Agricultural irrigation of the South Jingyang tableland in Shaanxi Province, China has led to a continuous rise of the groundwater level and has triggered a series of loess landslides, thereby seriously affecting the life and property safety of local residents. Research shows that the major cause of the landslide in the loess layer of the South Jingyang tableland is the rising groundwater level. Therefore, the research on the formation mechanism of landslide in this area should include the investigation of the stratigraphic structure and groundwater level distribution characteristics. On this basis, a series of approaches, such as electrical resistivity tomography (ERT), borehole, and laboratory tests, was carried out on the South Jingyang tableland, and the groundwater level distribution and stratigraphic structure in the study area were determined. The qualitative relationship between resistivity value and water content at different depths was detected using the inversion results of ERT and borehole data. Through laboratory tests, the quantitative relationship between resistivity values under different water contents was established. The precise depth of the groundwater level was inferred by connecting the qualitative relationship with the quantitative relationship, and then a detailed 3D geological model was established by linking the inversion results of ERT with the field borehole lithology data and geological survey data. The detection results show that when the qualitative and quantitative analyses of the ERT inversion results were combined, the distribution of the groundwater level was accurately judged. The ERT is effective in reflecting the stratigraphic structure and hydrological characteristics of the Loess Plateau, and its potential as a supplementary technology for detecting the groundwater level is reasonable. This study addresses the limitation and inaccuracy in determining the stratum structure and groundwater level by solely relying on borehole information or ERT. The established 3D geological model not only provides a basis for the study of groundwater table fluctuation, but also a technical guidance for the stability evaluation of loess slope, landslide prediction, and early warning in the study area.
为合理评价区域水资源分布与经济社会发展的空间均衡问题,在已有方法的基础上,提出了子区域基尼匹配系数与减法集对势相结合的水资源空间均衡评价模型.以水资源总量为基础,与人口数量、第二产业GDP 和耕地面积 3 项指标构建一一对应的匹配关系,利用洛伦兹曲线围成的单个子区域面积比来计算子区域基尼匹配系数,进而计算五元减法集对势,最终得到相应的评价等级,并对安徽省 2011-2018 年 16 个地级市的水资源空间均衡状态进行了评价.结果表明:在 3 组匹配关系中,空间均衡状态最好的为水资源总量-耕地面积,次之为水资源总量-人口数量,最差的一组为水资源总量-第二产业 GDP;3 对匹配关系空间均衡等级的多年均值表现为Ⅴ(反势)级,其中 2012 年和 2015 年的空间均衡状态最差,2018 年的空间均衡状态最佳.
桓仁水库以上的浑江流域内修建的大量水利工程,改变了流域的下垫面条件和产汇流特性.为科学指导水库防洪调度,开展了基于新安江模型的考虑上游水利工程影响的桓仁水库洪水预报方法研究.首先,基于聚合水库的思想,将研究区划分为不同的子流域,并计算各子流域对应的聚合水库库容;然后,根据该库容建立了描述聚合水库蓄泄关系的曲线,给出了聚合水库蓄泄量的计算步骤;最后,利用历史场次洪水资料率定了新安江模型的参数和聚合水库的蓄泄参数.结果表明:率定得到的聚合水库蓄泄关系曲线基本能反映水利工程对洪水过程的影响规律;对于场次洪水,不论是产流还是汇流过程,其模拟精度均得到了较大提高,产流量的预报合格率由 85%提高到 100%,洪峰流量和峰现时间的预报合格率由 80%提高到95%.该研究成果可用于水库实时调度中,研究方法对类似水库洪水预报方案的制定具有借鉴意义.
数据短缺是制约陕北黄土高原区科学防御洪水灾害的关键性因素,探索数据短缺区域的洪水特征值分位数估算方法具有科学意义.以榆林市 28 个水文站点的实测最大一日流量(MDF)的分位数为响应变量,以集水面积、淤地坝控制面积、水文站点的经纬度等 12 个指标为解释变量,研究了线性 CCA 与非线性NLCCA两种同质区域识别方法与线性MLR和非线性GAM 两种区域水文分位数估计方法交叉耦合所形成的 4 种区域洪水频率分析模型的估算效能,并评价了其在陕北黄土高原的适用性.结果显示,NLCCA-GAM 凭借其非线性优势,相比其他耦合模型(CCA-MLR、NLCCA-MLR、CCA-GAM)具有更高的精度和鲁棒性,可作为陕北黄土高原无资料地区洪水特征值分位数的最优估计方法.
砒砂岩是一种风化严重、松散破碎的特殊互层岩体,集中分布在晋、陕、蒙交界地区,分布面积 1.17 万～3.20 万 km2,是黄河粗泥沙的主要来源.从砒砂岩区的生态建设、环境治理及砒砂岩利用的需求出发,对现有砒砂岩文献进行分析,论述了砒砂岩研究的主要进展,包括砒砂岩的成因及分布、物化组成、力学强度、侵蚀过程与机理、砒砂岩区治理进展、砒砂岩资源化利用等.基于砒砂岩的物化性质研究,结合"砒砂岩绿色资源化利用"的思路,展望了砒砂岩作为复配成土材料、改性建筑材料、矿区修复材料等应用前景,还提出了砒砂岩作为旅游资源的潜力.本研究成果可为砒砂岩的治理利用、保障黄河长治久安、推动黄河流域高质量发展提供重要参考.
