A small-scale water harvesting structure known as a sand dam has gained popularity across East Africa due to the efforts of non-governmental organizations. A sand dam is a subsurface water reservoir that stores water between sand grains. Stored thus, the water is filtered and protected from evaporation. This study uses remotely sensed data to investigate the impact of these structures on water storage and vegetative growth. The relationship between sand dams and water storage was modeled using a binary sand dam factor, climate data from the Famine Early Warning Systems Network Land Data Assimilation System (FLDAS), and water storage data measured by the Gravity Recovery and Climate Experiment (GRACE) twin satellites. The analysis revealed that GRACE largely fails to detect a statistically significant impact of sand dams on regional water storage. However, analysis of the Normalized Difference Vegetation Index (NDVI) indicated that sand dams have a significant impact on regional vegetation. Vegetative growth is correlated with groundwater levels, indicating that sand dams have a positive impact on water storage albeit on a smaller scale than GRACE can regularly detect. Significantly, this study shows that NDVI data can be used effectively to study small-scale, regional changes in vegetation and water storage.

由于非政府组织的努力，一种称为沙坝的小规模集水结构在整个东非广受欢迎。砂坝是一种在砂粒之间储存水的地下蓄水池。如此存储的水被过滤并被保护免受蒸发。这项研究使用遥感数据来研究这些结构对水存储和营养生长的影响。使用二元沙坝因子，饥荒预警系统网络土地数据同化系统（FLDAS）的气候数据以及重力恢复和气候实验（GRACE）测得的储水数据对沙坝和储水之间的关系进行建模卫星。分析显示，GRACE在很大程度上未能检测到沙坝对区域蓄水量的统计显着影响。但是，对归一化植被指数（NDVI）的分析表明，沙坝对区域植被具有重大影响。营养生长与地下水位相关，表明沙坝对储水有积极影响，尽管规模小于GRACE可以正常检测到的范围。重要的是，这项研究表明，NDVI数据可以有效地用于研究植被和储水量的小范围，区域性变化。