陕北风沙滩地区面向生态的地下水可持续开发方案

陕北风沙滩地区地处干旱半干旱地区,矿产资源丰富,生态环境脆弱。地下水是区域内生产生活用水的主要来源,同时也是控制区内生态环境演化的重要因子。在查明该区域地下水补径排条件与生态环境关系的基础上,应用地下水流数值模拟技术,以地下水开发-生态环境响应-地下水调控为主线,分析了地下水开发方案下的生态环境响应,确定了区域地下水开发的合理阈限,为区域地下水开发利用与生态环境的良性发展提供技术支撑。     

Non-point source pollution of Wujiang River watershed in Guizhou Province, SW China

The amount of pollution from non-point sources flowing in the streams of the Wujiang River watershed in Guizhou Province, SW China, is estimated by a GIS-based method using rainfall, surface runoff and land use data. A grid of cells, 100 m in size, is laid over the landscape. For each cell, mean annual surface runoff is estimated from rainfall and percent land use, and expected pollutant concentration is estimated from land use. The product of surface runoff and concentration gives expected pollutant loading from that cell. These loadings are accumulated going downstream to give expected annual pollutant loadings in streams and rivers. By dividing these accumulated loadings by the similarly accumulated mean annual surface runoff, the expected pollutant concentration from non-point sources is determined for each location in a stream or river. Observed pollutant concentrations in the watershed are averaged at each sample point and compared to the expected concentrations at the same locations determined from the grid cell model. In general, annual non-point source nutrient loadings in the Wujiang River watershed are seen to be predominantly from the agricultural and meadow areas.     

中国西北内陆干旱盆地地下水资源评估与开发

以多年的地下水勘查经验、成果为基础，总结西北内陆干旱盆地地下水资源评估与开发中的主要问题，分析了产生这些问题的客观和主观原因；认为地下水动态监测和水运行测量统计是实现逐步逼近地下水资源量的最有效方法；提出了开发地下水库，实施地表水、地下水联合调度，稳定供水，是西北内陆干旱盆地水资源开发的最佳模式。     

陕西省宝鸡市陈仓区吴家沟滑坡风险评价

吴家沟滑坡是2008年汶川Ms 8.0级大地震触发的黄土塬边的一个中型滑坡。在野外调查、室内分析测试和滑坡稳定性计算的基础上,参照前人的研究成果,分2种情况对该滑坡进行了地质灾害风险评估,为防灾减灾提供决策依据。评估结果表明,在只考虑强降雨对滑坡影响的情况下,吴家沟滑坡个人风险介于7×10-4~4.375×10-5之间,位于严格详细审查区;在考虑强降雨+地震对滑坡影响的情况下,吴家沟滑坡个人风险介于1.32×10-3~8.325×10-5之间,位于不可接受区和严格详细审查区,人员社会风险位于不可接受区。     

陕西省宝鸡市陈仓区吴家沟滑坡风险评价

吴家沟滑坡是2008年汶川Ms 8.0级大地震触发的黄土塬边的一个中型滑坡。在野外调查、室内分析测试和滑坡稳定性计算的基础上,参照前人的研究成果,分2种情况对该滑坡进行了地质灾害风险评估,为防灾减灾提供决策依据。评估结果表明,在只考虑强降雨对滑坡影响的情况下,吴家沟滑坡个人风险介于7×10-4~4.375×10-5之间,位于严格详细审查区;在考虑强降雨+地震对滑坡影响的情况下,吴家沟滑坡个人风险介于1.32×10-3~8.325×10-5之间,位于不可接受区和严格详细审查区,人员社会风险位于不可接受区。     

陕西渭北东部岩溶水环境同位素

陕西渭北东部岩溶水系统是一个复杂的地下水系统，碳酸盐岩大面积隐伏与深埋。使用传统手段和方法勘查岩溶地下水和研究可持续开发利用方案遇到诸多困难，不仅费时，而且耗资大。本文通过系统分析研究陕西渭北东部地区岩溶地下水T、D、^180、^14C环境同位素特征，揭示岩溶水的补给迳流排泄条件、岩溶水系统边界性质以及岩溶水与黄河洛河地表水、黄河岩溶泉与洛河岩溶泉之间的补排关系。结果显示环境同位素方法简便有效，能够达到预期目的。     

陕西渭北东部岩溶地下水中硫酸盐的形成

陕西渭北东部岩溶地下水的水化学和同位素研究表明,水中硫酸盐起源主要为海相硫酸盐的溶解,其次为南部泻湖相古沉积咸水的混入。岩溶地下水中的盐分的增加主要是溶滤作用的结果。     

Geochemical and qualitative assessment of groundwater of the High Mekerra watershed,NW Algeria

Groundwater constitutes the main source of water supply in the High Mekerra watershed of northwestern Algeria. This resource is currently under heavy pressures to meet the growing needs of drinking water and irrigation. This study assesses the geochemical characteristics of groundwater of the High Mekerra watershed at 21 points distributed across the two main aquifers (Ras El Ma and Mouley Slissen) in the region. Hydrochemical facies of Ras El Ma groundwater are dominantly MgCl and CaCl type, while those of Mouley Slissen groundwater are of CaHCO₃ type. Principal component analysis shows a strong correlation between groundwater mineralization and Ca²⁺, Na⁺, Cl^? and SO₄ ^2? ions stemming from the dissolution of carbonates, gypsum and anhydrite. Groundwater mineralization evolves from south to north. Geochemical modeling shows that the High Mekerra groundwater is saturated with respect to calcite and dolomite and undersaturated with respect to gypsum and anhydrite. Nitrate concentrations that exceed the WHO standard (50 mg L^?1) at several points are linked to the agro-pastoral activities in this region.     

Current situation and human health risk assessment of fluoride enrichment in groundwater in the Loess Plateau: A case study of Dali County,Shaanxi Province,China

This study aims to investigate the mechanisms and health risks of fluoride enrichment in groundwater in the Loess Plateau, China. By taking Dali County, Shaanxi Province, China as an example, this study obtains the following results through field investigation and the analyses of water, soil, and crop samples. (1) The groundwater can be divided into two major types, namely the Quaternary pore-fissure water and Karst water. The Karst area and sandy area have high-quality groundwater and serve as the target areas for optional water supply. The groundwater in the study area is slightly alkaline and highly saline. Meanwhile, high-fluoride groundwater is mainly distributed in the loess and river alluvial plains in the depression area of the Guanzhong Basin and the discharge areas of the groundwater, with the highest fluoride concentration exceeding seven times the national standard. (2) Fluoride in groundwater mainly originates from a natural source and human activities. The natural source refers to the fluoride-bearing minerals in rocks and soil, and the fluoride from this source is mainly controlled by natural factors such as climate, geologic setting, pH, specific hydrochemical environment, ion exchange, and mineral saturation. Human activities in modern life can be further divided into industrial and agricultural sources primarily. (3) The health risks of fluoride contamination are very high in the Loess Plateau, especially for children compared to adults. Meanwhile, the risks of fluoride exposure through food intake are higher than those through drinking water intake. The authors suggest selecting target areas to improve water supply and ensure the safety of drinking water in the study area. Besides, it is necessary to plant crops with low fluoride content or cash crops and to conduct groundwater treatment to reduce the fluoride concentration in drinking water. These results will provide a theoretical basis for safe water supply in the faulted basin areas in the Loess Plateau.© 2021 China Geology Editorial Office.     

Effect of saltwater intrusion on groundwater environment in Weihe River downstream,Shandong Province,China

Based on the geological and hydrogeological conditions along with dynamic changes of groundwater level, this paper analyzes the hydrodynamic characteristics of saltwater intrusion in the study area. According to monitoring data of groundwater quality, the distribution characteristics of macro component are analyzed, and then fuzzy comprehensive evaluation method is adopted to evaluate the impact of saltwater intrusion on groundwater environment. Concerning the influence degree of groundwater environment, the study area is divided into brine area, seriously influenced area, moderately influenced zone, slightly influenced zone and uninfluenced zone. The results can offer references for prevention and control of saltwater intrusion as well as the protection of water resources.     

Effect of saltwater intrusion on groundwater environment in Weihe River downstream,Shandong Province,China

Based on the geological and hydrogeological conditions along with dynamic changes of groundwater level,this paper analyzes the hydrodynamic characteristics of saltwater intrusion in the study area.According to monitoring data of groundwater quality,the distribution characteristics of macro component are analyzed,and then fuzzy comprehensive evaluation method is adopted to evaluate the impact of saltwater intrusion on groundwater environment.Concerning the influence degree of groundwater environment,the study area is divided into brine area,seriously influenced area,moderately influenced zone,slightly influenced zone and uninfluenced zone.The results can offer references for prevention and control of saltwater intrusion as well as the protection of water resources.     

Comprehensive evaluation on the ecological function of groundwater in the Shiyang River watershed

With an arid climate and shortage of water resources, the groundwater dependent ecosystems in the oasis–desert ecotone of the Shiyang River Watershed has been extremely damaged, and the water crisis in the oasis has become a major concern in the social and the scientific community. In this study, the degeneration characteristics of the groundwater ecological function was identified and comprehensive evaluated, based on groundwater depth data, vegetation quadrat and normalized difference vegetation index (NDVI) from Landsat program. The results showed that (1) the suitable groundwater depth for sustainable ecology in the Shiyang River Watershed is about 2-4 m; (2) the terms of degenerative, qualitative and disastrous stages of the groundwater ecological function are defined with the groundwater depths of about 5 m, 7 m and 10 m; (3) generally, the groundwater ecological function in the oasis-desert ecotone of the lower reaches of Shiyang River Watershed is weak with an area of 1 397.9 km² identified as the severe deterioration region, which accounted 74.7% of the total area. In the meantime, the percentages of the good, mild and moderate deterioration areas of groundwater ecological function are 3.5%, 5.5% and 16.3%, respectively, which were mainly distributed in the Qingtu lake area and the southeastern area of the Shoucheng town; (4) the degradation and shrinkage of natural oasis could be attributed to the dramatic groundwater decline, which is generally caused by irrational use of water and soil resources. This study could provide theoretical basis and scientific support for the decision-making in environmental management and ecological restoration of the Shiyang River Watershed.     

陕西省大荔县高氟地下水的形成条件分析

为了查明陕西省大荔县高氟地下水的分布、形成条件,本文通过环境地质调查及水样测试,从地层、气象、地质地貌、水文地质及水文地球化学等几个角度进行了系统分析。研究表明,大荔县高氟地下水的分布、形成条件受地质、气候、地貌和水文地质的控制,大气降水在入渗过程中通过水岩作用及淋滤作用将岩石和土壤中氟元素带入地下水中,在蒸发作用下浓缩,最终形成高氟地下水。该研究可为解决大荔县饮水安全问题提供水文地质依据。     

Assessment of climate change impact on the stream-flow in a typical debris flow watershed of Jianzhuangcuan catchment in Shaanxi Province, China

The study on the stream-flow change associated with future climate change scenarios has a practical significance for local socio-economic development and eco-environmental protection. A study on the Jianzhuangcuan catchments was carried out to quantify the expected impact of climate change on the stream-flow using a multi-model ensemble approach. Climate change scenarios were developed by ensemble four Global Climate Models, which showed good performance for Jianzhuangcuan catchment. Soil and Water Assessment Tool (SWAT), a physically based distributed hydrological model, was used to investigate the impacts on stream-flow under climate change scenarios. The model was calibrated and validated using daily stream-flow records. The calibration and validation results showed that the SWAT model was able to simulate the daily stream-flow well, with Nash–Sutcliffe efficiency >0.83 for Yaoping Long station, for calibration and validation at daily and monthly scales. Their difference in simulating the stream-flow under future climate scenarios was also investigated. The results indicate a 0.6–0.9 °C increase in annual temperature and changes of 12.6–18.9 mm in seasonal precipitation corresponded to a change in stream-flow of about 0.62–3.67 for 2020 and 2030 scenarios. The impact of the climate change increased in both scenarios.     

Impact of land use change on groundwater quality in a typical karst watershed of southwest China: a case study of the Xiaojiang watershed,Yunnan Province

The impact of land-use change on the quality of groundwater in the Xiaotjiang watershed, China was assessed for the period 1982–2004. Groundwater samples were collected from 30 monitoring points across the watershed, and were representative of the various changes, determined by remote sensing and geographical information systems. The results indicate that 610 km² (60% of the total watershed area) were subject to land-use change during the period. The most important changes were the conversion of 135 km² of forested land to cultivated land, and 211 km² of unused land to cultivated land. The main impact was ascribed to diffuse pollution from fertilizers applied to newly cultivated land, and from building development. Overall the groundwater pH value was significantly increased, as were the concentrations of ions , , , , and Cl⁻ in groundwater whilst the concentrations of Ca²⁺ and declined. More precisely, in the regions where forested land and unused land were converted into cultivated land, the pH value and the concentrations of Mg²⁺, , , , , Cl⁻ increased whilst the concentrations of Ca²⁺ and declined. However in the region where cultivated land was converted into construction land, the pH value and the concentrations of Ca²⁺, Mg²⁺, , , , , , Cl⁻ increased.

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Résumé  L’impact des changements de l’utilisation du territoire sur la qualité de l’eau souterraine dans le bassin versant de Xiaojiang, en Chine, a été évalué de 1982 à 2004. Des échantillons d’eau souterraine ont été récoltés à partir de 30 points d’observation éparpillés sur le bassin, représentant les divers changements déterminés par télédétection et système d’information géographique. Les résultats indiquent que 610 km² (soit 60% de la surface du bassin) ont été sujets à des modifications de l’utilisation du territoire sur cette période. Les changements les plus importants furent la conversion de 135 km² de forêt et 211 km² de terres inutilisées en terres cultivées. Le principal impact est attribué à la pollution diffuse des engrais utilisés en agriculture et pour les batiments. De manière générale le pH de l’eau souterraine a augmenté significativement, ainsi que les concentrations des ions , , , , et Cl⁻, tandis que les concentration en Ca²⁺ et ont diminué. Plus précisément dans les régions transformées en terres cultivées, la valeur du pH et les concentrations en Mg²⁺, , , , , Cl⁻ ont augmenté tandis que les concentrations en Ca²⁺ et ont diminué. Toutefois dans les régions cultivées converties en zones de construction, le pH et les concentrations en Ca²⁺, Mg²⁺, , , , , , Cl⁻ ont augmenté.

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Resumen  El impacto del cambio en uso de la tierra en la calidad del agua en la cuenca Xiaojiang, China fue evaluado para el periodo 1982–2004. Muestras de agua subterránea fueron tomadas de 30 puntos de monitoreo a través de la cuenca, y fueron representativas de los múltiples cambios, determinados por sensores remotos y sistemas de información geográfica. Los resultados indican que 610 km² (60% del área total de la cuenca) estaban sujetos a cambios de uso de la tierra durante el periodo estudiado. Los cambios más importantes fueron la conversión de 135 km² de bosques a tierra cultivada, y 211 km² de tierra sin uso (ociosa) a tierra cultivada. El impacto principal fue causado por contaminación difusa de fertilizantes aplicados a la tierra recientemente cultivada, y a desarrollo de construcciones. En general el pH en agua subterránea creció significantemente, al igual que las concentraciones de los iones , , , , y Cl⁻ en agua subterránea mientras que las concentraciones de Ca²⁺ y decrecieron. Mas precisamente, en las regiones donde bosque y tierra ociosa fueron convertidas en tierra cultivada, el valor de pH y las concentraciones de Mg²⁺, , , , , Cl⁻ crecieron mientras las concentraciones de Ca²⁺ y decrecieron. Sin embargo en la región donde tierra cultivada fue convertida en construcciones, el valor de pH y las concentraciones de Ca²⁺, Mg²⁺, , , , , , Cl⁻ crecieron.

     

Nitrate pollution of groundwater in the Yellow River delta,China

Nitrate pollution of groundwater in the Yellow River delta, China is an important issue related not only to nitrate dispersion and health concerns but also to mass transport and interactions of groundwater, sea, and river waters in the coastal area. The spatial distribution of nitrate, nitrate sources, and nitrogen transformation processes were investigated by field surveys and geochemical methods. Nitrate occurred mainly in shallow layers and had a spatial distribution coinciding with geomorphology and land/water use. Irrigation water from the Yellow River and anthropogenic waste are two main nitrogen sources of nitrate in the delta, and both denitrification and mixing processes could take place according to characteristics identified by ionic and isotopic data.     

安徽合肥地区浅层地下水质量评价

对合肥地区浅层地下水取样分析, 采用单因子评价法、分类指标评价法和综合评价法对浅层地下水质量进行评价.结果显示:可以直接饮用的地下水资源 (Ⅰ类水、Ⅱ类水和Ⅲ类水) 占59. 3%, 经过适当处理可以饮用的地下水资源 (Ⅳ类水) 占30. 5%, 不能直接饮用的地下水资源 (Ⅴ类水) 占10. 2%.在地下水评价指标中, 挥发性有机指标较好, 毒性重金属指标和半挥发性有机指标次之, 无机毒理指标和一般化学指标较差.影响地下水质量的化学组分主要为铁、锰、总硬度、溶解性总固体、氟、硫酸盐和钠+钾等无机组分, 与人类活动相关的化学组分主要为氨氮、硝酸盐、亚硝酸盐、六价铬、砷、铝、碘、氯化物等无机组分和苯并 (a) 芘等有机组分.影响地下水质量的原因主要为城市和乡镇工业污水、生活污水排放, 农村农药、化肥使用及生活垃圾污染.     

陕西省煤层气资源与勘探开发前景分析

陕西省煤层气资源相当丰富,埋深2000 m以浅的煤层气资源量为25624.88亿m³。通过对五大煤田煤储层展布、煤层气含量、煤层渗透率、煤变质特征、煤的吸附性能等条件的综合分析以及煤层气资源量的计算,认为陕西省煤层气开发储层条件比较优越,煤层气勘探开发条件最好的地区为渭北和陕北石炭二叠纪煤田,韩城矿区可作为煤层气勘探开发的靶区。     

Optimization and rationalization of karst groundwater resource in Feicheng Basin,China

Feicheng Basin is an important energy base in Shandong Province, China. The Ordovician limestone is the main aquifer for water supply in the basin. As a result of the current practice in which individual water users control the exploitation of the karst water, the regional groundwater level has dropped more than 30 m over the last 20 years. The groundwater is overdrawn in approximately 300 km² because of the poor management from 1981. A numerical model with distributed parameters is developed for the karst aquifer to help properly manage the water resource and sustain its utilization. The responding matrix method is used to couple the prediction model and the management model. The objective of the modeling exercises is to obtain the maximum amount of water while keeping the water level drawdown within an acceptable level. The optimum management scheme is selected among two proposed designs. The recommended measures from this study include (1) improvement of water use efficiency in industries, (2) comprehensive utilization of the water pumped from the mines, and (3) improvement of the irrigation practice. When the domestic water supply and corporates water demand take the top priorities, the numerical modeling provides a useful tool to help with the rational distribution of the karst water resources among different water users.