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

In China, the new land policy "household responsibility system", implemente d since late 1970s and early 1980s, has advanced China's agriculture and le d 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 Sh aanxi province, China, was studied by an interpretation of two aerial photo graphs (1975 and 1997). The land-use pattern in 1975 and 1997 was studied b y various pattern measures: areal percentage, patch number per unit area, m ean patch area, landscape diversity, fractal dimension and relative land-us e 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 pe rcentage of dense woodland, orchard and sparse wild grassland increased. Me an patch size of terrace farmland, dense woodland, bushland and sparse wild grassland became larger, while mean patch size of slope farmland, sparse w oodland and orchard became smaller. Fractal dimension analysis indicated th at, compared with 1975, the patch shape of orchard and slope farmland was b ecoming complex, while the patch shape of dense woodland, sparse woodland, bushland terrace farmland and sparse wild grassland was becoming more regul ar. Based on land-use suitability evaluation by calculating the R-value, th e present land-use structure appears to be suitable. (C) 2001 Elsevier Scie nce B.V. All rights reserved.