1954—2010年三江平原土地利用景观格局动态变化及驱动力

受自然因素和人为因素的影响,近60年三江平原土地利用景观格局发生了明显变化。以遥感影像为主要信息源,利用地理信息系统技术和数理统计方法,对1954—2010年三江平原土地利用景观格局动态变化及其驱动力进行分析。结果表明:1954—2010年三江平原耕地、居住建设用地和水域面积呈增长趋势,林地、草地和湿地面积呈减少趋势;土地利用综合动态度呈先增加后降低再增加的趋势;三江平原斑块密度、周长面积比、景观分离度和Simpson's多样性指数都呈先上升后下降的趋势,最小值出现在2010年,斑块密度和周长面积比的最大值出现在1976年,景观分离度和Simpson's多样性指数的最大值出现在1986年;1954—2010年三江平原斑块密度和周长面积比的高值区由东北向西南转移,低值区由中部向东部转移,景观分离度指数呈现先聚集后分散的趋势,Simpson's多样性指数由中间高四周低格局,逐渐转变为南部高北部低的格局。

Landscape pattern dynamics and driving forces analysis in the Sanjiang Plain from 1954 to 2010

The development of landscape pattern and driving forces are hot issues in the field of geography and ecosphere. Landscape pattern index is the important indicator to reflect the landscape structure, composition and spatial configuration characteristics indicators, landscape pattern. The Sanjiang Plain is a low floodplain, located in Heilongjiang Province of Northeast China. Influenced by natural factors and human agricultural development factors, the landscape pattern of the Sanjiang Plain has been changed seriously in the past 60 years. In this study, we analyzed the Sanjiang Plain landscape pattern dynamics and driving forces from 1954 to 2010 by using geo-information system (GIS) and mathematical statistics, based on the remote sensing images as the main source of information. The results showed that the cultivated land area, water area and the residential lands presented a tendency of increase, while the forestland, grassland and wetland decrease from 1954 to 2010. The significant reduction of wetlands mainly distributed in northeast and southeast of the Sanjiang Plain. The loss forestland occured mainly in the northeastern and south-central parts of the study area. In 2010, only a small amount of grassland remained along the rivers in the Sanjiang Plain. The increased cultivated lands mainly changed from the wetlands and grasslands reclamation, which mainly distributed in north and east parts of the study area. The comprehensive dynamic degree of land use showed the tendency of firstly increased, then decreased and finally increased, with the highest values between 1976 and 1986, and the lowest values between 1986 and 1995. The patch density, perimeter area ratio, landscape isolation index and Simpson's diversity index showed a downward trend after the first rise, with the minimum values in 2010. The maximum value of patch density and perimeter area ratio appeared in 1976, while the maximum value of landscape isolation index and Simpson's diversity index appeared in 1986. The high values zone of patch density and perimeter area ratio transferred from the northeast to the southwest of the Sanjiang Plain from 1954 to 2010, but the low values zone transferred from the middle to the east. The landscape division index showed firstly accumulation and then dispersion. Natural and human factors are main factors causing the variation of the Sanjiang Plain landscape pattern dynamics. The natural factors included air temperature, rainfall and runoff. The average air temperature appeared the trend of increase while rainfall and runoff decrease. Human factors are the main reasons of landscape pattern dynamics in the Sanjiang Plain, which including population growth, urbanization, farm development, protection area construction, laws and policies. The study provided scientific basis for l landscape planning wetland protection and management.