Remote Sensing and Their Advantage in National Coastal and Watershed Study

I.     REMOTE SENSING DEFINITIONS

·      The science and art of acquiring information by a recording device that is not in physical contact with the object under investigation (Yang, 2009).

·      A method to identify and determine object in Earth’s surface without direct contact with that object (Noor, 2011)

·      The science and art to acquiring information about object, area, or phenomenon through data analyze which come from tools or method without direct contact with that object, area, or phenomenon (Purwadhi & Sanjoto, 2009).

·      The technology of acquiring information about the Earth’s surface (land and ocean) and atmosphere using sensors onboard airborne (aircraft and balloons) or spaceborne (satellites and space shuttle) platforms (Wang, 2010).

·      The development and operational use of data and data products from a plethora of passive and active airborne and satellite-borne sensors, in particular hyperspectral and hyperspatial imaging, as well as active sensors – LIDAR and RADAR instruments (Franklin, 2009).

·      The science and art of identifying, observing, and measuring an object without coming into direct contact with it. This process involves the detection and measurement of radiation of different wavelengths reflected or emitted from distant objects or materials, by which they may be identified and categorized by class or type, substance, and spatial distribution (Wiscombe, 2010).

etc.

II.  APPROPRIATE REMOTE SENSING DEFINITIONS FOR COASTAL AND WATERSHED MANAGEMENT RESEARCH

In above pages, there are much of remote sensing definitions and have similar meanings. Appropriate terms of remote sensing to research is science and art of identifying, observing, and measuring  an object without coming into direct contact. For coastal and watershed management purpose, remote sensing is a method, tools to identify, observing, and measuring object in large area and high dynamic and fluctuating condition especially in coastal management.

III.   REMOTE SENSING ADVANTAGE FOR NATIONAL COASTAL AND WATERSHED STUDY

Remote sensing have capability of acquiring photos or images that cover large area, providing synoptic view that allow to identify objects, patterns, and human-land interaction. The coastal and watershed processes are operating over a rather large area, if we failed to observing the entire of coastal and watershed phenomenon may cause miss understood in analyze. For example, if we want to make research about coastal or watershed area land-cover change analysis, we must see entirely or holistic to know what the significance effect now and predict the risk happen in future. A phenomenon in coastal or watershed process must be correlate with each other systematically.

Coastal and watershed researcher frequently use data collected from field surveys and measurements. This considered to be accurate but may cause potential errors due to bias in sampling design. Field surveys and measurements can become expensive over a large area like coastal or watershed. Remote sensing can collect data in an unbiased and effectively research. Combination of field survey and measurement and remote sensing can make accurate results. For example in coastal natural resource mapping research like mangrove mapping. Accurate results about mangrove identification can be achieved with field survey and measurements but not effective and efficient in large area. Remote sensing can coverage large area to mangrove mapping, Recently, many remote sensing application has been held in mangrove research. Gao (1998) developed a two-tiered classification scheme based on SPOT image and applied it to the mangrove mapping in the Waitemata Harbour of Auckland, New Zaeland. This method was 81,4% accurate in classifying mangrove versus non-mangrove land cover. Held dkk (2003) employed an integrated analysis of data from the high spectral resolution scanner CASI and the airborne AIRSAR to map mangrove estuaries along the Daintree River in North Queensland, Australia. Higher classification accuracies of different habitats and mangrove forest type were achieved when hyperspectral and radar data were used in combination, etc.

Remote sensing allows retrospective viewing of the Earth surface, and time series (temporal) of remote sensor data can be quite useful to develop historical or time development perspective of coastal and watershed phenomenon or processes. For example to know the change of coastline in time series. These days many remote sensing monitoring research conducted to know what the main cause or predict what will happen in certain areas. Tarigan (2007) observe Cisadane Coastline, Banten, Indonesia in 2005 and overlay with the coastline digitations analysis from Landsat 5 TM 1997 and found several abrasion and accretion areas. He conclude it may be due to the effects of human activities and natural phenomenon such as high current and high wave during monsoon over that area.

Remote sensing can help make connections across level of analysis for coastal and watershed studies. Coastal science disciplines and subdisciplines have their own preferred levels of analysis and normally do not communicate across these levels. For example, geographers and coastal planners tend to work at community and ecosystem level; while oceanographers and coastal ecologists tend to work at oceanographical features or ecological units and coastal biologists tend to work with individual organisms and populations. On the other hand, the temporal scales used by these different coastal researchers vary greatly, from hourly until annual or decadal. Remote sensing provide coverage of data with individual pixels from variety range and with varying temporal resolution; such data can be combined to allow work at any levels of analysis.

Remote sensing integrated with other relevant geospatial technologies, such as geographic information systems, spatial analysis and modeling, offers an indispensible framework of monitoring, synthesis and modelling for the coastal and watershed environment. Integrated watershed management is natural resource management by performing utilization, maintenance, structuring, controlling, restoration, and developing watershed based on sustainability and harmonious environment for human welfare. Integrating remote sensing with other relevant geospatial technologies must be used to in integrated watershed management research. For example Byrd (2009) use remote sensing and spatial analysis of watershed and estuarine processes for conservation planning in Elkhorn Slough, Monterey County, California, US. He found that hyperspectral imagery has the potential to provide a spatially explicit synoptic view of vegetation response to nutrient enrichment. Watershed management applying spatial data also improve estuarine condition. Human activity, natural process have input to watershed system and affect the estuarine as a output. This technique also applicable in integrated coastal zone management. Integrated coastal zone management has a scope upstream of watershed, coastal land (beach, dune, wetland, etc), coastal water and estuary, free water area that influenced and be influenced by all activities in coastal area. The multispectral capabilities of remote sensing allow observation and measurement of biophysical characteristic, whereas the multitemporal and multisensory capabilities allow tracking of changes in high dynamic coastal environment. Digitizing of remote sensing data in GIS environment to build an information system so it can be used for decision maker in integratd coastal management.

REFERENCE :

Byrd, K., B. 2009. Remote Sensing and Spatial Analysis of Watershed and Estuarine Processes for Conservation Planning in Elkhorn Slough, Monterey County, California. Dalam X. Yang (Ed). Remote Sensing and Geospatial Technologies for Coastal Ecosystem Assessment and Management. (hlm 495-520). Berlin: Springer.

Franklin, J. 2009. Mapping Species Distribution – Spatial Inference and Prediction. New York: Cambridge University Press

Gao, J. 1998. A Hybrid Method Toward Accurate Mapping of Mangroves In A Marginal Habitat from SPOT Multispectral Data. International Journal Remote Sensing. 10: 1887-1899

Held, A., dkk. 2003. High Resolution Mapping of Tropical Mangrove Ecosystem using Hyperspectral and Radar Remote Sensing. International Journal Remote Sensing. 24: 2739-2759

Noor, D. 2011. Geologi untuk Perencanaan. Yogyakarta: Graha Ilmu

Purwadhi, F.,S., H., & Sanjoto, T., B. 2009. Pengantar Interpretasi Citra Penginderaan Jauh. Semarang: LAPAN dan Jurusan Geografi UNNES

Tarigan, M., S. 2007. Perubahan Garis Pantai di Wilayah Pesisir Perairan Cisadane, Provinsi Banten. Makara Sains. Vol. 11 No. 11 April 2007: 49-55

Wang, Y. 2010. Remote Sensing of Coastal Environments: An Overview. Dalam Y. Wang (Ed). Remote Sensing of Coastal Environments. (hlm 1-21) London: CRC Press Taylor & Francis Group.

Wiscombe, W. 2011. Remote Sensing: Introduction and History. Diperoleh dari http://earthobservatory.nasa.gov/Features/RemoteSensing/ tanggal 5 November 2012.

Yang, X. 2009. Remote Sensing, Geospatial Technologies and Coastal Ecosystem. Dalam X. Yang (Ed). Remote Sensing and Geospatial Technologies for Coastal Ecosystem Assessment and Management. (hlm 1-16). Berlin: Springer.