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利用2015年8月至2016年7月在印度河上游流域Bagrot山谷降水稳定同位素（δ18O和δD）观测结果以及当地气象资料,利用同位素示踪及统计分析方法,并结合HYSPLIT模型,对研究区降水稳定同位素变化特征、大气水线以及水汽来源进行了分析。结果表明,观测期间Bagrot山谷降水稳定同位素的季节变化明显,δ18O与δD秋冬季偏低,春夏季偏高,且与气温变化一致,存在显著的温度效应,而降水量效应不明显。而且发现,研究区局地大气水线截距和斜率均低于全球的,反映了降水过程中云下二次蒸发作用较为强烈,特别是,不同的降水形态导致该研究区局地大气水线的斜率和截距不同。当液态降水（降雨）发生时,由于在较为干旱的气候环境下,雨滴在降落的过程中受到二次蒸发相对较强,使得局地大气水线的斜率和截距偏低;而当固态降水（降雪）发生时,由于温度较低,受再循环水汽和二次蒸发的影响较小,导致局地大气水线的斜率和截距均偏高。Bagrot山谷及其周边地区,从南到北局地大气水线的斜率相差不大,而其截距总体上随着纬度升高而降低,可能与云下二次蒸发导致稳定同位素发生的不平衡分馏逐渐强烈有关。通过Bagrot山谷站点降水稳定同位素观测结果并结合HYSPLIT模型的后向追踪,研究还发现,研究区全年主要受西风环流以及局地环流的影响。但与研究区以北的临近站点（慕士塔格、和田等）相比有所不同,由于Bagrot山谷位置更靠南,其仍然偶尔受到来自南方的海洋性水汽影响。这一研究结果可能对该地区树轮稳定同位素记录的解译具有一定的指示意义。 相似文献
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In India, the annual production of tea is ca. 857,000 tonnes, which is 27.4% of the total world production. The amount of tea factory waste (TFW) produced per annum after processing is ca. 190,400 tonnes. TFW can be used as a low cost adsorbent for the removal of toxic metals from the aqueous phase. An investigation was carried out to study the feasibility of the use of TFW as an adsorbent for the removal of the heavy metal, zinc. Equilibrium, kinetic and thermodynamic studies were reported. The straight line plot of log (qe–q) versus time t for the adsorption of zinc shows the validity of the Lagergren equation. The various steps involved in adsorbate transport from the solution to the surface of the adsorbent particles were dealt with by using a Weber‐Morris plot, qe versus t0.5 for the TFW. The rate controlling parameters, kid,1 and kid,2, were determined and it was found that the macro‐pore diffusion rate was much larger than micro‐pore diffusion rate. A batch sorption model, which assumes the pseudo‐second‐order mechanism, was used to predict the rate constant of sorption, the equilibrium sorption capacity and the initial sorption rate with the effect of initial zinc (II) ion concentration. Equilibrium data obtained from the experiments were analyzed with various isotherms, i. e., Freundlich, Langmuir, Redlich‐Peterson and Tempkin. The adsorption equilibrium was reached in 30 min and the adsorption data fitted well to all models. The maximum adsorption capacity of TFW for zinc (II) ions was determined to be 14.2 mg/g. The capacity of adsorption on Zn(II) increased with increasing temperatures and pH. The maximum uptake level of zinc was observed at pH of 4.2. The various thermodynamic parameters, i. e., ΔG°, ΔH° and ΔS°, were estimated. The thermodynamics of the zinc ion/TFW system indicated a spontaneous, endothermic and random nature of the process. The results showed that the TFW, which has low economical value, is a suitable adsorbent for the removal of zinc (II) ions from aqueous solutions. 相似文献
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Mohammed Atif Kishk 《GeoJournal》1993,31(1):77-84
This paper briefly presents the current state of land degradation in Egypt and then discusses the socio-economical and institutional aspects that are relevant to the problem and have bearings on possibilities of sustaining agricultural development efforts. 相似文献
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Conceptual issues in dealing with land degradation/conservation problems in developing countries 总被引：1，自引：0，他引：1
Mohammad Atif Kishk Dr. 《GeoJournal》1990,20(3):187-190
Among experts in the field, there is general agreement that land degradation/conservation is a matter of life or death to hundreds of millions of people. There is general agreement too that in spite of the great efforts being made to combat desertification in the last 10 years, the problem is growing worse every day. On the other hand the technology and know-how to deal with all sorts of land degradation problems is available everywhere in abundance. Why then do we in the developing world, the most affected by the problem, seem handicapped or not able to deal effectively with it? What do we really lack? Do we lack the knowledge, the experience, the money or do we lack the will to live? This paper, while trying to give at least partial answers to all those questions, assumes that the right way of thinking in dealing with resources degradation is the most serious thing we are lacking. With some examples from Egypt and other developing countries, the paper will point to some aspects that may constitute part of the conceptual framework that is required to save our world and to keep the forthcoming disasters at an acceptable level. 相似文献
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Atif AHMAD WANG Chao TANG Yixian Mubbashra SULTAN Attia FALAK DUAN Wei WANG Jing 《资源与生态学报(英文版)》2022,13(5):826-841
The judicious use and management of natural resources is vital to achieve sustainable development. Land and water are prime natural resources, and their depletion and degradation can lead to serious threats like land subsidence. Land subsidence is a phenomenon of the alteration of elevation at a point on the earth through the sinking of the surface. It occurs when the earth’s surface loses its support. The major causes of land subsidence include groundwater extraction, mining, construction overload, and other similar factors that increase pressure on the surface and eventually subsidize the land. Urban centers with excessive groundwater extraction and infrastructure development are at a high risk of subsidence. Lahore, the second-largest city in Pakistan, is undergoing an enormous increase in population density, uncontrolled urbanization with very large-scale construction projects, and intensive groundwater extraction which are responsible for subsidence directly or indirectly. Therefore, studies on groundwater status and unplanned urban appraisals have seriously urged monitoring of the subsidence in Lahore. Herein, we used freely available Sentinel-1 data for one year (from August 2018 to August 2019), with a high spatial and temporal resolution, to monitor subsidence in Lahore. The data were processed using the SNAP/StaMPS approach for Persistent Scatterer Interferometric Synthetic Aperture Radar (PSI) analysis, which is an advanced InSAR technique. The displacement velocity map from InSAR processing shows a significant land deformation in the area with values ranging from -114 to 15 mm yr-1. Along with the Sentinel-1 data, we also used supplementary data obtained from various government agencies of Pakistan to study the land cover map, transportation network and waterways of Lahore, soil types, population density, and field points for assessing the results and understanding the roles of various factors in the occurrence of uplift or subsidence. A strong correlation was established between subsidence and various parameters such as groundwater extraction and lowering of the water table, soil type variations, land cover changes, surface water channels, and population density. The deformation map confirms the greatest subsidence in the central part of Lahore, while the uplift is observed in the less populated and rural areas situated near Ravi River. The land subsidence and uplift could be attributed to groundwater extraction and recharge through the canal system and the river, respectively. 相似文献
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H. Neumeister Klaus D. Aurada A. Wallner Jörg Roesler Jarmo Eronen Mohammed Atif Kishk 《GeoJournal》1992,26(2):230-232
The accumulation of geographical scholarship since the late nineteenth century has encouraged a fusion of historical and geographical skills and interests. In the process, the study of the history of geographical thought should continue to strengthen its central position within the subject as a whole. Yet at the same time, research into this modern era insists upon a more generous incorporation of significant contributions to environmental appraisal and landscape authorship developed by government and non-government actors, and a consideration of vernacular or non-scientific modes of inquiry. The Commission's work draws attention to these important trends and lays the foundation for a broader discussion of their implications. 相似文献
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While historically significant for ancient civilizations, the Indus basin is also known for its floods and complex anthropogenic management history. Resulting from years of modifications by the pre-British era Mughal rulers followed by the post-partition division of river waters among the two neighbors, India and Pakistan, Pakistan faces severe management and financial challenges of water management. This study investigates the intricacies arising from this complicated management doctrine for the lower Indus basin. A detailed remote sensing-based analysis of the significant floods to hit the lower Indus basin since 2000 has been provided. Flood years were identified, and Moderate Resolution Imaging Spectroradiometer (MODIS) data for the years 2003, 2005, 2006, 2010, 2011, 2012, 2015, and 2016 were used to map their spatiotemporal extents. Almost all the flood water accumulated in the north is released in one river channel of the lower Indus basin. Further, the challenges were exacerbated due to the excessive rainfall in 2011 and 2012 in southeastern Sindh. A trend analysis of rainfall data shows an increase in the southern basin in the last 21 years, particularly toward the central plains and Sindh Province. The floodwater accumulated in the lower basin for as many as?~?425 days on average, stretching to?~?800 days of stagnancy in some places. The water stagnation period has been the highest in the river floodplain, highly populated and cultivated. The analyses of the current study suggest that the riverine channel has been better managed after the 2010 floods; however, the monsoon’s shift in 2011 and 2012 led to widespread disaster in low-lying regions of Sindh Province.
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