ABSTRACT

Uncontrolled extraction of water from groundwater aquifers causes groundwater depletion, which in turn triggers the formation of sinkholes in many parts of the world. Monitoring and detection of these geomorphologic features are of utmost importance and priority for the decision-makers to minimize significant environmental as well as socio-economic implications of land deformation. In this study, a systematic approach is proposed to investigate the spatio-temporal associations of groundwater storage changes with sinkhole evolution and land deformation by using a number of remotely sensed and modeled data as well as in-situ observations. The proposed approach is implemented and tested in Konya Closed Basin (KCB), Turkey, which is one of the most critical areas in central Turkey concerning sinkhole formation. The results of GRACE (Gravity Recovery and Climate Experiment) estimates suggest that there is a descending trend in the temporal variations of TWSA (Terrestrial Water Storage Anomalies) and GWSA (Groundwater Storage Anomalies) over KCB with an average storage depletion of 4.12 ± 0.34 cm/yr and 3.40 ± 0.61 cm/yr, respectively. The analysis of land deformation from ICESat/ICESat-2 (Ice, Cloud, and Land Elevation Satellite) altimetry data also indicates a descending trend with an estimated average vertical displacement of 5 cm/yr for the study area, which seems to be in rational accord with the sinkhole evolution over KCB. The results further suggest that the sinkhole evolution over KCB has an acceptable association with the variations of groundwater storage, groundwater use, and precipitation. Compared with previous works implemented over KCB, the findings of this study manifest a good performance for the proposed methodology. The integrated analysis of GRACE gravity measures, ICESat/ICESat-2 altimetry data, modeled groundwater abstraction, and in-situ observations of precipitation yields acceptable results for the detection and monitoring of sinkhole events provided that appropriate distribution of the elevation points from ICESat/ICESat-2 is accessible for the given study area.

摘要

不受控制地从地下水含水层中抽取水会导致地下水枯竭，这反过来又会在世界许多地方引发落水洞的形成。监测和检测这些地貌特征对于决策者来说是最重要和优先考虑的，以尽量减少土地变形对环境和社会经济的重大影响。在这项研究中，提出了一种系统方法，通过使用大量遥感和建模数据以及现场观测，研究地下水储存变化与天坑演化和土地变形的时空关联。提议的方法在土耳其科尼亚封闭盆地 (KCB) 实施和测试，该盆地是土耳其中部有关天坑形成的最关键地区之一。GRACE（重力恢复和气候实验）的估计结果表明，KCB 的 TWSA（陆地储水异常）和 GWSA（地下水存储异常）的时间变化呈下降趋势，平均储水枯竭为 4.12 ± 0.34 cm /年和 3.40 ± 0.61 厘米/年，分别。来自ICESat/ICESat-2（冰、云和陆地高程卫星）测高数据的土地变形分析也表明研究区域的平均垂直位移估计为5厘米/年呈下降趋势，这似乎是合理的符合 KCB 的天坑演化。结果进一步表明，KCB 上的落水洞演化与地下水储存、地下水利用和降水的变化具有可接受的关联。与之前在 KCB 上实现的工作相比，这项研究的结果表明所提出的方法具有良好的性能。对 GRACE 重力测量、ICESat/ICESat-2 测高数据、模拟地下水抽取和降水原位观测的综合分析为检测和监测落水洞事件产生了可接受的结果，前提是 ICESat/ICESat 的高程点分布适当-2 对于给定的研究区域是可访问的。