Home Articles Assessing land resource by using the GIS technique

Assessing land resource by using the GIS technique

Dr Tran Ngoc Nam
Dr Tran Ngoc Nam
Head, Department of Geosciences, Hue University
of Sciences, 77-Nguyen Hue, Hue city, Vietnam
[email protected]

Mr Nguyen Quang Tuan
Assistant Teacher, GIS Laboratory,
Faculty of Geography and Geology,
Hue University of Sciences, Vietnam.

Dr. Ha Van Hanh
Head, GIS Lab. Faculty of Geography and Geology,
Hue University of Sciences.

Shifting cultivation occurs popularly in Nam Dong. The landscapes are used mostly for farming and pastoralism, which is considered as a major mean for the rural people to obtain their livelihoods. The people’s livelihoods in the Nam Dong district are unstable, their economic conditions meet trouble, and the land-soil is gradually fading. Therefore, an application of the geographical information system (GIS) technology and FAO’s new achievements in land resource evaluation in the Nam Dong district have become very essential and greatly meaningful.

Land is one of the most precious natural resources. It is “the source of agricultural production” and an “irreplaceable manufactural material”, and is the source of life for creatures and human beings. Evaluating land resource to give out directions for proper land use and protection is of great necessity and significance.

Nam Dong is a mountainous district located in South-West of Thua Thien Hue province, Vietnam, with natural area of 656 square kilometers and population of 21,453 people, of which the ethnic population occupies over 75%. Shifting cultivation occurs popularly here. The landscapes are used mostly for farming and pastoralism, which is considered as a major mean for the rural people to obtain their livelihoods. The people’s livelihoods in the Nam Dong district are unstable, their economic conditions meet trouble, and the land-soil is gradually fading. Therefore, an application of the geographical information system (GIS) technology and FAO’s new achievements in land resource evaluation in the Nam Dong district have become very essential and greatly meaningful.

Based on the application of FAO-UNESCO land evaluation methods (land resources evaluating method and land use planning) for particular conditions in the Nam Dong district we have studied the soil properties of the landscape, identifying 196 land units for the district. A data system and a map of land resources for the district has been built by using the GIS technology (Map Digitizing Method and Information Overlaying Method).

Evaluating and Grading the Land in the Nam Dong District
To classify land units for the Nam Dong district we applied FAO-UNESCO land evaluation methods. The chart of land evaluation and planning process by FAO-UNESCO is summaried as shown in Fig. 1. [1, 2, 3]. To build a land unit map, we firstly chose and graded the map criteria. It depends on the map scale and conditions of the research area [4]. Land unit map for the Nam Dong district was built, based on 5 land types (Table 1) and on 8 soil criteria (Table 2). To evaluate the adaptability of land use type, our basis was land use demand of the major type in the research area. As for Nam Dong district we combined three major land use groups to evaluate the adaptability. They were: Two crops wet rice, Short-term upland plant and Long-term industrial trees and fruit trees.