Declining water resources in dry regions requires sustainable groundwater management as trends indicate increasing groundwater use, but without accountability. The sustainability of groundwater is uncertain, as little is known about its extent and availability, a challenge that requires a quantitative assessment of its current use. This study assessed groundwater use for irrigated agriculture in the Venda-Gazankulu area of Limpopo Province in South Africa using crop evapotranspiration and irrigated crop area derived from the normalised difference vegetation index (NDVI). Evapotranspiration data was derived from the Water Productivity through Open access of Remotely sensed Actual Evapotranspiration and Interception (WaPOR) dataset (250 m resolution), and irrigated areas were characterised using dry season NDVI data derived from Landsat 8. Field surveys were conducted for four years to assess accuracy and for post-classification correction. Daily ET for the dry season (May to September) was developed from the actual ET for the irrigated areas. The irrigated areas were overlaid on the ET map to calculate ET for only irrigated land parcels. Groundwater use during the 2015 dry period was 3627.49 billion m³ and the irrigated area during the same period was 26% of cultivated land. About 82 435 ha of cultivated area was irrigated using 44 million m³/ha of water, compared to 186.93 million m³/ha on a rainfed area of 237 847 ha. Groundwater management is essential for enhancing resilience in arid regions in the advent of water scarcity.

干旱地区水资源的减少需要可持续的地下水管理，因为趋势表明地下水的使用量正在增加，但没有责任感。地下水的可持续性尚不确定，因为对其范围和可用性知之甚少，这一挑战需要对其当前用途进行定量评估。这项研究使用农作物蒸散量和归一化差异植被指数（NDVI）得出的灌溉作物面积，评估了南非林波波省Venda-Gazankulu地区的灌溉农业地下水利用量。蒸发蒸腾量数据是通过对遥感实际蒸发蒸腾量和截距（WaPOR）数据集（250 m分辨率）的开放访问而从水生产率中获得的，并使用了从Landsat 8得出的旱季NDVI数据来表征灌溉区域。进行了四年的现场调查，以评估准确性和进行分类后的更正。干旱季节（5月至9月）的每日ET是根据实际ET用于灌溉区。将灌溉区域覆盖在ET地图上，仅计算灌溉土地块的ET。2015年枯水期的地下水使用量为36274.9亿m ³，同一时期的灌溉面积为耕地的26％。使用44,000,000 m ³ / ha的水灌溉了约82 435公顷的耕地，相比之下，在237 847 ha的雨养区灌溉了1.8693亿m ³ / ha。在缺水的到来中，地下水管理对于增强干旱地区的复原力至关重要。