山东省大中型水库鱼产力的综合评估

A COMPREHENSIVE ASSESSMENT OF FISH PRODUCTIVITY OF LARGE-AND MIDDLE-SIZED RESERVOIRS IN SHANDONG PROVINCE

1989、1990 两年调查了山东全省有代表性的36座大中型水库的鱼产力性状。根据调查结果用系统聚类法,等级法和回归分析法进行了鱼产力评估。用等级法将这些水库根据鱼产力的高低分成了五级,并以二座经营较好、放养充分的典型水库的多年连续平均鱼产量为基准,根据浮游生物的平均丰度,估计了各级水库的鱼产力依次为 440、370、290、220 和150kg·ha^(-1)。回归分析法的评价结果表明影响这些水库鱼产力相对高低的主要因素是集雨区的土壤肥力、人口密度和植被覆盖率;以及库水的总磷、总氮、电导率、化学耗氧量和浮游生物的丰度,其中又以土壤肥力影响力最强。

Fish productivity characteristics of 36 representative large- andmiddle-sized reservoirs in Shandong Province were investigated in 1989 and 1990.17 items concerning characters of the drainage areas, morphological, hydrolo-gical, hydrochemical and biological features, and the status of reservoir fisherywere completely included in the investigation. On the basis of these results, fishproductivity of the reservoirs was assessed with systematic cluster analysis,ranking method and regression analysis. In assessing with the ranking method a systematic approach was followed toclassify the reservoirs into five ranks, and on the basis of the average fish produc-tion of 2 well--managed typical reservoirs over a number of successive years andin accordance with the average plankton abundance of the reservoirs in each rankthe fish productivity of each rank was estimated to be 440, 370, 290, 220 and150 kg.ha^(-1) respectively. From the results of regression analysis it was shownthat the major factors affecting the levels of reservoir fish produotivity were:the soil fertility, the density of population and the rate of vegetation cover withinthe drainage area; and the total phosphorus, the total nitrogen, the electric conduc-tivity, the chemical oxygen demand and the plankton abundance of the reservoirwater. Among all of them soil fertility was the strongest one.