Channel Wetlands Evolution Analysis From Liujiaxia to Togtoh County of Inner Mongolia in the Last Three Decades
Xarapat Ablat;LIU Gaohuan;LIU Qingsheng;HUANG Chong;GUAN Xudong;State Key Laboratory of Resources and Environment Information System, Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences;University of Chinese Academy of Sciences;
In the river basin ecosystem, channel wetland is located in aquatic terrestrial ecotone. The bridge and the link between terrestrial and aquatic ecosystems play an irreplaceable role in water detention, water purification, soil-water conservation, maintaining biodiversity and ecological balance. In this paper, we used Landsat satellite images of 1986, 1996, 2000, 2006 and 2015 to extract different types of river wetland systems between the Liujiaxia and Togtoh County of inner Mongolia in the last three decades. Then, we used spatial stastics analysis, transfer matrix and centroid position change method to analyze dynamic evolution and driving factors of wetland types. The results shows that, during 1986-2015 years, channel wetland area in the study area gradually decreased from 173×104 ha to 122×104 ha(~29.0%). Wetland transformation of the study area mainly occurs between the river, nude beach, herbal-wetland and farmland. In the last thirty years, the range of active channel wetland changes far greater than non-active channel wetland. The area of active channel wetland decreased from 15.46 ×104 ha in 1986 to 10.41×104 ha in 2015, decreased by 32.7%. The evolution of the active channel wetlands mainly occurs between the natural wetland types, namely, the river-bare Beach-swamp wetland. The non-active wetland area is basically stable, and the area is between 1.84-2.28 × 104 ha. It has characteristics of transformation between the natural wetland-constructed wetland and between natural wetland-agricultural land. The centroid position change of forest wetland, canal wetland and pond wetland are more prominent compared to other wetland types. The results of the single land use dynamics shows that, due to gradually accelerating urbanization pace, antrophy of the natural wetlands, increase the weight of farmland salinity, hydroelectric station system construction caused gradually decrease in the river area. The cropland to forest policy and the grassland to cropland policy result to accelerated dynamic change of forset, pounds, river,farmland, abandonedland and bareland. Through the analysis of channel wetlands, the change of active channel wetland mainly contribute to the wetland change of whole study area. The change of non-active channel wetlands was less affected by channel wetland changes. Our results are related to temperature, water conservancy, hydropower engineering and irrigation water, urbanization degree and ice flood season, but less sensitive to precipitation.
【Fund】： 资源与环境信息系统国家重点实验室自主创新项目(08R8A010YA);; 国际科技合作专项项目(2012DFG22050);; 中国科学院战略性先导专项项目(XDA05050601)
【CateGory Index】： P237;P942
【CateGory Index】： P237;P942