International Rice Research Institute, ICRISAT, Patancheru, Andhra Pradesh, India.
Environ Monit Assess. 2013 Apr;185(4):3561-79. doi: 10.1007/s10661-012-2810-y. Epub 2012 Aug 16.
Groundwater development across much of sub-Saharan Africa is constrained by a lack of knowledge on the suitability of aquifers for borehole construction. The main objective of this study was to map groundwater potential at the country-scale for Ghana to identify locations for developing new supplies that could be used for a range of purposes. Groundwater potential zones were delineated using remote sensing and geographical information system (GIS) techniques drawing from a database that includes climate, geology, and satellite data. Subjective scores and weights were assigned to each of seven key spatial data layers and integrated to identify groundwater potential according to five categories ranging from very good to very poor derived from the total percentage score. From this analysis, areas of very good groundwater potential are estimated to cover 689,680 ha (2.9 % of the country), good potential 5,158,955 ha (21.6 %), moderate potential 10,898,140 ha (45.6 %), and poor/very poor potential 7,167,713 ha (30 %). The results were independently tested against borehole yield data (2,650 measurements) which conformed to the anticipated trend between groundwater potential and borehole yield. The satisfactory delineation of groundwater potential zones through spatial modeling suggests that groundwater development should first focus on areas of the highest potential. This study demonstrates the importance of remote sensing and GIS techniques in mapping groundwater potential at the country-scale and suggests that similar methods could be applied across other African countries and regions.
撒哈拉以南非洲大部分地区的地下水开发受到含水层是否适合钻孔建设的知识缺乏的限制。本研究的主要目的是绘制加纳全国范围内的地下水潜力图，以确定开发新供应源的位置，这些新供应源可用于各种用途。地下水潜力区是利用遥感和地理信息系统（GIS）技术从包括气候、地质和卫星数据的数据库中划定的。根据七个关键空间数据层中的每一个赋予主观分数和权重，并进行整合，根据总百分比得分从非常好到非常差的五个类别来确定地下水潜力。从这一分析中，估计具有极好地下水潜力的区域占地 689680 公顷（占全国的 2.9%），良好潜力的区域占地 5158955 公顷（21.6%），中等潜力的区域占地 10898140 公顷（45.6%），较差/极差潜力的区域占地 7167713 公顷（30%）。结果与钻孔产量数据（2650 个测量值）进行了独立测试，这与地下水潜力和钻孔产量之间的预期趋势相符。通过空间建模对地下水潜力区的满意划定表明，地下水开发应首先集中在潜力最高的地区。本研究表明了遥感和 GIS 技术在国家尺度上绘制地下水潜力图的重要性，并表明类似的方法可以应用于其他非洲国家和地区。
