海河流域平原河流非常规水源补给特性及其成因分析

统计分析海河流域水资源量和污废水入河量数据(2001—2012年)、降水量数据(1956—2012年),以及水资源利用、污废水排放、社会经济、人口等数据(1980—2012年),探究了海河流域平原河流非常规水源补给的特性及成因.结果表明,非常规水源补给的河流具有污径比高的特性:海河流域河流污径比高,平均污径比为35.7%,其中海河北系污径比最高,达到90.5%,滦河及冀东沿海污径比最低,为25.6%.降水量的持续减少、山前水库带对水资源的截留以及平原区水资源开发利用率的增加导致河流径流量减少,是海河流域平原河流非常规水源补给的一个主要原因:降水量持续减少,1956—1980年平均降水量为559 mm,至2012年平均降水量降低至502 mm;水库、闸坝等水利设施的建设使得73%的山区河流流量被水库截留;流域地表水资源平均开发利用率高达63%,这些均导致平原河流径流量持续减少.人口和社会经济快速发展导致污废水排放量增加,是海河流域平原河流非常规水源补给形成的另一个主要原因:工业产值、城镇人口数量均与污废水排放量显著正相关,复相关系数均超过50%.海河流域中部平原区河流以非常规水源补给将长期存在,考虑非常规水源水质水量的协同保障,对满足生态需水量、改善缺水河流生态环境等具有积极的作用.

Characteristics and causes analysis of unconventional water resources supply for plain rivers in the Haihe river basin

Based on statistical analysis, data of water resources and wastewater flux into river from 2001 to 2012, precipitation from 1956 to 2012, water utilization, wastewater discharge, economy and population from 1980 to 2012 were collected. These data were used to explore characteristics and causes of unconventional water resources supply for plain rivers in the Haihe river basin. The results indicate that unconventional water resources supplied rivers had high ratios of wastewater to runoff: the ratio of wastewater to runoff was high in the Haihe river basin, with an average of 35.7%. This ratio in the north river system was the maximum of 90.5%, and in the Tuhaimajia River was the minimum of 25.6%. The reduced runoff caused by declining precipitation, water interception from reservoirs, and increasing water utilization constituted one main reason of unconventional water resources supply for plain rivers: The precipitation declined continually. The average precipitation from 1956 to 1980 was 559 mm and declined to 502 mm until 2012; 73% of the stream discharge was intercepted by reservoirs in upstream mountain area; The average surface water resources utilization was up to 67%. All of the above three reasons resulte in a reduction of natural runoff. The increasing wastewater discharge created by population and GDP growth was the second main reason of unconventional water resources supply for plain rivers: industry output value and urban population both related to wastewater discharge significantly, and the multiple correlation coefficients were more than 50%. Unconventional water resources supply for plain rivers in the Haihe river basin will exist for a long time. Thus, ensuring the quality and quantity of unconventional water resources will play a positive role in meeting the ecological water requirement and improving the ecological environment.