Remote sensing quantification and change detection of natural resources over Delhi

Abstract. Remote Sensing along with Geographical Information System (GIS) has been proven as a very important tools for the monitoring of the Earth resources and the detection of its temporal variations. A variety of operational National applications in the fields of Crop yield estimation , flood monitoring, forest fire detection, landslide and land cover variations were shown in the last 25 years using the Remote Sensing data. The technology has proven very useful for risk management like by mapping of flood inundated areas identifying of escape routes and for identifying the locations of temporary housing or a-posteriori evaluation of damaged areas etc. The demand and need for Remote Sensing satellite data for such applications has increased tremendously. This can be attributed to the technology adaptation and also the happening of disasters due to the global climate changes or the urbanization. However, the real-time utilization of remote sensing data for emergency situations is still a difficult task because of the lack of a dedicated system (constellation) of satellites providing a day-to-day revisit of any area on the globe. The need of the day is to provide satellite data with the shortest delay. Tasking the satellite to product dissemination to the user is to be done in few hours. Indian Remote Sensing satellites with a range of resolutions from 1 km to 1 m has been supporting disasters both National & International. In this paper, an attempt has been made to describe the expected performance and limitations of the Indian Remote Sensing Satellites available for risk management applications, as well as an analysis of future systems Cartosat-2D, 2E ,Resourcesat-2R &RISAT-1A. This paper also attempts to describe the criteria of satellite selection for programming for the purpose of risk management with a special emphasis on planning RISAT-1(SAR sensor).

Soil seed banks are important to vegetation recruitment, ecosystem functioning and land management. We evaluated composition of 0–5 cm soil seed banks and relationships of seed banks with forest community types (ranging from low-elevation pinyon–juniper to high-elevation bristlecone pine), vegetation cover and environmental variables within a 40,000-ha relatively undisturbed coniferous forest landscape in Nevada, USA. We collected samples from 36 sites and used the emergence method to assay seed banks. Seed density averaged 479 seeds m− 2across sites and a total of 39 taxa were detected. Most (79%) of these taxa were perennials and 35 of 39 (90%) were native. Moreover, 62% of seed-bank taxa were in the vegetation of mature forests, an uncommon finding in studies of forest soil seed banks. Seed-bank density, species richness and composition did not display strong relationships with forest community types, vegetation cover or environmental variables. Weak relationships likely arose from the relatively uniform seed-bank density among sites, where 50% of sites had seed densities in the range of 106–282 m− 2. Results suggest that while seed banks on this landscape are not large, they provide recruitment potential for some native perennial species of mature, relatively undisturbed communities.

Detecting vulnerability of humid tropical forests to multiple stressors

Assessing effects of the Returning Farmland to Forest Program on vegetation cover changes at multiple spatial scales: The case of northwest Yunnan, China

The Sahel region of Sudan is a highly vulnerable ecosystem that faces significant pressures from climate change, land degradation, and human activities. Monitoring changes in vegetation cover is essential for understanding the extent of these pressures and for informing effective mitigation and adaptation strategies. Satellite-based remote sensing approaches provide a cost-efficient means of collecting information on the world’s forests and repeatedly surveying large or inaccessible forest areas. However, it may not always be possible to ground-truth associated findings using direct ecological field surveys conducted by trained forest scientists. Local ecological knowledge (LEK) is an alternative form of data that can be used to complement, interpret, and verify information from satellite data. In this study, we integrated remote sensing and LEK data to measure indicators of vegetation cover and understand patterns and drivers of forest cover change. LEK reports often concurred with or provided key information to enable the interpretation of satellite data. This reveals that between 1975 and 2000, North Kordofan experienced high, but uneven, rates of deforestation. There was a pronounced shift in the study area deforestation in the mid-1980s, coinciding with a period of extreme drought and famine, and associated with the clearance of trees in areas as an economic and fuel resource, as well as the conversion of forest to agricultural cropland. Threats increase the vulnerability of the study area's socio-ecological systems to future environmental change and are an obstacle to the recovery of threatened species across the Sahel zone. This research reviews key indicators used to assess changes in vegetation cover in the Sudanese Sahel, in Sudan, North Kordofan State - Al Dodyia and Umm Seimema area, focusing on remote sensing-based, and the role of ground-based surveys and local ecological knowledge (LEK) in validating remote sensing data and providing valuable insights into the drivers and indicators vegetation change

Congressman Leavitt gives a very clear, direct and comprehensive picture of the agricultural, industrial and social losses that result from erosion and floods, and which may go on inconspicuously but in the end attain calamitous proportions. He discusses the causes and their correction from a national viewpoint. He recognizes that floods cannot be prevented entirely and that the erosion and flood problem varies with local conditions. At the same time he accepts the function and importance of engineering works but emphasizes the necessity of supplementing such works and making them more effective by "nature's own methods of protection through a forest or other natural vegetative cover." He proposes legislation for a more comprehensive national program of research that will sift out facts from surmise.

Forest cover dynamics are an important indicator for climate change as well as for land conversion studies. Based on an analysis of 30 years of Landsat data a forest cover time series was generated and analyzed for the Dhofar mountains in Oman. The Dhofar mountains in Southern Oman with its semi-arid cloud forest is an important asset for livestock, water resources, and tourism. In this study we investigated whether forest cover trends are distinguishable and what impact forest cover changes have on water availability. To cope with gaps in the Landsat dataset the Dhofar mountains were divided into regions of interest (ROIs) that were based on hydrologic catchment boundaries. The results show, that, despite increasing pressure from tourism and increasing livestock numbers, the forest cover shows slight but not significant increases in most ROIs and significant forest cover increases in three ROIs. Overall, forest cover during the past 30 years is at least stable and most probably slightly increasing. With regard to water resources results show that, the impact of cloud forest interception amounts to an additional subcanopy water input of about 15 to 150 % of annual rainfall. This additional water is only available below tree cover. Part of that water is, of course used by plant transpiration, however, the stemflow portion which is exceptionally high in this region infiltrates directly into deeper soil layers and eventually leads to groundwater recharge.

The launch of the first Indian Remote Sensing Satellite in 1988 ushered in a new era of utilization of satellite data and technology in natural resources monitoring, coastal area management, disaster mitigation, weather and climate change studies. India with its very long coast line, areal extent, resources and population would have been a huge challenge to the coastal researchers and administrators if not for the Indian Remote Sensing satellite data that provided the much needed temporal, thematic information for effective mapping, monitoring and management of the coastal areas. The country’s large and diverse coastal regions are economically important and ecologically rich but also extremely vulnerable and highly prone to natural and anthropogenic hazards. Through the last three decades, the Indian remote sensing programme has contributed immensely to our understanding of the coast and ocean processes, coastal ecosystems, habitats, marine pollution and the vulnerability of the coast to natural hazards. IRS-1C with its improved spatial resolutions, additional spectral band, improved repetitively ushered in a new era of research specifically in the management of coastal areas and resources. Availability of spatial data at various resolutions, low cost, advances in technology resulted in new applications for management coastal areas. IRS-1C also can be aptly termed as the precursor for thematic satellite series such as OCEANSAT, RESOURCESAT and CARTOSAT, thereby setting the environs for thematic research in coastal areas. Integrated utilization of remote sensing data, numerical models, GIS and GPS has paved the way for the development of operation systems for management of coastal areas, thereby realizing the vision of Dr. Vikram Sarabhai, the father of Indian Space Programme, of building a self-reliant and indigenous Space Programme for the betterment of quality of life of the common people.

Agricultural environments have a critical role in the global conservation of biodiversity, but the persistence of forest and woodland-dependent species in these systems is often limited by insufficient habitat. Modified or semi-natural ‘countryside’ (matrix) vegetation is used by many species, but its value at the landscape scale is rarely tested. Do such habitats simply provide additional resources for populations sustained by remnant native vegetation in the landscape, or can they enhance populations over and above that sustained by natural vegetation cover? We surveyed woodland-dependent birds in all types of landscape element in 27 farmland mosaics (100 ha each) in south-eastern Australia. Four measures of wooded vegetation cover were quantified: native vegetation only; and combinations of native vegetation plus scattered trees and/or tree plantations. We used an information-theoretic approach to compare the responses of 30 species to each measure of vegetation cover. Woodland birds were well represented in agricultural mosaics (65% of the regional species-pool); however, almost half were recorded only in mosaics with >20% native vegetation cover. The incidence of 23 species was positively related to measures of wooded cover, indicating increased occurrence in mosaics with a greater cover of wooded vegetation. For 12 species, scattered trees and plantations provided supplementary habitat that enhanced their population status at the landscape scale, beyond that sustained by native vegetation cover. While native vegetation has a critical role for conservation in agricultural environments, careful management of wooded countryside elements (such as scattered trees, tree plantations) offers additional benefits to the woodland-dependent avifauna.

In 1986 and 1987, a study on factors governing revegetation on ski grounds was conducted at Teine ski ground (built in 1971) located near the city of Sapporo in northern Japan. Soil movement, slope gradient, distance from forest edge, vegetation cover, and number of species on the ski ground were examined. Although artificial sowing of exotic plants was undertaken in the whole ground surface at the time of opening, bare land occurred in ca. 50% of surveyed plots and the ski ground was mostly covered with native plants. The number of species was positively correlated to vegetation cover, which was low in the sites where intensive soil erosions occurred in winter. A principal component analysis of plant species distinguished three major groups of factors, i.e., vegetation cover (first axis, contribution rate 30.3%), soil erosion in winter and slope gradient (second, 23.1%), and distance from forest edge (third, 16.3%). The vegetation characteristics on the ski ground were not determined by a single environmental gradient but by the combination of factors described above. In particular, soil movements, which are mostly derived from snowmelt, are considered to be the initiator of vegetation changes.

Forest mapping using remote sensing has made considerable progress over the past decade, but substantial uncertainties remain in complex regions, particularly where terrain and climate vary dramatically. Yunnan Province, China, represents such a challenging case, with its diverse climatic zones ranging from tropical to temperate and its topography spanning over 6500 m in elevation. These factors contribute to substantial variation in vegetation types, complicating the accurate identification of forest cover through remote sensing. This study aims to enhance forest mapping in Yunnan by leveraging multi-temporal remote sensing data from Sentinel-2 and Landsat 8/9 imagery, incorporating key phenological stages—such as the leaf greening (GRN) period, as well as the senescence, defoliation, and foliation (SDF) stages of deciduous forests—along with kNDVI and terrain factors. A random forest (RF) classifier was applied on the Google Earth Engine (GEE) platform to create a 10 m resolution forest map (LS2-RF). This map achieved an overall accuracy of 96.35% when validated with 1572 ground samples, significantly outperforming existing global datasets, such as Dynamic World (73.88%) and WorldCover (87.66%). These maps agreed well in extensive forested areas; discrepancies were noted in mixed land types, including farmland, urban areas, and regions with fragmented landscapes. In 2022, Yunnan’s forest cover was 60.40%, with higher coverage in the southwestern region and lower in the northeast. The largest forested area was found in Pu’er City, while the smallest was in Yuxi City. Forests were most abundant at elevations between 1500 and 2500 m (occupying 52.29% of the total forest area) and slopes of 15° to 25° (occupying 39.19% of the total forest area). Conversely, forest cover was lowest in areas below 500 m elevation (occupying 0.64% of the total forest area) and on slopes less than 5° (occupying 2.40% of the total forest area). The analysis also revealed a general trend of increasing forest cover with decreasing latitude and longitude, with peak forest coverage at mid-elevations and slopes, followed by a decline at higher elevations. The resultant forest map provides valuable data for ecological assessments, forest conservation initiatives, and informed policy decision-making.

India sustains some of the world's most imperiled forests. The Forest Survey of India recently announced that forest cover in India had expanded by nearly 5% over the past decade. This result, while technically accurate, is misleading. The Forest Survey estimates forest cover by using automated algorithms to analyze satellite imagery—an approach that fails to distinguish native forests from tree plantations, which are often monocultures of exotic species that have limited value for endangered biodiversity. Since the early 1990s, tree plantations have expanded in India at an estimated rate of roughly 15,400 km 2 /year. Subtracting plantations from total forest cover shows that native forests in India have declined by 1.5%–2.7% per year. The limited precision of our estimate highlights a paucity of data on native forest cover in India—a problem requiring urgent attention. Forest cutting for fuelwood has been the biggest driver of forest loss and thinning in India. Like India, many nations now rely on satellite imagery to discern changes in vegetation cover, and these frequently lump native, exotic, and degraded forest types. Without sufficiently high‐resolution imagery and adequate safeguards, such approaches could paint a misleading picture of the fate of the world's native forests.

The country, Pakistan has only five percent (5%) land cover is under forest which is on decline rapidly. Most of the forest is in the northern areas but several factors are influencing negatively. Climate change phenomenon has expedited deforestation. With increase in population, pressure on forest in Baltistan has also increased while climate change factors are unfavorable for its regeneration. Present study was aimed at investigation into community perception on climate change and forest cover changes in district Skardu, Baltistan. Research revealed that forest cover has on decline (either highly decreasedor decreased) like vegetation cover which has also decreased, particularly near villages more as compared to pastures. Similarly, temperature has increased in winter and spring as compared to summer and autumn. Snowfall has decreased during spring more as compared to winters. Contrast to snowfall, rainfall has increased in spring followed by winter, autumn and summer. Glacier sizes are shrinking and monsoon floods have highly increased flowed by melt water increase in channels. Due to change in other climatic factors, crop sowing, fruiting and harvesting periods have prolonged and have a backward shifting trend. Diseases on the plants have increase but in contrast annual yield has increased. Overall indigenous biodiversity has decreased but new bird species have increased. We conclude that there is a visible but unfavorable change is underway forcing every corner of life to shift and adjust itself with new adaptation strategies. Agro pastoral communities in the area feel a threat to their livelihood options if these pathetic changes continue in the future as their reliance has increased on natural resources and ecosystem services for their survival. Climate change and forest decline are some physically verifiable factors and phenomenon and not a simple scientific theory in the lives of rural communities of Baltistan like rest of Gilgit-Baltistan. Government, non-government and civil society organizations need to consider diversification of livelihood options and impacting on adverse factors contributing into climate change undesirably in the area.

Forest cover in Bengkulu is reduced. Data from WARSI shows, 1990 forest cover areas in the province are approximately 1,009,209 hectares or 50.4 % of the land area reaching 1,979,515 hectares. But now, it is only 685,762 hectares of the area of his blood. That is, the period of 25 years, there is a forest cover decline of 323,447 hectares. Forest and land cover changes are the largest contributor to greenhouse gas emissions. The purpose of this article is to see land cover changes based on carbon stock in the years 2009 and 2018. Model of land cover change based on carbon stock year 2028 and 2038. The method of this research uses the calculation of the Stock Difference Approach with spatial analysis of national land closure of Landsat imagery 2009-2018 and biomass data for forest inventory results Geographic Information System (GIS). The results of this research were the reduced forest area and the change in land use changed from 2009 and 2018. So carbon stock is also increasingly reduced.

Epiphytes are highly dependent on atmospheric inputs of water and nutrients. Reductions in water availability associated with warming and climate change and continual atmospheric nitrogen (N) deposition can affect plant growth but few studies have evaluated the effects of changes in both water and nutrient availabilities on epiphytes. We experimentally tested whether epiphyte growth is more water- or nutrient-limited, if nutrient limitation was stronger for nitrogen or phosphorus, and whether nutrient limitation interacts with water availability. We applied watering (high and low) and nutrient addition (control, +N, +P, +N+P) treatments to greenhouse-grown Asplenium nidus, a common epiphytic fern found in many tropical and subtropical wet forests. We measured leaf area production and leaf elemental concentrations to assess how A. nidus growth and physiology respond to changes in water and nutrient availabilities. We found that leaf growth of A. nidus was more affected by water availability than nutrient addition and the effect of adding nutrients was not fully realized under low-water availability. Among the different nutrient treatments, +N+P had the greatest effects on A. nidus growth and physiology in both watering treatments. Watering treatment changed leaf elemental concentrations but not their ratios (i.e. C:N and N:P). Nutrient addition altered C:N and N:P ratios and increased the concentration of the added elements in leaves, with more pronounced increases in the high-watering treatment. We conclude that the growth of A. nidus is more water- than nutrient-limited. When nutrient limitation occurs (i.e. under high-water availability), nutrient co-limitation is stronger than limitation by N or P alone. This result taken together with studies of other epiphytes suggests greater water than nutrient limitation is likely widespread among epiphytic plants. The limited effects of nutrient addition in the low-water treatment suggest that the effect of atmospheric N deposition on epiphyte growth will be limited when water availability is low.