proportion of the area below the sustainability criteria. Besides the biophysical factors, such as land quality, evapotranspiration, and erosion severity, the socioeconomic indicators, such as sources of farm income, multiple cropping, fertilizer application, accessibility, land tenure, crop-based income, and proportion of non-farm earnings of the gross household earnings were the significant indicators of land use sustainability. Altogether five sustainability models described by different number of predictive indicators are presented for evaluating the land use sustainability. iv Land use alternatives are developed for the study area under two major scenarios likely to occur in the future. The goal of the first scenario named as 'production maximizing' is to maximize the production for increasing the household earnings under minimal or pa1tial intervention of policy measures towards soil and water conservation. The 'production optimizing' scenario is geared towards bringing desired future of an increased sustainability of the land uses by optimizing the production and committed soil and water conservation. Optimization, however looks simpler in terms of a process or technique, its objectives are difficult to define. Optimal is meant here in the sense that emphasis be placed to protect the ecological quality of the land or soil, and thus improve the sustainability gradually. Finally, a prototype of sustainability evaluation, which integrates biophysical and socioeconomic information, is developed for spatial decision support system along with sets of topical recommendations for planning and the research. |
| Year | 1999 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural, Conservation and Rural Development (AC) |
| Chairperson(s) | Apisit Eiunoh; |
| Examination Committee(s) | Weber, Karl E. ;Kaew Nuanchawee ;Sornthep Tumwasorn ;Freitag, Ulrich; |
| Scholarship Donor(s) | Asian Institute of Technology; Thai Tapioca Development Institute AIT/ST AR Doctoral Student Research Fund; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1999 |