淮河生态经济带不同水文时期水质的时空特征研究

目的]揭示淮河生态经济带不同水文时期水质的时空特征,为水污染治理提供科学依据。方法]应用统计方法和地理空间分析方法,阐明不同水文时期水质的时空特征。结果](1)时间上,不同水质指标在各水文时期的中位值总体接近,但波动幅度差异较大;丰水期前期水质偏差而后期较好,而平水期和枯水期污染物浓度以2月、3月偏高。(2)空间上,不同水文时期的水质表现为干流较好而北侧支流较差的格局。各水文时期pH总体稳定,DO仅在丰水期时空间差异略大;不同水文时期COD_(Mn)和NH_3-N的浓度差异较大,空间分异较突出,北侧支流水系浓度较高水质偏差。(3)水质时序差异与不同水文时期降水径流的消解作用和水利工程的调节控制有关;而水质的空间差异主要受南北水系不对称且降水南多北少的水文差异和水体自净能力影响。结论]淮河生态经济带各水文时期的水质在时间上波动差异较大,而空间上干流水质较好但北部支流水质较差,应当重点加强经济带内淮河干流北侧支流的水体污染治理。

SPATIO TEMPORAL PATTERN OF WATER QUALITY IN DIFFERENT HYDROLOGICAL PERIODS IN HUAIHE ECO ECONOMIC BELT

To reveal the spatio temporal pattern of water quality in different hydrological periods in Huaihe Eco economic Belt (HEB) is of great importance for the decision making of the water pollution countermeasures.Statistical methods and geospatial analysis method were used to evaluate the variation of spatial pattern of water quality in different hydrological periods in HEB. Results showed that (1) Temporally, the median values of different water quality indices in different hydrological periods were generally close, but the fluctuation ranges were different. Water quality was relatively good in the early months of the flood period, but it was getting a bit worse in the later months. The value of the water pollution indices were higher in the February and March in the level period and the drought period respectively. (2) Spatially, water quality was generally better in the main stream and worse in the northern branch of the Huaihe river. The pH values reached the standard of the water quality in different periods. In flood period, the DO values varied greatly for the different water quality stations, but the values of the CODMn and NH3 N were higher in the northern tributaries in different hydrological periods. (3) The temporal change of water quality was related to the dilution and digestion of runoff and the regulation and control of water conservancy projects in different hydrological periods. The spatial difference of water quality was mainly affected by the difference of hydrological characteristics and the self purification ability of water bodies, which caused by the asymmetry of the water system from north to south and the less precipitation in the north part. Generally, water quality in different hydrological periods in Huaihe Eco economic Belt varies greatly in time, while water quality in the main stream is better and poor in the northern branch of the Huaihe river. So that the water pollution prevention in the northern tributaries of Huaihe Eco economic Belt should be strengthened.