There is an increasing evidence that smallholder farms contribute substantially to food production globally, yet spatially explicit data on agricultural field sizes are currently lacking. Automated ...field size delineation using remote sensing or the estimation of average farm size at subnational level using census data are two approaches that have been used. However, both have limitations, for example, automatic field size delineation using remote sensing has not yet been implemented at a global scale while the spatial resolution is very coarse when using census data. This paper demonstrates a unique approach to quantifying and mapping agricultural field size globally using crowdsourcing. A campaign was run in June 2017, where participants were asked to visually interpret very high resolution satellite imagery from Google Maps and Bing using the Geo‐Wiki application. During the campaign, participants collected field size data for 130 K unique locations around the globe. Using this sample, we have produced the most accurate global field size map to date and estimated the percentage of different field sizes, ranging from very small to very large, in agricultural areas at global, continental, and national levels. The results show that smallholder farms occupy up to 40% of agricultural areas globally, which means that, potentially, there are many more smallholder farms in comparison with the two different current global estimates of 12% and 24%. The global field size map and the crowdsourced data set are openly available and can be used for integrated assessment modeling, comparative studies of agricultural dynamics across different contexts, for training and validation of remote sensing field size delineation, and potential contributions to the Sustainable Development Goal of Ending hunger, achieve food security and improved nutrition and promote sustainable agriculture.
This paper demonstrates a unique approach to quantifying and mapping agricultural field size globally using crowdsourcing. A campaign was run in June 2017 where participants were asked to visually interpret very high resolution satellite imagery from Google Maps and Bing using the Geo‐Wiki application. The results show that smallholder farms occupy up to 40% of agricultural areas globally, which means that, potentially, there are many more smallholder farms in comparison with the two different current global estimates of 12% and 24%. The global field size map and the crowdsourced data set are openly available.
Remote sensing and geographic information systems (GISs) are increasingly being used in protected area monitoring and habitat suitability studies. In this article, Erdas Imagine's Expert Classifier ...tool was used to assess the specific trajectories of habitat suitability change during 1994–2007 in the Sonitpur elephant habitat, India. Sonitpur has been witness to increasing human–elephant conflict in the past decade. The suitability analysis took into account information relating to forest type and density, elevation, slope, source of water, human activities in terms of settlement, agriculture, tea plantations, roads, and railways. Satellite imagery, data from topographical maps, digital elevation data, and global positioning system readings formed the major data inputs that were incorporated into a GIS. Various decision rules were created and confidence levels assigned to the input layers to generate high, medium, and low habitat suitability. The area witnessed a sharp decline in suitability from 63% in 1994 to less than 38% by 2007. The high-suitability area declined by more than 50% during this period. The unique natural protected areas of Sonitpur, which are a mix of reserved forests, wildlife sanctuaries, and a national park, urgently need to be protected from further habitat degradation.
Land cover is of fundamental importance to many environmental applications and serves as critical baseline information for many large scale models e.g. in developing future scenarios of land use and ...climate change. Although there is an ongoing movement towards the development of higher resolution global land cover maps, medium resolution land cover products (e.g. GLC2000 and MODIS) are still very useful for modelling and assessment purposes. However, the current land cover products are not accurate enough for many applications so we need to develop approaches that can take existing land covers maps and produce a better overall product in a hybrid approach. This paper uses geographically weighted regression (GWR) and crowdsourced validation data from Geo-Wiki to create two hybrid global land cover maps that use medium resolution land cover products as an input. Two different methods were used: (a) the GWR was used to determine the best land cover product at each location; (b) the GWR was only used to determine the best land cover at those locations where all three land cover maps disagree, using the agreement of the land cover maps to determine land cover at the other cells. The results show that the hybrid land cover map developed using the first method resulted in a lower overall disagreement than the individual global land cover maps. The hybrid map produced by the second method was also better when compared to the GLC2000 and GlobCover but worse or similar in performance to the MODIS land cover product depending upon the metrics considered. The reason for this may be due to the use of the GLC2000 in the development of GlobCover, which may have resulted in areas where both maps agree with one another but not with MODIS, and where MODIS may in fact better represent land cover in those situations. These results serve to demonstrate that spatial analysis methods can be used to improve medium resolution global land cover information with existing products.
Recent estimates of additional land available for bioenergy production range from 320 to 1411 million ha. These estimates were generated from four scenarios regarding the types of land suitable for ...bioenergy production using coarse-resolution inputs of soil productivity, slope, climate, and land cover. In this paper, these maps of land availability were assessed using high-resolution satellite imagery. Samples from these maps were selected and crowdsourcing of Google Earth images was used to determine the type of land cover and the degree of human impact. Based on this sample, a set of rules was formulated to downward adjust the original estimates for each of the four scenarios that were previously used to generate the maps of land availability for bioenergy production. The adjusted land availability estimates range from 56 to 1035 million ha depending upon the scenario and the ruleset used when the sample is corrected for bias. Large forest areas not intended for biofuel production purposes were present in all scenarios. However, these numbers should not be considered as definitive estimates but should be used to highlight the uncertainty in attempting to quantify land availability for biofuel production when using coarse-resolution inputs with implications for further policy development.
Land-use/land-cover change is an important agent of ecological degradation in tropical areas where forests are under threat from the pressure of human activities. This study assesses land-use change ...(1973-2007) in the Nameri Tiger Reserve (NTR) in Assam, India using Landsat imageries. Dense forests decreased sharply while open forest increased marginally. The increases in the degraded and open forest categories occurred at the expense of dense forests, which decreased at an average annual rate of 288 ha year
−1
, or at 0.56% annually. The number of patches in the NTR landscape recorded a fivefold increase indicating a high degree of fragmentation of the habitat. While the number of patches of the dense forests increased by 338% from 270 in 1973 to 1138 in 2007 at an annual rate of increase of 9.9% per annum, their mean patch area declined from 19.09 to 12.82 ha. Both class- and patch-level changes corroborate the trend of fragmentation with a consistent increase in the number of smaller patches. Encroachment by small farmers has been the chief agent in the conversion of dense forest into degraded forest.
The Kameng and Sonitpur Elephant Reserves in northeastern India are comprised of trans-border subtropical evergreen to tropical moist deciduous forests of Arunachal Pradesh and Assam. The reserves ...are facing deforestation and habitat loss in recent years. The present study attempts to investigate the loss of habitat in these reserves using temporal satellite imagery of periods 1994, 1999 and 2002. The on-screen visual interpretation of the three-period imagery revealed alarming and continuous habitat loss from 1994 to 2002. The overall habitat loss was found to be 344 km2 between 1994 and 2002. The average annual rate of deforestation worked out to be 1.38%, which is much higher than the national average. The rate of deforestation was highest between 1999 and 2002. The study indicated that at this rate much of the forests in the study area would be depleted within the next few years. It also showed that moist deciduous forests, which possess highest biodiversity in Assam, are facing maximum deforestation. High deforestation has resulted in high man–elephant conflicts. The study suggests rehabilitation of affected forests in the larger interest of elephants and biodiversity.
The underdevelopment of Northeast India is quite often explained in terms of economic isolation primarily on account of its geographical peripherality. To address this challenge, a new imagination, ...through the Look (Act) East Policy has been proposed. This approach, makes India’s Northeast the centre of a unified economic, physical and social space through its integration with the trans-border neighbouring regions. In this article, an attempt has been made to examine the logic of developing an ‘extended Northeast’ and how it has been sought to be realized. The article argues that the actualization of this proposed integrated space is ridden with serious difficulties and the internal fragmentation of Northeast India and the exceptional rules and administrative arrangement that are in place in the region along with the geopolitical compulsion of India may act as significant barriers in this regard. And most importantly there are apprehensions that the proposed integrated space may lead to the appropriation of resources of the Northeast by the corporate houses without benefiting the people of the region.
•Accessed the impact of climate change and the potential distribution of the Endangered White Winged Wood Duck for management planning.•The potential habitat in the Indian Eastern Himalayan region is ...confined in the states including Arunachal Pradesh, Assam, Nagaland, Tripura, and Meghalaya.•The extent of potential distribution is greatest in Assam, covering 1.66% of the area.•With the impact of climate change, species will shift their range and decrease potential habitat.•Immediate attention required on high potential areas to safeguard the species from extinction.
The White-Winged Wood duck (Asarcornis scutulata) is an endangered forest wetland bird currently on the verge of extinction due to an array of anthropogenic pressures. It has been reported that global climate change could affect the distribution of many bird species globally. Therefore, an understanding the potential distribution of the White-Winged Wood duck in future climate scenarios could facilitate the creation of immediate conservation plans and the mitigation of subsequent threats. This is the first ever study on the distribution of White-Winged Wood Duck (WWWD) where Representative Concentration Pathway (RCP) 8.5 scenario was used to forecast the distribution of the WWWD in the Indian Eastern Himalayan region in the 2050s and 2070s. The study revealed that 1.87 % of the total area of IEH has the high potential distribution of WWWD. The state of Assam alone includes 1.68 % of the highly potential habitat in the region. It was predicted that 436.61 km2 of highly potential habitat would be lost by 2070. Changes in the annual temperature range, precipitation in the wettest months (June to September), and precipitation decrease in the warmest quarter (October to December) would result in the loss of highly potential habitats. Under the influence of climate change, the habitat of WWWD in the eastern part of the region is likely to shift towards the western part. It was found that there will be a decline in potential habitat in the Indian states of Arunachal Pradesh, Assam, Nagaland, and Tripura located in the IEH under future climate scenarios. The potential of areas located at the Bhutan and Assam border would increase for supporting WWWD as this species' requires the average annual precipitation about 1000–1200 mm. However, the simultaneous anthropogenic activity would further destroy potential habitats in the future. The current study has provided baseline data on the potential distribution of WWWD in the IEH region for immediate conservation management plans.
India’s neighbourhood policy seems to be devoid of any strategy to integrate national interests with the concerns of border regions like Northeast India. India’s security-centric approach prevented a ...cooperative relationship from emerging with its neighbours, while a deeper and intense engagement with them would have benefitted India and helped solve many of the problems that Northeast India is facing today. However, the recent move by India under the Act East Policy to cultivate a much closer relationship with its eastern neighbours is full of possibilities to make India’s neighbourhood policy more accommodative and sensitive towards the needs of Northeast India. In the light of this, the proposed article intends to examine the nature of India’s neighbourhood policy, to assess its implications for the Northeast and finally, to examine whether the recent transnational engagements can initiate development of the Northeast by relieving it from its peripheral and landlocked status.
The fruits of six Ficus species, including F. auriculata Lour., F. maclellandii King., F. hirta Vahl., F. nervosa Heyne ex. Roth., F. racemosa Linn., and F. semicordata Buch-Ham.ex. Roth, are ...traditionally consumed by local people in North East India. The fruits were studied for their total phenolic content (TPC) and total flavonoid content (TFC). The 90% ethanolic extract of the fruits were screened for potential antioxidant capacity by employing different in vitro assays like ABTS •⁺ (2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid), FRAP (ferric reducing antioxidant power), DPPH • (2,2′-diphenyl-1-picryl hydrazyl) scavenging activity, hydrogen peroxide radical scavenging activity, hydroxyl radical scavenging activity, chelating power, and reducing power properties. Extract from F. maclellandii and F. racemosa showed higher antioxidant activity in all of the systems than other species. It was concluded that these two species are promising sources of natural dietary antioxidants. According to statistical analysis, the TPC and TFC appear to be responsible for the excellent antioxidant capacity of the extract and all of the extract exhibited dose-dependent antioxidant activity.
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