基于遥感信息的植被变化对岱海湖面积的影响

Influence of vegetation change on the area of Daihai Lake based on remote sensing information

【目的】通过探索植被覆盖变化对岱海湖面积的影响,明确人类生产活动方式及范围与湿地变化的相互关系,为科学制定湖泊保护规划提供理论依据。【方法】研究区域为岱海湖主要支流形成的流域,在获取1990—2020年7期该区域遥感资料的基础上,采用重心迁移分析、土地类型转移矩阵、相关性分析等方法,分析流域内植被变化对岱海湖面积的影响。【结果】1990—2020年岱海湖面积呈下降趋势,1990年为110.8330 km^(2),2020年为48.1225 km^(2),减小62.7105 km^(2),2005年以前湖面重心快速向东北方向转移,2005年以后逐步向北偏西方向迁移;岱海湖面积变化与旱地、草本覆盖、水浇地、林地呈显著负相关,相关系数分别为-0.90、-0.90、-0.93、-0.86;与草原和稀疏植被呈显著正相关,相关系数分别为0.82和0.80;岱海湖周边1 km内旱地、草本覆盖、水浇地、草原的面积与岱海湖面积变化相关性较高,相关系数分别为-0.95、-0.94、-0.96、0.92。【结论】岱海湖周边1 km内的农田开垦对原始草原植被的破坏是岱海湖面积缩减的主要生产活动因素。

【Objective】By exploring the impact of changes in vegetation coverage on the area of Daihai Lake,clarify the relationship between the mode and scope of human production activities and wetland changes,provide a theoretical basis for the scientific formulation of lake protection planning.【Methods】The research area was the basin formed by the main tributaries of Daihai Lake.Based on seven sets of remote sensing data of the area from 1990 to 2020,the impact of vegetation change on the surface area of the Daihai Lake was analyzed using gravity center migration analysis,land type transfer matrix and correlation analysis.【Results】From 1990 to 2020,the surface area of Daihai Lake had a declining trend,which was 110.8330 km^(2) in 1990 and 48.1225 km^(2) in 2020,decreased by 62.7105 km^(2).Prior to 2005,the gravity centre of the lake surface shifted rapidly to the northeast,and gradually moved to north by west after 2005.With correlation coefficients of-0.90,-0.90,-0.93 and-0.86,respectively,the area change of Daihai Lake was significantly negatively correlated with dry land,herbaceous cover,irrigated cropland and forest,and significantly positively correlated with grassland and sparse vegetation,with correlation coefficients of 0.82 and 0.80 respectively.The area of dry land,herbaceous cover,irrigated cropland and grassland within 1 km around Daihai Lake had high correlations with the area change of Daihai Lake,with correlation coefficients of-0.95,-0.94,-0.96 and 0.92 respectively.【Conclusion】The destruction of the native grassland vegetation by agricultural reclamation within 1 km around Daihai Lake was the primary production activity that contributed to the decrease in Daihai Lake′s surface area.