齐齐哈尔市土地利用变化及其对地下水水质的影响

为了探究齐齐哈尔市土地利用变化及其对地下水水质的影响,利用1995年、2003年、2011年遥感影像解译结果,比照地下水水质长期监测数据开展相关研究。结果表明,研究区土地利用类型以旱田、湿地和建设用地为主,其中旱田面积最大,占45%以上;近20a来,湿地面积持续减少,减少面积达112.38km2,主要转变为旱田、水田和建设用地,而建设用地的增加主要来自于开发旱田;1995~2003年、2003~2011年2个时期的综合土地利用动态度分别为0.97%、0.60%,研究区2003年之前总体土地利用变化程度明显高于后期。地下水中NO-3-N、SO2-4、Cl-和总硬度浓度变化趋势,与建设用地和旱田间的相互转变密切相关。城镇化建设快速发展及工矿用地土地资源的长期开发,成为对该地区地下水水质产生直接影响的主要土地利用方式。

Effects of Land Use Change on Groundwater Quality in Qiqihar City

The effects of land use and land cover change (LUCC) on groundwater quality in Qiqihar city was analyzed by contrast land use change with groundwater quality change. The research method of LUCC is that based on three temporal remote sensing images of 1995, 2003, 2011. The dynamic trend and degree of land use in the district was also analyzed. At the same time, a regression equation was used to analyze time trend of groundwater quality by EXCEL soft. Results show that the main landuse types were dry land, wetland and construction land in the study area. And the area of dry land was the largest, accounting for higher than 45% of the whole study area. During the recent two decades, the areas of wetland have decreased continuously(112.38 km²) and transformed into dry land, paddy land and construction land. The overall degree of land use changes has been retarded since 2003. There was a dynamic relationship between the groundwater quality and the change of land use. Trend of NO₃^--N concentration in groundwater was closely related to the transformation between construction land and dry land. Nitrogen pollution of groundwater in the study area was mainly affected by urban and rural residents living and industrial production, instead of chemical fertilizers in agricultural production. Area where SO₄^2-, Cl^- and total hardness concentrations rose with the fastest speed had been used as construction land, on the contrary, area where SO₄^2-, Cl^- and total hardness concentrations decreased with the fastest speed areconstruction land convertedinto other types of land. The rapid development of urbanization and industrial long-term land resources, has become the main land use which has a direct impact on groundwater quality in the area.
Therefore, based on the administrative region served as research unit, the research of land use change and its effects tohydrogeologic environment are very important for the protection of the resources and environment of Qiqihar City.