A Study on Wetland Landscape Transition Pattern of Lianbo Beach Along Middle Yellow River

Abstract: The Wetland of Middle Yellow River refers to the "L-shaped" river segment and its wetlands from Yumenkou in Shanxi province to Dongbatou in junction of Henan and Shandong province.The 618- km-long river segment covers the most part of the Middle Yellow River and part of the Lower Yellow River,with the total area of 0.48 million hectare.Lianbo Beach is located in the central part of the Middle Yellow River,where is abundant in flora and fauna partially due to optimal climatic conditions.This study integrated the survey data to evaluate the present wetland resources in Lianbo Beach.Meanwhile,the remote sensing and GIS technology were used to analyze the wetland landscape pattern in an effort to realize the scientifically-sound management,conservation and sustainable utilization of wetland resources.This study examined the data extracted from the multi-band satellite remote sensing images of Lianbo Beach at four phases of 1990,1995,2000 and 2005.The analyses employed a series of spatial landscape pattern indices such as patch density,length of patch edge,landscape diversity index,species dominance,landscape fragmentation index,and the mean fractal dimension index to systematically scrutinize the spatial alteration patterns of the wetland landscape at Lianbo Beach since 1990.The results are as follows.1.The changes in patch areas from 1990 to 2005 show the increase in grassland,farmland and woodland but the decrease in water bodies and beaches.Such changes were related to climate and hydrology features and heavily depended on local agricultural policies and economic interests. 2.The intensive anthropogenic activities corresponded to the enlarged landscape heterogeneity as demonstrated by the increase of wetland landscape diversity index of 0.9947～1.1247 between 1990 and 2005. Consequently the growing landscape types led to the increase in dominance index of 0.3619～0.4847 between 1990 and 2000,and the fragment index of 1.2785～1.2942 between 1990 and 2005.3.The significant alterations of Lianbo Beach wetland occurred after 1990 when it coincided with ever-intensive anthropogenic activities and the changing natural factors.This is shown in the increases of patch numbers, patch density and the length of patch edge,all indicating the enhanced degree of fragmentation in this region.4.The major natural factor to wetland degradation at Lianbo Beach is the significantly reduction of runoffs along the Fenhe River to and the Yellow River due to long-lasting drought.The salinization tendency in the floodplain is also noted,where the emergence of Chinese tamarisk community shows the deteriorating and worsening conditions in water content and the overall ecological environment in the wetland area.5.The population pressure serves as the ultimate cause for wetland degradation.For a long time,people failed to properly deal with the relationship between socio-economic development and the protection of ecological environment.The over-farming activities and the extensive works of water resources all contributed to reduction of water discharge to wetland, along with the water pollution,flora degradation,and fauna habituate loss.With the knowledge of the causes for the wetland degradation at Lianbo Beach of Middle Yellow River,this paper proposed conservation strategies, including strengthening management,regional pollution control,soil erosion reduction,improvement in conservation projects,and intensive scientific research,aiming at the fundamental protection and restoration of the wetland ecological environment…
Key words: Middle Yellow River; Lianbo Beach; Wetland; Landscape pattern; Fragmentation; Protection strategy