Groundwater use for irrigation

Owned by Maiwenn Herpe
Last updated: May 31, 2021 by Frederika Mourot
2 min read

Satellite(s) and derived dataset(s)

Landsat-8,
Water Productivity through Open access of Remotely sensed Actual Evapotranspiration and Interception (WaPOR) dataset.

Monitoring element

Land spectral reflectance.

Also fits domain

Land

Description technique

Nhamo et al. (2020) propose a qualitative assessment of groundwater use for irrigated agriculture. It is based on crop evapotranspiration (derived from the WaPOR dataset) , and irrigated areas (characterised using dry season NDVI data derived from Landsat-8). Field surveys were conducted for verification, accuracy improvement and post-classification correction on both agricultural and irrigated areas, respectively.

Accuracy / Resolution

Spatial resolutions:

  • Landsat-8 (visible, NIR, SWIR): 30 m.

  • WaPOR: 250 m.

Case study

Venda-Gazankulu area of Limpopo Province in South Africa.

Benefits

  • The method uses freely available datasets.

  • It can be used as a guide to support groundwater management in terms of planning and groundwater consenting.

Limitations

  • The WaPOR dataset is reliable but remains too coarse (at 250 m spatial resolution) for smallholder croplands of about 2 ha.

Applicability for Northland

Yes, possibly.

The resolution of the evapotranspiration estimates would have to be higher. Assessments could be compared to groundwater used for irrigation data.

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 references

Nhamo L, Ebrahim GY, Mabhaudhi T, Mpandeli S, Magombeyi M, Chitakira M, Magidi J, Sibanda M. 2020. An assessment of groundwater use in irrigated agriculture using multi-spectral remote sensing. Physics and Chemistry of the Earth, Parts A/B/C. 115:102810. doi:10.1016/j.pce.2019.102810.

https://www.sciencedirect.com/science/article/pii/S147470651930049X

Other references

FAO, IHE-Delft, 2019. WaPOR Quality Assessment. Technical Report on the Data Quality of the WaPOR FAO Database Version 1.0. Food and Agriculture Organisation of the United Nations (FAO), and IHE Delft Institute for Water Education (IHE DELFT), Rome, Italy, p. 134.

http://www.fao.org/3/ca4895en/CA4895EN.pdf