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171.
172.
The role of forests is being actively considered under the agenda of REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus) aimed at reducing emissions related to changes in forest cover and forest quality. Forests in general have undergone negative changes in the past in the form of deforestation and degradation, while in some countries positive changes are reported in the form of conservation, sustainable management of forests and enhancement of carbon stock. The present study in the Kashmir Himalayan forests is an effort to assess historical forest cover changes that took place from 1980 to 2009 and to predict the same for 2030 on the basis of past trend using geospatial modeling approach. Landsat data (Multispectral Scanner (MSS), Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+)) was used for the years 1980, 1990 and (2001, 2009) respectively and change detection analysis between the dates was performed. The maps generated were validated through ground truthing. The study area (3375.62 km2) from 1980-2009 has uffered deforestation and forest degradation of about 126 km2 and 139.02 km2 respectively which can be claimed under negative options of REDD+, while as the area that experienced no change (1514 km2) can be claimed under conservation. A small area (23.31 km2) observed as positive change can be claimed under positive options. The projected estimates of forest cover for 2030 showed increased deforestation and forest degradation on the basis of trend analysis using Cellular Automata (CA) Markov modeling. Despite the fact that country as a whole has registered a net positive change in the past few decades, but there are regions like Kashmir region of western Himalaya which have constantly undergoing deforestation as well as degradation in the past few decades. 相似文献
173.
Jamal Jokar Arsanjani Linda See Amin Tayyebi 《International Journal of Digital Earth》2016,9(9):873-891
Global land cover (LC) maps have been widely employed as the base layer for a number of applications including climate change, food security, water quality, biodiversity, change detection, and environmental planning. Due to the importance of LC, there is a pressing need to increase the temporal and spatial resolution of global LC maps. A recent advance in this direction has been the GlobeLand30 dataset derived from Landsat imagery, which has been developed by the National Geomatics Center of China (NGCC). Although overall accuracy is greater than 80%, the NGCC would like help in assessing the accuracy of the product in different regions of the world. To assist in this process, this study compares the GlobeLand30 product with existing public and online datasets, that is, CORINE, Urban Atlas (UA), OpenStreetMap, and ATKIS for Germany in order to assess overall and per class agreement. The results of the analysis reveal high agreement of up to 92% between these datasets and GlobeLand30 but that large disagreements for certain classes are evident, in particular wetlands. However, overall, GlobeLand30 is shown to be a useful product for characterizing LC in Germany, and paves the way for further regional and national validation efforts. 相似文献
174.
Magdy Y. Amin 《Astrophysics and Space Science》1998,260(3):405-420
We have followed the chemistry of W3 IRS4, as one of the most famous regions with a chemistry similar to that found in quiescent
molecular clouds. Here the time scale, since star formation, has probably been long enough for the gas-phase ion-molecule
chemistry to become dominant again. We have constructed a reaction system containing the chemical families of H, C, O, N,
S and metals (Me:Fe, Mg, Na and Si). A total of 282 species have been included and a network of 1270 reactions has been used.
The chemical kinetic equations were integrated as a function of pseudo-time-dependent approach. The evolution of the different
chemical species are followed in models of density n equal to 106 cm-3 and temperature T equal to 55 K. Different initial abundances have been assumed. Our results are in reasonable agreement
with the observation, especially in Model 6. The resulting molecular abundances are compared with those obtained in the intermediate
mass star NGC 2264 IRS1, as well as the low mass IRAS 16293-2422.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
175.
Hosseini Shahab Monjezi Masoud Bakhtavar Ezzeddin Mousavi Amin 《Natural Resources Research》2021,30(6):4773-4788
Natural Resources Research - This study developed a new perspective of artificial neural networks using dimensional analysis to be applicable to certain prediction problems. To this end,... 相似文献
176.
Microbial activity has the potential to alter all cultural heritage in mining and metallurgy, due to metal mobilization by leaching. This communication shows the consequences of the bioleaching ability of two natural enrichments on copper slag samples from a historic ore smelting site in Sangerhausen (Mansfeld, Südharz, Saxony-Anhalt, Germany). Enrichment cultures gained from mine drainage were dominated by either the iron and sulfur-oxidizing Acidithiobacillus ferrivorans, or by the iron-oxidizing Leptospirillum. During 35 days of bioleaching in media containing copper slag pulp, inoculated with these enrichments, the change in pH and solubilized metal concentrations of the systems were monitored. Both bacterial strains were completely different from each other in their pattern of pH variation and rates of metal solubilization. The maximum removal of Cu (1725 mg/l) and Zn (715 mg/l) from copper slag substrate was achieved with enrichment culture of A. ferrivorans SCUT-1. However, maximum Mn (207 mg/l), Pb (86 mg/l), and Ni (75 mg/l) removal was observed with enrichment culture of Leptospirillum strain YQP-1. Implications for metal mobilization along with alteration of artifacts from not only historic mining areas but also aspects of decontamination and remediation are discussed. 相似文献
177.
Somia Hamil Siham Arab Amin Chaffai Mounia Baha Abdeslem Arab 《Arabian Journal of Geosciences》2018,11(23):754
This study explores the water quality status and pollution sources in Ghrib Dam, Algeria. It allows us to obtain more accurate information on water quality by applying a series of multivariate statistical techniques, including principal component analysis (PCA)/factor analysis (FA), hierarchical cluster analysis (CA), and multiple regression analysis (MRA). On 19 physicochemical parameters dataset over 5 years and from 6 different sites located in and around the lake. One-way analysis of variance (ANOVA) was used to investigate the statistically considerable spatial and seasonal differences. The results of ANOVA suggest that there exist a statistically significant temporal variation in the water quality of the dam for all parameters. On the other hand, only organic matter has a statistically significant spatial variation. In the multiple linear models, an association between organic and inorganic parameters was found; their origin comes from the mechanical erosion process of agricultural lands in the watershed. The PCA/FA identifies five dominant factors as responsible of the data structure, explaining more than 94.96% of the total variance in the water quality dataset. This suggests that the variations in water compounds’ concentration are mainly related to the multiple anthropogenic activities, as well as natural processes. The results of cluster analysis demonstrate that the sampling stations were divided in two similar groups, which indicates spatial homogeneity. While seasonal grouping has showed that the source of pollution was related to the level of runoff in the seasons. 相似文献
178.
Phosphorus dynamics and corn growth under applications of corn stalks biochar in a clay soil 总被引:1,自引:0,他引:1
Abu El-Eyuoon Abu Zied Amin 《Arabian Journal of Geosciences》2018,11(14):379
Biochar prepared from corn stalks is used as a source of phosphorus in this study. The hypotheses were to investigate effects of biochar applications in clay soil on availability, changes of phosphorus pools and maximum adsorption of phosphorus as well as corn growth. The soil was placed in plastic pots with each contains 3 kg of this soil. Biochar was added at levels of 0 (control), 6.5 (B1), 19 (B2), and 38 (B3) g pot?1. In this experiment, the pot was planted with corn (Zea mays). The results of this study revealed that the biochar application enhanced available phosphorus (Olsen-P) from 11.51 to 17.10 mg kg?1. Adding biochar significantly increased the amount of NH4Cl-P, NaHCO3-Po, and NaOH I-Po fractions (p?≤?0.05), but it significantly decreased HCl-Pi fraction (p?≤?0.05). Addition of biochar at the highest level increased the fresh and dry matter productions by up to about 75 and 48.7%, respectively, compared to the control. The phosphorus uptake by corn plants significantly increased with increasing levels of biochar. The removal efficiency (% sorption) and maximum adsorption (b) of phosphorus increased with increasing level of biochar addition compared to control. Consequently, it is recommended to add biochar produced from corn stalks to the soil in order to substitute phosphate fertilizers. 相似文献
179.
180.
Ashraf Muhammad Arshad Adnan Patel Praharsh M. Khan Adeel Qamar Huma Siti-Sundari Ristina Ghani Muhammad Usman Amin Ali Babar Jamilur Rehman 《Natural Hazards》2021,109(3):2127-2151
Natural Hazards - Climate change-induced disasters show the highest risk for agriculture and livelihoods in rural areas of developing countries. Due to changing rainfall pattern, the arid and... 相似文献