BIẾN ĐỘNG SỬ DỤNG ĐẤT LÂM NGHIỆP TẠI XÃ NGỌC PHÁI, HUYỆN CHỢ ĐỒN, TỈNH BẮC KẠN, VIỆT NAM (1990-2005)

Đàm Việt Bắc và cs Tạp chí KHOA HỌC & CÔNG NGHỆ 77(01): 97 - 102

97

FOREST LAND-USE CHANGE IN NGOC PHAI COMMUNE,

CHO DON DISTRICT, BAC KAN PROVINCE, VIETNAM (1990-2005)

Dam Viet Bac, Dam Xuan Van*

College of Agriculture and Forestry - Thai Nguyen University

SUMMARY

The study was conducted at the Ngoc Phai Commune, Cho Don District, Bac Kan Province,

Vietnam. The aimed to determine land-use changes (LUCs) for the last 15 years (1990-2005) of

Doi Moi (renovation) ra in the mountainous region of northern Vietnam. For spatial data, the

Geographic Information System (GIS) was applied as a tool for determining LUCs. Three land-use

maps (1990, 1998 and 2005) were overlaid and grouped into two intervals (1990-1998 and 1998-

2005). Several thematic maps were created such as slope, elevation, drainage and road maps.

Moreover, the study site was divided into 204-grid cells with 500 m x 500 m/cell or 25 ha/cell to

identify and quantity the area and location of the land-use changes associated with the grid cell

level. For the period 1990-1998, the total area of forest degradation was 109.31 ha. This occurred

at 15°-35° slope, 500-700 masl and at a distance of 500-1000m from location of LUCs to the main

road. Forest restoration for the same time period was 108.30 ha mainly at 15°-35° slope, 400-700

mal and at a distance of 100-250 m followed by 250-500 m and 500-750 m. For the period 1998-

2005, forest degradation had a total area of 625.47 ha mainly at 15°-35°slope, 400-600 masl and at

a distance of 250-500 m followed by 500-750 m and 750 – 1000 m. Forest restoration for the same

time period was 657.94 ha mainly at 15°-35° slope, 400-700 mal and at a distance of 250-500 m

followed by 500-750 m and 750-1000 m.

Keywords: Land use change, mountainous region, northern Vietnam

INTRODUCTION*

Three-quarters of Vietnam‟s total land area of

33.104 million hectares is occupied by hills

and mountains. The remaining one-third is

home to the national population which have

undergone rapid changes following socio￾economic developments. Forest and land, the

main sources of local production system, has

been impacted severely over the last decades.

Researches on land-use and land-use planning

have been carried out in Northern Vietnam

but have not fully looked into the driving

forces of land-use change as influenced by

renovation policies. For this reason, research

in this area was conducted. The study

attempted to review the biophysical and

socio-economic conditions, estimate land-use

change across three-time periods by using

Geographic Information System (GIS),

identify the driving forces of land-use change

both at the local and exogenous levels and

create GIS database. Results of the study

would contribute to policymakers in creating

*

Tel: 0982166696; Email: [email protected]

guidelines relevant to forestry and rural

development sectors.

MATERIALS AND METHODS

GIS Processing for Analysis of Land-Use

Changes

For spatial data, existing digital GIS files of

land-use maps (1990, 1998, and 2005) from

SAM Project and Natural and Environmental

Office of Bac Kan province were used. This

was combined with ground verification

generated during the time of data gathering by

intersecting land-use themes 1990-1998, and

1998–2005. Aside from these,

topographical, drainage and slope maps

were interpreted in Philippines and

intersected with several thematic maps by

ArcGIS 9.0. Finally, grid cell level (25

ha/cell) for the study site was made.

For temporal data, all the attribute tables on

Arcview GIS 3.2a and AcrGIS 9.0 were

exported to dBase IV files of Excel program,

and then to SPSS 12.0 for statistical analysis

of output tables. Means, frequencies, ranges,

percentages land-use change matrices and

charts were used to compare the data of land￾Số hóa bởi Trung tâm Học liệu - Đại học Thái Nguyên http://www.lrc-tnu.edu.vn