The Challenges of Water Pollution, Threat to Public Health, Flaws of Water Laws and Policies in Pakistan

In an era of unprecedented urbanization, population and industrial growth pressure is serious threat for the water management in Pakistan in present days. Water pollution from raw sewage, industrial wastes, and agricultural runoff limited natural fresh water resources in the country. Human health is facing serious problems due to deteriorating drinking water quality. Current review paper provides an insight to the water quality problems in Pakistan with an attempt to emphasize the challenges of water laws enforcement. Although Pakistan has developed many water laws the state of implementation is dominant, intermediate pollution crises are still remaining. We could come to the conclusion that strictly enforcement is compulsory for water environment regulations in Pakistan. Moreover, it is necessary to establish a reliable risk assessment system for water quality, human health and ecological safety.

Seepage field distribution and water inflow laws of tunnels in water-rich regions

Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the accompanying disturbances to the ecological environment have become the main problems that affect the structural safety of tunnels in water-rich regions.In this paper,a tunnel seepage model testing system was used to conduct experiments of the grouting circle and primary support with different permeability coefficients.The influences of the supporting structures on the water inflow laws and the distribution of the water pressure in the tunnel were analyzed.With the decrease in the permeability coefficient of the grouting circle or the primary support,the inflow rate of water into the tunnel showed a non-linear decreasing trend.In comparison,the water inflow reduction effect of grouting circle was much better than that of primary support.With the increase of the permeability coefficient of the grouting ring,the water pressure behind the primary lining increases gradually,while the water pressure behind the grouting ring decreases.Thus,the grouting of surrounding rock during the construction of water-rich tunnel can effectively weaken the hydraulic connection,reduce the influence range of seepage,and significantly reduce the decline of groundwater.Meanwhile,the seepage tests at different hydrostatic heads and hydrodynamic heads during tunnel operation period were also conducted.As the hydrostatic head decreased,the water pressure at each characteristic point decreased approximately linearly,and the water inflow rate also had a gradual downward trend.Under the action of hydrodynamic head,the water pressure had an obvious lagging effect,which was not conducive to the stability of the supporting structures,and it could be mitigated by actively regulating the drainage rate.Compared with the hydrostatic head,the hydrodynamic head could change the real-time rate of water inflow to the tunnel and broke the dynamic balance between the water pressure and water inflow rate,thereby affecting the stress state on the supporting structures.

Overburden fracture evolution laws and water-controlling technologies in mining very thick coal seam under water-rich roof

Considering the danger of water inrush in mining very thick coal seam under water-rich roof in Majialiang Coal Mine,the universal discrete element(UDEC)software was used to simulate the overburden fracture evolution laws when mining 4#coal seam.Besides,this study researched on the influence of face advancing length,speed and mining height on the height of the water flowing fractured zones(HWFFZ),and analyzed the correlation of face advancing length and change rules of aquifer water levels and goaf water inflow.Based on those mentioned above,this research proposed the following water-controlling technologies:draining the roof water before mining,draining goaf water,reasonable advancing speed and mining thickness.These water-controlling technologies were successfully used in the feld,thus ensured safely mining the very thick coal seam under water-rich roof.

On the Law Right of the Gas Water of Water Resources

With the development of science and technology, the researches and application of water resources including the gas water have been constantly developed. Through an analysis on the flaws of the water right theory, and by executing reconstruction and renewal of the theory and system of water right in modern society, the water right position of the gas water will be estab- lished, leading to the maturity of the whole law effectiveness and substantial results of water right.

Preliminary Study on Water Demand Law of 1-0 Rooted Cuttings of Populus szechuanica

In order to provide theoretical basis and technical support for the afforestation and artificial water supply of P.szechuanica in arid areas,the characteristics of water consumption of P.szechuanica were explored,and the law of water demand of P.szechuanica was grasped.In this paper,potted seedlings of 1-0 rooted cuttings of P.szechuanica were taken as research objects,and change situation of water consumption under different water control gradients was measured regularly by using weighing method,further analyzing dynamic change of water consumption of P.szechuanica and revealing water demand law of 1-0 rooted cuttings of P.szechuanica.The results showed that total change of water consumption of 1-0 rooted cuttings of P.szechuanica had"slow-fast-slow-fast"double-peak trend in the growth period of the current year,and corresponded with univariate linear relation(R^(2)=0.7137),with significant difference.In whole growth period,water consumption in August was the highest,which was 2.7 times of that in June and July and 1.5 times of that after September.In different water control treatments,the dynamic changes of daily and monthly water consumption were significantly different.In seven water control treatments,monthly water consumption was between(6315.95±1690.70)and(10105.28±3065.30)g/month,and mean was(8211.07±2308.23)g/month.With intensification of water control treatment,water consumption increased,but there was no seedling death due to water shortage.P.szechuanica has great plasticity in water demand,and can survive in both arid and humid environments.Meanwhile,it is revealed that P.szechuanica is the most widely distributed tree species in the region.

Study on Development Law of Complex Fluvial Reservoir under Water

The Bozhong oilfield (Hereinafter referred to as BZ oilfield) is a typical representative of complex fluvial reservoirs in the Bohai Sea, located in the southern Bohai Sea, with an average porosity of 30.3% and an average permeability of 643 × 10-3 μm2, belonging to medium high porosity and permeability reservoir, the reservoir has good connectivity, and the average underground crude oil viscosity is 5 mPa·s. There are many plane fault blocks, and the longitudinal oil well section is long, so the oil-water relationship is very complex. With the further development of the oilfield, the vertical and horizontal oil-water movement law, residual oil distribution and potential are unclear, resulting in rapid bottom water coning, unbalanced injection and production in the oilfield, and increasingly prominent contradictions among layers, planes and layers in the oilfield. Through numerical simulation analysis and comparison of displacement law and recovery degree under different influence conditions, this paper studies the development effect of actual sand body under different influence conditions such as different well types, different development methods and well layout positions, and takes appropriate development methods for the oilfield, which is of great significance to improve the development effect of the oilfield.

Leak Detection in Water Distribution Systems Using Bayesian Theory and Fisher’s Law

A leak detection method based on Bayesian theory and Fisher’s law was developed for water distribution systems. A hydraulic model was associated with the parameters of leaks (location, extent). The randomness of parameter values was quantified by probability density function and updated by Bayesian theory. Values of the parameters were estimated based on Fisher’s law. The amount of leaks was estimated by back propagation neural network. Based on flow characteristics in water distribution systems, the location of leaks can be estimated. The effectiveness of the proposed method was illustrated by simulated leak data of node pressure head and flow rate of pipelines in a test pipe network, and the leaks were spotted accurately and renovated on time.

水下声学超表面异常折射方向调控研究

针对波束调控的问题,本文提出了一种控制波前相位的声学超表面。本文依据广义斯奈尔定律,利用不同声速的均匀介质构建了水中多频声学超表面模型,给出声学超表面产生异常声折射的基本原理,验证了声学超表面在多个频点下可以实现异常声折射现象,揭示了频率以及声波入射角对声学超表面异常折射现象的影响规律,制备了声学超表面实物在水箱中对理论结果进行验证。结果表明:在入射波频率为基频的整数倍时,超表面模型可以实现折射角相同的异常折射现象,并且入射角在一定范围内可以实现负折射现象。实验测量了水中钢板和超表面的折射情况,相较于均匀介质,在不同入射角度下设计的超表面均可以实现异常折射,并且测量值与理论值吻合较好。

多分水口长距离输水工程停泵水锤防护措施

为了能够有效避免多泵且多分水口输水系统在无防护抽水断电时可能出现较为严重的负水锤带来的危害,建立了全长106.46 km的大型供水工程的数学模型进行系统过渡过程计算,选择空气阀与两阶段液控蝶阀联合防护与单向塔防护2种方案消除其负水锤,在前者远不达理想防护效果后针对后者进行优化.结合工程实际在确定了单向塔的数量、位置以及塔高后,对不同位置单向塔的底面积进行多种方案的对比选取,最终选用塔1#的底面积为28.26 m^(2),塔2#的底面积为176.63 m^(2);为了防止单向塔漏空需要分水口以及供水终端调流阀配合关闭,在确保管道最大压力不超出其承压能力的前提下,创新性地对各分水口调流阀与供水终端调流阀的关闭时间规律进行了效果比较,使输水系统能够更加经济安全地稳定运行,为此类长距离多分水口多泵供水工程的水锤防护提供了优化方向.

断块油藏高含水井关井后剩余油再动用运移规律微观模拟

基于微观可视化光刻玻璃模型,从微观角度定性、定量研究了断块油藏高含水井关井后剩余油再动用运移规律,并开展了影响因素分析。结果表明:水驱后关井期间剩余油再动用类型主要为滴状、柱状和簇状。关井期间剩余油会沿模型倾斜方向向高部位运移聚集,有利于后续水驱阶段进一步提高驱油效率。地层倾角的增大、原油黏度的减小有利于剩余油再动用;关井时间的增加有利于剩余油向高部位采出端接近聚集;后续水驱阶段注入速度的增大会增加波及面积。

金矿尾渣固结体重金属浸出规律和水质评价

以贵州某金矿尾渣固结体为研究对象,通过静态浸泡实验,分析尾砂直接浸泡以及固结养护不同时期(7、14、28 d)后浸出的重金属浓度变化情况。研究结果表明:(1)尾渣固结后浸出的重金属Ni、Cd、Sb的浓度比固结前更小,并且养护龄期越长,其浸出量越小;(2)尾渣直接浸泡所测的重金属浸出浓度值与浸泡时间进行函数拟合发现,离子的浸出最大浓度在达到平衡后分别为Ni 2.45μg/L、Cd 0.14μg/L、Sb 360.46μg/L,而Cu离子在此静态浸泡的过程中易饱和沉淀及再浸出,难以达到一个平衡量;(3)固结后尾渣浸出重金属Ni、Cd、Cu、Sb的浓度会最终达到一个平衡量,且随着固结养护龄期越长,各重金属离子浸出的最大浓度越小;(4)尾渣固结前后浸出的重金属浓度均使得水质为Ⅴ类水,但是尾砂固结后,水质整体得到了很大的改善,且养护龄期越长,对地下水水质改善的效果越明显。

新时期长江流域水资源保护规划及管理工作的思考

组织编制并实施水资源保护规划是国家赋予水行政主管部门的法定职责,也是水利部门履行水资源管理和生态环境保护责任的重要工作。长江流域水资源保护规划经历了从起步、探索、实践与发展到形成完善体系的过程,推进了流域水资源保护与管理科学有序发展。随着国家机构改革部门职能调整和《中华人民共和国长江保护法》出台,为更好地推进和落实新时期长江流域水资源保护规划和管理工作,系统梳理长江流域水资源保护规划发展历程与成效,分析当前流域水资源保护面临的形势与挑战,厘清流域水资源保护工作定位和思路,并据此提出新时期流域水资源保护规划及管理的工作建议,对凝聚流域水资源保护规划共识、建立流域水资源保护规划体系、推进水资源保护高质量发展、助力实现治江现代化具有重要的指导意义。

煤矿井下含水层超前疏放水钻孔涌水量衰减规律数值模拟分析

钻孔涌水量衰减规律可以为煤矿失水灾害提供一种有效治理手段,为了保证煤矿的安全生产,对煤矿井下含水层超前疏放水钻孔涌水量衰减规律进行数值模拟分析。以Q煤矿为研究对象,结合SEEP/W软件,模拟分析钻孔涌水量的变化规律,构建了涌水量衰减规律数值模拟模型,实现对钻孔涌水量衰减规律的预测。结果表明,增大初始水头和渗透系数后,钻孔的峰值涌水量和似稳定涌水量增大;增大弹性给水度,钻孔的峰值涌水量增大,而似稳定涌水量保持稳定;随着钻孔孔径、钻孔仰角与斜长的增大,钻孔的峰值涌水量和似稳定涌水量都逐渐增大;增大钻孔的数量和覆盖范围后,单个钻孔、钻区的涌水衰减明显,位于钻区中心的钻孔,其疏水能力受到群孔的干扰最大。

民国时期水利法制之转型

民国时期,随着西方水利科学知识和法治理念与制度的传入,中国水利法制开始近代化的摸索与尝试。民国时期水利法制近代化主要体现在三个方面:一是民国政府走出传统窠臼,吸收西方依法治水的科学理念,参酌固有习惯,初步构建以国家法、地方法规、民间习惯法为主体的多元水利法律体系;二是打破延续千年来中央水利行政机构杂乱无章、权责不符的局面,开创从中央到地方的统一水利行政系统;三是创新水权制度,明确水权归属,并建立多元的水权纠纷近代化解决机制。民国时期的水利法制既积极吸收和引进西方近代先进水利法制思想和实践,又保留传统水利社会的一些内容,在“变”与“不变”中迈向近代化转型之路。

运城市主要粮食作物灌溉需水量时空变化研究

明确运城市主要粮食作物冬小麦和夏玉米灌溉需水量的时空变化规律,为未来该市灌溉用水的科学配置提供基本参数。基于运城市域内13个气象站点的长期观测资料,利用Penman-Monteith公式确定参考作物蒸散量,结合有效降雨量和作物系数等参数,计算分析了运城市近50 a冬小麦与夏玉米的灌溉需水量及其时空变化特征。结果表明:在研究时段内,冬小麦和夏玉米年灌溉需水量整体均呈现波动式降低的变化趋势,整体降低幅度分别为-0.7和-2.1 mm/(10 a)。冬小麦在4月和5月的灌溉需水量较多,分别为80.5 mm和108.4 mm;夏玉米则为8月份的灌溉需水量最大,约为85.3 mm。冬小麦和夏玉米全生育期的平均灌溉需水量都呈现从东向西逐渐递增的趋势,冬小麦灌溉需水量的变化范围处于283.6~336.8 mm,夏玉米则为165.4~253.9 mm。相关分析结果表明,水汽压差与太阳辐射对运城市冬小麦和夏玉米灌溉需水量的影响较大。运城市冬小麦与夏玉米灌溉需水量在时间上呈波动降低趋势,在空间上则由东向西逐步递增;气温与降水的变化趋势显示运城市的气候正在朝暖湿化方向发展,未来灌溉方案的制定与优化应当予以充分考虑。

基于分形理论的毛细水上升高度模型及试验验证

沿海地区的路基工程中,毛细水上升会产生路基病害,影响道路运营的安全性和耐久性,因此研究毛细水上升高度尤为重要。文章视毛细水上升为一种非饱和土的渗流现象,引入分形维数对非饱和土渗透系数进行修正,进而提出了基于分形理论的毛细水上升高度模型,得到了毛细水上升高度随时间变化的曲线;而后对南通某干线公路路基土样进行竖管法毛细水上升高度试验,改变土样的干密度及初始粒径的分形维数分布做对照组试验。研究结果表明:毛细水上升呈现初期先快速增加,然后缓慢增加,最终趋于稳定的趋势;土样颗粒粒径分布的分形维数越大,得到的毛细水上升高度越大;土样的干密度越小,即孔隙率越大,得到的毛细水上升高度越大。文章提出的毛细水上升高度模型中,毛细水上升高度与试样孔隙率、饱和渗透系数、进气值对应的毛细水上升高度、分形维数等参数相关。在模型理论值计算中认为分形维数变化仅改变进气值对应的毛细水高度,不改变饱和渗透系数,而干密度变化即孔隙率变化仅导致饱和渗透系数变化,不改变进气值对应的毛细水高度,由此得到的模型计算结果与试验结果趋势一致,验证了理论模型的正确性,可以为公路路基毛细水病害防治提供理论指导。

衢州市开化县水政执法的措施与成效

遏制水事违法案件的发生,保护水域功能的正常发挥,推动水政执法高质量发展。通过积极宣传法律法规,全方位开展行政检查,常态化进行河道巡查等方式,加强与公安、环保、自然资源等部门合作,采取多种形式的联合执法,共同打击水事违法分子。2022年,分发资料1000+份,行政检查68次,河道巡查45次,巡河长度4050 km,制止乱建、乱占、乱堆、乱采行为70次,取得了较好的整治效果。通过强化治水理念,实施铁腕治水,水事秩序明显好转,确保了一江清水流下游。

城市污水处理厂进水水质规律分析及应用

利用城市污水处理厂的实际运行数据,分析水质变化情况及水质指标关联度,总结水质水量的变化规律,为后续污水处理提标改造提供定量依据。结果表明,该污水厂进水流量、NH_(3)-N、TN和TP等指标季节因素起决定性影响,季节因素对COD、BOD_(5)的影响较小。通过对城市污水处理厂进水水质分析,掌握污水厂进水情况,可为污水处理厂设计和运行提供基础数据,也可为其他类似工程提供可供借鉴的思路。

富水环境下强–中风化硅质板岩吸水特性及微观演化规律

为探讨富水环境下强–中风化硅质板岩的吸水特性及吸水过程微观演化规律,以玉溪至楚雄段国家高速公路旧寨隧道中的强–中风化硅质板岩为研究对象,开展浸水试验、电镜扫描试验和X射线衍射试验。试验结果表明:富水环境下强–中风化硅质板岩吸水过程可分为急速吸水阶段(0~2 h)、缓速吸水阶段(2~24 h)和平衡吸水阶段(超过24 h)等3个阶段。急速吸水阶段,岩石结构变得较为松散、孔隙及微裂隙逐步延伸发展;缓速吸水阶段,胶结物溶解、脱落,岩石结构进一步松散、孔隙及裂隙进一步发育,逐渐形成显著的贯穿性裂隙;动态平衡吸水阶段,岩石结构松散程度、孔隙及裂隙发育程度基本达到稳定状态。强–中风化硅质板岩主要矿物组成为石英和黏土矿物,随着浸水试验的进行,石英相对含量增加,黏土矿物含量不断减小;伊利石、伊蒙混层等黏土矿物遇水极不稳定,既能与水发生化学反应,转化成石英和其他黏土矿物,又能与水发生物理反应,表现出膨胀、破碎和分解等特性。研究成果可为开展强–中风化硅质板岩吸水软化特性的理论研究提供参考。