关键词: 土地利用, 景观格局, 关中地区, 数量结构, 时空变化, 驱动力

Abstract: The Guanzhong area in Shaanxi Province is the core area of Guanzhong-Tianshui Economic Zone.It is an important part of the national “seven zones and twenty-three zones” agricultural development strategy and a new starting point for the economic belt of the Silk Road that is currently in the full construction at the same time.Influenced by the natural environment and human activities,the land use and landscape pattern in the study area were changed obviously in recent 25 years.Based on the four periods of 30 m grid land use data of Shaanxi Province during the period from 1990 to 2015,the temporal and spatial variation characteristics and driving forces of land use and landscape pattern in the study area in recent 25 years were analyzed by using GIS technology and landscape ecological methods.There were six types of land use in the study area,and the results showed that the main land use types were cultivated land,forestland and grassland.The area of cultivated land was the largest and accounted for 46.25%,45.81%,44.73% and 43.94% in 1990,2000,2010 and 2015,respectively.During the study period,the areas of cultivated land and grassland were continuously shrunk,especially the area of cultivated land was sharply shrunk by 12.79×10⁴ hm².The areas of forestland,waters,urban construction and rural housing land were holistically in an enlarging trend.The area of urban construction and rural housing land was enlarged by 14.94×10⁴ hm².with an enlargement of 69.88%.The area of unused land was shrunk by 0.58×10⁴ hm².with a reduction of 38.16%.Because of the intervention of human activities,the mutual conversion among land use types was frequent in the study area.The cultivated land was changed into urban construction and rural housing land,grassland and forestland.The whereabouts and sources of grassland were mainly cultivated land and forestland,and the whereabouts and sources of forestland were mainly cultivated land and grassland.The landscape pattern index highly condenses the information of landscape pattern,which can be used to quantitatively reflect the characteristics of its structural composition,spatial configuration and dynamic change.There are many indexes describing landscape pattern,and some indexes have strong correlation.After fully understanding the ecological significance represented by each index and the emphasis of the landscape pattern reflected by it,a set of reasonable and widely used landscape pattern indices was selected.The landscape shape index was increased from 204.693 4 to 211.805 5,the landscape diversity index was increased from 1.774 6 to 1.851 8,and the landscape evenness index was increased from 0.574 1 to 0.599 1,these indicated that the landscape fragmentation and the landscape heterogeneity were increased during the period from 1990 to 2015.The change of land use and landscape pattern reflected the interaction between human activities and natural factors,and the main driving forces were different from different regions.Landscape pattern change and driving forces have temporal and spatial dynamic relationship.Principal component analysis was used to analyze the ten selected indexes by SPSS 22.0 in this study.The result showed that the driving factors of land use and landscape pattern change in the study area were the socio-economic development,regional policies and agricultural production.

Key words: land use, landscape pattern, Guanzhong area, quantitative structure, temporal and spatial change, driving force