西藏直孔水电站大坝混凝土防渗墙超前支护成槽试验研究及施工

在西藏直孔水电站松散砂卵石地层混凝土防渗墙成槽施工中，结合坝基水文地质及工程地质特点，创造性地提出了超前支护成槽方案，通过三维应力模拟和渗透试验，结合现场生产试验，对原方案更进一步完善，在施工中加以应用获得了成功。     

压力注浆在常张高速公路岩溶路基处理中的应用

岩溶性地基处理是公路建设中时常遇到的问题之一。结合常(德)—张(家界)高速公路岩溶路基注浆施工，介绍了压力注浆处理岩溶路基的施工工艺及相关的施工参数，并针对施工中出现的特殊问题提出了相应的处理措施。     

喀斯特地区旅游开发的自然景观保护--以贵州省绥阳县为例

该文以贵州省绥阳县为例，针对我国西南喀斯特地区旅游开发中自然环境的特点，探讨溶洞景观的保护、喀斯特地表生态环境保护、水体的保护与综合治理等问题。     

不同石漠化程度岩溶峰丛洼地系统景观格局的比较

利用花江岩溶峡谷区南坡不同石漠化程度的5个独立的岩溶峰丛洼地系统景观要素的实测数据,分析了多样性、优势度、破碎度、分离度等景观格局指标的变化规律及其所指示的生态学意义。结果表明,这些指标在不同峰丛洼地系统都能较好地评价石漠化过程中景观格局的动态变化规律,对分析石漠化土地的发展趋势具有较好的指示意义。但多样性指数、优势度指数、均匀度指数也与各峰丛洼地系统的景观基质有关,在不同石漠化程度的峰丛洼地系统中,反映的景观生态意义是不一样的。景观格局分析不仅强调面积,而且还考虑所研究石漠化土地的空间分布特征(格局)、景观组成特点与石漠化过程的关系和对石漠化的影响,在石漠化程度判定和石漠化指标的研究中景观格局是一个不可忽视的问题。     

Simulating runoff generation and its spatial correlation with environmental factors in Sancha River Basin: The southern source of the Wujiang River

Journal of Geographical Sciences - Runoff generation is an important part of water retention service, and also plays an important role on soil and water retention. Under the background of the...     

Using hysteretic behaviour and hydrograph classification to identify hydrological function across the “hillslope–depression–stream” continuum in a karst catchment

In cockpit karst landscapes, fluxes from upland areas contribute large volumes of water to low-lying depressions and stream flow. Hydrograph hysteresis and similarity between monitoring sites is important for understanding the space–time variability of hydrologic responses across the “hillslope–depression–stream” continuum. In this study, the hysteretic feature of hydrographs was assessed by characterizing the loop-like relationships between responses at upstream sites relative to subsurface discharge at the outlet of a small karst catchment. A classification of hydrograph responses based on the multi-scale smoothing Kernel -derived distance classifies the hydrograph responses on the basis of similarities between hillslope and depression sites, and those at the catchment outlet. Results demonstrate that the temporal and spatial variability of hydrograph hysteresis and similarity between hillslope flow and outlet stream flow can be explained by the local heterogeneity of depression aquifer. Large depression storage deficits emerging in the highly heterogeneous aquifer produce strong hysteresis and multiple relationships of upstream hydrographs relative to the outlet subsurface discharge. In contrast, when depression storage deficits are filled during consecutive rainfall events, depression hydrographs at the high permeability sites are almost synchronous or exhibit a monotonous function with the hydrographs at the outlet. This reduced hydrograph hysteresis enhances preferential flow paths in fractured rocks and conduits that can accelerate the hillslope flow to the outlet. Therefore, classification of hydrograph similarities between any upstream sites and the catchment outlet can help to identify the dominant hydrological functions in the heterogeneous karst catchment.     

A nonstationary extreme value distribution for analysing the cessation of karst spring discharge

The effects of climate change and population growth in recent decades are leading us to consider their combined and potentially extreme consequences, particularly regarding hydrological processes, which can be modeled using a generalized extreme value (GEV) distribution. Most of the GEV models were based on a stationary assumption for hydrological processes, in contrast to the nonstationary reality due to climate change and human activities. In this paper, we present the nonstationary generalized extreme value (NSGEV) distribution and use it to investigate the risk of Niangziguan Springs discharge decreasing to zero. Rather than assuming the location, scale, and shape parameters to be constant as one might do for a stationary GEV distribution analysis, the NSGEV approach can reflect the dynamic processes by defining the GEV parameters as functions of time. Because most of the GEV model is designed to evaluate maxima (e.g. flooding, represented by positive numbers), and spring discharge cessation is a ?minima’, we deduced an NSGEV model for minima by applying opposite numbers, i.e. negative instead of positive numbers. The results of the model application to Niangziguan Springs showed that the probability of zero discharge at Niangziguan Springs will be 1/80 in 2025, and 1/10 in 2030. After 2025, the rate of decrease in spring discharge will accelerate, and the probability that Niangziguan Springs will cease flowing will dramatically increase. The NSGEV model is a robust method for analysing karst spring discharge. Copyright © 2013 John Wiley & Sons, Ltd.     

滕州荆泉水源地岩溶塌陷特征与成因分析

自2015年6月以来,在山东滕州荆泉水源地范围内连续发生多起岩溶塌陷。通过研究区域地质条件,在已有认识的基础上分析得出发育的浅层开口岩溶洞隙的存在,一定厚度的松散覆盖层及地下水位大幅下降是该区产生岩溶塌陷的基本条件。阐述了岩溶塌陷形成发育过程及影响因素,得出长期过量抽采岩溶水是区内岩溶塌陷的主要因素,合理减少地下水开采量是预防岩溶塌陷最有效的方法。     

A novel approach for estimating karst groundwater recharge in mountainous regions and its application in Switzerland

A pragmatic and simple approach for estimating the groundwater recharge of karst aquifers in mountainous regions by extrapolation of the hydrological regimes of gauged and well‐documented systems is presented. Specific discharge rates are derived using annual precipitation and spring measurements by taking into account catchment size and elevation, which are assumed to be the dominant factors. Reference sites with high data reliability are used for calibration and regional extrapolation. This is performed with normalized values employing spatial precipitation deviations and correlation with the elevation of the catchment areas. A tiered step procedure provides minimum and maximum normalized gradients for the relationship between recharge quantity and elevation for karst regions. The normalized recharge can therefore be obtained and extrapolated for any location using the spatial precipitation variability to provide an estimate of annual groundwater recharge. The approach was applied to Switzerland (approximately 7500 km² of karst terrain situated between 200 and over 4000 m a.s.l.) using annual precipitation data from meteorological stations for the years 2000 to 2011. Results show that the average recharge rates of different Swiss karst domains range from 20 to 46 L/km²s, which corresponds to an infiltration ratio between 0.6 and 0.9 of total precipitation. Despite uncertainties inherent in the approach, these results provide a benchmark for renewable karst groundwater resources in Switzerland of about 8.4 km³/year. The approach can be applied to any other mountainous karst region, that is, where a clear relationship between elevation, precipitation and recharge can be assumed. Copyright © 2015 John Wiley & Sons, Ltd.