Al-Abadi Alaa M, Pradhan Biswajeet, Shahid Shamsuddin
Department of Geology, College of Sciences, University of Basrah, Basrah, Iraq.
Faculty of Engineering, Department of Civil Engineering, Geospatial Information Science Research Centre (GISRC), University Putra Malaysia, DarulEhsan, 43400, Serdang, Selangor, Malaysia.
Environ Monit Assess. 2015 Oct;188(10):549. doi: 10.1007/s10661-016-5564-0. Epub 2016 Sep 6.
The objective of this study is to delineate groundwater flowing well zone potential in An-Najif Province of Iraq in a data-driven evidential belief function model developed in a geographical information system (GIS) environment. An inventory map of 68 groundwater flowing wells was prepared through field survey. Seventy percent or 43 wells were used for training the evidential belief functions model and the reset 30 % or 19 wells were used for validation of the model. Seven groundwater conditioning factors mostly derived from RS were used, namely elevation, slope angle, curvature, topographic wetness index, stream power index, lithological units, and distance to the Euphrates River in this study. The relationship between training flowing well locations and the conditioning factors were investigated using evidential belief functions technique in a GIS environment. The integrated belief values were classified into five categories using natural break classification scheme to predict spatial zoning of groundwater flowing well, namely very low (0.17-0.34), low (0.34-0.46), moderate (0.46-0.58), high (0.58-0.80), and very high (0.80-0.99). The results show that very low and low zones cover 72 % (19,282 km(2)) of the study area mostly clustered in the central part, the moderate zone concentrated in the west part covers 13 % (3481 km(2)), and the high and very high zones extended over the northern part cover 15 % (3977 km(2)) of the study area. The vast spatial extension of very low and low zones indicates that groundwater flowing wells potential in the study area is low. The performance of the evidential belief functions spatial model was validated using the receiver operating characteristic curve. A success rate of 0.95 and a prediction rate of 0.94 were estimated from the area under relative operating characteristics curves, which indicate that the developed model has excellent capability to predict groundwater flowing well zones. The produced map of groundwater flowing well zones could be used to identify new wells and manage groundwater storage in a sustainable manner.
本研究的目的是，在地理信息系统（GIS）环境下开发的数据驱动证据信度函数模型中，描绘伊拉克纳杰夫省的地下水自流井区潜力。通过实地调查绘制了一张包含68口地下水自流井的清单地图。70%（即43口井）用于训练证据信度函数模型，其余30%（即19口井）用于模型验证。本研究使用了七个主要源自遥感（RS）的地下水调节因子，即海拔、坡度角、曲率、地形湿度指数、河流功率指数、岩性单元以及与幼发拉底河的距离。在GIS环境下，使用证据信度函数技术研究了训练自流井位置与调节因子之间的关系。利用自然间断点分类法将综合信度值分为五类，以预测地下水自流井的空间分区，即极低（0.17 - 0.34）、低（0.34 - 0.46）、中等（0.46 - 0.58）、高（0.58 - 0.80）和极高（0.80 - 0.99）。结果表明，极低和低区覆盖了研究区域的72%（19282平方公里），主要集中在中部；中等区集中在西部，覆盖13%（3481平方公里）；高和极高区延伸至北部，覆盖研究区域的15%（3977平方公里）。极低和低区的广阔空间分布表明，研究区域内地下水自流井的潜力较低。利用接收者操作特征曲线对证据信度函数空间模型的性能进行了验证。相对操作特征曲线下的面积估计成功率为0.95，预测率为0.94，这表明所开发的模型具有出色的预测地下水自流井区的能力。生成的地下水自流井区地图可用于识别新井并以可持续方式管理地下水储存。
