土地利用、溪流级别与溪流河水理化性质的关系

为研究土地利用对溪流水质的影响 ,对黑龙江省尚志市帽儿山境内阿什河流域的 1～ 5级溪流河水进行采样 ,同时记载森林覆盖度、邻近土地利用类型及地貌特征。对溪水样品的的 p H,浑浊度 ,NH 4- N、NO- 3- N和 PO3 3- P浓度进行分析测定。对不同溪流级别和土地利用类型的溪流河水进行分析。结果表明 :随着溪流级别的升高和土地利用类型由森林变为农田和村镇 ,溪流河水的 p H,浑浊度 ,NH 4- N、NO- 3- N和 PO3- 3- P浓度均显著升高。森林植被保存相对较好的 1、2级溪流水质最佳 ,但溪水中溶解无机磷和无机氮的浓度与美国温带地区相似的低级溪流相比 ,分别高 30倍和 1 0 0倍。河岸带破坏 ,土地利用的变化 ,放牧、樵采等频繁干扰造成的土壤侵蚀和养分流失输入是造成该流域溪流富营养化的主要原因

Land-use, stream order and stream water physical and chemical qualities

Stream water sampling was conducted along the Ash River continuum from 1st order to 5th order in the Maoershan Experimental Forest of the Northeast Forestry University, near Maoershan Township, Shangzhi City, Heilongjiang Province. The pH, turbidity, concentrations of NH~ 4-N, NO~- 3-N and PO~(3-) 4-P were measured/analyzed. Forest coverage, surrounding land-use type and landscape characteristics of each sampling location were recorded. Land-use category was later determined from recent aerial photos and field observations for each sampling location. Water quality variables were evaluated in response to changes in stream order and land-use types. Both stream order and land-use (forest, agriculture and urban) were positively correlated to pH, turbidity, concentrations of NH~ 4-N, NO~- 3-N and and dissolvable phosphate. Although water quality was better in the forested 1st-2nd order streams, the concentration of dissolvable phosphate and inorganic N were more than 30 and 100 times higher, respectively, than those in the comparable pristine forested streams in temperate North America. Soil erosion, lack of riparian protection, grazing, over fertilization and frequent disturbances likely contributed to eutrophication of the streams.