土地覆盖对孟加拉国山区流域小溪和渗透水质量的影响(英文)

Effect of land cover on water quality of creek and seepage in mountainous watershed in Bangladesh

为了调查不同土地植被覆盖对水质量的影响,在孟加拉吉大港山区兰加马蒂的三个地区(Manikchari,Ghagra和Muralipara)对小溪和渗透水采集流动水样,进行化学分析。结果表明,在Manikchari地区,与自然植被和人工林混交植被相比,在成熟和幼年的石梓(Gmelina arborea)人工林植被流动的溪流水样中,SO2-、Ca2+的浓度和pH值较高 (p<0.05),Na+浓度较低。在Ghagra地区,与衰退的自然植被中的水域中采集的水样比较,在8年生的柚木(Tectona grandis)人工林水域流动的溪流水样中,有明显高浓度SO42-和K+、高传导率和高总溶解固体物,但HCO3-、NO3-和PO43-浓度明显较低。在Muralipara地区,与轮作地的渗透水中采集的水样相比,在自然植被和耕地混交地中采集的流动的溪流水样中,有明显高浓度的HCO3-、NO3-、Na-、k-、Ca2+和Mg2+,同时,其电导率和总溶解固体量也明显高于渗透水和轮作耕地管井水。表2参13。

The flowing water was collected from very small creeks and seepage water from small dug holes at three different areas,viz.Manikchari,Ghagra and Muralipara in Rangamati district of Chittagong Hill Tracts,Bangladesh to investigate the impact of the existing varied land covers on water quality.Chemical analyses shows that flowing creek water from either mature mixed plantation or young gamar（Gmelina arborea） plantation had significantly（p〈0.05） higher pH value,SO4^2-and Ca^2＋ concentrations,and significantly lower Na＋ concentration at Manikchari,compared to natural vegetation and plantation in combination.In flowing creek water of Ghagra,the concentrations of SO4^2-and K＋,conductivity and total dissolved solids from watershed of 8-year-old teak（Tectona grandis） plantation were significantly higher and the concentrations of HCO3^-,NO3^-and PO4^3-were significantly lower,compared to those of watershed of degraded natural vegetation.At Muralipara,flowing creek water from natural vegetation and shifting cultivated land in combination showed significantly higher concentrations of HCO3^-,NO3^-,Na＋,K＋,Ca^2＋ and Mg^2＋,and conductivity and total dissolved solids than seepage water as well as tube well water installed in shifting cultivated area alone.