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1.
Qi AN Shenggao CHENG Gang ZHU 《中国地球化学学报》2006,25(B08):94-94
Conservation of Urban Forest Site in Jiufeng is constructed as an ecotourism function urban forest conservation combining mountain and vegetation resource around. According to fieldwork, the conservation is located in the outskirts of the city where non-point pollution is dominant. In order to master the source intensity and its distribution, data from Quickbird remote sensing in 2004 and field collection are adopted to establish the environment database including data layers of districts, land use, map, soil map, DEM, water and road systems, soil property and economy. Traditional quantitative analysis of non-point pollution intensity has encountered with the following difficulties： （1） Large area of vegetation landscape reconstruction will create tremendous ecological benefits, but calculation of pollution decrease brought by reconstruction is difficult to achieve. （2） In conservation reconstruction will be implemented in the residential are step by step, i.e., of moving, repairing and centralization, which is a complex project with wide time span, leading to inaccurate prediction. （3） Construction of the conservation will speed up the development of local tourism, thus if a single society index is chosen to predict the pollution intensity, the development trend of the region could not be figured out completely. Consequently acreage of different planning land use is counted and models of urban and rural areas respectively help to compute unit pollution load. In the urban area, the pollution load of the same land use is regarded as the function of population density, clean frequency and precipitation, while in the rural area, SCS model, universal soil loss equation （USLE） and pollution transfer model are applied to compute unit pollution load of TN and TP. The results of total pollution load are TN 179.706 kg/a and TP 33.814 kg/a. For impracticability of routine planning measures, the project applies measures of distribution controlling against water erosion and soil loss and concentrated-dispersive controlling to lighten non-point pollution brought by living sewage. 相似文献
2.
Natural Hazards - The mixing process of upstream and downstream waters in the dam break flow could generate significant ecological impact on the downstream reaches and influence the environmental... 相似文献
3.
P. Ya. Tishchenko T. A. Mikhailik G. Yu. Pavlova P. P. Tishchenko A. M. Koltunov Jing Zhang 《Geochemistry International》2017,55(3):282-293
The paper suggests an accurate approach to studying carbonate equilibrium in the water of the Razdol’naya River. The approach involves measuring pH by Pitzer’s scale, using a cell without liquid junction; measuring the total alkalinity by Bruevich’s technique; and using apparent constants of carbonate equilibrium with regard for the organic alkalinity. The Pitzer technique was employed to calculate the apparent constants of carbonate equilibrium in solution that models the riverine water: Ca(HCO3)2–NaCl–H2O within the range of alkalinity of 0–0.005 mol/kg and temperatures of 0–25°C. Carbonate equilibrium in the water of the Razdol’naya River was sampled for studying at eight sites during all four seasons. Although the contents of biogenic compounds in the water are high, they can merely insignificantly affect the acid–base equilibrium, which is controlled in the riverine water by carbonate equilibrium and the concentrations of humic substances, which play the greater role, the greater the discharge of the river. In addition to the production and destruction of organic matter, carbonate equilibrium in the river is also affected by the supply of humic substances with soil waters and total alkalinity with groundwaters. The fluxes of alkalinity and humic substances annually brought by the Razdol’naya River to Amur Bay are evaluated at 1.33 × 109 mol and 9.9 × 106 kgC, respectively. The carbon dioxide export with the Razdol’naya River is equal to the alkalinity flux and does not depend on the weathering mechanisms. 相似文献
4.
Qinghui HUANG Jianhua LI Jianfu ZHAO Ran XU Li XIE 《中国地球化学学报》2006,25(B08):181-182
Biandansha, Qingcaosha and Meimaosha sands located respectively in the upper, middle and lower reaches of the Yangtze （Changjiang River） estuary are regarded as strategic drinking water sources of Shanghai City. In the coming decade, the Qingcaosha Reservoir will first be built and gradually take the place of present water sources in the Huangpu River. However, there is little report on the occurrence of persistent organic pollutants （POPs） such as organochlorine pesticides （OCPs） in those strategic water sources. Water samples collected from those strategic water sources were filtered in-situ by Whatman GF/F filters in April 20-23, 2006. Pesticides in the filtrates were enriched on ENVI-18 solid phase extraction （SPE） tubes. OCPs eluted from SPE tubes were determined by GC-μECD method with a mixed standard solution of 20 OCPs compounds. Pentachloronitrobenzene was added as internal standard. Total concentrations of OCPs varied between 15.1 and 83.1 ng/L in water samples from Shanghai strategic water sources. A half of twenty objective OCPs compounds including DDTs were not detected. In Qingcaosha waters, there were six compounds such as a-HCH, dieldrin, endrin, endrin ketone, β-endosulfan and endosulfan sulfate. Total concentrations of these OCPs ranged from 15.1 to 31.6 ng/L and averaged 19.9 ng/L. OCPs had higher concentrations at low water tide than at high water tide, and in bottom water than in surface water. In Biandansha and Meimaosha waters, lindane （T-HCH） of 9.0 ng/L and γ-chlordane of 8.8 ng/L were found, respectively. There was no significant difference between total OCPs concentrations in surface water from Biandansha and Qingcaosha, which are much lower than those in the downstream Meimaosha waters. 相似文献
5.
Hussein A. Amery 《GeoJournal》1998,44(1):19-33
The current location of the border between Lebanon and Palestine, today's Israel, is a product of various competing forces. The Zionist Organization aspired to include the entire Galilee region up to the lower reaches of the Litani River (also known as the Kassimiyah River) within Palestine. The river itself was the desired northern border of the country. The Zionists supported their position by employing instrumental arguments that were largely related to the availability of water resources. On the other hand, residents of the upper Galilee, today's southern Lebanon, demanded that they be included with Lebanon. They used their trade links with Beirut, and cultural and familial ties with other parts of Lebanon to support their position. These instrumental and expressive arguments appear to have assisted in the demarcation of the border between Lebanon and Palestine. Currently, access to the water resources, not necessarily control over them, is likely to influence negotiations between Israel and Lebanon over the future of the Israeli-occupied security zone in southern Lebanon. 相似文献
6.
Zhijun Yao Jian Liu He-Qing Huang Xianfang Song Xiaohui Dong Xin Liu 《Environmental Geology》2009,57(3):551-556
The stable hydrogen and oxygen of lake, river, rain and snow waters were investigated to understand the water cycle characteristics
of the drainage basin of Manasarovar Lake in Tibet. Both δD and δ
18O of river water are larger than those of lake water and the effect of altitude on both δD and δ
18O is not very significant. This phenomenon was suggested to occur because Manasarovar basin is located in Qinghai–Tibet Plateau
which has low latitude, high altitude, abundant glaciers, thin air and intensive solar radiation, resulting in higher evaporation
in lake water. 相似文献
7.
Doklady Earth Sciences - High variability in methane fluxes at the water–atmosphere boundary was found for the first time for the period 1990–2016 using expeditionary data. Variability... 相似文献
8.
Community perception of forest–water relationship was gathered using participatory rural appraisal tools in four watersheds of the Blue Nile River Basin in Ethiopia. These were compared and contrasted with the observational records of forest cover and water flow. Upstream and downstream communities were assessed separately to check for differences in perception based on location within a watershed. The key result of the study was that people in the study watersheds had a range of perceptions about the forest–water relationship which were watershed specific. The perceptions were generally consistent with observational evidence from the same watersheds. This study highlighted the need for locale-specific approaches to land and water management in the Basin, as well as the potential value of using community perceptions to complement the observational records which can have spatial and temporal limitations. 相似文献
9.
Paul W. Hanson 《Geoforum》2012,43(6):1182-1193
For nearly two decades, participatory conservation projects in Madagascar have failed to gain the backing of rural populations. I believe that the concept of participation as it is currently theorized and practiced by conservationists in Madagascar lies at the heart of the problem. It is essential, therefore that the notion of participation be unpacked, an egalitarian framework for the notion be formulated and the theoretical and methodological infrastructure needed to enable effective conservation praxis reconstructed. Toward this end, this paper considers two general theories of democratic political action: a Habermasian-inspired conception of deliberative democracy and Jacques Rancière’s post-structuralist account of dissensus politics. I argue that by tacking between the results of a critique of the notions of normative legitimacy and political efficacy in the deliberative model and Rancière’s politics of radical equality, users and managers of natural resources in Madagascar and elsewhere will have a set of conceptual tools toward reconstructing a more powerful, transformative participatory conservation. Ethnographic data collected from the Ifanadiana/Ranomafana region of southeastern Madagascar helps illuminate the argument. 相似文献
10.
Xun Zhou 《Environmental Earth Sciences》2014,71(3):1311-1317
In a coastal zone an understanding of the distance of the fresh water–salt water interface and its extension inland is important for prevention of sea water intrusion. In this article estimating methods are described for calculating the distance of a fresh water–salt water interface in a coastal confined aquifer based on the submarine fresh groundwater discharge. This groundwater discharge is controlled not only by the aquifer properties and hydraulic head difference, but also by the position of the fresh water–salt water interface in the coastal zone. A homogeneous and isotropic coastal confined aquifer is considered and fresh groundwater flow in the confined aquifer is thought to be at a steady state. Two observation wells at different distances in a profile perpendicular to the coastline are required in calculation of the distance of the interface toe in the coastal zone. Four coastal confined aquifers with horizontal and sloping confining beds and with varying thickness are also considered. Reasonable results are obtained when examples are used to illustrate the application of the methods. The methods require hydraulic head data at the two wells and thickness of the confined aquifers, but the hydraulic conductivity and fresh groundwater flow rate of the confined aquifers are not needed. 相似文献
11.
Wang Qiong Wang Shanyong Su Wei Pan Dongyue Zhang Zhen Ye Weimin 《Acta Geotechnica》2022,17(7):2943-2954
The design of grouting engineering in practice is either based on conventional soil mechanics or empirical procedures ignoring the effect of degree of saturation (water content). In this study, a series of laboratory-pressurized grouting tests were conducted on unsaturated sand to reveal the influence of soil water content on the grouting characteristics. With combination of direct shear tests at constant water content, water retention tests as well as microscopy observations, the mechanisms that controlling the strength and in turn the grouting characteristics in unsaturated sand were interpreted from the perspective of water–air interface. It was found that the non-monotonic phenomena of grouting characteristics (injectability and diffusion characteristics) with increasing water content were strongly dependent on the shear strength, which is influenced by the apparent cohesion induced by capillary mechanisms relating to the water–air interface. The threshold value of the injectability and diffusion pattern is corresponding to the boundary of the two transition zones (two different desaturation mechanisms) in the water retention curve. In the primary transition zone, the water phase is interconnected with air bulbs entrapped. With the drainage of bulk water in the large pores, the amount of water menisci increases, generating larger and larger surface tension force between particles. Therefore, less and less grout was injected as the bearing capacity and shear strength increase. However, in the second transition zone, with the drainage of menisci water, the menisci area of each pores decreases, inducing less and less surface tension force. Thus, more and more grout was injected as the bearing capacity and shear strength decrease. It is hoped that the work in this study will facilitate researching the grouting mechanisms in unsaturated soil, thus optimizing the grouting parameters in engineering practice.
相似文献12.
A thermodynamic model of the behavior of heavy metals in bottom sediments during their eutrophication is developed. The results
show that liberation of heavy metals from the reduced ferrous sorbent is accompanied by sorption on clay and organic sorbents.
The process is complicated by competitive correlations between heavy metals and calcium ions, while the formation of carbonate
cement in the sediments yields additional sorption. As a result, the predicted concentrations of the majority of microelements,
namely heavy metals, in the interstitial water of the reduced bottom sediments do not exceed the maximum permissible concentration
(MPC). 相似文献
13.
《Geoforum》2016
In Southeast Asia’s green economy, conservation interventions intensify the production of resources as commodities through land sparing activities and zoning in extensively used landscapes. Such initiatives encounter problems where poor resource users diversify livelihoods in multi-functional landscapes over time. In terms of ‘livelihood bricolage’ – the mixing, matching and building of portfolios – we describe how forest users enhance security by building dynamic livelihood portfolios based on the economic and socio-cultural considerations of place. Philippine case studies show how disrupting livelihood bricolage in multi-functional landscapes with ‘intensifying interventions’ spatially constrains livelihood security and conservation objectives. We conclude that more equitable forest governance supports land sharing with diverse, extensive livelihoods in varied landscapes. 相似文献
14.
Changes in hydraulic heads with space and time and evolution of the location of fresh water–salt water interface are important
for groundwater development in coastal aquifers. Measurements of piezometric heads at 11 well clusters consisting of three
piezometric wells of different depths with a 5-day interval for 15 months show that the piezometric heads at nearly all the
wells near the northwestern coast in Beihai decrease with increasing depth and increase with increasing distance from the
coast. Changes in piezometric heads at the wells during the measurement period were caused by seasonal precipitation and induced
by the tide. The depth of the sharp interface between fresh water–salt water can be estimated based on measurements of piezometric
heads at a piezometric well tapping at a point in the salt water zone below the interface and measurements of the water table
at the same well. The calculations of the interface for well H5 range from 40 to 80 m below sea level in the measurement period,
which are believed to be more reasonable than those estimated with the Ghyben–Herzberg relation.
An erratum to this article can be found at 相似文献
15.
16.
J. R. Smyth C. M. Holl F. Langenhorst H. M. S. Laustsen G. R. Rossman A. Kleppe C. A. McCammon T. Kawamoto P. A. van Aken 《Physics and Chemistry of Minerals》2005,31(10):691-705
Wadsleyite II is a variably hydrous magnesium-iron silicate phase similar to spinelloid IV and a potential host for H in the Transition Zone of the Earths mantle. Two separate samples of wadsleyite II synthesized at 17.5 GPa and 1400°C and at 18 GPa and 1350°C have been characterized by electron microprobe, single-crystal X-ray diffraction, visible, IR, Raman, and Mössbauer spectroscopies, and transmission electron microscopy including electron energy-loss spectroscopy. The two samples have the following chemical formulae: Mg1.71Fe0.18Al0.01H0.33Si0.96O4 and Mg1.60Fe0.22Al0.01 H0.44Si0.97O4. Mössbauer spectroscopy and electron energy loss spectroscopy (EELS) indicate that about half of the iron present is ferric. Refinement of the structures shows them to be essentially the same as spinelloid IV. Calculated X-ray powder diffraction patterns show only subtle differences between wadsleyite and wadsleyite II. The hydration mechanism appears to be protonation of the non-silicate oxygen (O2) and possibly the oxygens surrounding the partially vacant tetrahedral site Si2, charge-balanced by cation vacancies in Si2, M5 and M6. The unit cell volume of this phase and its synthesis conditions indicate that it may be an intermediate phase occurring between the fields of wadsleyite and ringwoodite, if sufficient trivalent cations are available. The unit cell parameters have been refined at pressures up to 10.6 GPa by single-crystal X-ray diffraction in the diamond anvil cell. The refined bulk modulus for the sample containing 2.8 wt% H2O is 145.6 ± 2.8 GPa with a K of 6.1 ± 0.7. Similar to wadsleyite and ringwoodite, hydration has a large effect on the bulk modulus. The presence of this phase in the mantle could serve to obscure the seismic expression of the phase boundary between wadsleyite and ringwoodite near 525 km. The large apparent effect of hydration on bulk modulus is consistent with hydration having a larger effect on seismic velocities than temperature in the Transition Zone. 相似文献
17.
E. Bocanegra O. M. Quiroz Londoño D. E. Martínez A. Romanelli 《Environmental Earth Sciences》2013,68(8):2347-2357
This paper gives an account of the assessment and quantification of the water balance and the hydrogeological processes related to lake–groundwater interaction in the Pampa Plain by using hydrogeochemical, isotopic and flow numerical modeling techniques. La Salada is a permanent shallow lake, with an area of 5.8 km2, located on the SE of Buenos Aires Province. A total of 29 lake water samples and 15 groundwater samples were collected for both hydrochemical analysis and environmental stable isotope determination. Water table depths were measured in wells closed to the lake. Groundwater samples appear grouped on the Local Meteoric Water Line, suggesting a well-mixed system and that rainfall is the main recharge source to the aquifer. Water evaporation process within La Salada is also corroborated by its isotopic composition. The model that best adjusts to La Salada Lake hydrochemical processes includes evaporation from groundwater, calcite precipitation with CO2 release and cationic exchange. The annual water balance terms for the lake basin indicates for each hydrological component the following values: 1.16 E08 m3 rainfall, 8.15 E07 m3 evapotranspiration, 1.90 E06 m3 runoff, 1.55 E07 m3 groundwater recharge, 6.01 E06 m3 groundwater discharge to the lake, 9.54 E06 m3 groundwater discharge to the river, 5.00 E05 m3 urban extraction and 4.90 E06 m3 lake evaporation. Integrated analysis of hydrochemical and isotopic information helped to calibrate the groundwater flow model, to validate the conceptual model and to quantitatively assess the basin water balance. 相似文献
18.
Water pollution is a widespread problem in different areas of the world. Some of these problems originated from point contamination sources and widespread contaminant outlet sources which are observed in every country. The major elements and chemical loads of surface water have been dominated by constituents derived directly or indirectly from human activities and/or industrial practices that have increased additives in the last several decades. The point sources of contamination may result from the direct wastewater discharges to the dam sites, which are considered to be the most commonly encountered water pollution problems. One of these problems is the eutrophication process which usually occurs in the static water mass of lakes and other surface water reservoirs. This process may be caused by the continuous increase of nitrogen and phosphorus contents and decrease of O2 level in water causing an anaerobic condition which may stimulate algae-growth flow in these water bodies, consequently reducing the quality of water. Of course, there are many research methods for determining the various kinds of water pollution. In this research, the hydrochemical parameters were evaluated to estimate the types of pollution sources, the level of pollution, and its environmental impacts on the Tahtal dam reservoir. 相似文献
19.
Saumya Singh A. B. Samaddar R. K. Srivastava H. K. Pandey 《Journal of the Geological Society of India》2014,83(3):295-302
Water consumption is likely to increase substantially in the future on account of rising population, economic growth, and social development. Rapid urbanization and population growth of Allahabad city, has necessitated thinking about the declination in ground water level as well as supply of sufficient quantity of water for future either for drinking purpose or industrial use. In the present study, rainfall recharge of Allahabad city has been computed on GIS platform (ArcInfo). Groundwater recharge potential zones of Allahabad city have also been found out using GIS. Case study of recharge of ground water through roof top rainwater harvesting at Vikas Bhawan (a multistoryed building), Allahabad is discussed. An implementation of this analysis and decision making software is expected to work for sustainable water management. 相似文献
20.
Application of syringe-driven chelate-minicolumn in determination of trace elements in water samples
《中国地球化学学报》2006,(Z1)
The direct determination of most trace elements in natural water samples is still very difficult even if the high-sensitivity atomic analytical instrument, such as ICP-MS, is available. The reasons are (1) the natural concentrations of most trace elements… 相似文献