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1.
Ghulam Jeelani Rouf Ahmad Shah Rajendrakumar D. Deshpande Ashok P. Dimri Suraj Mal Anupam Sharma 《水文研究》2021,35(11):e14406
Western disturbances (WDs) and Indian summer monsoon (ISM) led precipitation play a central role in the Himalayan water budget. Estimating their contributions to water resource is although a challenging but essential for hydrologic understanding and effective water resource management. In this study, we used stable water isotope data of precipitation and surface waters to estimate the contribution of ISM and WDs to the water resources in three mountainous river basins - Indus, Bhagirathi and Teesta river basins of western, central and Eastern Himalayas. The study reveals distinct seasonality in isotope characteristics of precipitation and surface waters in each river basin is due to changes in moisture source, hydrometeorology and relief. Despite steady spatial variance in the slope and intercept of regression lines from the Teesta to Indus and the Bhagirathi river basins, the slope and intercept are close to the global meteoric water line and reported local meteoric water line of other regions in the Himalayas and the Tibetan Plateau. The two-component end-member mixing method using d-excess as tracer were used to estimate the contribution from ISM and WD led precipitation to surface water in aforementioned river basins. The results suggest that the influence of the ISM on the water resources is high (>72% to annual river flow) in Teesta river basin (eastern Himalayas), while as the WDs led precipitation is dominantly contributing (>70% average annual river flow) to the surface waters in the Indus river basin (western Himalayas). The contribution of ISM and WD led precipitation in Bhagirathi river basin is 60% and 40%, respectively. The findings demonstrate that the unusual changes in the ISM and WD moisture dynamics have the potential to affect the economy and food security of the region, which is dependent on the availability of water resources. The obtained results are of assistance to policy makers/mangers to make use of the information for better understanding hydrologic response amid unusual behaviour of the dual monsoon system over the region. 相似文献
2.
Risk assessment of maize drought disaster in southwest China using the Environmental Policy Integrated Climate model 总被引：2，自引：0，他引：2
The East Asian monsoon has a tremendous impact on agricultural production in China. An assessment of the risk of drought disaster in maize-producing regions is therefore important in ensuring a reduction in such disasters and an increase in food security. A risk assessment model, EPIC(Environmental Policy Integrated Climate) model, for maize drought disasters based on the Erosion Productivity Impact Calculator crop model is proposed for areas with the topographic characteristics of the mountainous karst region in southwest China. This region has one of the highest levels of environmental degradation in China. The results showed that the hazard risk level for the maize zone of southwest China is generally high. Most hazard index values were between 0.4 and 0.5,accounting for 47.32% of total study area. However,the risk level for drought loss was low. Most of the loss rate was 0.1, accounting for 96.24% of the total study area. The three high-risk areas were mainlydistributed in the parallel ridge–valley areas in the east of Sichuan Province, the West Mountain area of Guizhou Province, and the south of Yunnan Province.These results provide a scientific basis and support for the reduction of agricultural drought disasters and an increase in food security in the southwest China maize zone. 相似文献
3.
Multi-factor impact analysis of agricultural production in Bangladesh with climate change 总被引：1，自引：0，他引：1
Alex C. Ruane David C. Major Winston H. Yu Mozaharul Alam Sk. Ghulam Hussain Abu Saleh Khan Ahmadul Hassan Bhuiya Md. Tamim Al Hossain Richard Goldberg Radley M. Horton Cynthia Rosenzweig 《Global Environmental Change》2013,23(1):338-350
Diverse vulnerabilities of Bangladesh's agricultural sector in 16 sub-regions are assessed using experiments designed to investigate climate impact factors in isolation and in combination. Climate information from a suite of global climate models (GCMs) is used to drive models assessing the agricultural impact of changes in temperature, precipitation, carbon dioxide concentrations, river floods, and sea level rise for the 2040–2069 period in comparison to a historical baseline. Using the multi-factor impacts analysis framework developed in Yu et al. (2010), this study provides new sub-regional vulnerability analyses and quantifies key uncertainties in climate and production. Rice (aman, boro, and aus seasons) and wheat production are simulated in each sub-region using the biophysical Crop Environment REsource Synthesis (CERES) models. These simulations are then combined with the MIKE BASIN hydrologic model for river floods in the Ganges-Brahmaputra-Meghna (GBM) Basins, and the MIKE21 Two-Dimensional Estuary Model to determine coastal inundation under conditions of higher mean sea level. The impacts of each factor depend on GCM configurations, emissions pathways, sub-regions, and particular seasons and crops. Temperature increases generally reduce production across all scenarios. Precipitation changes can have either a positive or a negative impact, with a high degree of uncertainty across GCMs. Carbon dioxide impacts on crop production are positive and depend on the emissions pathway. Increasing river flood areas reduce production in affected sub-regions. Precipitation uncertainties from different GCMs and emissions scenarios are reduced when integrated across the large GBM Basins’ hydrology. Agriculture in Southern Bangladesh is severely affected by sea level rise even when cyclonic surges are not fully considered, with impacts increasing under the higher emissions scenario. 相似文献
4.
It is important to have qualitative as well as quantitative understanding of the hydraulic exchange between lake and groundwater for effective water resource management. Dal, a famous urban fresh water lake, plays a fundamental role in social, cultural and economic dynamics of the Kashmir Valley. In this paper geochemical, isotopic and hydrological mass balance approaches are used to constrain the lake water–groundwater interaction of Dal Lake and to identify the sources of lake water. Water samples of precipitation (n = 27), lake water (n = 18) and groundwater (n = 32) were collected across the lake and its catchment for the analysis of δ18O and δ2H. A total of 444 lake water samples and 440 groundwater samples (springs, tube wells and dug wells) were collected for the analysis of Ca2+, Mg2+, HCO3 ?, SO4 2?, Cl?, NO3 ?, Na+ and K+. Water table and lake water level were monitored at 40 observation locations in the catchment. Water table map including pH and EC values corroborate and verify the gaining nature of the Dal Lake. Stable isotopes of lake water in Boddal and Gagribal basins showed more deviation from the global meteoric water line than Hazratbal and Nigeen basins, indicating the evaporation of lake water. The isotopic and geochemical mass balance suggested that groundwater contributes a significant proportion (23–40%) to Dal Lake. The estimated average groundwater contribution to Dal Lake ranged from 31.2 × 103 to 674 × 103 m3 day?1 with an average of 276 × 103 m3 day?1. The study will be useful to delineate the possible sources of nutrients and pollutants entering the lake and for the management of lake water resources for sustainable development. 相似文献
5.
Considered is a case of the cumulonimbus cloud development in the southwestern part of Saudi Arabia with a very high precipitation intensity. The height of the cloud top amounted to 14 km and the radar reflectivity, to 60 dBZ. Carried out is the comparison of remote methods of measuring the intensity of precipitation from the cloud under study: the radar (using the relationship between the reflectivity and precipitation intensity) and satellite IR-radiometric (based on the results of sounding with the SEVERI radiometer installed at the Meteosat-8 satellite) methods. A split-window technique was used for detecting the position of the cloud top from the radiometric observations. The analysis enabled to select the best relationships for estimating the precipitation intensity from the data of radar and satellite measurements. The computations based on these relationships correspond most closely to the ground-based measurements with the precipitation gage. 相似文献
6.
Extreme events have gained considerable scientific attention recently due to their potentially catastrophic impacts. Heat waves are thought to be more pronounced now in most parts of the world, and especially in South Asia, but doubts remain. The aim of this study is to calculate the frequency and intensity of heat waves in South Asia, focusing on Pakistan and identifying the regions within Pakistan that are most vulnerable to heat waves. Analyses have been performed both at provincial and country levels from 1961 to 2009. The provincial level analysis shows positive trends for heat waves of magnitudes ≥40°C and ≥45°C for 5 and 7 consecutive days. Events of magnitude ≥40°C and ≥45°C for 10 consecutive days also increased in frequency in Punjab, Sindh, and Balochistan. These regions are therefore considered to be the regions most vulnerable to heat wave events in Pakistan. The Balochistan region shows a consistently increasing trend throughout the study period, which may lead to more frequent drought in the future. The country level analysis indicates an increase in the frequency of 5 and 7 consecutive days heat waves at all defined temperature thresholds. The 10-days heat waves spells show a slight increase at ≥40°C and no significant change at ≥45°C. The Gilgit Baltistan and Azad Jammu & Kashmir areas reported no events at ≥45°C for 5, 7 and 10 continuous days. It is anticipated that with a long term rise in temperatures around the globe, heat waves will become more frequent and intense in all parts of the world, including Pakistan. 相似文献
7.
一次引发南亚大暴雨的季风低压结构、涡度与水汽收支分析 总被引：12，自引：2，他引：10
对2003年夏季风期间,7月24～28日印度季风槽内季风低压发展西移与阿拉伯海中尺度低压合并引发南亚的一次大暴雨过程进行了诊断分析,探讨了印度季风槽、季风低压的三维结构以及低压区域的涡度、水汽收支.揭示和确认了一些事实:1)印度季风槽区对流层中下层存在明显的风场切变,槽区高温高湿,为单一性质的热带气团,低层为对流不稳定,槽区对应正涡度区;2)季风低压是一较深厚系统.动力结构为低层正涡度,高层负涡度,低层辐合,高层辐散.其西移速度约500 km·d.季风低压北侧整层为深厚的东风,南侧在对流层中低层为西风,在高层为东风.热力结构在低层(700～800 hPa)间存在弱冷区,而中高层几乎为暖心结构.低压对应高湿区,低压中心西侧整层为相对湿度大值区;3)季风低压的发展过程中,低层的辐合场制造正涡度,促进低压的发展;4)低压区水汽强烈辐合,西边界输入量最大.在此研究工作的基础上,作者还比较了夏季风期间南亚印度季风槽和东亚梅雨锋系统的异同. 相似文献
8.
Assessment of Trace Metal Contamination of Drinking Water in the Pearl Valley,Azad Jammu and Kashmir
Saboor Javaid Syed Ghulam Sarwar Shah Abdul Jabbar Chaudhary Mohammad Haleem Khan 《洁净——土壤、空气、水》2008,36(2):216-221
The aim of this study was to assess trace metal contamination of drinking water in the Pearl Valley, Azad Jammu and Kashmir (Pakistan). The objectives were to determine physical properties and the dissolved concentration of five trace metals, i. e., lead, copper, nickel, zinc, and manganese, in drinking water samples collected from various sites of municipal water supply, natural water springs and wells in the valley. Concentrations of the metals in the water samples were determined by flame atomic absorption spectrometry. Results showed physical parameters, i. e., appearance, taste and odor within acceptable limits and pH was between 5.5 and 7.0. The observed concentrations of the metals varied between sources of water samples and between sampling sites. Maximum dissolved concentration observed was 4.7 mg/L for Pb and Mn, 4.6 mg/L for Zn, 2.9 mg/L for Ni and 2.8 mg/L for Cu. The observed concentrations of the metals were compared with the World Health Organization's guideline values for drinking water. Overall, the quality of water samples taken from the water springs at Mutyal Mara and Bonjosa was good; however, the water quality was unsuitable for drinking in Kiraki, Kharick, and Pothi Bala localities particularly. Finally, the authors discuss possible causes for increased concentrations of the trace metals in drinking water in the study area. 相似文献
9.
3D geological modeling of Punjab platform,Middle Indus Basin Pakistan through integration of Wireline logs and seismic data 总被引：1，自引：0，他引：1
3D Geological control in an area is a key to success for exploration of hydrocarbon. Any discrepancy in geological control leads towards dry wells and ultimately high economic loss. The aim of this study is to build a 3D subsurface geologic model of Punjab platform, Pakistan by integrating mud logs, wire line logs and seismic data for interpreting the structural trends of pre-tertiary geological formations. For this purpose, wire line and mud logs of eighteen wells and about 1500LKm 2D seismic data of Punjab platform was collected from Directorate General of Petroleum Concession (DGPC) Islamabad, Pakistan. A well correlation profile is developed using Petrel and CorelDraw software to assess the distribution of subsurface geological sequences. Synthetic seismograms were developed and then correlated with seismic stacks to pick the horizons of different formations. Time Contour, velocity contour, depth contour and isopach maps are constructed. These maps were then loaded in Structural Modeling window of Petrel software for final construction of 3D geological model. The proposed model indicates that there is a sub-surface monoclinal trend dipping towards a western side of the study area. Further, an anticline at Cambrian level near Fortabbas-Bijnot area is extending to the East in the neighbouring India. In addition, horst and graben structures are also identified at Cambrian level by seismic data. The proposed model is confirmed by results of earlier data, and it is, therefore, recommended that 3D seismic data should further be acquired to explore the structural and stratigraphic traps of Punjab platform, Pakistan. 相似文献
10.
A. A. Sin’kevich T. W. Krauss A. S. Ghulam A. B. Kurov 《Russian Meteorology and Hydrology》2013,38(9):587-597
Analyzed is the development of three cumulonimbus clouds seeded with the crystallizing reagent in Saudi Arabia. Continuous satellite and radar observations of the clouds were carried out during the five-hour period. Obtained are the data on the dynamics of cumulonimbus clouds and their anvils. The vertical development of cumulonimbus clouds and the increase in the radar reflectivity and amount of precipitation were observed after the seeding. The significant increase in the precipitation was observed in all three cases. The results obtained in the present analysis are in agreement with theoretical concepts of the seeding effects on dynamic properties of clouds and precipitation characteristics. They demonstrate a big potential of seeding for increasing the precipitation falling from cumulonimbus clouds. 相似文献