Eco-hydrological modeling of a forest ecosystem using spatial datasets and climate parameters
Student name: Ms Projjolita Mahanta
Guide: Dr P K Joshi
Year of completion: 2013
Host Organisation: North Eastern Space Applications Centre (NESAC), Umiam
Supervisor (Host Organisation): Mr Ngangbam Romeji Singh
Abstract: Hydrologic science, one of the fastest developing disciplines among all the other diverse subjects within
geosciences, has undergone numerous metamorphisms to become a prominent science since the day it was born.
It deals with every aspect of hydrology. With the identification of the fact that hydrological and ecological
processes within the terrestrial biosphere defines a close relationship and that the water cycle and other
hydrological processes strongly influence the elements cycle (nitrogen and carbon) and the growth of
vegetation, the interaction between hydrological processes, ecological processes and the climate received great
attention. This ultimately leads to another metamorphism in the field of hydrologic science which motivated the
genesis of Ecohydrology. In the present study, effort was made to find a succinct relation between the ecological
and hydrological processes within the catchment scale of Nongkhyllem Wildlife Sanctuary, Meghalaya. Spatial
datasets as ETM+ (Landsat 7), LISS-4 MX (IRS P6) and SAR imagery in HH and HV polarized modes
(RADARSAT-2) were used in this study to derive the NDVI, EVI and LAI respectively. Hydrological models such
as ArcSWAT and HEC-HMS were also in use effectively to find the hydromorphological parameters along with
other terrain parameters. This study demonstrates that a significant relation exists between the different
ecological parameters such as NDVI, EVI and LAI and the hydrological parameters such as ET, PET, SMC,
total run off for each of the sub-watersheds formed. Spatial and temporal relations were established between the
above stated parameters. An explicit relationship with R2 = 0.91was found between LAI derived from the HH
polarized image of RADARSAT-2 (RS2) with ET. It was also found that there is a coherent correlation between
the Catchment Runoff and LAI derived from HH polarized image of RS2. (R2 = 0.61).No significant relation
between Catchment Runoff and EVI as well as NDVI could be ascertained from the present study. However by
considering the Runoff in terms of lognormal flow values, a considerable improvement in the correlation
coefficient could be achieved. Temporal relations for the considered year was also satisfactory between the total
Runoff and SMC, whereas it didn’t produce a good relation with ET and PT as there was lack of weather
parameters such as sun-shine for the determination of ET and PET effectively.
Keywords: Ecohydrology, SWAT, LAI, Runoff, ET, PET
