Stream water quality and its influencing factor in lower order streams in upriver sections of Ashihe River

Abstract

For understanding the reasons that caused the degradation of water quality in lower order streams, systematic sampling was conducted at different spatial locations along the low order streams (1st–5th) of Ashihe River continuum in Maoershan Experimental Forest of Northeast Forestry University, Shangzhi City, Heilongjiang Province, China. The indexes of stream water quality, i.e., the pH, dissolved oxygen(DO), turbidity, temperature, PO₄ ³⁻−P, NO₃ ⁻−N and NH₄ ⁺−N concentrations, total dissolved inorganic nitrogen (TDIN-N, including concentrations of NO₃ ⁻−N and NH₄ ⁺−N), and total phosphorus (inorganic and organic phosphorous, TP) were measured and analyzed. The stream order, related environmental settings and land-use type were recorded for each sampling location. The indexes of stream water quality at different locations with different stream orders and land use types were compared by ANOVA analysis. The indexes of stream water quality at different sampling locations were analyzed by Hierarchical cluster analysis. Result showed that water quality had significant difference in different stream orders and land use types; some locations with different stream features (stream order and land use type) were grouped into same clusters, indicating that random disturbances produced the variations in water quality, which made the spatial variances of stream water quality inconsistent with the general rules.

Keywords

Stream water quality / Land-use / Stream order / Hierarchical cluster analysis / S715.3 / A