排序方式： 共有9条查询结果，搜索用时 296 毫秒
1
1.
Oshan Taylor M. Wolf Levi J. Sachdeva Mehak Bardin Sarah Fotheringham A. Stewart 《Journal of Geographical Systems》2022,24(3):293-324
Journal of Geographical Systems - Scale is a central concept in the geographical sciences and is an intrinsic property of many spatial systems. It also serves as an essential thread in the fabric... 相似文献
2.
The practice of gathering and harvesting wild foods has seen renewed interest in recent decades. In addition to contributing to food security and food sovereignty, foraging plays a role in promoting socioecological resilience and creating communities of belonging. However, foraging is generally prohibited by regulations governing public lands in the United States and elsewhere. The growth in food forests suggests public policymakers and land managers’ may be interested in reconsidering this broad prohibition of foraging but require an information base to do so. While a body of research on foraging exists, news media coverage of foraging represents an additional, readily available source of input. As a consequence, framings of foraging in media coverage likely influence managers’ deliberations on this practice. The current paper uses automated content analysis to understand how the practice of gathering and consuming wild foods is framed in print and digital news media, and how these depictions have varied in a 15-year period that includes the Great Recession. Our results show that prevalent framings of foraging represent it variously as a self-provisioning practice or a source of luxury commodities and experiences, with economic uncertainty appearing to affect the frequency of each framing by news media sources. Given managers’ ease of access to them, these distinct framings may influence future regulatory landscapes of foraging. 相似文献
3.
With the growing recognition to myriad forms of current and future threats in the mountain agriculture systems,there is a pressing need to holistically understand the vulnerability of mountain agriculture communities.The study aims to assess the biophysical and social vulnerability of agriculture communities using an indicator-based approach for the state of Uttarakhand,India.A total of 14 indicators were used to capture biophysical vulnerability and 22 for social vulnerability profiles of15285 villages.Vulnerability analysis was done at village level with weights assigned to each indicator using Analytical Hierarchical Process(AHP).The results of the study highlight the presence of very high biophysical vulnerability(0.82 ± 0.10) and high social vulnerability(0.65 ± 0.15) within the state.Based on the results,it was found that incidences of high biophysical vulnerability coincide with presence of intensified agriculture land and absence of dense forest.Higher social vulnerability scores were found in villages with an absence of local institutions(like Self Helping Groups(SHGs)),negligible infrastructure facilities and higher occupational dependence on agriculture.A contrast was observed in the vulnerability scores of villages present in the three different altitudinal zones in the study area,indicating respective vulnerability generating conditions existing in these three zones.Biophysical vulnerability was recorded to be highest in the villages falling in the lower zone and lowest in the upper zone villages;whereas,social vulnerability was found to be highest in the middle zone villages and lowest in lower zone villages.Our study aids policy makers in identifying areas for intervention to expedite agriculture adaptation planning in the state.Additionally,the adaptation programmes in the region need to be more context-specific to accommodate the differential altitudinal vulnerability profiles. 相似文献
4.
Priya Narayanan Ashoke Basistha Sumana Sarkar Sachdeva Kamna 《Comptes Rendus Geoscience》2013,345(1):22-27
Spatial and temporal variability of rainfall over different seasons influence physical, social and economic parameters. Pre-monsoon (March, April and May – MAM) rainfall over the country is highly variable. Since heat lows and convective rainfall in MAM have an impact on the intensity of the ensuing monsoons, hence the pre-monsoon period was chosen for the study. The pre-whitened Mann Kendall test was used to explore presence of rainfall trend during MAM. The results indicate presence of significant (at 10% level) increasing trend in two stations (Ajmer, Bikaner). The practical significance of the change in rainfall was also explored as percentage changes over long term mean, using Theil and Sen's median slope estimator. Forecast using univariate ARIMA model for pre-monsoon months indicates that there is a significant rise in the pre-monsoon rainfall over the northwest part of the country. 相似文献
5.
Rampant pasture burning has lead to various forest fires taking their toll over the health of many forests. Nanda Devi Biosphere Reserve, located in the northern part of India, witnessed a majority of these incidents in the recent past, though, it remains comprehensively untouched from research studies. The scale of these wildfires has led to an immense requirement of preventive measures to be taken for recuperating from such events. This requires for an in-depth analysis of the study area, its history of wildfires and their causes. These efforts would assist in laying a blueprint for a contingency plan in the event of a wildfire. This work proposes an evolutionary optimized gradient boosted decision trees for preparing wildfire susceptibility maps for the study area that would aid in the government’s forest preservation and disaster management activities. The study took 18 ignition factors of elevation, slope, aspect, plan curvature, topographic position index, topographic water index, normalized difference vegetation index, soil texture, temperature, rainfall, aridity index, potential evapotranspiration, relative humidity, wind speed, land cover and distance from roads, rivers and habitations into consideration. The study revealed that approximately 1432.025 km2 of area was very highly susceptible to forest fires while 1202.356 km2 was highly susceptible to forest fires. The proposed model was compared against various machine learning models such as random forest, neural networks and support vector machines, and it outperformed them by achieving an overall accuracy of 95.5%. The proposed model demonstrated good prospects for application in the field of hazard susceptibility mappings. 相似文献
6.
Jagdish Chandra Joshi Tankeshwar Kumar Sunita Srivastava Divya Sachdeva Ashwagosha Ganju 《Natural Hazards》2018,91(3):1127-1164
Seismic hazard assessment is the key tool for rational planning, safety and design of infrastructures in seismically vulnerable regions. Gujarat is the only state in peninsular India with the maximum seismic hazard of large shallow earthquakes originating from intra-plate seismicity. Probabilistic seismic hazard assessment (PSHA) of Gujarat is carried out in this paper. Three seismogenic sources, namely Kutch, Saurashtra and Mainland Gujarat, are considered, and seismicity parameters are estimated separately for each region taking into account the completeness of the available earthquake data. Peak ground acceleration (PGA) of the horizontal component and spectral acceleration at specific periods are considered as the intensity measures. Ground motion predictive equation chosen was reported to be based on simulated ground motions and verified against the strong motion records in the study region. Results are reported for the 17 major cities at the bedrock and also for the soil sites. Apart from hazard curves, 2475 and 475 years of return periods are considered for the PGA and uniform hazard spectra (UHS). The results are compared with the present recommendations of Indian Standards. Key observations include (1) Indian Standards underpredict PGA in the entire Gujarat when the soil sites are considered and in a few cities even at the bedrock; (2) amplification of PGA (or short period hazard) on account of soil sites should be included in the Indian Standard, which is currently absent; (3) shape of the UHS indicates that a separate amplification is required at the hyperbolic portion; and (4) ratio of 2475–475 years of PGA, which is considered 2.0 in Indian Standard, should be reduced to 1.5. Time-dependent recurrence model is also included in this paper and compared with conventional PSHA. General observations include that (1) hazard may increase significantly on account of time dependency; (2) this also influences the disaggregation and in turn the selection of ground motions; and (3) time since last earthquake significantly influences the extent of the effect of time dependency. 相似文献
7.
Journal of Geographical Systems - The concept of ‘spatial scale’, or simply ‘scale’ is implicit in any discussion of global versus local models. The raison d’etre of... 相似文献
8.
Agriculture communities in the Himalayas are disproportionately vulnerable due to the emerging challenges from climatic and non-climatic stressors. In this study, we systematically review peer-reviewed literature focused on vulnerability assessment of agriculture communities (n = 26) in the five Himalayan countries (Bhutan, China, India, Nepal, and Pakistan). We examine the yearly distribution, geographical scale, methodological approach, stress in consideration, indicators used, and assessment communication methods of the reviewed papers. Our findings indicate that vulnerability assessment of agriculture communities in the Himalayas is a recent practice, as all of the reviewed articles were published after 2007. About 62% of the assessments were conducted at local (household, community, and village) level, and few assessments at sub-national (19%) and basin (12%) levels. Indicator-based methods using primary quantitative data were most common (54%). Further, 90% of the studies addressed vulnerability to a single stressor with 50% of papers dealing with the vulnerability of agriculture communities to climate change and/or climate variability. From the analysis of the literature, it was found that multi-level, multi-stress, and comprehensive socio-ecological assessments were seldom attempted. Mostly the studies were done in isolated pockets and failed to identify the patterns of vulnerability. We advocate that to holistically understand the vulnerability-creating and differentiating mechanisms in agriculture communities, vulnerability assessment should adopt a multi-level approach by integrating both social and ecological determinants, firstly to identify the hotspots of vulnerability and then to deeply understand the root causes in the identified hotspots through integrated analysis. 相似文献
9.
Arjun Kumar S. S. Rai Anand Joshi Himanshu Mittal Rajiv Sachdeva Rohtash Kumar Vandana Ghangas 《地震科学（英文版）》2013,26(2):99-105
Earthquakes began to occur in Koyna region (India) soon after the filling of Koyna Dam in 1962. In the present study, three datasets 1964–1993, 1993–1995, and 1996–1997 are analyzed to study the b-value and fractal dimension. The b-value is calculated using the Gutenberg–Richter relationship and fractal dimension D corr. using correlation integral method. The estimated b-value and D corr. of this region before 1993 are found to be in good agreement with previously reported studies. In the subsequent years after 1995, the b-value shows an increase. The estimated b-values of this region are found within the limits of global average. Also, the pattern of spatial clustering of earthquakes show increase in clustering and migration along the three zones called North-East Zone, South-East Zone (SEZ), and Warna Seismic Zone. The earthquake events having depth ≤5 km are largely confined to SEZ. After 1993, the D corr. shows decrease, implying that earthquake activity gets clustered. This seismic clustering could be helpful for earthquake forecasting. 相似文献
1