The Study On Resilience Of Degradation Of Wetland Ecological System Based On RS And GIS

Wetland protection and restoration become an urgent issue because of the seriouswetlands degradation of the world at present. Wetland ecosystem resilience is the basis ofwetland restoration. The Yellow River Delta wetland is the most complete, most wide andyoungest wetland ecosystem in warm temperate regions. Reclamation and theunreasonable development and utilization has led to its severe degradation, after thedevelopment and construction of the Yellow River Delta high-efficiency ecologicaleconomic zone has been raised as the national strategy, the development and constructionactivities became further strengthened, the degraded wetland ecosystem must be facedserious challenge. Resilience of the degradation wetland was quantitatively evaluated, itwas the basis of protection the Yellow River Delta wetland and promotion of regionalsustainable development.Through on-the-spot investigation and technology of RS and GIS, combined with thedata of topography, hydrology, soil, and statistics, this paper analyzed the evolution oflandscape pattern and the degradation process in the modern Yellow River Delta wetland, used Robert wetland restoration potential estimation model, and evaluated quantitativelyresilience of the degraded wetland. The result:(1) During1995to2010, the total area of the Yellow River delta wetland decreased266.68km~2, the area of natural wetland cut1453.16km~2and the area of artificial wetlandincreased1186.49km~2. With continuously decreased, the area of Natural wetland wasreplaced by artificial wetland mainly. The early development of Artificial wetlandextended towards the shore, the development of it converted to land since2000.(2) During1995to2010, the landscape pattern of Yellow River delta changedsignificantly, landscape structure became more complex, the number of landscape patchesand patch density increased, the degree of fragmentation aggravated, degree of separatingincreased, wetland landscape shape got complicated, Aggregation index reduced, thelandscape diversity enriched.(3) During1995to2010, area of natural wetlands completely-degradation(disappeared or converted into construction land) cut184.63km~2, the area of naturalwetlands which converted into artificial wetland cut117.62km~2; During2000to2006,completely-degraded natural wetlands area reduced156.24km~2, the area of naturalwetlands which converted into artificial wetland cut591.6km~2; During2006to2010, completely-degraded natural wetland area cut149km~2, the area of natural wetlands whichconverted into artificial wetland cut107.50km~2. In1995, the proportion of wetland areaof vegetation coverage with level of highest, medium, lower, lowest was8.43:78.97:9.18:3.42. In2010, the area of the vegetation coverage from high to low was7.51:13.55:41.27:37.67.(4) With decreasing sediment of the Yellow River into the sea and strengtheningcoastal erosion effect, the Yellow River Delta epeirogenic area decreases, the delta landarea has reduced the143.27km~2since1995. With the development of economicconstruction, the natural wetland faded rapidly. Compared with2010in1995, more thanhalf of area of the natural wetland reduced.(5) The resilience of the degraded wetland in the Yellow River Delta, the area of thewetland which caught the highest level covered15.4%of the total area, the area of themiddle level covered16.1%of the total area, the area of the low level covered29.8%ofthe total area, the area of the lowest level covered36.7%of the total area.