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Clustering of the Districts of West Bengal Based on Spatial and Temporal Distribution of Groundwater Table Depth Towards Effective Monitoring and Management of the Valuable Water Resources
2015
Vishwajith K. P. | Sahu P. K. | Noman Md. | Dhekale B. S. | Narasimhaiah L.
Fluctuations of groundwater table (GWT) has great role in agriculture through assured supply of irrigation in industry and other fronts. As such, probability of possible GWT also plays an important role in terms of efficient usages of this valuable resource. An attempt has been made to find probability distributions taking seasonal (January, May, August and November for 2005 to 2013) information on GWT for the districts under five agro-climatic zones of West Bengal. The study reveals that 17 districts of West Bengal, India, can be categorised into 6 probability model groups: Weibul, Normal, Weibul (3P), Log Logistic (3P), Log Normal (3P) and Gamma (3P). These models can be used to ascertain the probability of occurrences of GWT in specific district. Cluster analysis, using GWT figures for various seasons over the period of study reveals that the districts could be grouped into four clusters, which in-turn may facilitate clusterwise strategy for restricting the depletion of GWT depth or maintenance of the same. These techniques can be used for intradistrict GWT analysis for efficient monitoring of GWT.
Показать больше [+] Меньше [-]GIS Based Oil Spill Risk Assessment Model for the Niger Delta’s Vegetation
2015
Mohamadi Bahaa | Xie Zhong | Liu Fujiang
Frequent oil spills in the Niger Delta have severely influenced the environment in oil production and transportation areas. Vegetation degradation is one of the remarkable results of oil spills in the region. Hence, GIS was used to build an Oil Spill Risk Assessment Model for Vegetation (OSRAMV) in the southern part of the Rivers state, mainly in the Bonny district to define areas under high levels of oil spill hazard and vegetation areas under high oil spill risk. Oil Spill Hazard Model (OSHM) was examined to ensure its accuracy by recorded oil spill impacted areas | 71.6% of impacted areas pixels were in severe hazard areas. Whereas none of impacted areas were located in very low, or low oil spill hazard areas. The final OSRAMV showed that 66.5% of the examined oil spill sites were located in high risk areas.
Показать больше [+] Меньше [-]Growth Characteristics of Oxyrrhis marina and Chattonella marina in their Co-culture Systems
2015
An Xinlong | Li Xuemei | Li Zhixia
This study was aimed to investigate the growth characteristics of Oxyrrhis marina and Chattonella marina in co-culture to provide experimental evidences for discussing successions of harmful algal blooms (HABs) and coastal biological communities. The colour changes of culture media of C. marina and growth characteristics of O. marina and C. marina in co-culture were analysed by the combined methods of macroobservation, microscopic examination and counting. In co-culture, the colours of culture media of C. marina had changed and their transparencies had increased with increasing elapsed incubation time after inoculated by O. marina under different initial cell densities. With the increase of the initial density of O. marina (0.17×104 cells/mL, 0.50×104 cells/mL and 0.64×104 cells/mL in C. marina culture media), the time required, that the populations of O. marina reached the stationary phases, was shorter i.e. 6d, 5d and 3d after inoculated by O. marina, respectively, and the death time of all cells of C. marina became shorter, i.e. 7d, 6d and 4d after inoculated by O. marina, respectively. During the 15 days culture period, all C. marina populations were evolved to O. marina populations. Residues of C. marina adhering to precipitates and chromatophores scattering in the culture media could strengthen the colour of culture media, C. marina populations were evolved to O. marina populations respectively within the concentrations designed in co-culture in this experiment. Disturbance feeding was one of the reasons for successions, and the results provide experimental evidences for discussing successions of red tides and coastal biological communities.
Показать больше [+] Меньше [-]Evaluation and Comparison of the Resource and Environmental Carrying Capacity of the 10 Main Urban Agglomerations in China
2015
Zhang Jiansheng | Hu Xiuzhong | Li Qin | Kopytov Celly
A comprehensive evaluation index system is established in this study, and evaluation and comparison of resource and environmental carrying capacity from 2005 to 2012 are conducted from four aspects, namely, land, water resource, transportation and environment. Research results show that from 2005 to 2012, the carrying capacity of the 10 main urban agglomerations increased, except for the wing of Beijing and Tianjin urban agglomeration. A significant difference in carrying capacity was observed. Among the top 10 urban agglomerations, the resource and environmental carrying capacity of the eastern region is the highest, followed by that of the central region. The resource and environmental carrying capacity of the western region is the lowest. Traffic capacity, circular economy development level, water resource consumption, and industrial pollution emission are the main reasons for the difference in resource and environmental carrying capacity.
Показать больше [+] Меньше [-]Response of Ecological Base Flow to Water and Sediment Dispatching in Irrigation Areas Along Water-Deficient and Sediment-Laden River
2015
Wang Hongjie | Gao Jianen | Ji Jianmei | Xu Xiuquan | Zhao Chunhong
Ecological base flow is a basic requirement of water flow for a healthy river ecosystem. But in Weihe River the ecological flow is not guaranteed because of the water shortage, high sediment concentration and considerable agricultural water use along the river. In this study, Baojixia under-tableland irrigation area was selected as a representative area to which a mathematical model of one-dimensional steady water non-uniform sediment regulation was applied, to analyse the impact of channel desilting on guaranteeing the ecological base flow of Weihe River. The results indicated that scouring and silting of the channel was significantly correlated with the channel water capacity and sediment content in water flows. In addition, channel desilting contributed to 55.9×104m3 and 79.2×104m3 water saving in the irrigation area in January and December which belonged to the dry season. Their contribution rates to basic flow were 3.5% and 4.9%, respectively.
Показать больше [+] Меньше [-]Quantifying the Impact of Climate, Irrigation and Nitrogen on Winter Wheat Yield in Guanzhong Plain of Northwest China
2015
Ji Jianmei | Cai Huanjie | He Jianqiang | Wang Jian
Wheat (Triticum durum) yields have increased significantly because of the increasing higher irrigation and fertilizer inputs since the last half of 20th century. With varying climate and rising population, increasing focus is being given to enhancing resource use efficiency while increasing yields. This study utilized the CERES (Crop Estimation through Resource and Environment Synthesis) - Wheat model to analyse the impact of irrigation, nitrogen (N) and climate on wheat yield, using 58-year climate data. Analyses were conducted using four assumed scenarios with step-by-step method. Results showed that the optimum irrigation and nitrogen ranges were not uncertain when taking into account a single factor. When considering both irrigation and nitrogen, the impact of irrigation on simulated grain yield was greater than that of nitrogen, which was similar to the results obtained from the experiments. The average variation in grain yield was attributed to irrigation (46.8%), nitrogen (5.5%) and climate (2.4%). Besides, relative humidity and maximum temperature were consistently and significantly correlated with grain yield under all conditions, while precipitation had a significant correlation with grain yield when no irrigation or N was applied, or one of them was applied. However, solar radiation was significantly correlated with grain yield when both irrigation and N were available.
Показать больше [+] Меньше [-]Bispyribac Sodium Persistence in Soil, Plant and Grain in Direct Seeded Rice and its Effect on Soil Properties
2015
Ramprakash T. | Madhavi M. | Yakadri M. | Srinivas A.
A field experiment on direct-seeded rice was conducted during kharif 2011 and 2012 at the College Farm, ANGRAU Hyderabad, to study the influence of different doses of bispyribac sodium 10% SC (10, 15, 20, 25 and 40 g a.i/ha) on physical, physico-chemical and fertility properties of the soil. Persistence of the herbicide in soil from application to harvest of the crop and the residues in plant samples at harvest were also studied. No significant changes in physical (texture, bulk density, particle density, pore space, maximum water holding capacity), physico-chemical (pH, EC, CEC, organic carbon) and fertility properties of the soil (available N, P2O5 and K2O) were noticed at any of the applied doses. Bispyribac sodium dissipation in soil followed a first-order decay process. Half-life (DT50) of bispyribac sodium was 13.10 days, 10.21 days and 9.93 days at 40 g/ha, 25 g/ha and 20 g/ha doses respectively. DT90 values were also calculated. No detectable residues of bispyribac sodium were found in the straw or grain at the time of harvest.
Показать больше [+] Меньше [-]A Study on Coupling and Coordinating Development Mechanism of China’s Low-carbon Development and Environmental Resources System
2015
Cong Haibin | Zou Deling | Wu Fuxiang | Zhang Qiufang
With the rapid development of China’s modern industry, human beings have consumed enormous amounts of high-carbon energy resources. This has caused huge destruction to the systems of environmental resources. Low-carbon development is the best solution to the irrational demand for natural resources, environmental pollution and other associated problems. This study discusses the coupling and coordinating mechanism of low-carbon development and environmental resource system. Herein, we argue that lowcarbon development is a necessary requirement for the improvement of environmental resource system and it can promote an effective utilization of environmental resource. The improvement of environmental resource system is also conducive to low-carbon production. This paper studies 31 provinces, municipalities and autonomous regions in China, establishes index system, comprehensively applies entropy evaluation method and coupling coordination model, measures the coupling and coordination degree of two systems, and arrives at the following conclusions. From 2000 to 2013, the comprehensive level and the coordinating degree of China’s low-carbon development and environmental resource system generally increased, Shandong and Guangdong rank at the top of provincial-level administrative region, the two provinces also have a high coordinating degrees. Also, this study puts forward several policy recommendations to upgrade the coupling and coordinating development of low-carbon and environmental resource system.
Показать больше [+] Меньше [-]Delineation of Groundwater Potential Zones in Vettikavala Block, South Kerala, India Using Geospatial Technology
2015
Vidhya G. S. | Binoj Kumar R. B.
Geospatial technology was utilized in this study to specifically delineate groundwater potential zones. IRS-LISS III data in conjunction with Survey of India toposheet (1:50,000) and extensive field data were used for the preparation of various thematic maps. Various thematic maps have been prepared for geology, geomorphology, slope, relative relief, land use, drainage density, lineament density, transmissivity, storativity and water table fluctuation. Thematic maps have been integrated in GIS by assigning suitable rank and weightage to each parameter based on their respective significance. Integrated groundwater potential map is a genuine tool decidedly resourceful for sustainable groundwater development and management. The charisma of this innovative method is that, this model can be used in any other area to functionally demarcate groundwater potential zones, and hence will be of immense societal significance.
Показать больше [+] Меньше [-]Influence of Mulching and NPK Levels on Growth, Yield and Economics of Pearl Millet in Bael Based Agri-Horticultural System under Rainfed Vindhyan Region
2015
Kumar Sandeep | Kumar Achin | Rai Sumit | . Suryakant | Singh Rajesh
A field experiment was conducted during kharif season of 2013 to find out the effect of mulching and NPK levels on pearl millet (Pennisetum glaucum) in bael (Aegle marmelos) based agri-horti system under rainfed condition of Vindhyan region. There were twelve treatment combinations comprised of three levels of mulching (no mulch, wheat straw mulch and dust mulch) and four levels of RDF NPK (50%, 75%, 100%, 125%). The experiment was laid out under split-plot design with three replications. Significant improvement was recorded in growth and yield attributes viz., plant height, number of leaves per plant, number of tillers per plant, dry matter accumulation per plant, number of ears per plant, ear length, number of grains per ear, 1000-grain weight, grain yield, stover yield, harvest index (%), nutrient uptake and economic returns. Significantly higher yield of pearl millet (1908 kg/ha) was observed in the plot that received 125% RDF, which was found at par with the 100% RDF and in case of mulching, the maximum yield was observed with dust mulch (1942 kg/ha) than all other treatments. The application of dust mulch and 125% of the recommended dose of fertilizer (RDF) NPK (T12) treatment have distinct superiority as compared to all other treatments under bael based agri-horti system and more suitable for moisture conservation practice in pearl millet.
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