How modern Geospatial technology can be an asset in climate change studies?

How modern Geospatial technology can be an asset in climate change studies?

 

Introduction:

Climate change is the most important and defining issue in the present scenario. Climate change refers to the changing climatic pattern and rise in the average surface temperature of the earth. Climate change is evident from the changing weather pattern, melting of polar ice caps and rise in sea level. Climate change is a geographic phenomenon. With the advancement in satellite remote sensing as well as GIS tools, geospatial technologies can prove to be a powerful tool in studying the changing climatic pattern. In recent years, geospatial technology has been used widely by scientists and researchers for climate-related problems. It is powerful in strategic decision making and monitoring climate change detections. It is widely used in agriculture sector, disaster management, forest fire risks etc. GIS is widely used in spatio-temporal mapping of certain weather parameters like rainfall, temperature, wind direction etc. Geospatial data is also used to monitor carbon and nitrogen content present in the atmosphere. Climate mapping and predictions for future climate can easily be done with the help of geospatial technology. GIS climate change modeling is also useful to predict impact on locations. Geospatial tools are helpful in revealing changing weather patterns, sea level rise and growing risk to human health in informative visualizations which can help scientists, researchers, local government, non profits and other organizations for making strategized decisions.

 

 

 

Role of Satellite remote Sensing in Climate studies

The large collection of past and present RS imagery makes it possible to analyse spatiotemporal pattern of environmental elements and impact of human activities in past decades. For climate change analysis, RS is a required tool for up-to-date environmental data acquisition both at local and synoptic levels. With the help of sensors on board of geodetic satellites, satellite remote sensing acquires information about the Earth’s surface, subsurface and atmosphere remotely. The observation of states and processes of the atmosphere, land and ocean at several spatio-temporal scales can be achieved with the help of satellites. Satellite remote sensing is one of the most efficient approaches for monitoring land cover and its changes through time over a variety of spatial scales. Satellite data are frequently used with climate models to simulate the dynamics of the climate system and to improve climate projections.

Climate monitoring and analysis is an important task in order to improve the understanding of climate dynamics and climate change. Therefore, Satellite Remote Sensing is becoming more and more important for this issue for different reasons. Few of the reasons are:

• Many regions in the world are characterized by the lack of a dense network of ground based measurements.
• Some parameters can only be observed from space, or can be observed with a better accuracy from space. (example, top of atmosphere radiation budget)
• Remote Sensing provides climate variables with a large regional coverage up to global coverage.
• Assimilation of satellite data has largely increased the quality of reanalysis data.
• Satellite derived products have the potential to increase the accuracy of gridded climate data sets gained from dense ground based networks.

Remote sensing of the climate system.

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Application of Geospatial technology in Climate change studies

The modern geospatial tools provide certain applications for climate change detection.

1. Ice/Glacier Monitoring

The retreat of snow and ice-cover is an important indicator of global warming. Melting of seasonal snow- and ice cover can cause a positive feedback by lowering the albedo of the Earth’s surface, and the latter contributes to sea-level rise. Satellite data has played a crucial role in monitoring the dynamics of snow extent and ice covers. Snow-cover extent can be monitored using visible-band sensors and passive microwave-band sensors carried by satellites. The extent of sea ice is primarily monitored by passive microwave sensors such as the special sensor microwave/imagers (SSM/I). Satellite images of the ice sheets can track their growth and recession over the years.

Geospatial tools are potentially useful for monitoring glaciers particularly in the advancement  and  recession  mapping,  measurement  of  mass  balance,  glacier  inventory,  glacier  hazard monitoring, snow depth measurement, among others. As glaciers partially regulate atmospheric properties, sea level variations, surface and regional hydrology and topographic evolution information about them is very crucial for adaptation, and this can best be ensured by using RS and GIS.

Greenland Glaciers in a Landsat 8 image from Aug 12, 2019 (right image), and a composite image from Landsat 1 scenes collected in September 1972 (left image)

(Image source: NASA/Christopher Shuman)

2. Ocean and Coastal Monitoring

Sea surface temperature (SST), El Nino, sea level, biomass, precipitation, surface wind and sea surface height relative to the ocean geoids are important features that determine global weather conditions. These can be captured very easily by satellite in space.

Many of the dynamics of the open ocean and changes in the coastal region can be mapped and monitored using remote sensing techniques. Applications of remote sensing in ocean monitoring can be:

• Identification of Ocean pattern
  • currents, regional circulation patterns, shears
  • frontal zones, internal waves, gravity waves, eddies, upwelling zones, shallow water bathymetry ,
• Storm forecasting
  • wind and wave retrieval
• Fish stock and marine mammal assessment
  • water temperature monitoring
  • water quality
  • ocean productivity, phytoplankton concentration and drift
  • aquaculture inventory and monitoring
• Oil spill
  • mapping and predicting oilspill extent and drift
  • strategic support for oil spill emergency response decisions
  • identification of natural oil seepage areas for exploration
• Shipping
  • navigation routing
  • traffic density studies
  • operational fisheries surveillance
  • near-shore bathymetry mapping
• Intertidal zone
  • tidal and storm effects
  • delineation of the land /water interface
  • mapping shoreline features / beach dynamics
  • coastal vegetation mapping

Coastal monitoring using satellites

3. Atmosphere Monitoring

 

The atmosphere and atmospheric processes play a crucial role in life on Planet Earth. Important atmospheric parameters are radiation, temperature, pressure, wind, perceptible water and water vapor, and atmospheric components including clouds, aerosols, greenhouse gases and trace gases such as ozone, nitrogen dioxide, sulphur dioxide, ammonia, volatile organic compounds and a wide range of other trace gases. All of these interact with each other, as well as with the surface and biosphere, and play different roles in atmospheric chemistry, climate and climate change, air quality and many other aspects. Their values and concentrations often vary on time scales from seconds to days, spatial scales from local to global, and with the seasons. Knowledge on their magnitude or concentration is important, e.g., to understand the water, carbon and nitrogen cycles, socioeconomic impacts such as on renewable energy, degradation of materials and cultural heritage, health issues, food production, land, road, ship traffic and air quality management, development of adaptation strategies for climate change, etc. Atmospheric composition data are available from ground-based in situ and airborne measurements, including remote sensing, sometimes with a high degree of sophistication and temporal resolution, but with limited representativeness in a spatial sense. Satellite remote sensing can provide the spatial variation of atmospheric variables, using the same sensor and technique to retrieve the desired information, over the whole planet, but with less detail. Meteorological satellites are designed to measure emitted and reflected radiation from which atmospheric temperature, winds,  moisture, and  cloud  cover  can be  derived. Level of air pollutants in the atmosphere can be measured with the help of satellite remote sensing.

 

 

4. Drought Monitoring

Dr?ught  is  ?  ??m?lex  ?nd  re?urring  n?tur?l  dis?ster  th?t  ???urs  thr?ugh?ut  the  w?rld  ?nd  ?ften  h?s  neg?tive  im???ts  ?n  m?ny  se?t?rs  ?f  s??iety.  Dr?ught  m?nit?ring  is  ?h?llenging  given  the  ??m?lex  s??ti?-tem??r?l  dimensi?ns  ?f  dr?ught  ?nd  its  severity.

In  the  ??st  few  de??des,  s?tellite-b?sed  rem?te  sensing  h?s  ?r?vided  rel?tively  high  s??ti?l  res?luti?n  (i.e.,  l???l  t?  syn??ti?  s??le)  ?nd  high  tem??r?l  res?luti?n  (i.e.,  h?urs  t?  d?ys)  ?bserv?ti?ns  ?f  the  E?rth.  Rem?tely  sensed  im?gery  ?r?vides  s??ti?l  ??ntinu?us  s?e?tr?l  me?sures  ??r?ss  l?rge  ?re?s  th?t  refle?t  b?th  ?tm?s?heri?  ?nd  l?nd  surf??e  ?h?r??teristi?s.  ?s  ?  result,  rem?te  sensing  d?t?  h?s  been  in?re?singly  used  f?r  l?rge-?re?  dr?ught  m?nit?ring.  F?r  ex?m?le,  sever?l  s?tellite-derived  veget?ti?n  indi?es  h?ve  been  devel??ed  t?  m?nit?r  dr?ught  fr?m  l???l  t?  gl?b?l  s??les.  Rese?r?hers  ?re  m?king  ?r?gress  in  devel??ing  better  dr?ught  m?nit?ring  t??ls  t?  ?ssess  dr?ught-rel?ted  veget?ti?n  stress  ?nd  ev?lu?ting  with  gr?und  ?bserv?ti?ns.  In  re?ent  ye?rs,  hybrid  dr?ught  indi?es  th?t  integr?te  ?lim?te,  s?tellite,  ?nd  envir?nment?l  d?t?  h?ve  been  devel??ed.  In  ?dditi?n,  rem?te  sensing  d?t?  ??lle?ted  by  sever?l  re?ent  s?tellite-b?sed  instruments  h?ve  ?ls?  been  used  t?  estim?te  sever?l  key  v?ri?bles  rel?ted  t?  dr?ught  th?t  in?lude  l?nd  surf??e  tem?er?ture,  ev???tr?ns?ir?ti?n,  s?il  m?isture,  ?nd  ?re?i?it?ti?n.  S?tellite-b?sed  mi?r?w?ve  ?nd  r?d?r  instruments  ?re  ?ls?  in?re?singly  being  used  f?r  s?il  m?isture  ?nd  ?re?i?it?ti?n  estim?ti?n. ?urrently,  ?n  in?re?sing  number  ?f  new  ?nd/?r  m?re  s??histi??ted  rem?te  sensing  te?hniques  h?ve  been  used  f?r  estim?ting  veget?ti?n  dr?ught  stress,  ev???tr?ns?ir?ti?n,  s?il  m?isture,  gr?und  w?ter  fluxes,  ?nd  ?re?i?it?ti?n.  ?s  ?  result,  the  dem?nd  f?r  the  devel??ment  ?f  ??er?ti?n?l  dr?ught  m?nit?ring  ?nd  e?rly  w?rning  system  (EWS)  using  these  new  te?hn?l?gies  is  gr?wing  in  m?ny  ??rts  ?f  the  w?rld.  Im?r?ved  ??er?ti?n?l  EWS  m?y  need  m?re  s??histi??ted  ?n?lysis  ?nd  m?deling  te?hniques,  ?s  well  ?s  im?r?ved  s?ientifi?  kn?wledge  fr?m  the  b?si?  rese?r?h.

Drought Monitoring System

 

5. Flood Monitoring

????rding  t?  the  Intern?ti?n?l  Dis?ster  D?t?b?se  (EM-D?T),  fl??ds  re?resent  the  m?st  frequent  ?nd  m?st  im???ting,  in  terms  ?f  the  number  ?f  ?e??le  ?ffe?ted,  ?m?ng  the  we?ther-rel?ted  dis?sters:  ne?rly  0.8  billi?n  ?e??le  were  ?ffe?ted  by  inund?ti?ns  in  the  l?st  de??de  (2006–2015),  while  the  ?ver?ll  e??n?mi?  d?m?ge  is  estim?ted  t?  be  m?re  th?n  $300  billi?n.  Des?ite  this  eviden?e,  ?nd  the  ?w?reness  ?f  the  envir?nment?l  r?le  ?f  rivers  ?nd  their  inund?ti?n,  ?ur  kn?wledge  ?nd  m?delling  ?????ity  ?f  fl??d  dyn?mi?s  rem?in  ???r,  m?inly  rel?ted  t?  the  ?v?il?bility  ?f  me?surements  ?nd  ?n?ill?ry  d?t?.
In  this  ??ntext,  rem?te  sensing  re?resents  ?  v?lue  s?ur?e  ?f  d?t?  ?nd  ?bserv?ti?ns  th?t  m?y  ?llevi?te  the  de?line  in  field  surveys  ?nd  g?uging  st?ti?ns,  es?e?i?lly  in  rem?te  ?re?s  ?nd  devel??ing  ??untries.  The  im?lement?ti?n  ?f  rem?tely-sensed  v?ri?bles  (su?h  ?s  digit?l  elev?ti?n  m?del,  river  width,  fl??d  extent,  w?ter  level,  l?nd  ??ver,  et?.)  in  hydr?uli?  m?delling  ?r?mises  t?  ??nsider?bly  im?r?ve  ?ur  ?r??ess  underst?nding  ?nd  ?redi?ti?n.  fl??ds  ??n  be  m???ed  ?nd  m?nit?red  with  rem?tely  sensed  d?t?  ??quired  by  ?ir?r?ft  ?nd  s?tellites.  The  sens?rs  ?nd  d?t?  ?r??essing  te?hniques  th?t  exist  t?  derive  inf?rm?ti?n  ?b?ut  fl??ds  ?re  numer?us.  Instruments  th?t  re??rd  fl??d  events  m?y  ??er?te  in  the  visible,  therm?l  ?nd  mi?r?w?ve  r?nge  ?f  the  ele?tr?m?gneti?  s?e?trum.  Due  t?  the  limit?ti?ns  ??sed  by  ?dverse  we?ther  ??nditi?ns  during  fl??d  events,  ??tive  r?d?r  (S?R  ?nd  ?ltimetry)  is  inv?lu?ble  f?r  m?nit?ring  fl??ds;  h?wever,  if  ?  visible  im?ge  ?f  fl??ding  ??n  be  ??quired,  retrieving  useful  inf?rm?ti?n  fr?m  this  is  ?ften  m?re  str?ightf?rw?rd.  ???rt  fr?m  ?r?viding  dire?t  inf?rm?ti?n  ?b?ut  fl??ding,  rem?te  sensing  d?t?  ??n  ?ls?  be  integr?ted  with  fl??d  m?dels  ?r  ?r?vide  fl??d?l?in  t???gr??hy  d?t?  t?  ?ugment  the  ?m?unt  ?nd  ty?e  ?f  inf?rm?ti?n  ?v?il?ble  f?r  effi?ient  fl??d  m?n?gement.

 

Flood Monitoring using Satellite Data

 

Conclusion:

Climate change is a global issue. Modern geospatial techniques using remote sensing and GIS can be an important assessment tool for climate change monitoring. Large amount of data available from satellites is an efficient method for such studies. Potential of geospatial technology is evident from the fact that monitoring of ocean, weather, atmosphere, ice, sea level can easily be done with the help of satellite data and mapping can be done with help of GIS tools.