Abdullateef Lawal, Tijani Moshood N, Nuru Nabage A, John Shirputda, Mustapha Aliyu
Department of Applied Geology, Abubakar Tafawa Balewa University Bauchi, Nigeria.
University of Ibadan-Ibadan, Nigeria.
Heliyon. 2021 Apr 30;7(4):e06762. doi: 10.1016/j.heliyon.2021.e06762. eCollection 2021 Apr.
The increasing demand for water occasioned by harsh climatic conditions, population explosion, and increasing urbanization has necessitated more attention and reliance on groundwater resources, particularly in water-limited regions. Thus, judicious management of available groundwater resources becomes crucial to meet the freshwater requirements in such zones. In this study, remote sensing and geographic information system were deployed to delineate groundwater recharge zones in semi-arid geological transition zones of Bauchi, northeastern Nigeria. Seven thematic layers comprising elevation, slope, land use/land cover, drainage density, lithology, magnetic lineament density, and hydraulic head were integrated based on their degree of influence in groundwater recharge. Normalization of the weights was achieved through the analytical hierarchical process (AHP), while the overall integration of the thematic maps was actualized by overlay analysis in ArcGIS 10.3.1 environment to generate a final groundwater recharge zone map of the area. The resulting map was delineated into three different zones: low, moderate, and high, occupying 20% (627 km), 77% (2352 km), and 3% (80 km) respectively. The overall assessment of recharge zones revealed that a high percentage of the southwestern part of the study are characterized dominantly by poor groundwater recharge potential, attributable to high elevations and impervious rock outcrops with associated steep slopes, thus limited infiltration owing to the high velocity of runoff. The northwestern and parts of the southwestern zones, underlain by migmatite/gneiss, and partly granites, however, exhibited medium-low recharge potential, owing to the occurrence of considerably lower altitudes and occupied by thicker regoliths and underlying rocks of medium-high lineament densities. The sandstones revealed predominantly medium-high recharge potential, attributable to high permeability, lower hydraulic heads, and relatively flat geomorphology which enhances meteoric recharge and base flow processes.
恶劣气候条件、人口爆炸和城市化进程加快导致对水的需求不断增加，这使得人们有必要更加关注和依赖地下水资源，尤其是在水资源有限的地区。因此，合理管理现有的地下水资源对于满足这些地区的淡水需求至关重要。在本研究中，利用遥感和地理信息系统来划定尼日利亚东北部包奇半干旱地质过渡带的地下水补给区。基于七个专题图层（包括海拔、坡度、土地利用/土地覆盖、排水密度、岩性、磁力线密度和水头）对地下水补给的影响程度进行整合。通过层次分析法（AHP）对权重进行归一化处理，同时在ArcGIS 10.3.1环境中通过叠加分析实现专题地图的整体整合，以生成该地区最终的地下水补给区地图。生成的地图被划分为三个不同的区域：低补给区、中等补给区和高补给区，分别占20%（627平方公里）、77%（2352平方公里）和3%（80平方公里）。对补给区的总体评估表明，研究区西南部的很大一部分地区主要以地下水补给潜力差为特征，这归因于高海拔、不透水岩石露头以及相关的陡坡，因此由于径流速度快，入渗有限。然而，西北部和西南部部分地区，其下伏岩石为混合岩/片麻岩，部分为花岗岩，由于海拔较低、覆盖有较厚的风化层以及中等高线密度的下伏岩石，表现出中低补给潜力。砂岩主要显示出中高补给潜力，这归因于其高渗透性、较低的水头以及相对平坦的地貌，有利于大气降水补给和基流过程。
