沙质荒漠化土地评价指标体系研究

Study on Monitoring and Assessment Indicator Systems of Sandy desertification in China

本研究根据我国沙质荒漠化 (亦称沙漠化 )土地现状评价与监测工作的需求 ,在实地调查的基础上 ,依据地表形态、植被、土壤三大特征 9项指标 (裸沙占地百分比、地表结皮、植被盖度、植被生物量、土壤有机质、全氮量、速效磷、速效钾、土壤物理粘粒含量 ) ,应用多元回归方法筛选评价指标 ,采用多因素综合指标分级数量化法建立了地方、区域、国家 3种尺度的沙质荒漠化土地现状监测评价指标体系。经三个不同气候区野外实地验证 ,结果表明 ,地方、区域、国家 3种评价尺度的判对率分别为 81 .0 3%、84.48%、89.66%。该指标体系具有实用性、可操作性、准确性高、简便易行、便于推广等特点 ,适用于我国各层次的沙漠化土地监测与评价 。

To meet the needs for monitoring and assessment indicator system,on the basis of field investigation,9 indicators including bare soil ratio,microbiotic soil crust,biomass,vegetation coverage,soil organic matter,total nitrogen,available potassium,available phosphate,and soil clay content were selected,and multivariate regression method was applied.The monitoring and assessment indicator systems of sandy desertification at three scales i.e.local,regional and national scales were set up by quantitative classification method of the multifactor integrated indicators.The rates of accurate judgement at local,regional and national scales are 89.66% and 84.48%and 81.03% separately validated by field investigation in arid and semi-arid and dry sub-humid areas.This system is characterized by simple application and extension and high accuration,which can be applied to monitoring and assessment practices of sandy desertification at different scales in China and be as reference for other countries affected by desertification.