Study On Carrying Capacity Of Water Environment In Daling River Basins

To realize the aims of using and management and protection of water resource reasonably and scientifically in Daling River Basin, the methods of isoline and Mathematical Statistics have been used to evaluate the surface water resource condition and the discharge estuary condition. The water quality of main rivers in Daling River Basin and water quality of water function area have been evaluated by single index method. The carrying capacity of the water body for contamination has been analyzed and calculated by using mathematical model. The capacity has been calculated under the thinking of not only the safest condition but different Guarantee Ratio minimum flow, as well, the seasonal feature of the river in the dry area of North china and the uneven yearly run-off have been thought in the calculation. According the calculation above, the water environmental carrying capacity in different months in Daling River Basin has been worked out.The calculating result shows that the main problems of water resource using in Daling River Basins are deficient water resource quantity and unbalance use and severe water pollution and exasperate water environment. The sustainable capacity of Daling River Basins is very low. The capacity of COD is 8691.6t/a in dry month with 90% guarantee ratio. The capacity is 44.7% under the condition of monthly 90% guarantee ratio in one year. The capacity of Ammonia Nitrogen is 385.2t/a in dry month with 90% guarantee ratio. The capacity is 43.7% under the condition of monthly 90% guarantee ratio in one year. The environmental capacity calculated with the condition of dry month is advantageous for realizing the aims of water function area. But the result of the capacity is too low. If it is calculated with monthly a year and high guarantee ratio, the water sustainable environmental capacity will be much more.