荆州市浅层地下水环境质量综合评价与分区

通过实地调查荆州市浅层地下水环境，合理选择评价指标集（16项），分别采用模糊数学综合评价法和F值法对该浅层地下水环境质量进行综合评价，分析对比两种方法的评价结果，对浅层地下水环境进行分区和污染分析。评价结果表明：浅层地下水环境质量不容乐观，整体状况较差。浅层地下水中主要超标组分为Fe、Mn、NO-3、NO-2、As、Ba等，对比分析荆州市2006~2011年主要超标组分的平均含量，可知6 a来，Fe、Mn、NO-2的平均含量均超过地下水Ⅲ类水质标准，NO-3、As、Ba的平均含量虽然均未超过地下水Ⅲ类水质标准，但其平均含量呈现随着年份递增的趋势。浅层地下水环境质量分区结果显示：严重区面积为2 623 km2约占305%，较严重面积为1 33128 km2约占1548%，合格区面积为3 07192 km2约占3572%，较好区面积为1 5738 km2仅占183%。浅层地下水环境质量在很大程度上不仅受当地特有的区域原生地质环境影响，还与人类活动有密切关系

SHALLOW GROUNDWATER ENVIRONMENTAL QUALITY COMPREHENSIVE ASSESSMENT AND ZONING IN JINGZHOU CITY

Groundwater environment is facing more and more dynamic and complex factors caused by human economic activities. The present study was carried out aiming at a better understanding of the present situation of groundwater environment and a reasonable utilizzation on the groundwater resources in Jingzhou City. According to the field investigation on shallow groundwater environment, sixteen evaluation indexes were selected to form the index set. Fuzzy mathematics comprehensive evaluation method and F value method were successively used to complete the comprehensive assessment. Based on the previous analysis and comparison of the two methods assessment result, this paper accomplished the shallow groundwater environmental zoning and pollution analysis. Assessment result showed that shallow groundwater environmental quality was not optimistic, with Ⅳ or Ⅴclass in quite a part of the monitoring point and the overall situation was in poor condition. Main overproof components were Fe, Mn, NO-3, NO-2, As, Ba, etc. and the over limit ratio of which were 4149%, 7142%, 2143%, 1191%, 714%, and 2929%, respectively. Comparative analysis of the main overproof components averaged from year 2006 to year 2011 showed that average content of Fe, Mn and NO-2 exceeded the Ⅲ class groundwater quality standard; average content of NO-3, As and Ba were in average range of the Ⅲ class water quality standard yet, but their average content showed an increasing tendency. Results of environmental quality zoning depicted that high risk area was 3 50192 km2, being about 305% of the total area 8 600 km2, and the medium serious area covered 1 33128 km2 with a percentage of 1548%, while qualified area was 3 07192 km2 with a percentage of 3572% and good groundwater quality area was 1 57380 km2 accounting for only 1830%. Shallow groundwater environmental quality, to a great extent, not only is affected by the local characteristic of regional primary geological environment, but also has close relationship with human activities. In order to improve risk forecast and warning capability of high risk area and medium serious area, the safety operation and management mechanism of groundwater and a long term monitoring network should be established. Seepage control work should be well done in the related large industrial region to prevent effects from sewage infiltration to the groundwater environment. Fe, Mn pollution problems of groundwater should be highly emphasized in rural area. Conditional places are suggested to build centralized drinking water plant and adopt engineering measures to solve the water pollution problems caused by primary geological environment