Land-use change in a small catchment of northern Loess Plateau, China

In China, the new land policy "household responsibility system", implemented since late 1970s and early 1980s, has advanced China's agriculture and led to some changes in land-use structure. In this study, land-use change due to this land policy in a small catchment of the Loess Plateau, northern Shaanxi province, China, was studied by an interpretation of two aerial photographs (1975 and 1997). The land-use pattern in 1975 and 1997 was studied by various pattern measures: areal percentage, patch number per unit area, mean patch area, landscape diversity, fractal dimension and relative land-use suitability index. The results indicated that after implementation of the new land policy, the area percentage of terrace farmland, slope farmland, sparse woodland and bushland decreased obviously, while the area and the percentage of dense woodland, orchard and sparse wild grassland increased. Mean patch size of terrace farmland, dense woodland, bushland and sparse wild grassland became larger, while mean patch size of slope farmland, sparse woodland and orchard became smaller. Fractal dimension analysis indicated that, compared with 1975, the patch shape of orchard and slope farmland was becoming complex, while the patch shape of dense woodland, sparse woodland, bushland terrace farmland and sparse wild grassland was becoming more regular. Based on land-use suitability evaluation by calculating the R-value, the present land-use structure appears to be suitable. (C) 2001 Elsevier Science B.V. All rights reserved.