Effects of Qinghai-Xizang Highway on Land Use and Landscape Pattern Change: from Golmud to Tanggulashan Pass
青藏公路对区域土地利用和景观格局的影响——以格尔木至唐古拉山段为例

Based on digital land use maps of 1995, 2000 and road map of Resources and Environment Data Center of IGSNRR, CAS, the land use and landscape pattern change(LULPC) of Golmud, Qumaleb, Zhidoi are studied, in macro-scale, exerting Arc/GIS 8.1 and landscape ecology methods. LULPC of road buffer zones and the bound of construction land expansion is stressed. The conclusions are given as follows: 1. Prominent changes have taken place in land use and landscape pattern from 1995 to 2000. (a) Woodland area increased 0.4%, grassland area reduced 6.26%, water area increased 7.17%, construction land area increased 323.8%, unused land area increased 6.96%, cultivated land area reduced 51.43%. Especially, land degraded seriously, grassland area reduced 22.8% and unused land area increased 43.96% in Qumaleb. (b) The comprehensive land use dynamic degree is 2.25 and the land use dynamic degree of construction land is the biggest, while cultivated land takes the second place and woodland takes the least. (c) The land use degree comprehensive index is 195.2 in 1995, and 156.4 in 2000, reduced 38.8. The fundamental reason is that a great deal of grassland had been transformed into unused land in 5 years. (d) Landscape changed dramatically. The sum of patches increased 1999 and the landscape fragmentation degree increased from 0.115 to 0.124, showing the enhancement of land fragmentation degree. The diversity index increased from 1.308 to 1.331, implying the enhancing of landscape heterogeneity. The fractal degree increased from 1.453 to 1.456 and the shape of patches got complicated. 2. Differed from the corridor effect of other traffic main lines, the corridor effect of this section of road is not obvious and its“point”radiation effect can be seen easily. (a) The land use degree comprehensive index of road buffer zones dropped except the 1 km zone, 40-45 km zone and 50-60 km zone. The land use dynamic index enhanced when the distance to the road get longer, obviously differing from other study areas due to sparse population and sluggish economic development. The landscape diversity index and fractal dimension has no relationship with the distance to the road. (b) The expanding range of Golmud City is confined in 3 km buffer, for Wudaoliang buffer, it is 1 km. No land use change happened in Nanshankou buffer. 3. The new formula ( K = (Ua +Ub - 2Uc) Ua -1T-1 ×100% ) is used to nicely define the land use dynamic degree exactly.