近30年广西喀斯特地区石漠化时空演变

Temporal and Spatial Distributions of Rocky Desertification in Guangxi Karst Area in the Past 30 Years

关键词:  石漠化  多源遥感数据  广西喀斯特地区  时空演变

Key words:  rocky desertification  multi-source remote sensing data  Guangxi karst area  spatial and temporal distribution

摘要:

[目的]开展广西喀斯特地区石漠化时空演变特征分析，为广西开展石漠化生态恢复重建和综合治理提供科学参考依据。[方法]利用美国Thematic Mapper（TM）和国产环境减灾卫星HJ遥感数据，结合实地调查采样数据，在分析石漠化遥感光谱特征的基础上，以植被覆盖状况作为石漠化评价指标，采用框式分类方法对广西1988时相、2002时相、2007时相、2015时相4个时相石漠化状况进行等级制图并分析其时空演变。[结果]2002时相广西石漠化面积最大，1988时相次之，2015时相最小。近30年来，广西石漠化面积呈先增加后减少的变化趋势，即1988-2002年呈增加趋势，2002-2015年呈逐渐减少趋势，石漠化程度得到控制。其中，1988时相，广西的喀斯特地区中部石漠化比较严重；2002时相，中部石漠化得到改善，西部加重；2007时相，西部石漠化得到改善，中东部加重；2015时相，全区石漠化得到全面的改善，呈现重度转中度、中度转轻度、轻度转潜在石漠化的良好态势。[结论]植被覆盖是衡量石漠化程度的有效标志，TM和HJ数据可较好的监测大范围石漠化时空演变。

Abstract:

[Objective] The spatial and temporal evolution characteristics of rocky desertification in the karst area of Guangxi were carried out,which provided a scientific reference for the ecological restoration,reconstruction and comprehensive management of rocky desertification in Guangxi.[Methods] Based on the remote sensing data of the United States Thematic Mapper (TM) and the domestic environmental disaster reduction satellite HJ,combined with the field survey sampling data,based on the analysis of the remote sensing spectral characteristics of rocky desertification,the vegetation coverage status was used as the evaluation index of rocky desertification,and the box classification method was adopted for level mapping of rocky desertification in 1988,2002,2007,2015 and their temporal and spatial evolution.[Results] In 2002,the area of rocky desertification was the largest in Guangxi,the second in 1988,and the smallest in 2007.In the past 30 years,the area of rocky desertification in Guangxi increased first and then decreased. That was,it showed an increasing trend from 1988 to 2002 and a decreasing trend from 2002 to 2015,and the degree of rocky desertification was controlled. Among them,in 1988,the rocky desertification in the central part of Guangxi was more serious; in 2002,the central rocky desertification was improved,and the western part was aggravated; in 2007,the western rock desertification was improved,the central and eastern parts were aggravated; the rocky desertification in the whole region had been comprehensively improved,showing a good trend of heavy to moderate,moderate to mild,and mild to potential rocky desertification.[Conclusion] Vegetation cover is an effective indicator to measure the degree of rocky desertification.TM and HJ data can better monitor the spatiotemporal evolution of large-scale rocky desertification.