Integrated Landsat Image Analysis and Hydrologic Modeling to Detect Impacts of 25-Year Land-Cover Change on Surface Runoff in a Philippine Watershed

Abstract

Landsat MSS and ETM+ images were analyzed to detect 25-year land-cover change in the critical Taguibo Watershed in Mindanao Island, Southern Philippines. This watershed has experienced historical modifications of its land-cover due to the presence of logging industries in the 1950s, and continuous deforestation due to illegal logging and slash-and-burn agriculture in the present time. To estimate the impacts of land-cover change on watershed runoff, land-cover information derived from the Landsat images was utilized to parameterize a GIS-based hydrologic model. The model was then calibrated with field-measured discharge data and used to simulate the responses of the watershed in its year 2001 and year 1976 land-cover conditions. The availability of land-cover information on the most recent state of the watershed from the Landsat ETM+ image made it possible to locate areas for rehabilitation such as barren and logged-over areas. We then created a "rehabilitated" land-cover condition map of the watershed (re-forestation of logged-over areas and agro-forestation of barren areas) and used it to parameterize the model and predict the runoff responses of the watershed. Model results showed that changes in land-cover from 1976 to 2001 were directly related to the significant increase in surface runoff. Runoff predictions showed that a full rehabilitation of the watershed, especially in barren and logged-over areas, will be likely to reduce the generation of a huge volume of runoff during rainfall events. The results of this study have OPEN ACCESSRemote Sens. 2011, 3 1068 demonstrated the usefulness of multi-temporal Landsat images in detecting land-cover change, in identifying areas for rehabilitation, and in evaluating rehabilitation strategies for management of tropical watersheds through its use in hydrologic modeling.

Vertical Accuracy Assessment of 30-M Resolution Alos, Aster, and SRTM Global Dems Over Northeastern Mindanao, Philippines

“…This is despite the fact that DEMs such as those from SRTM and ASTER are being used as major sources of topographic information for many applications including hydrological analysis and simulations (e.g., Jaranilla-Sanchez et al, 2011;Santillan et al, 2011;Sarmiento et al, 2012;Clutario and David, 2014;Chen and Senarath, 2014), flood modelling and hazard mapping (e.g., Abon et al, 2011;Ignacio and Henry, 2013), geological hazard analysis (e.g., Lagmay et al, 2012), and landslide mapping characterization (e.g., Evans et al, 2006;Oh and Lee, 2011). The quality and accuracy of the DEMs used and their suitability for these applications were not adequately assessed.…”

Preparing Landsat Image Time Series (LITS) for Monitoring Changes in Vegetation Phenology in Queensland, Australia

“…Their number and placement of spectral bands is also an important advantage over other similar sensors. The TM and ETM+ sensors acquire the images in visible, near infrared and shortwave infrared portions of the electromagnetic spectrum, making them appropriate for studies of vegetation properties across a wide range of vegetation communities, in diverse environments [1][2][3][4].…”

Water Balance Modeling in a Semi-Arid Environment with Limited in situ Data Using Remote Sensing in Lake Manyara, East African Rift, Tanzania

“…Some ground measurement and satellite gravimetry derived equivalent water thickness has been employed to verify the trend of the Lake Manyara water balance [10]. Over recent years, several studies have both applied remote sensing observations and gravimetry recovery and climate experiment (GRACE) measurements to study the hydrological cycles of lakes, rivers and associated basins in the East African Rift and elsewhere [10][11][12][13][14][15]. Changes in a basin's water budget are directly linked to local gravity variations [16].…”