Collaborating Institution
Asian Institute of Technology, Thailand
     C. Kwei Lin
     Yang Yi

Research Institute for Aquaculture No. 1, Vietnam
     Le Thanh Luu

The University of Michigan
     James S. Diana

Objectives
1) Conduct survey on biophysical features, land and water uses, and socioeconomic conditions of watershed areas in Thai Nguyen.

2) Develop a detailed GIS database for planning of aquaculture development in the study area.

3) Identify and estimate suitable watershed ponds for aquaculture.

Significance
A large number of watershed ponds and reservoirs were created mostly for household water supply and crop irrigation in mountainous areas in central and northern Vietnam. Occasionally, these ponds are also used for fish culture. Thai Nguyen district, situated approximately 100 km north of Hanoi, is a population center serving as a gateway to northern Vietnam. The area possesses numerous small reservoirs and watershed ponds used for irrigating tea plantations, rice fields and fruit orchards; some are also used for aquaculture. To most inhabitants in mountainous areas in northern Vietnam, supply of animal protein is relatively limited, including small contributions from fish. Recently, the Vietnamese government has initiated aquaculture development in those areas as a means to increase protein availability. Therefore, the development of aquaculture in Thai Nguyen will also serve as a model for watersheds in other provinces.

In recent years, surveys have been conducted in Thai Nguyen to evaluate biological, physical, social and economic conditions for aquaculture development. However, most lack systematic spatial data. Planning activities to promote aquaculture in Thai Nguyen need spatial analysis because of geographical variation in biophysical features and socio-economic status (Kapetsky et al., 1987; Nath et al., 2000). This project proposes to develop a GIS database of watershed ponds, coupled with other physical, biological, and social attributes of northern Vietnam. Development of a GIS database is a first step in formally evaluating the effects of local geographic and social conditions on the production of fish in watershed ponds.

With an adequate database, Geographic Information Systems (GIS) can serve as a powerful analytic and decision-making tool for aquaculture development. Furthermore, it can also be used for management and to test consequences of development (Aguilar-Manjarrez and Ross, 1995). GIS systems are a strong component of research at both University of Michigan and the Asian Institute of Technology. These systems will be available and applied to aquaculture development in northern Vietnam.

Anticipated Benefits
This study will provide objective means for planners to determine potential aquaculture development in Thai Nguyen province. The results will provide governmental agencies, the private sector, and non-governmental organizations involved in aquaculture development. It also will establish a model case in planning for watershed aquaculture development in other parts of Vietnam.

Research Design
This study consists of two components. The first component is a survey to assess the current state of aquaculture systems in watershed ponds, and the second is the data to develop a GIS database and identify suitable watershed ponds for aquaculture.

Location: Thai Nguyen province, 100 km from Hanoi; Research Institute for Aquaculture No. 1, Vietnam

Research Methods

Survey

Specific Objectives
• To describe different aquaculture practices in term of species, production and management in different farming systems (VAC system­ garden-pond-livestock; rice-fish system; cage culture; pond culture)
• To identify the importance of socio-economic and environmental factors in aquaculture (infrastructure, regulation, water availability, soil type, soil pH, and water quality)
• To identify the attitude of farmers to watershed ponds and aquaculture (the importance of watershed ponds for irrigation, domestic use or aquaculture; the importance of aquaculture in household economy)

Data Collection and Analyses

Secondary Data Collection: Socio-economic conditions have a strong interaction with aquaculture. Data about socio-economic conditions in study areas will be collected at the Department of Statistics of Thai Nguyen and the district level. At the same time relevant information on aquaculture practices will also collected;

Primary Data Collection: One-hundred households will be selected for interview, and one-hundred watershed ponds for soil and water quality analyses. Pond analyses will be done monthly following standard CRSP methods. Pond selection will be based on the location and culture system. The location of the farm will be recorded by GPS coordinates for transfer to the GIS database. The interviews will focus on farmers' socio-economic status and attitudes on aquaculture as well as potential and constraints for aquaculture;

Data Analysis: Statistical methods and socio-economic methodologies will be used to analyze the data. The analytic hierarchy process (Canada et al., 1996) will be used to identify the importance of the different factors on aquaculture.

GIS Database Development

Data Collection
Remote Sensing Data: two satellite images will be obtained for dry (SPOT January 2001) and wet seasons (SPOT July 2001). Land use classification and simple overlay will be carried out to identify the potential and changing areas of watershed ponds in the dry and wet seasons;

Secondary Data: secondary data will be collected from relevant government offices. These data will be divided into three broad categories: physical and environmental characteristics (water resources, climate, temperature, soils, topography), socio-economic (land use, infrastructure, population density, income distribution), and constraints for aquaculture (protected land, polluted areas, and urban centers);

Primary Data: primary data will be gathered by the field survey that will collect additional data as well as confirm the secondary data. This survey will involve the inspection of the study area in term of hydrological investigation and land use;

Weighting and Scoring: weight and score will be based on the level of importance of the factor that will influence aquaculture. The weight for each factor will be determined by using the Analytic Hierarchy Process (Canada et al., 1996). The score of each level of each factor will be determined from the result of the first component and input decision from experts.

Data Processing: data processing is a process of transforming spatial data and non-spatial data (attributes) into a database system using ARC/INFO software. There are several steps involved:

Digitizing (Data Input): Digitizing is the way to input the spatial data into a computer. The data, which are in the form of maps, can be digitized directly. But data in the form of tables and reports will be used to create attribute tables, and then the attribute tables will be integrated with polygon maps.

Overlay Maps: The main purpose of overlays is to find the land suitable for aquaculture. All digitized maps (physical, environmental characteristics and socio-economic status) will be overlaid with their relative attribute data so that comparable mapping units will be produced. The total score will be calculated for each comparable mapping unit as a sum of the weighted scores. Dissolved function will be used to produce suitability maps. Boolean classification will be used to overlay suitability maps with constraint maps to eliminate unsuitable areas.

Regional Integration
The results of this study will be made available to relevant governmental agencies for consideration in aquaculture development in the area. Our project counterpart is actively involved in aquaculture development in the mountainous areas in northern Vietnam.

The information and GIS database from this study will establish objective criteria for aquaculture development based on an integrated approach. This model will set an example for the Indochina region.

Schedule
August 2001 to December 2002
Report submission: March 2003

Literature Cited
Aguilar-Manjarrez, J. and L.G. Ross, 1995. Geographical information system (GIS) environmental models for aquaculture development in Sinaloa State, Mexico. Aquaculture International, 3:103­115.

Canada, J.R., W.G. Sullivan, and J.A. White, 1996. Capital investment analysis for engineering and management. Prentice Hall International, Inc, USA.

Kapetsky, J.M., L. McGregor, and H.E. Nanne. 1987. A geographical information system and satellite remote sensing to plan for aquaculture development: a FAO-UNEP/GRID cooperative study in Costa Rica. FAO Fish. Tech. Paper 287.

Nath, S.S., J.P. Bolte, L.G. Ross, and J. Aguilar-Manjarrez, 2000. Applications of geographical information systems (GIS) for spatial decision support in aquaculture. Aquacultural Engineering, 23:233­278.