阿什河源头水源涵养林在水分传输过程中对水质的影响

Influence of the Water Conservation Forest in the Headstream of Ashi River on Water Quality

对阿什河源头地表水来源过程中各环节(包括大气降水、穿透水、树干径流和地表径流)的水化学性质进行分析比较。结果表明:树干径流的酸化最为明显,地表径流对林分水质酸化有很好的缓冲作用;大气降水经过落叶松人工林生态系统后,穿透水和树干径流的电导率、总溶解固体、K和Mg元素含量增加;穿透水7、8、9月Na元素含量都低于大气降水,为负淋溶;对穿透水、树干径流和地表径流而言,Zn元素含量在观测时间内变化趋势相同,都是6—9月逐渐降低;各月树干径流和地表径流的Mn和Fe元素平均含量都高于大气降水和穿透水;地表径流经过林地土壤层的深层交换和净化后汇集成溪水,浊度和总溶解固体含量明显降低;溪水和河水中的Mg和Zn元素含量在观测时间内变化趋势一致,Mg元素含量变化都呈"W"形,Zn元素含量都是6月最高,9、10月份未检出;各月河水中总N、总P、电导率和总溶解固体都高于溪水,且Na、Mg和Ca元素含量也都高于溪水;溪水综合评价结果属于Ⅱ类水体,河水综合评价结果属于Ⅳ类水体。

The water quality of rainfall, throughfall, stemflow and runoff in the headsteam of Ashi River was studied. The results showed ： The acidification of stemflow was most obvious, the runoff had better buffering ability of water acidification ; The content of COND, TDS, K and Mg increased in the throughfall and stemflow through the larch forest canopy; The content of Na in throughfall was lower than rainfall in July, August and September; The temporal variation of Zn was consistent in the throughfall, stemflow and runoff, that was the content of Zn decreased gradually from June to September; The monthly average contents of Mn and Fe in stemflow and runoff were higher than that in rainfall and throughfall ; After running off through the soil, the content of TURB and TDS in the stream reduced obviously; The temporal variation of Mg and Zn was similar between in the brook and river, the content of Mg was the highest in June and the lowest in September, the content of Zn was the highest in June, and nothing was found in September and October; The content of total nitrogen, total phosphor,COND, TDS, Na, Mg and Ca in the river was higher than that in the brook every month; In general evaluation, the brook water quality belongs to class Ⅱ , while the river water quality to class Ⅳ.