State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, Sichuan 610059, China.
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, Sichuan 610059, China.
Sci Total Environ. 2021 Jan 10;751:142340. doi: 10.1016/j.scitotenv.2020.142340. Epub 2020 Sep 10.
Understanding the relation between land use and groundwater recharge is of direct interest in areas that are prone to geohazards. This study was performed to characterize the effects of land use on groundwater table (GWT) distribution in the Heifangtai (HFT) loess terrace under long-term flood irrigation, as irrigation intensity was governed by the crop types. In light of the regional temperature-vegetable dryness index (TVDI) and optical images obtained in different seasons over four years, the dataset incorporated the growth cycles of the local crops, which in turn improved the workload and accuracy of land use detection. Irrigation intensities for different crops were recorded during field investigations. A total of 26 electrical resistivity tomography (ERT) profiles were conducted to estimate the GWT distribution of HFT terrace, which was further utilized to reveal the relation between land use (i.e. irrigation) and GWT fluctuations. The results indicated that high local GWT was associated with vegetable fields which had the highest irrigation intensity, and by contrast, low local GWT was attributed to the perennial fruit tree fields with the lowest irrigation intensity. The discharge was monitored intermittently for over three years to analyze the effect on the local GWT close to margin of HFT. The result showed a strong correlation between spring discharge and GWT fluctuations along the margin of HFT, indicating that groundwater recharge was affected by both irrigation and spring discharges. These results suggested that incorporating growth cycles of crops can effectively facilitate the interpretation of remote sensing data for land use detection, and the results can provide useful guidance for improving irrigation programs and for alleviating geohazards in regions that are under long-term irrigation.
了解土地利用与地下水补给之间的关系，对于那些容易发生地质灾害的地区具有直接的意义。本研究旨在描述在长期洪水灌溉下，土地利用对黑方台黄土台塬地下水埋深分布的影响，灌溉强度由作物类型决定。根据四年间不同季节的区域温度-植被干燥指数（TVDI）和光学图像，该数据集纳入了当地作物的生长周期，从而提高了土地利用检测的工作量和准确性。在实地调查中记录了不同作物的灌溉强度。共进行了 26 条电阻率层析成像（ERT）剖面，以估算黑方台台塬的地下水埋深分布，进一步揭示了土地利用（即灌溉）与地下水埋深波动之间的关系。结果表明，局部高地下水埋深与灌溉强度最高的蔬菜地有关，而局部低地下水埋深则与灌溉强度最低的多年生果园有关。对近黑方台边缘的局部地下水埋深进行了三年多的间歇性监测，以分析对其的影响。结果表明，黑方台边缘的春季流量与地下水埋深波动之间存在很强的相关性，表明地下水补给受到灌溉和春季流量的共同影响。这些结果表明，纳入作物的生长周期可以有效地促进对土地利用遥感数据的解释，研究结果可为改进灌溉方案和缓解长期灌溉地区的地质灾害提供有用的指导。
