Rice ecosystem mapping and soil moisture monitoring for rainfed lowlands using radar remote sensing in northeastern Thailand | |
| Author | Srisaang Kaojarern |
| Call Number | AIT Diss. no.SR-00-1 |
| Subject(s) | Synthetic aperture radar--Thailand, Northeastern Rainfed low land rice--Thailand, Northeastern Soil moisture--Remote sensing--Thailand, Northeastern |
| Note | A dissertation submitted in partial fulfilment of the requirements the Degree of Doctor of Technical Science |
| Publisher | Asian Institute of Technology |
| Abstract | The synthetic aperture radars (SARs) of the European ERS satellites series were launched in 1991 (ERS-1) and 1995 (ERS-2), and the canadian Radarsat satellite in 1995. A few years after Thailand began to receive radar signals from those satellites on a regular basis. However applications of the radar are quite limited due to a lack of full understanding of scattering behaviors and also the lack of methodological tools necessary for processing ART images. In this stury, two applications on rice ecosystem mapping and soil moisture monitoring in the rainfed rice lowlands in Northeast Thailand were demonstrated. The first was mapping a broad area of rice ecosystem classes and, the second was to obtain an inside picture of available soil moisture content after harvest in one of the eosystem classes in order to recommend a possible second crop in some areas. The research was deal with developing methods and approaches keeping in mind that such methods and approaches should derive a general rule that can be applied elsewhere, not just a case study often encountered in the remote sensing community. The emphasis was put more on methodological development than thematic results. In radar remote sensing, the methods and algorithrns to handle SAR multitemporal data are quasi non-existing. For these applications, there was a new development using radar data, although the approach chosen brought together elements that were already studied elsewhere. But in terms of thematic results, mapping rainfed rice ecosystems into various sub classes is a subject that have been little studied by remote sensing means. Such an objective required multiternporal data during rice growing season. The SAR multiternporal data can be acquired independent of floud coverage wheras the optical data is hampered by cloud. Mapping redidual soil moisture in rice fields during dry season is also a new subject. Possibilities and limitations of the data and methods to achieve the thematic requirements have been indicated. The study area is in Northeastern Thailand where rice is a staple crop. Eighty five percent of the rice area in Thailand is rainfed lowland rice ecosystem and one-half of the rice land is located in the Northeast region. Thailand is the major ice exporter in the world market with areputation of high grain quality. The region is a heterogeneous rainfed lowland rice environment covering a broad area of natural complexity and therefore exhibiting diverse conditions of local landscapes, sparse forest trees, and coarse texture soils with low moisture retention. This variability of rice environment can add complexities to analysis and interpretation of SAR temporal signatures. The thematic results for mapping of rice and soil moisture distribution are useful for management strategies. However, the theatic values of these findings ned to be developed into practices. |
| Year | 2000 |
| Type | Dissertation |
| School | School of Advanced Technologies (SAT) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Space Technology Application and Research (SR) |
| Chairperson(s) | Andrianasolo, Haja; |
| Examination Committee(s) | Delsol, Jen-Pierre;Apisit Eiumnoh;Kaew Nualchawee;Kam Suan Pheng;Thuy Le Toan; |
| Scholarship Donor(s) | The French government; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology |