UA
V MONITORING FOR ENVIROMENTAL MANAGEMENT IN GALAPAGOS
ISLANDS
D. Bal
lari
a
,
*,
D. Or
ellana
b
, E
. Acosta
a
,
A. Espinoza
c
,
V. Morocho
c
a
Civ
il Engineering Department. Faculty of Engineering. University of Cuenca, Cuenca, Ecuador - (daniela.ballari,
enrique.acosta)@ucuenca.edu.ec
b
Fac
ulty of Agricultural Sciences. University of Cuenca, Cuenca, Ecuador - daniel.orellana@ucuenca.edu.ec
c
Com
puter Science Department. Faculty of Engineering. University of Cuenca, Cuenca, Ecuador - (angel.espinozav,
villie.morocho)@ucuenca.edu.ec
ThS11
KEY WORDS: UAV, monitoring, Galápagos, NDVI, OBIA classification, Random Forest, littoral vegetation
ABSTRACT:
In the Galapagos Islands, where 97% of the territory is protected and ecosystem dynamics are highly vulnerable, timely and accurate
information is key for decision making. An appropriate monitoring system must meet two key features: on one hand, being able to
capture information in a systematic and regular basis, and on the other hand, to quickly gather information on demand for specific
purposes. The lack of such a system for geographic information limits the ability of Galapagos Islands’ institutions to evaluate and act
upon environmental threats such as invasive species spread and vegetation degradation. In this context, the use of UAVs (unmanned
aerial vehicles) for capturing georeferenced images is a promising technology for environmental monitoring and management. This
paper explores the potential of UAV images for monitoring degradation of littoral vegetation in Puerto Villamil (Isabela Island,
Galapagos, Ecuador). Imagery was captured using two camera types: Red Green Blue (RGB) and Infrarred Red Green (NIR). First,
vegetation presence was identified through NDVI. Second, object-based classification was carried out for characterization of vegetation
vigor. Results demonstrates the feasibility of UAV technology for base-line studies and monitoring on the amount and vigorousness
of littoral vegetation in the Galapagos Islands. It is also showed that UAV images are not only useful for visual interpretation and
object delineation, but also to timely produce useful thematic information for environmental management.
1. INTRODUCTION *
A critical factor for rational natural resources management is
information availability (De Gruijter et al., 2006). In the
Galapagos Islands, where 97% of the territory is protected and
ecosystem dynamics are highly vulnerable, timely and accurate
information is key for decision making. An appropriate
monitoring system must meet two key features: on one hand,
being able to capture information in a systematic and regular
basis; and on the other hand, to quickly gather information on
demand for specific purposes. The lack of such a system for
capturing geoinformation limits the ability of Galapagos Islands’
institutions to evaluate and act upon environmental threats such
as invasive species spread and environmental degradation.
I
t was reported that anthropogenic impacts have already caused
the degradation of 5% of the Archipelago (Watson et al., 2010).
Large populated places in Galapagos are located near the
coastline, where dominant vegetation are shrubs and mangroves.
Degradation of littoral vegetation, and mangroves in particular,
is critical for both, land and marine species. As an example, the
critically endangered mangrove finch (Camarhynchus
heliobates) was historically recorded in five mangrove forests on
Isabela Island and one of them was close to Puerto Villamil’s
urban area. This specie is currently confined to only three small
mangrove patches on the island (Fessl et al., 2010) and the
population size is estimated in only about 100 individuals
(BirdLife International, 2015). Littoral vegetation monitoring is
therefore of utmost importance in Galapagos, in order to trigger
early warning alerts when vegetation degradation is detected.
*
Corresponding author
Im
agery from remote sensing satellite platforms has been used in
Galapagos for several decades for environmental research and
management (Trueman et al., 2013; Trueman et al., 2014).
However, a number of disadvantages limit the applications of
such platforms in regions such as Galapagos (Matese et al.,
2015). On the one hand, the high frequency of cloud coverage
above the islands along the year makes difficult to obtain clear
imagery at regular time intervals. On the other hand, the
relatively low spatial resolution of free and low-cost products
limits the possibilities for timely detection of changes at small
scales. These limitations hinder the potential of satellite imagery
based monitoring systems in Galapagos. In this context, UAVs
(unmanned aerial vehicles) are a promising technology for
environmental monitoring in the Galapagos Islands. They offers
a low-cost and rapid deployment alternative for geoinformation
generation (Anderson and Gaston, 2013). UAVs are
revolutionizing the way in which georeferenced imagery is
captured (Colomina and Molina, 2014). Images have very high
spatial resolutions (sub-decimeter) which generate a huge
amount of information (several billion pixels) (Hardin and
Jensen, 2011). Conversely , spectral resolution is usually low due
the limited characteristics of the sensors that are generally used
(Teodoro and Araujo, 2016).
UAV
technology is currently in growth and expansion, providing
a wide range of available options in the market. Colomina and
Molina (2014) provided an UAV classification according to their
main characteristics. In relation to its weight, they range from
micro UAV (less than 5kg), mini (less than 30kg), to tactical (less
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XLI-B1, 2016
XXIII ISPRS Congress, 12–19 July 2016, Prague, Czech Republic
This contribution has been peer-reviewed.
doi:10.5194/isprsarchives-XLI-B1-1105-2016