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Poster Session
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Using TM data to quantify the contribution of
chlorophyll, phytoplankton and fish productivity
B. Analysis of the correlation coefficient between CHL and TM data
Generally, the concentration of chlorophyll in large water body is always bellow 10g/1. According to the spectral properties of TM bands, (seetable2.) the correlation between CHL and band6 band7 will not be considered. Because the maximum reflection of CHL is in TM band5 and band2, so we select the TM and2 and band5 to calculate the contribution of CHL in the whole lake with establishing mathematic model of CHL concentrations. Also we know the band1 would be one of the best and to determine water quality i.e. suspended suspended solids in the water [2], so the formula: (band (I-band1)/ band (I))+ (I=2 or 5) is used to modify the effection of the suspended solids for band 2 or band 5 the correlate results between CHL sampling data and TM data are listed in table. 3.
Table 3.
| band (s) |
different TM bands combination |
correlate coef. |
| 1 |
B*band 1+C |
0.360 |
| 2 |
B*band2+C |
0.639 |
| 2 |
B*ln (band2) +C |
0.641 |
| 3 |
B*band3 +C |
0.455 |
| 4 |
B*band4+C |
0.283 |
| 5 |
B*band5+C |
0.660 |
| 1,2 |
B*SQRT((band 2-band1)/(band2+ band1)+C 0.851 |
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| 2,3 |
B*SQRT ((band2-band3)/ band2+ band3))+C - 0.322 |
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| 1,2,5 |
B*SQRT ((band2- band1)/( band2+ band1))+ band5+C |
0.856 |
| 1,2,5 |
B*Ln((band2- band1)/( band2+ band1)+ band5) +C |
0.861 |
Table3 shows that the chlorophyll has a good correlation with band
1,2,5,which the regression model is CHL = gain in ((BAND2-BAND1)
/ BAND2-BAND1)+BAND5) + offset. The CHL contribution map is showed as Fig. 1.
Fig. 1 Image of CHL distribution,1:750000
The different color has the different CHL concentration
- The calculation of primary fish productivity
Presently, there are three ways to estimate the fish productivity (1)
- To establish the relationship or models between feed biomass or non-biomass factor and fish productivity.
- To estimate the fish productivity from feed biomass according to the energy transferring o ecosystem or feed population.
- To gain the result of different kinds of fish productivity based on analization of bio-factor and non-biofactor.
Since 1960 there are many regression models between feed biomass and fish productivity, and we will introduce two models which use CHL or phytoplankton biomass to determine fish productivity.
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Model (1) | log (Yf) = -1.92+1.17*log (CHLS)
Yf ----dried weight of fish production (g/m2)
CHLs --- CHL concentration in summer (mg/1)
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| Model (2) | Yfc = WPB* 0.004
Yfc --- fish production (g/m3, per day)
WPB ---wet weight of phytoplankton biomass (mg/m3)
0.004 --statistic transfer coefficient (80% *20% /40) |
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