Study On The Relationship Between Vegetation Landscape Pattern And Hydro-ecological Process In Arid Regions

One of the core issues in landscape ecology is the relationships between the landscape pattern and hydro-ecological process, which contains many fields on the basis of specific pattern and process. The relationships between the dynamic vegetation landscape pattern changing characteristics and hydro-ecological process in arid regions are studied in the research into the correlation of vegetation landscape pattern and hydro-ecological process in arid regions. Due to climate featured by great amount of evaporation and scarce rainfall, arid regions are constantly in short of water and mainly covered by the desert vegetation; hence the hydro-ecological process dominating the ecological system as well as the changing of vegetation landscape pattern. To the arid region, the study of correlation between vegetation landscape pattern and hydro-ecological process is of great importance to the protection and restoration of the ecological system.The Hei River is the second largest inland river in the northwest of China, which is located in Hexi Corridor, originated in Qilian mountains and flows into Ejina Banner of Inner Mongolia and gives birth to the Ejina natural oasis. Since the 1960s, as the overusing of water in the middle Hei River, the amount of water fall into Ejina natural oasis decreased markedly which lead to a series of ecological and environmental problems. Under these circumstances, the project of water distribution was launched in 2001 to promote the ecological system restoration of the oasis. This paper takes the Ejina natural oasis as the research subject. Adopting the remote sensing techniques and on-the-spot survey of vegetation quadrat, the NDVI index, landscape pattern index and data of vegetation quadrat are studied. Based on the surface water, underground water data, the correlation between vegetation pattern changing and dynamic changes of water ecological process are studied, in order to provide reference for the protection and restoration of the ecological system. The findings are as follows:â‘ Surface water is the main source of water for vegetation growth in arid regions, since it is transformed into underground water through the infiltration to affects vegetation growth directly.â‘¡There is a positive correlation between the surface water and the coverage of vegetation which is dominated by the surface water. The increasing of the runoff will lead to the rising of the vegetation coverage and vice verse. Vegetation coverage will respond to the changes of surface water with a time lag.â‘¢The vegetation growth condition was improved with the rising of underground water level:the vegetation density, growth height, coverage have certain improvements, species richness is increased and the change of herbaceous is most obvious.â‘£The landscape pattern of the subject area tends to be complex, diverse and uniform with the rising of underground water level. The dominance of the matrix landscape type (desert) is reduced, while the fragmentation of vegetation landscape pattern improves.