Study on limiting factors of water eutrophication of the network of rivers in plain.

Influences of light intensity, temperature and nutrients (N, P) on algal growth in the water of network of rivers in plain were studied in this test. It is shown that amount of algae increased logarithmically with increase in light intensity in the range of 1 000 5 000 luxes and with rise in temperature from 15 ℃ to 30 ℃, and 4 000 luxes and 30 ℃ is most favorable. But the influence of temperature was more obvious than that of light intensity. When consistency of T P was 0.1 0.75 mg/L in water, the algal increases logarithmically with the consistency growing up, but it didn't happen with the T N. The specific growth is the highest when the consistency of T P0.5 mg/L, T N1.0 mg/L, and the influence of P is greater than N.