Research On Landscape Dynamics Of Agricultural Ecosystems In The Flooded Area Of The Yellow River From 1938 To 2002

By using GIS and remote sensing technology, we study the agricultural landscape pattern change of the flooded area of the Yellow River from 1938 to 2002 through use the landscape ecology basic principle. Historical document data information, the land use data, the remote sensing data and investigation data of different times have carried on analysis. And we also analysis the driver of the agricultural landscape pattern change and ecological effects of the agricultural landscape change in study area. We hope to rational distribution of agricultural landscape from macro-control, through avoiding the negative factors and giving its full potential and advantages, to maintain and improve agricultural landscape ecosystems virtuous circle in this area.Conclusion: The agricultural landscape pattern of the flooded area of the Yellow River has had the remarkable change under the natural process and the human activity. (1) Kuomintang pushed the dike of Yellow River in HuaYuanKou in 1938,which caused the big area farmland to submerge. This process was the landscape sudden change. Landscape types primarily were water, bog and sandy waste landscape from 1938 to 1947. The farmland of the flooded area of the Yellow River was established in 1951, the landscape type transforms gradually into by the agricultural landscape type primarily under the national value and people painstaking efforts, which showed the landscape process gradation. In this process, the construction land landscape type area increases continuously; the cultivated landscape increases fast in the early time, the cultivated landscape area achieves enlarges with the unused land reducing and developing difficulty. And then the cultivated landscape area will assume the reduced tendency because the construction and other landscape type's occupancy. In addition, the forest landscape, the orchard landscape, the water landscape, the paddy field and arid landscape in the cultivated landscape has had certain change in the different times under the disturbance of human activity. The fragmentation degree of the whole landscape also presents increases first, and then reduced. (2) Since the founding of the nation, the human activity is the main factor of the agricultural landscape ecosystem dynamic changes has enhanced continuously. (3) From resilience of the agricultural landscape ecosystem of the flooded area of the Yellow River, we can found that the influence of natural factor change was reducing day by day. Constantly improved the level of production which also brought on some negative effects to soil, water resources and other environmental factors at the same time. The stability of the agricultural landscape ecological system has decline, we must rely on inputting external energy to maintain.The entire paper is divided into six parts.Part I: focuses on the integration of agriculture and landscape ecology.3S technology and basic principles of landscape ecology are applied to agricultural research. This part also gave a briefing on the progress of agricultural landscape pattern dynamic, driving force mechanism and dynamic landscape ecological effects.Part II: describes the overview of study area, including location, regional context, the natural profile and socio-economic profile.Part III: studied the dynamics of agricultural landscape ecosystem in Yellow River area by using different approaches in three sessions. This paper described the landscape changes of the Yellow River area by using historical documents in 1938 to 1950.It conducted quantitative research from the perspective of the agricultural ecosystem dynamics with statistics in 1951 to 1978.On the basis of remote sensing interpretation of agricultural landscape ecosystem types in the area of the Yellow River, it analyzed landscape pattern features to 1978, 1987 and 2002 by using landscape pattern changes model. Then, this part analyzed the dynamic overall features of agricultural landscape ecosystem on the Yellow River area which reached a conclusion of the dynamic development trend of the regional agricultural landscape ecosystem.Part IV: On the basis of the third part, the fourth part analyzed the natural driving force and human driving force of landscape change. This part focused on the role of human activities on the agricultural landscape pattern and the dynamic impact on the agricultural landscape of national policy, social security, economic and natural disasters and environmental changes.Part V: simple analysis and evaluation are did on the ecological effects of dynamic changes in the agricultural landscape pattern of the Yellow River area nearly 70 years mainly from the agricultural landscape ecosystem resilience.Part VI: Conclusion and the discussion part of this paper.