黄河三角洲1961—2000年水资源时空变化特征

采用降水量、径流量、地下水位及埋深4个指标对1961—2000年水资源的时空变化特征进行分析。结果表明:①降水量年内及年际变化均较大,年内降水量集中于夏季,年际呈下降趋势,空间分布呈自南向北逐渐下降的趋势。②黄河入境径流量年内及年际变化均较大,根据趋势分析1986年之前径流量变化较平缓,之后呈线性下降趋势。当地径流量年内变化较大,夏季径流量超过全年的80%;年际变化较小,呈峰-谷-峰的变化趋势。③东营市浅层地下水位年内变化较小,其中广饶县年内及年际变化均较大,自20世纪80年代至21世纪初平均下降了12.78m。④广饶县地下水埋深自70年代至90年代增幅达到14.70m。1975—2000年广饶县地下水埋深呈显著线性增加趋势(R2=0.93),年均增速达到0.72m/a。

Spatial and temporal characteristics of water resources in Yellow River Delta from 1961 to 2000

The spatial and temporal characteristics of water resources in the Yellow River Delta from 1961 to 2000 were analyzed based on four indicators： precipitation, runoff, water table, and bury of groundwater. A ease study was conducted in Dongying City, which is the main part of the Yellow River Delta. The results show the following： （ 1 ） Both the intra-annual and inter-annual changes of precipitation were significant. The intra-annual precipitation was concentrated in summer. The inter-annual precipitation had a decreasing trend. The spatial distribution of precipitation showed a gradual declining trend from south to north. （2） The intra-annual and inter-annual changes of inflow of the Yellow River were significant. A trend analysis indicated a slight fluctuation and linear decline of runoff before and after 1986, respectively. The local runoff showed significant intra-annual change, with the runoff in surnmer being over 80% of that over a whole year, and a small inter-annual change, with a peak-valley-peak trend. （3） There was a slight change in the water table of the shallow groundwater in Dongying City, but large intra-annual and inter-annual changes in Guangrao County, where an average decrease of 12.78 m of the water table was observed from the 1980s to the early 21st century. （4） The bury of groundwater in Guangrao County increased by 14.70m from the 1970s to the 1990s. A notable linear increase （ R^2 = 0.93） of the bury of groundwater in Guangrao County was observed from 1975 to 2000, with an average growth rate of 0.72 m per year.