不同深度鱼塘水温状况分析

滆湖位于江苏省常州市西南13km处,水面面积164km~2,平均水深1.26m,是太湖湖群的重要组成部分。其氮、磷平衡研究结果表明:①入湖氮、磷总量分别为4120.29t/a和270.03t/a;其中以河道入湖量最大,分别占入湖总量的71.9％和57.1％,其次是养殖投饵,分别占入湖总量的12.4％和29.9％;氮、磷的滞留系数分别为0.36和0.35,年滞留量分别为1481.6t和94.82t。②湖水的氮、磷负荷较大,但由于水草的吸收净化作用,湖水水质仍能保持较低水平。③网围养殖区底泥氮、磷释放强度大。非网围区水草根系的吸收对底泥氮、磷释放起到一定的抑制作用。

Analysis of water temperature different depths of fish ponds

Gehu Lake is a macrophyte type shallow lake located in the Taihu Lake groups in the southeast plain to Changzhou City, Jiangsu Provence, with an area of 164 km2, and an average depth of 1. 26m. The nutrient balance results show: (1) The total nutrients inputted are N 4120. 29 t/a and P 270. 03t/a, coming separately from its inlets(N 2961. 86t/a, P 154. 38t/a), land around the lake( N 45. 83t/a, P 1. 46t/ a),cage aquaculture and artifitial food (N 509. 95t/a, P 80. 60t/a), released sediments (N 362. 20 t/a, P 19. 16t/a) and atmospheric precipitation (N 240. 45 t/a. P 14. 43t/a). The total nutrients drained are N 2632. 91t/a and P 175. 21 t/a, outflowing through rivers(N 2172. lit/a, P 77. 03t/a), harvest of fish (N 230. 64t/a, P 59. 66t/a), harvest of aquatic plants (N 210. OOt/a. P 37. 80t/a), irrigation and factory utilization around the lake (N 20. 16t/a, P 0. 72t/a). The N deposits 1487. 38t/a(deposit efficient 0. 361) and the P deposits 94. 82t/a (deposit cofficient 0. 3511). The main input and output ways of N and P are rivers. The input N by rivers occupies 71. 88% of total input and P 57. 17%. (2) Nutrient load is much higher, N is 25. 12g/(m2 ?a) and P 1. 647g/(m2 ?a). ( 3) The amount of nutrients released from the sediments of the cage aquaculture region is great. The daily releasing of N is 14. 3 mg/m2 and P 0. 65mg/m2.