中国干旱内陆流域水体N、P负荷特征与动态变化——以黑河流域为例

Abstract

This study was undertaken to investigate the loading features, temporal-spatial distribution and dynamical changes of plant nutrient elements N and P in arid inland water bodies including ground water, spring water, reservoir and river in the midstream area of the Heihe river basin through river section monitoring and sample analyses at selected sites over the past 11 years. NO3-N contents in shallow ground water and river water were commonly higher than 1.1mg/L; NH4-N contents in most of plain reservoirs exceeded 0.3mg/L; TP, NH4-N and NO3-N contents showed a significant increase tendency from the mountain valley mouth to the downstream area of the river basin. Further more, they also tended to increase significantly with time, of which NH4-N contents in the river water at the mountain valley mouth and the lower reach on an average annually increased 0.11mg/L and 0.114mg/L respectively. N and P contents in the basin's water bodies also exhibited obvious seasonal change, during the low water period from late spring to early summer, TP, NH4-N and NO3-N contents in a large part of the river section reached a peak values of a year or even exceeded polluted water quality level. The control of N and P pollution especially in water period should be viewed as a key content for the protection of water resources in the arid inland river basin.