| Wetland is a special ecosystem that is accompanied by land and water.The spatial pattern and change of water usually have an important influence on the landscape structure and landscape dynamics of wetland,and such change also has certain temporal characteristics.So the change of spatial pattern of moisture will affect the landscape dynamic change,the impact on the stability of wetland landscape analysis and evaluation has a certain meaning,by studying the effect,after for wetland management and planning to provide the scientific reference basis,the optimization of the wetland and development play a positive role,is advantageous to the sustainable development of wetland.Taking Zhalong wetland and Huihe wetland as the study area,based on remote sensing data and the measured data,the selection of Zhalong wetland in 1979-2019 and 2004-2019 Huihe wetland remote sensing image data and the corresponding meteorological data such as precipitation,air temperature,with the support of geographic information system and remote sensing technology,the selection of specific indicators and landscape index to analyze the spatial distribution of moisture in wetland landscape pattern and its changes,and through this kind of landscape spatial pattern of distribution for the influence of wetland landscape dynamic characteristics,discusses the influence of different wetland landscape dynamic mechanism.The main contents are as follows:(1)Through the corresponding data processing,it can be concluded that the Open water area of Zhalong Wetland has been reduced in the past 40 years,and with the decrease of Open water,the wetland is gradually shrinking,among which the change of water condition of Wuyuer River has an obvious influence on the wetland.Especially in the surface wetland area reduced sharply after 1989 years ago,in the later recovered,the cause of the change and after the reform and opening up development of wetlands,multiple traffic splitting the overall structure of the wetland,and the channel was already made wetland water entry and transit line truncation,multiple channel wetlands original water space distribution pattern was divided,wetland shrinks.The area of dry land has been increasing year by year.Since 2002,due to the policy of returning farmland to wet land,the area of cultivated land has been almost unchanged and the location has been fixed.However,due to the degradation of wetland,the area still shows an increasing trend.From the perspective of landscape transformation range of Zhalong Wetland,the wetland landscape decreased year by year and showed a degradation trend.The wetland xerophytic landscape increased year by year and had a tendency to catch up with the wet landscape,even in the years with more precipitation,this trend could not be changed.(2)The main landscape type of Huihe wetland is grassland,and most of the wetlands are located near the Huihe watershed and river channels.From the perspective of spatial scale,the bright water landscape of Huihe wetland was almost unchanged during the 15 years,and the spatial position change of dryland landscape was relatively stable.The change of surface water wetland and non-surface water wetland fluctuated with the change of interannual rainfall and the water situation of Huihe river.In years of heavy rainfall,the wetland of Huihe River is in good condition.In the years with low rainfall,the wetland decreased with the decrease of the spatial distribution of open water surface.It can be said that the development of Huihe wetland is seriously affected by hydrology,and the wetland is affected by the spatial distribution pattern of water and depends on the development of water situation in Huihe River.In Huihe wetland,the change of landscape conversion range is not obvious,the xerophytic landscape is generally increasing,and the hygrophytic landscape is generally decreasing.In the years with abundant rainfall,the Huihe River is rich in water,and the spatial distribution of water expands,and the wetland changes from xerophytic to humid.(3)Wetland landscape dynamics is represented by landscape conversion coefficient calculated over many years,and the appropriate landscape index is selected through experiments.According to the data analysis,the CV and SD of interannual landscape conversion coefficient in Zhalong wetland decreased with the increase of Division,while the CV and SD of interannual landscape conversion coefficient in Huihe wetland had an opposite trend with the increase of Division.With the increase of LSI,the CV and SD of interannual landscape conversion coefficient of Zhalong wetland showed a slight downward trend,while that of Huihe wetland showed an upward trend.Meanwhile,in the hypothetical statistical average model established,the observed values of Zhalong Wetland are always within the model limit and close to the upper limit,while the observed values of Huihe Wetland are far beyond the model upper limit.Therefore,it can be concluded that Zhalong Wetland is affected by the overall mechanism,while Huihe Wetland is affected by the heterogeneous mechanism.(4)The distribution of water spatial pattern in the wetland has a certain influence on the landscape dynamics of the two wetlands,and the influence on the landscape dynamics of the Huihe wetland is more obvious.Although Zhalong wetland is also affected by the influence,the influence of water spatial pattern distribution on the landscape dynamics of the wetland is stabilized and weakened on the whole.Based on two different landscape in the study area landscape conversion coefficient of correlation analysis,confirm the results,only Open water zhalong wetland landscape and has a certain correlation between the surface water wetland landscape,combined with the spatial distribution of rainfall and 40 years data can be found that wetland Open water and surface water does exist mutual supply relationship between wetland,although this relationship shows that water distribution of zhalong wetland landscape dynamic change,but the effect was weakened by the connection between the overall landscape.However,the influence of water spatial distribution is more obvious in Huihe wetland,and there is a significant correlation among the water-bearing landscapes in the wetland,which further indicates that the change of wetland landscape is affected by the distribution of water spatial pattern.This influence is particularly prominent,showing the mechanism of heterogeneity. |
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