Using TM data to quantify the contribution of
chlorophyll, phytoplankton and fish productivity
According to Model(1). the primary fish productivity (PFP) are computed in table 4.
Table 4
| Subarea |
Area(acre) |
CHLs(ug/l) |
Depth(m) |
Total CHL(kg) |
PFP(kg) |
| DONGTAIHU |
199962 |
1.8 |
2.6 |
239.7 |
0.016/3.31 |
| SANSHANHU |
186259 |
7.0 |
2.6 |
868.3 |
0.078/16.41 |
| ZHUSHANHU |
45706 |
3.5 |
2.6 |
87.5 |
0.052/10.93 |
| GONG HU |
247953 |
4.0 |
2.6 |
660.5 |
0.041/8.51 |
| XIAOMEIKO |
255951 |
3.5 |
2.6 |
511.5 |
0.035/7.28 |
| YIXINGTAN |
490192 |
2.9 |
2.6 |
950.0 |
0.028/5.85 |
| TAIHUQV |
2174000 |
3.5 |
2.6 |
5067.6 |
0.035/7.28 |
| TOTAL |
364000 |
----- |
----- |
8527.6 |
----- |
According to Model (2) the primary fish productivity ( PFP ) are computed in Table 5.
| Sub lake |
Area ( acre ) |
PPP ( mg/I ) |
Depth ( m) |
Total ( PPB Kg. ) |
PFP ( Kg. ) |
| DONGTAIHU |
119962 |
6.4 |
2.6 |
853.4 |
0.017/3.54 |
| SANSHANHU |
186259 |
30.0 |
2.6 |
3727.0 |
0.081/17.0 |
| ZHUSHANHU |
45706 |
19.0 |
2.6 |
579.2 |
0.051/10.6 |
| GONGHU |
247953 |
15.0 |
2.6 |
2480.8 |
0.040/8.48 |
| XIAOMEIKO |
255951 |
13.5 |
2.6 |
2304.7 |
0.036/7.73 |
| YIXINGTAN |
490192 |
10.5 |
2.6 |
3433.1 |
0.029/60.06 |
| TAIHUQV |
21740000 |
13.5 |
2.6 |
19575.8 |
0.036/7.73 |
| TOTAL |
3640000 |
--- |
--- |
32954.0 | --- |
Where:
|
Depth(m) ----- | the average water depth of 12 sampling stations
|
| CHLs(ug/1) ----- | Mean CHL concentration which calculated by image processing system for each sublake
|
| TOTAL CHL(kg) ----- | Total CHL quantity of each sub lake [5]
|
| PPP(mg/l) ----- | average concentration of phytoplankton for each sub lake
|
| total PPB (kg) ----- | daily production per acre/whole year's production per acre
|
| PFP(kg) ----- | daily production per acre/ whole year's production per acre |
Total fish production of the whole Taihu lake (include 7 sub lakes ) in one year calculated as:
Total fish production (TFP) = subarea*FFP (about one year )
= 27520000(kg)
One year's fish production per acre (YFPA) can be calculated as:
YFPA = TFP/total area = 27520000/3640000
= 7.54 (kg)
Results and discussion
- Although the two methods described above only involved one time sampled data of CHL and phytoplankton biomass, but we stultified with the two similar results about the primary fish productivity using the two methods. To estimate the concentrations of CHL, phytoplankton biomass and fish productivity by using Landsat TM data and computer image processing system
is successful in our research.
- During the 1980 to 1981, the primary fish productivity in Taihu lake was 4.55 kilogram/acre (use regular investigation) and it's 7.54kg/acre in 1989. This is because chlorophyll concentration has been changed from 4.84 (ug/1) to 10.5 (ug/1) [7]
- It is new method to estimate the natural resources for reproduction and aquaculture in the fresh waterbodies.
References
- Fresh Water Aquatic Organism, Dalian College of Fish. and Aqui.
- Li Jilong et al, The Study Of Using Landsat TM Data To Quantify Daihai Chlorophyll And Lake Weed. 90's Asian and Pacific Regional Oceangraphy and Fishery Remote Sensing Symposum.
- Zhanglin, Huang Qiquan, Monitoring Aquiculture Resources BY Using Remote Sensing Technique in Lake Gerhu. Remote Sensing Center of Chinese Academy of Fishery Sciences.
- M. Godoy JR; E.M.L.M. Novo, TM/Landsat Data Processing FOR Inland Water Monitoring.
- O. Jarret, Jr; C. A. Brown; J.W.Cambell etal: Measurement OF Chlorophyll A FlouresceneWith AN Airbone Flourescene
- J. M. Hill, Inference About Water Quality AND Quality Based Land AND Land USE , R.S. Luisiana Uni.
- Bao Jianping, The Calculation OF Taihu's Phytoplankton AND Fish Productivity, materials Collection of Taihu Natural resources Investigation.
