CAJ | 학술논문

为准确把握西部生态脆弱区耕地质量现状，了解重金属污染对西部地区耕地质量的影响程度，采用第二次全国土地调查、多目标区域地球化学及农用地基础地力调查等数据，运用GIS技术及统计方法，以兰州市榆中县为例，在考虑重金属污染的条件下，对西部生态脆弱区耕地自然质量进行综合评价研究。结果显示：①研究区耕地立地条件、土壤物理性状相对较好，质量较好的4级耕地最多；而土壤肥力较差，质量较差2、3级耕地占耕地总面积的99．63％；②研究区As、Cd、Cr、Cu、Hg、Pb、Zn等重金属元素的平均含量均高于地区背景值，其中Cd和As最大值超过土壤环境质量污染评价标准值；③土壤重金属污染综合评价结果显示北部青城镇、中部和平镇和马坡乡的东北部为污染高值区；④耕地质量综合评估结果显示研究区耕地自然质量南部和中部川区较好，北部山区较差，除部分区域出现异常点值外，基本呈现由南向北逐渐变差的规律。以上研究结果表明，西部生态脆弱区耕地自然质量虽然主要受降雨量、坡度等自然条件的影响，但重金属造成的土壤污染已成为该区域不可忽视的耕地质量问题。
위준학파악서부생태취약구경지질량현상，료해중금속오염대서부지구경지질량적영향정도，채용제이차전국토지조사、다목표구역지구화학급농용지기출지력조사등수거，운용GIS기술급통계방법，이란주시유중현위례，재고필중금속오염적조건하，대서부생태취약구경지자연질량진행종합평개연구。결과현시：①연구구경지입지조건、토양물이성상상대교호，질량교호적4급경지최다；이토양비력교차，질량교차2、3급경지점경지총면적적99．63％；②연구구As、Cd、Cr、Cu、Hg、Pb、Zn등중금속원소적평균함량균고우지구배경치，기중Cd화As최대치초과토양배경질량오염평개표준치；③토양중금속오염종합평개결과현시북부청성진、중부화평진화마파향적동북부위오염고치구；④경지질량종합평고결과현시연구구경지자연질량남부화중부천구교호，북부산구교차，제부분구역출현이상점치외，기본정현유남향북축점변차적규률。이상연구결과표명，서부생태취약구경지자연질량수연주요수강우량、파도등자연조건적영향，단중금속조성적토양오염이성위해구역불가홀시적경지질량문제。
In order to accurately understand the status of farmland quality and the impact of heavy metal pollution in ecologically fragile zone in western China ,based on the data of second national land survey ,multi-objective regional geo-chemical survey and soil fertility survey of agricultural land ,using GIS technology and statistical methods ,the compre-hensive evaluation of farmland natural quality considering heavy metal pollution was conducted in Yuzhong County , Lanzhou City ,Gansu Province .The results showed :① The site conditions and soil physical properties of farmlands were relatively good in the study area ,in which the class-4 farmlands whose quality was relatively good took the highest pro-portion .However ,the fertility of farmlands was relatively poor ,in which the class-2 and class-3 farmlands whose quality was relatively poor took 99 .63% of the total area .② The average contents of As ,Cd ,Cr ,Cu ,Hg ,Pb and Zn were higher than the regional background values ,in which those of Cd and As exceeded the assessment standard of soil envi-ronment quality .③ According to the comprehensive evaluation of soil heavy metal pollution ,Qingcheng Town ,Heping Town and northeastern part of Mapo Town were highly polluted areas .④ The farmland natural quality in the southern and central area was better than that in the northern mountainous area ,and it showed an overall trend of gradual deterioration from south to north except for some abnormal sites .In conclusion ,soil pollution caused by heavy metals has become a se-rious problem in the ecologically fragile zone of western China ,although the natural quality of farmlands is mainly affected by rainfall ,slope and other natural conditions .