The Evolution On Landscape Pattern Of Riparian Zones In Suzhou City, Jiangsu Province, China

As critical transporting channel of energy and substance, riparian zones is thepivot linked aquatic ecosystems and terrestrial ecosystems, and which is animportant habitat and ecological corridor between them. In recent decade years,Economic development and enduring rapid urbanization is accelerating in Suzhou,which contributed to great transformation in the land use of riparian zones. Theecological degeneration of riparian zones, as well as the consequent environmentalcrisis, has substantially and potentially hindered the sustainable development ofSuzhou. Therefore, investigating on the present riparian landscape and analyzingchanges of the landscape patterns will provide fundamental understanding andvaluable insights for the scientific conservation and the related policy-making.With Landsat TM images interpretation, landscape graphical analysis and fieldinvestigations, the author researched the present riparian landscape types indifferent grains. The results showed that built-up areas, accounting for60percentapproximately, was the predominate type with high aggregation and large size.Roads had enormous impacts on the riparian landscape. Traditional configurationof agricultural landscape changed much mainly due to industrial land. As thegrain size augmented, the proportion of greenland decreased from60percent to40percent, which indicated the greenland consist of small and fragmental patcheswith low quality. The natural riparian zones are almost extinct due to the71.9percent of them transformed to artificially hard upright embankment. There wasgradient in the horizontal distributions of the riparian landscape. Thecomposition of riparian landscape presented urban-rural gradient due to impactsfrom the matrix.The author also investigated landscape pattern changes of Suzhou riparianlandscape in the span of15years with landscape index, and analyzed the landscapechanges with synthesized landscape graphic and bio-energetic approach. Theresults were as follows: During the recent fifteen years,the proportion of farmlandin the1000m riparian buffer area decreased from56.4percent to25.9percent,while built-up area increased from32.2percent to58.3percent. The matrix ofriparian landscape transfered from agricultural land to built-up areas. Thebuilt-up areas increased firstly with increasing amount of small patches withrandom sprawl, then the growing small patches aggregate to large patches, finallythe large patches compacted due to internal refilling. The agricultural land decreased with large patches divided into small ones, and then the small patcheschanged to other landscapes (mainly construction area) gradually. The turningpoint of landscape changes occurred in2000. The connectivity of naturallandscape in riparian area decreased significantly with many subordinate watersextinct. The persistent natural nodes decreased so much that the risk of theirextinction is possible.Based on the above studies and the present management conditions, the authorproposed measures to improve the landscape patterns of riparian area in Suzhou,and recommended a synthesized strategies and principles for the riparian landscapemanagement.