基于岩溶水动态模拟的补给面积计算方法

岩溶水系统补给面积的确定是岩溶水文地质调查与研究中的一个难点。基于水均衡原理与水文脉冲函数, 介绍了求取补给面积的计算方法, 并探讨了模型参数的物理意义。选取了广西桂林丫吉试验场岩溶泉、湖北兴山雾龙洞地下河、沪蓉高速峡口隧道集中涌水点3个典型的南方岩溶水系统, 对其水文过程进行模拟, 利用最优模型参数分别求得补给面积, 与其他方法综合确定的补给面积得到了较好的验证。基于岩溶水文过程模拟的补给面积计算方法是对岩溶水系统补给面积求取方法的一种新的补充, 在中小尺度规模的南方岩溶水系统中具有较好的应用前景。      

基于岩溶演化模型的隧道突水危险性评价

岩溶隧道是否发生涌突水,主要取决于洞身岩溶发育程度和岩溶系统结构类型,而这与岩溶系统的演化过程密切相关。岩溶系统的发育演化始于具有侵蚀性的水对可溶性岩体中裂隙的溶蚀扩展。基于此,本研究耦合了渗流模型和溶蚀扩展模型,并结合鸡公岭隧道区水文地质背景资料,建立了隧道区岩溶系统岩溶演化模拟模型,模拟再现了隧道区岩溶含水介质的发育情况。结果显示:随着岩溶系统的发育演化,整个系统中裂隙不断被溶蚀扩展,差异性溶蚀越来越显著,岩溶含水介质的非均质性越来越强;同时随着埋深的增加,岩溶发育程度及非均质性越来越弱;浅部和深部裂隙的平均溶蚀扩展率相差近1 500倍;鸡公岭隧道洞身标高处岩溶发育微弱,裂隙溶蚀扩展较小,仍为裂隙岩体,其等效渗透系数为0.51m/d,岩溶突水概率极低,隧道发生涌水时的涌水量为127.9m3/d,对隧道施工影响较小。      

山东省济南市区泉水与西郊岩溶水水力联系的研究

为进一步查明济南市区泉水与西郊岩溶地下水的水力联系,从地层结构、水动力场角度,通过抽水试验、示踪试验、制作Piper三线图等方法,进行了系统分析。研究表明,西郊刘长山—郎茂山—万灵山一带地下水流场不存在异常,两侧等水位线连续平缓,水位大致相同;刘长山北侧槐苑广场—九中—十四中一带在埋深350m左右揭露连续的岩溶含水地层,市区和西郊通过隐伏于岩浆岩体的三山子组地层岩溶发育段存在水力联系。市区泉水与西郊岩溶地下水水化学类型一致,二者具有相同的演化环境,水力联系密切。     

基于圆盘概化模型的岩溶裂隙渗流路径构建算法

岩溶裂隙网络的识别与重构,一直是岩溶地下水资源和岩溶区地质环境保护研究的热点与难点。基于地表原始裂隙数据、经过克里格插值后的地表裂隙数据、以及通过蒙特卡洛预测得到的地下裂隙数据,本文针对三维裂隙构造中的水流通路识别模块,提出了一种基于圆盘模型的渗流路径构建方法,采用有向图的数据结构来模拟圆盘模型概化后水流沿裂隙的渗流路径,并以邻接矩阵的形式存储其渗流路径数据。同时,为满足大规模裂隙数据快速求交的需要,本文给出了三维R树索引算法缩减遍历各个采样点所用的时间,提高了整套算法运行的效率。最后,以北京市房山区张坊地区地表采样裂隙数据为基础,借助遥感地质调查、重点岩溶区精细地质测量及取样分析等手段,开展三维裂隙空间网络分布模型研究,对岩溶裂隙渗流路径构建算法进行计算机仿真实现,为张坊地区岩溶发育机理的研究及岩溶水裂隙数值模拟提供可视化的分析手段。     

基于信息熵的岩溶水监测网优化:以徐州市典型水源地为例

在各级水利与自然资源部门地下水监测数据共享机制逐步完善背景下,针对日益凸显的原有监测系统中存在的监测井布局不合理问题以及岩溶含水系统具有的非均质性和各向异性特征,选取徐州市丁楼-茅村和七里沟2个典型水源地,分别采用互信息-距离(T-D)和最大信息最小冗余(MIMR)模型对研究区监测网信息冗余性和最优监测井组合进行了研究。结果显示：丁楼-茅村水源地水位监测数据离散程度、信息熵、信息传递量和信息衰减速率均大于七里沟水源地,2个水源地在ε取10^-1时的水位信息有效传递距离分别为4.7,4.8 km,指示出两地相似的岩溶发育程度和水力传导性能。通过对比监测井控制范围的实际值和理论值发现2个水源地监测井之间均存在信息冗余。现有监测条件下,丁楼-茅村水源地最优监测井数为6眼,最优监测井组合为D1-D2-D4-D5-D7-D9;七里沟水源地最优监测井数量为5眼,最优组合为Q1-Q3-Q4-Q5-Q7。将优化结果与原监测网相比,2个水源地监测井数量均减少3眼,分别能提供原监测网信息总量的98.5%,94.9%,监测网控制范围分别下降0.4%,1.2%,信息冗余量分别减少49.0%...     

基于地表形态信息系统的岩溶生态环境的分析

本文基于地表形态信息系统对贵州省的岩溶生态环境的复杂性和多样性以及其脆弱性和生态被破坏的严重性进行了较系统的分析。最后就其生态环境的保护 ,提出了若干对策措施.     

基于水动力量化因子的岩溶强发育深度研究

地下水垂向循环水动力条件是岩溶发育深度的主要控制因素。为探求川东背斜构造岩溶区多级水流系统控制下的岩溶强发育深度,采用地理信息系统(GIS)技术,选取地形指数和水动力坡降构建岩溶水动力强弱的量化因子F_HQ,并结合钻孔数据推求假角山背斜构造区地下岩溶强发育深度。研究显示：水动力因子F_HQ与地形指数、水动力坡降在空间上呈明显正相关关系,同时可指示岩溶水流系统向深循环的深度,以此推求背斜构造区地下岩溶的强发育深度下限。假角山背斜两翼F_HQ集中在0.1～0.4之间,岩溶水动力整体偏弱,深沟F_HQ值整体高于浅沟。东、西翼深沟控制下的地下岩溶强发育深度分别约40～100 m和110～180 m;浅沟控制下的地下岩溶强发育深度分别约15～60 m和10～90 m。研究成果可进一步丰富川东背斜区岩溶发育评价方法体系,为隧道工程岩溶突水灾害预测防治提供理论依据。     

基于Fisher判别分析法的岩溶塌陷预测

为了更准确地预测岩溶塌陷,基于Fisher判别分析法,首先选择内聚力、内摩擦角、覆盖层厚度、覆盖层厚度减高水位埋深、覆盖层厚度减低水位埋深5个最主要的影响因素作为判别因子;接着以桂林市20组岩溶塌陷案例为学习样本进行计算,建立相应的Fisher线性判别函数;然后利用回代估计法对上述20组样本的预测结果进行逐一检验,其正确率为100%;随后将上述预测结果与前人运用逐步判别、神经网络判别等方法得到的结果进行比较分析,认为Fisher判别分析法具有不需进行模型和参数的选择以及不受人为因素的影响等优点;最后将建立的Fisher线性判别函数用于另外的10组实际案例进行预测分析,预测结果与实际情况完全吻合。结果表明:用Fisher判别分析法进行岩溶塌陷预测,简易方便,正确率高,实用性好;该方法是岩溶塌陷预测的一种新方法。     

基于AHP法的鲁中某高铁岩溶塌陷易发性评价

鲁中地区隐伏岩溶广泛分布,多年来岩溶塌陷灾害频发,给区内高速铁路的勘察、施工与运营管理带来了较多困难。本文以泰安东地区某拟建高速铁路为研究对象,在对线路穿越段地质构造、水文地质条件、岩溶塌陷发育现状总结分析的基础上,选取了8项岩溶塌陷影响因子作为评价指标,并运用AHP法计算了各评价指标的权重,构建了有针对性的评价指标体系,结合GIS空间分析方法进行了岩溶塌陷易发性评价。结果表明：研究区易发性高区面积约11.0km²,占比37.6%,易发性中等区面积约9.6km²,占比32.9%,易发性低区面积约7.8km²,占比26.8%,需在高速铁路建设过程中有针对性地采取进一步的防治工程措施。本研究成果可为高铁线路方案的确定及工程处理提供地质依据,也可为同类覆盖型岩溶区高速铁路工程的规划建设与防灾减灾管理提供参考。     

基于系统空间特征识别的岩溶地下水污染成因分析

岩溶地下水系统空间结构复杂,含水层渗透性强、防污性能差,一旦发生污染,污染物扩散迅速且修复难度较大。以南方某岩溶大泉为例,在水文地质调查的基础上,结合水化学图解及多元示踪技术,分析岩溶地下水系统边界及暗河管道分布,识别岩溶泉的主要污染物、来源及污染途径,探索岩溶地下水污染成因模式。研究结果表明,Q₁岩溶地下水系统为典型的“多源单汇”地下水循环模式,存在南北2条主要径流通道;其主要污染物质为锰、菌落总数、氨氮、总磷,分别为地下水质量标准阈值的17,14,7.2,3.8倍;建筑垃圾堵塞原有的暗河通道,工程勘察和强夯活动破坏了垃圾堆场下部天然黏土防渗层,生活垃圾及渗滤液进入岩溶管道,两者共同导致了岩溶地下水的污染。该研究对于岩溶地下水系统污染防治工作具有重要的借鉴意义。     

The spring prediction barrier in ENSO hindcast experiments using the FGOALS-g model

The Flexible Global Ocean-Atmosphere-Land System Model-gamil (FGOALS-g) was used to study the spring prediction barrier (SPB) in an ensemble system. This coupled model was developed and maintained at the State Key Laboratory of Atmospheric Sciences and Geophysical Fluid Dynamics (LASG). There are two steps in our hindcast experiments. The first is to integrate the coupled model continuously with sea surface temperature (SST) nudging, from 1971 to 2006. The second is to carry out a series of one-year hindcasts without SST nudging, by adopting initial values from the first step on January 1 st , April 1st , July 1st , and October 1st , from 1982 to 2005. We generate 10 ensemble members for a particular start date (1st ) by choosing different atmospheric and land conditions around the hindcast start date (1st through 10th ). To estimate the predicted SST, two methods are used: (1) Anomaly Correlation Coefficient and its rate of decrease; and (2) Talagrand distribution and its standard deviation. Results show that FGOALS-g offers a reliable ensemble system with realistic initial atmospheric and oceanic conditions, and high anomaly correlation (>0.5) within 6 month lead time. Further, the ensemble approach is effective, in that the anomaly correlation of ensemble mean is much higher than that of most individual ensemble members. The SPB exists in the FGOALS-g ensemble system, as shown by anomaly correlation and equal likelihood. Nevertheless, the role of the ensemble mean in reducing the SPB of ENSO prediction is significant. The rate of decrease of the ensemble mean is smaller than the largest deviations by 0.04-0.14. At the same time, the ensemble system "equal likelihood" declines during spring. An ensemble mean helps give a correct prediction direction, departing from largely-deviated ensemble members.     

Effects of spatial information of soil physical properties on hydrological modeling based on a distributed hydrological model

The spatial distribution of soil physical properties is essential for modeling and understanding hydrological processes. In this study, the different spatial information (the conventional soil types map-based spatial information (STMB) versus refined spatial information map (RSIM)) of soil physical properties, including field capacity, soil porosity and saturated hydraulic conductivity are used respectively as input data for Water Flow Model for Lake Catchment (WATLAC) to determine their effectiveness in simulating hydrological processes and to expound the effects on model performance in terms of estimating groundwater recharge, soil evaporation, runoff generation as well as partitioning of surface and subsurface water flow. The results show that: 1) the simulated stream flow hydrographs based on the STMB and RSIM soil data reproduce the observed hydrographs well. There is no significant increase in model accuracy as more precise soil physical properties information being used, but WATLAC model using the RSIM soil data could predict more runoff volume and reduce the relative runoff depth errors; 2) the groundwater recharges have a consistent trend for both cases, while the STMB soil data tend to produce higher groundwater recharges than the RSIM soil data. In addition, the spatial distribution of annual groundwater recharge is significantly affected by the spatial distribution of soil physical properties; 3) the soil evaporation simulated using the STMB and RSIM soil data are similar to each other, and the spatial distribution patterns are also insensitive to the spatial information of soil physical properties; and 4) although the different spatial information of soil physical properties does not cause apparent difference in overall stream flow, the partitioning of surface and subsurface water flow is distinct. The implications of this study are that the refined spatial information of soil physical properties does not necessarily contribute to a more accurate prediction of stream flow, and the selection of appropriate soil physical property data needs to consider the scale of watersheds and the level of accuracy required.     

武汉两湖隧道岩溶水系统结构及水循环规律

武汉市两湖隧道是国内最长、世界规模最大的城市湖底隧道,其东湖段穿越岩溶区,识别其岩溶水系统结构对隧道建设和运营安全具有重要意义。为查明区内岩溶水系统结构及水循环特征,综合利用地质及水文地质勘探、水文地球化学分析等方法刻画了岩溶含水系统边界,总结了岩溶发育规律,识别了洞穴沉积物来源,分析了岩溶水与孔隙水和地表水之间的水力联系,探讨了岩溶水循环模式。结果表明：研究区可划分为南北2个岩溶含水系统,北段岩溶含水系统的岩溶发育程度强于南段岩溶含水系统,北段和南段岩溶含水系统由断层带连通而具有统一的水力联系。洞穴沉积物主要来源于第四系残积层和洞穴围岩风化。第四系冲洪积层孔隙水与下伏岩溶水的水力联系较弱,而第四系残积层孔隙水与下伏岩溶水的联系紧密。本研究利用多种技术方法精细刻画湖底隧道的岩溶水系统结构,可服务于隧道工程的涌突水风险评价和安全施工。     

Water quality evaluation in Tidal River reaches of Liaohe River Estuary, China using a revised QUAL2K model

Rivers in the Liaohe River Estuary area have been seriously polluted by discharges of wastewater containing petroleum pollutants and nutrients. In this paper, The Enhanced Stream Water Quality Model (QUAL2K) and its revised model as well as One-dimensional Tide Mean Model (1D model) were applied to predict and assess the water quality of the tidal river reach of the Liaohe River Estuary. Dissolved oxygen (DO), biochemical oxygen demand (BOD₅), ammonia nitrogen (NH₃-N) and total phosphorus (TP) were chosen as water quality indices in the two model simulations. The modelled results show that the major reasons for degraded rivers remain petroleum and non-point source pollution. Tidal water also has a critical effect on the variation of water quality. The sensitivity analysis identifies that flow rate, point load and diffuse load are the most sensitive parameters for the four water quality indices in the revised QUAL2K simulation. Uncertainty analysis based on a Monte Carlo simulation gives the probability distribution of the four water quality indices at two locations (6.50 km and 44.84 km from the river mouth). The statistical outcomes indicate that the observed data fall within the 90% confidence intervals at all sites measured, and show that the revised QUAL2K gives better results in simulating the water quality of a tidal river.     

Projection of future streamflow of the Hunza River Basin,Karakoram Range (Pakistan) using HBV hydrological model

Hydrologiska Byrans Vattenbalansavdeling(HBV) Light model was used to evaluate the performance of the model in response to climate change in the snowy and glaciated catchment area of Hunza River Basin. The study aimed to understand the temporal variation of streamflow of Hunza River and its contribution to Indus River System(IRS). HBV model performed fairly well both during calibration(R2=0.87, Reff=0.85, PBIAS=-0.36) and validation(R2=0.86, Reff=0.83, PBIAS=-13.58) periods on daily time scale in the Hunza River Basin. Model performed better on monthly time scale with slightly underestimated low flows period during bothcalibration(R2=0.94, Reff=0.88, PBIAS=0.47) and validation(R2=0.92, Reff=0.85, PBIAS=15.83) periods. Simulated streamflow analysis from 1995-2010 unveiled that the average percentage contribution of snow, rain and glacier melt to the streamflow of Hunza River is about 16.5%, 19.4% and 64% respectively. In addition, the HBV-Light model performance was also evaluated for prediction of future streamflow in the Hunza River using future projected data of three General Circulation Model(GCMs) i.e. BCC-CSM1.1, CanESM2, and MIROCESM under RCP2.6, 4.5 and 8.5 and predictions were made over three time periods, 2010-2039, 2040-2069 and 2070-2099, using 1980-2010 as the control period. Overall projected climate results reveal that temperature and precipitation are the most sensitiveparameters to the streamflow of Hunza River. MIROC-ESM predicted the highest increase in the future streamflow of the Hunza River due to increase in temperature and precipitation under RCP4.5 and 8.5 scenarios from 2010-2099 while predicted slight increase in the streamflow under RCP2.6 during the start and end of the 21 th century. However, BCCCSM1.1 predicted decrease in the streamflow under RCP8.5 due to decrease in temperature and precipitation from 2010-2099. However, Can ESM2 predicted 22%-88% increase in the streamflow under RCP4.5 from 2010-2099. The results of this study could be useful for decision making and effective future strategic plans for water management and their sustainability in the region.     

Water Requirements and Irrigation Scheduling of Spring Maize Using GIS and CropWat Model in Beijing-Tianjin-Hebei Region

Due to the over use of available water resources, it has become very important to define appropriate strategies for planning and management of irrigated farmland. In this paper, Beijing-Tianjin-Hebei (Jing-Jin-Ji) region was chosen as the case study area for its special political and economic status and its severe water problem. To achieve effective planning, the information about crop water requirements, irrigation withdrawals, soil types and climatic conditions were obtained in the study area. In the meantime, a GIS method was adopted, which extends the capabilities of the crop models to a regional level. The main objectives of the study are: 1) to estimate the spatial distribution of the evapotranspiration of spring maize; 2) to estimate climatic water deficit; 3) to estimate the yield reduction of spring maize under different rainfed and irrigated conditions. Based on the water deficit analysis, recommended supplemental irrigation schedule was developed using CropWat model. Compared to the rainfed control, the two or three times of supplemental water irrigated to spring maize at the right time reduced the loss of yield, under different scenarios.     

Assessment of point and nonpoint sources pollution in Songhua River Basin,Northeast China by using revised water quality model

Individual participation of pollutants in the pollution load should be estimated even if roughly for the appropriate environmental management of a river basin. It is difficult to identify the sources and to quantify the load, especially in modeling nonpoint source. In this study a revised model was established by integrating point and nonpoint sources into one-dimensional Streeter-Phelps (S-P) model on the basis of real-time hydrologic data and surface water quality monitoring data in the Jilin Reach of the Songhua River Basin. Chemical oxygen demand (COD) and ammonia nitrogen (NH_3-N) loads were estimated. Results showed that COD loads of point source and nonpoint source were 134 958 t/yr and 86 209 t/yr, accounting for 61.02% and 38.98% of total loads, respectively. NH_3-N loads of point source and nonpoint source were 16 739 t/yr and 14 272 t/yr, accounting for 53.98% and 46.02%, respectively. Point source pollution was stronger than nonpoint source pollution in the study area at present. The water quality of upstream was better than that of downstream of the rivers and cities. It is indispensable to treat industrial wastewater and municipal sewage out of point sources, to adopt the best management practices to control diffuse pollutants from agricultural land and urban surface runoff in improving water quality of the Songhua River Basin. The revised S-P model can be successfully used to identify pollution source and quantify point source and nonpoint source loads by calibrating and validating.     

集合卡尔曼滤波在流域水文模型流量预报中的应用

针对流域降雨入渗过程,引入集合卡尔曼滤波(EnKF)理论,视整个边坡流域为一个随机动态系统,将边坡流域流量观测值作为系统的输出,用集合卡尔曼滤波模型来描述系统的状态;结合流域流量计算方法,实现水文模型参数的随机动态估计,在有效获得待估参数的同时还给出估计值的不确定性.通过数值算例表明,集合卡尔曼滤波可以有效地对含噪声的量测数据进行处理,能够跟踪水文模型的动态变化.相对于常用最优化算法,集合卡尔曼滤波同时给出反演结果和先验知识的后验分布,显示出更好的实时性和可靠性.     

Distribution assessment of soil erosion with revised RUSLE model in Tianshan Mountains

Soil degradation caused by soil erosion is one of the world’s most critical environmental issues. Soil erosion in the Tianshan Mountains has caused various environmental problems in the surrounding areas. This study used remote sensing data to analyze the distribution of the factors influencing soil erosion, and the revised universal soil loss equation(RUSLE) to calculate the total amount and distribution characteristics of soil erosion in the Tianshan Mountains in 2019. Due to the large error o...