SENSITIVITY ANALYSIS OF MANGROVE FOREST RELATIVE ABUNDANCE DUE TO ANTHROPOGENIC ACTIVITIES USING NUMERICAL COMPUTATIONAL APPROACH

In studying the sensitivity analysis of mangrove forest relative abundance due to anthropogenic activities using numerical computational approach. for a time, interval of 0(10)120months using Matlab ODE45 numerical scheme, three different mangrove sites which are N21, N22 and N23 in the Niger delta and considered as natural mangrove forest vegetation sites in the absence of artisanal hydrocarbon whereas N1, N2 and N3 were considered as present of artisanal hydrocarbon. The results output shows that all the coordinates have a 0.01unit relative abundance on the base day, the data base result shows a monotonic increasing pattern in the relative abundance in the coordinates of N21, N22 and N23 of which the value of the coordinates of N21 was recorded as 0.0246units on the tenth (10th) month to a saturating value of 0.2427units on the one hundred and twentieth (120th) months. In the same scenario, the same observation is noted on the N22 and N23 coordinates as the value on the N22 coordinates is recorded 0.0580units on the tenth (10th) month to a saturating value of 0.488units on the one hundred and twentieth (120th) months as well as N23 coordinates having 0.0471units on the tenth (10th) month to a saturating value of 0.1974units on the one hundred and twentieth (120th) months. However, due to the percentage variation of the growth rates, the database of the simulated result indicates that from the base day up to the tenth month of our experimental time, there was a severe depletion in the mangrove vegetation which further depleted to the 120th month on comparing with the coordinates of the mangrove forest vegetation in the absence of hydrocarbon. In this scenario, the coordinates which depleted due to a 50% variation of the growth rates parameters in the presence of hydrocarbon decreases monotonically down the trend These observations show a strong increase in the numerical strength of the relative abundance of the N22 coordinates follows by N21 coordinates with a slow increase in numerical strength and a strong increase pattern in the N23 coordinates which converges earlier to its saturated value. The novel result is presented and discussed as well.