紫色土丘陵区典型小流域水体N、P含量及其环境特征

N、P各形态浓度在川中丘陵区小流域的水体中显示出明显的时空特征,在地表水中,以旱地为主的小流域上部的硝态氮、氨态氮、全氮要低于小流域下部水田的,而以流域人口密度较大的群英池和小流域下部的沟道水中氨态氮浓度较高,说明人为活动对其影响较大。在地下水中以小流域上部为最高,明显高于该流域的中下部;它们的季节变化与流域降水的季节变化基本是一致的。紫色土丘陵区水体富N,地下水NO_3~--N超标率达60％,;地表水和地下水均尚未出现P的富营养,但潜在的污染不可忽视。

STUDY ON ENVIRONMENT FEATURES OF N AND P OF WATER IN WATERSHED IN HILLY AREA OF PURPLE SOIL

Results showed Nitrogen and phosphorus in watershed have a distinct character in different spacetime. As to ground water, NO_3-N, NH_4-N and all Nitrogen in the upper part of watershed was the most serious. But in surface water, their changes behaves to opposite situation. They changed with precipitation along seasonal alteration. N in surface water tends to be eutrophied. 60% of NO_3-N in the ground water was higher than WHO drinking water standard. Ground water contamination of NO_3-N comes from cropland. P eutrophication is not serious in watershed.