Groundwater storage
Satellite(s)MODIS, Sentinel-2, GRACE. | Monitoring elementLand spectral reflectance. |
---|---|
Description techniqueBhanja et al. (2019) investigated the possibility of using Normalized Difference Vegetation Index (NDVI) as an indicator of groundwater storage. They used artificial neural network and support vector machine approaches and sand in-situ observations from groundwater wells. | Accuracy / ResolutionGood correlation (r> 0.6) between NDVI and groundwater levels in natural vegetation covered areas (i.e., forest lands, shrubs, and grasslands). |
Case studyIndia (> 15,000 wells). | |
Benefits
| Also fits domainLand. |
LimitationsCorrelation between observed groundwater levels and NDVI is not good in agricultural regions, suggesting human influences on these parameters. | |
Applicability for NorthlandYes, likely applicable. A method based on Normalized Difference Vegetation Index (NDVI), as an indicator of groundwater storage, could be investigated for natural vegetation covers. Correlations would need to be confirmed in the Northland context and finer spatial resolution imagery (e.g. Sentinel-2) would be more relevant to use. GRACE-derived information would be too coarse for local applications. Techniques applying optical data will be limited in coverage and temporal granularity by the persistent cloud cover in the region, particularly during the winter months. Mature cloud-masking techniques are directly available for open access multispectral data (e.g. Landsat and Sentinel-2). When using commercial data, care must be taken to ensure that there is sufficiently cloud free imagery available, as cloud masking is not as mature, and ordering a large volume of imagery to ensure complete cloud free coverage between multiple observations can become cost prohibitive.
| |
Publication referencesBhanja SN, Malakar P, Mukherjee A, Rodell M, Mitra P, Sarkar S. 2019. Using Satellite-Based Vegetation Cover as Indicator of Groundwater Storage in Natural Vegetation Areas. Geophysical Research Letters. 46(14):8082-8092. doi:10.1029/2019GL083015. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL083015 | |
Other referencesAbiy AZ, Melesse AM. 2017. Evaluation of watershed scale changes in groundwater and soil moisture storage with the application of GRACE satellite imagery data. CATENA. 153:50-60. https://doi.org/10.1016/j.catena.2017.01.036
|