[Possibility of total dissolved solid as one of nutrient baselines in inner Mongolia-Xinjiang plateau]

The temporal changes of total dissolved solid concentrations were analyzed according to the investigations and regular monitoring data in the Inner Mongolia-Xinjiang plateau. The result showed that the salinization process in the Inner Mongolia-Xinjiang plateau became strong. Integrated regression equation indicated that, the environmental physical and chemical factors affecting chlorophyll-a were total phosphorus and TDS. The relationship between the nutrient and biological variables was analyzed in typical examples in the Inner Mongolia-Xinjiang plateau. The results showed that, dissolved oxygen, pH, total nitrogen, chlorophyll-a, transparency were significant factors that affected TDS of the Inner Mongolia-Xinjiang plateau. It presented a significantly negative relationship (P<0.01) between dissolved oxygen, pH and TDS, whereas it presented a significantly positive relationship (P<0.01) between total nitrogen, chlorophyll-a, and TDS, and a positive relationship (P<0.05) between transparency and TDS was observed. The linear relationship between TDS, eutrophication response variables (i. e., chlorophyll-a and transparency) and reasonable variables (i. e., total phosphorus and total nitrogen) was investigated as well in this paper. The result suggested that TDS should be classified into the nutrient criteria of the Inner Mongolia-Xinjiang plateau, which provides a theoretical basis to determine the candidate variables and indicator for lake nutrient criteria in the Inner Mongolia-Xinjiang plateau.