放牧背景下青藏高原若尔盖盆地非流动性地表水的质量特征

探讨青藏高原若尔盖盆地放牧背景下非流动性地表水的质量特征,以禁牧草场为对照,针对长期过牧的夏秋草场、冬春草场的地表水,采用国标、ICP-OES等方法测定物理、化学和生物学及重金属共18种质量指标.结果表明,两种放牧草场地表水质量指标COD、TDS等高于禁牧草场(P0.01);夏秋草场地表水Cr、TP、粪大肠菌群高于禁牧草场(P0.01或P0.05);冬春草场地表水TP、TN、粪大肠菌群等高于禁牧草场(P0.01).冬春草场地表水COD、TP、TN、粪大肠菌群等高于夏秋草场(P0.01或P0.05).并且,BOD_5、TN、TP、粪大肠菌群等之间都存在高度正相关(P0.01或P0.05),具有共同来源;放牧草场地表水COD、BOD_5、TN、TP超过国家地表水Ⅴ类标准,Cr和粪大肠菌群超过国家畜禽饮用水标准.结论:长期过牧背景下,草场非流动性地表水质量下降,冬春草场下降较夏秋草场严重;草场非流动性地表水质量存在潜在风险,放牧应避开流动性小的地表水.

Quality characteristics of nonliquid surface water in Ruoergai basin of Qinghai- Tibet plateau under grazing background

Study on quality characteristics of nonliquid surface water in Ruoergai basin of Qinghai Tibet Plateau under grazing background, grazing forbidden field as control,according to the surface water of long-term grazing in summer-autumn and winter-spring, the national standard, ICP-OES method was used to measure the physical, chemical, biological and heavy metal of 18 kinds of quality indicators.The results show that two kinds of grazing grassland surface water quality indexes of COD, TDS and so on were higher than that of ungrazed grassland; Cr, TP ,fecal coliform and so on of surface water in surface water of summer-autumn grassland were higher than that of ungrazed grassland; TP, TN, fecal coliform and so on of surface water in winter-spring grassland were higher than ungrazed grassland; COD, TP, TN, fecal coliform and so on of surface water in winter-spring grassland were higher than those in summer-autumn grassland.Also, there was a high positive correlation between BOD5, TN, TP, fecal coliform and so on, with a common source.The COD, BOD5, TN and TP of surface water in grazing grassland exceeded the national surface water V Class standard, Cr and fecal coliform exceeded the national standards for livestock and poultry drinking water. Conclusion: the quality of nonliquid surface water decreased in the long-term over grazing grassland , winter-spring grasslands is serious; the quality nonliquid surface water there is a potential risk, we should avoid the nonliquid of small surface water.