71 research outputs found

    Preliminary Characterization of Underground Hydrological Processes under Multiple Rainfall Conditions and Rocky Desertification Degrees in Karst Regions of Southwest China

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    Karst regions are widely distributed in Southwest China and due to the complexity of their geologic structure, it is very challenging to collect data useful to provide a better understanding of surface, underground and fissure flows, needed to calibrate and validate numerical models. Without characterizing these features, it is very problematic to fully establish rainfall–runoff processes associated with soil loss in karst landscapes. Water infiltrated rapidly to the underground in rocky desertification areas. To fill this gap, this experimental work was completed to preliminarily determine the output characteristics of subsurface and underground fissure flows and their relationships with rainfall intensities (30 mm h−1, 60 mm h−1 and 90 mm h−1) and bedrock degrees (30%, 40% and 50%), as well as the role of underground fissure flow in the near-surface rainfall–runoff process. Results indicated that under light rainfall conditions (30 mm h−1), the hydrological processes observed were typical of Dunne overland flows; however, under moderate (60 mm h−1) and high rainfall conditions (90 mm h−1), hydrological processes were typical of Horton overland flows. Furthermore, results confirmed that the generation of underground runoff for moderate rocky desertification (MRD) and severe rocky desertification (SRD) happened 18.18% and 45.45% later than the timing recorded for the light rocky desertification (LRD) scenario. Additionally, results established that the maximum rate of underground runoff increased with the increase of bedrock degrees and the amount of cumulative underground runoff measured under different rocky desertification was SRD > MRD > LRD. In terms of flow characterization, for the LRD configuration under light rainfall intensity the underground runoff was mainly associated with soil water, which was accounting for about 85%–95%. However, under moderate and high rainfall intensities, the underground flow was mainly generated from fissure flow

    Spatiotemporal Tradeoffs and Synergies in Vegetation Vitality and Poverty Transition in Rocky Desertification Area

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    Vegetation recovery and poverty alleviation are critical problems in the karst national designed poor counties (NPDC) in southwest China. However, little information is available about the relationship between poverty and vegetation dynamics in these areas. In this study, we used remote sensing and statistical datasets from 2000 to 2015 to identify the relations between vegetation dynamics and poverty among the NPDC in southwest rocky desertification areas. We estimated the vegetation dynamics using the Normalized Difference Vegetation Index and poverty with the rural per capita net income. Local indicator of spatial association and the space-time transition type of poverty were applied to identify spatial patterns of the poverty spatial distribution relationship and transition. Also, poverty, natural and ecological governance factorswere assessed using the Geodetector method to uncover the driving factors of karst vegetation. The results showed that vegetation increased significantly (p < 0.05) in karst NPDC (82.82%) and rocky desertification control counties (78.77%). The karst NPDC was significantly clustered. The hot spots of rural per capita net income changed from west and north (2000) to only north (2015) and cold spots changed from east and south (2000) to only south (2015). The rural per capita net income spatiotemporal transitionwas higher in 2000 than in 2015.Wefound aweak synergy between vegetation change and poverty type transition in 42.86% of the browning counties, 45.45% in the slowly greening counties, and 43.65% in stable greening counties. However, 57.50% of counties in the quick greening counties showed a tradeoff relationship with the poverty type transition. The rocky desertification rate and ecological engineering measures affected vegetation dynamics importantly. The results will help decisionmakers to understand the interdependence between vegetation and poverty. This will contribute to better policies formulation to tackle poverty in the karst rocky desertification area

    Karst of Gunung Sewu Land Use and Land Covers Dynamics: Spatio-Temporal Analysis

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    A study of karst land use and land cover dynamics is critical for managing karst areas, which provide many pivotal services for people. This study aims to study such dynamics, especially in relation to the karst of Gunung Sewu, due to its development as a new emerging sector. Using a mixed methods approach, the study combines spatial data analysis with qualitative analysis. Spatial analysis was performed to examine the dynamic of the land cover derived from 2013 and 2021 Landsat 8 imagery, analyzed with the Google Earth Engine tool, together with analysis of spatial patterns using Global Moran’s I and LISA. The spatial analysis results were complemented by a qualitative analysis of the environmental history and development trends, as an explanatory method. The land cover analysis reveals a conversion from vegetation to agriculture, while the spatial pattern analysis shows that such conversion has mostly taken place in the northern part of the study area of Wonosari Basin. The environmental history of teak forest exploitation and agriculture is key to understanding current land use related to the emerging tourism sector, which is fundamental to the region. To manage the negative impacts, sustainable land use with a firm policy framework urgently needs to be implemented

    Geomorphology from space: A global overview of regional landforms

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    This book, Geomorphology from Space: A Global Overview of Regional Landforms, was published by NASA STIF as a successor to the two earlier works on the same subject: Mission to Earth: LANDSAT views the Earth, and ERTS-1: A New Window on Our Planet. The purpose of the book is threefold: first, to serve as a stimulant in rekindling interest in descriptive geomorphology and landforms analysis at the regional scale; second, to introduce the community of geologists, geographers, and others who analyze the Earth's surficial forms to the practical value of space-acquired remotely sensed data in carrying out their research and applications; and third, to foster more scientific collaboration between geomorphologists who are studying the Earth's landforms and astrogeologists who analyze landforms on other planets and moons in the solar system, thereby strengthening the growing field of comparative planetology

    Vegetation Dynamics Revealed by Remote Sensing and Its Feedback to Regional and Global Climate

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    This book focuses on some significant progress in vegetation dynamics and their response to climate change revealed by remote sensing data. The development of satellite remote sensing and its derived products offer fantastic opportunities to investigate vegetation changes and their feedback to regional and global climate systems. Special attention is given in the book to vegetation changes and their drivers, the effects of extreme climate events on vegetation, land surface albedo associated with vegetation changes, plant fingerprints, and vegetation dynamics in climate modeling

    Ecosystem Service and Land-Use Changes in Asia

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    This book highlights the role of research in Ecosystem Services and Land Use Changes in Asia. The contributions include case studies that explore the impacts of direct and indirect drivers affecting provision of ecosystem services in Asian countries, including China, India, Mongolia, Sri Lanka, and Vietnam. Findings from these empirical studies contribute to developing sustainability in Asia at both local and regional scales

    Threatened ecosystems of Myanmar. An IUCN Red List of ecosystems assessment. Version 1.0.

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    [Excerpt:] Myanmar's Red List of Ecosystems is a tool to understand our threats and plan for conservation and sustainable management. Forests constitute the dominant ecosystems in Myanmar, and we are blessed with high forest cover (42.92%) and diversity, with 36 of our 64 ecosystems identified as forest and mangrove. These forests and biodiversity underpin a range of ecosystem services which are central to Myanmar’s sustainable development, supporting human and resource needs, and contributing to a more stable climate. The loss of forests and our biodiversity leads to degradation and deterioration of ecosystem services and threatens Myanmar’s irreplaceable ecological heritage. We often discuss ecosystem services but this study documents Myanmar’s terrestrial ecosystem typology and spatial distribution for the first time. This is one of the first ecosystem red lists developed within ASEAN and this will inform our implementation for decades to come to inform legislation, land-use planning, protected area expansion, monitoring and reporting, and ecosystem management. To sustain our forests and our biodiversity we need to sustainably manage all of these incredible ecosystems

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    Status, trends and future dynamics of biodiversity and ecosystems underpinning nature's contributions to people

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    Biodiversity at the species and ecosystem levels is currently under multiple threats almost everywhere in the Asia-Pacific region, and in many areas the situation is now critical (well established). Of the various ecosystems, lowland evergreen forests, alpine ecosystems, limestone karsts, inland wetlands, and estuarine and coastal habitats are most threatened (well established). Genetic diversity within species, both wild and domestic, is also decreasing in many cases as a result of decreasing ranges (established but incomplete). In several countries there has been a small increase in the forest cover which is mostly attributed to monoculture forestry plantations and enabling policies of the governments. Forest fires associated with rapid loss of forest cover is leading to enormous environmental and socio-economic loss (well established) {3.2.1; 3.2.2; 3.2.3; 3.2.4; 3.2.5; 3.3.1}. There has been a steady decline in the populations of large vertebrates due to poaching and illegal trade in wildlife parts and products in the Asia-Pacific region (well established). As a result, most of these species now survive only in the best-managed protected areas (well established). Widespread loss of large vertebrates has had a measureable impact on several forest functions and services, including seed dispersal (established but incomplete). Australia has the highest rate of mammal extinction (>10 per cent) of any continent globally. Bird extinctions on individual Pacific islands range from 15.4 per cent to 87.5 per cent for those with good fossil records, and these extinctions have resulted in the loss of many ecological functions previously performed by birds (well established). Besides wildlife, there is a massive regional trade in timber, traditional medicines and other products (well established). Without adequate protection, remediation and proper policies, the current decline in biodiversity and nature's contributions to people on land, in freshwaters, and in the sea will threaten the quality of life of future generations in the Asia-Pacific region {3.2.1.1; 3.2.1.2; 3.2.1.4; 3.2.1.7; 3.2.2.1; 3.3.1} With the current rate of human population growth, expansion of urban industrial environments, transformation of agriculture in favour of high yielding varieties, transforming forests to uniform plantations of oil palm, rubber or timber trees, the biodiversity and nature's contributions to people in the Asia-Pacific region are likely to be adversely affected in the coming decades (well established). It is predicted that most of the biodiversity in the next few decades may be confined to protected areas or in places where the local communities have taken the lead in local level conservation in lieu of economic incentives and equitable compensation by the stake-holders. Unprecedented increase in human population of the Asia-Pacific region has stressed the fragile ecosystems to their limits; while arable cropping has been extended to sites which were not entirely suitable for it, resulting in soil degradation and erosion (well established) {3.2.1.1; 3.2.1.2; 3.2.1.5; 3.2.2.2; 3.2.2.4; 3.3; 3.3.1; 3.3.6; 3.4}. Freshwater ecosystems in the Asia-Pacific region support more than 28 per cent of aquatic and semi-aquatic species but nearly 37 per cent of these species are threatened due to anthropogenic and climatic drivers (well established). Cumulative impacts of global warming and damming of rivers in some of the river basins will have significant negative impacts on fish production and environmental flows (well established). Likewise, degradation of wetlands has had severe negative impacts on migratory waterfowl, fish production and local livelihoods (well established). However, there are scientific data gaps on the current status of biodiversity and nature's contributions to people in most of the river basins, inland wetlands and peatlands of the region {3.2.2.1; 3.2.2.2; 3.2.2.3; 3.2.2.4}. Coastal and marine habitats are likewise threatened due to commercial aquaculture, overfishing, and pollution affecting biodiversity and nature's contributions to people (well established). Detailed analyses of fisheries production in the region have shown severe decline in recent decades. It is projected that if unsustainable fishing practices continue, there could be no exploitable stocks of fish by as early as 2048. This could lead to trophic cascades and collapse of marine ecosystems (established but incomplete). Loss of seagrass beds which forms main diet of several threatened species such as dugong is a major concern (well established). There is a need to conduct systematic and region-wide assessment of fisheries stocks and coastal habitat in the region to aid conservation, management and restoration. {3.1.3.1; 3.2.3.3; 3.2.3.6; 3.2.4.6; 3.4}. Mangrove ecosystems in the Asia-Pacific region are most diverse in the world. They support a rich biodiversity and provide a range of provisioning, regulating and supporting services, which are crucial for the livelihood of local communities (well established). Both mangrove and intertidal habitats form a buffer from siltation for offshore coral reefs protection hence affecting productivity of reefs including seagrass. However, up to 75 per cent of the mangroves have been degraded or converted in recent decades (well established). The conversion of mangroves to aquaculture, rice, oil palm, and other land-use changes is leading to the loss of the buffer between sea and land which can reduce the impact of natural disasters such as cyclones and tsunamis. It is projected that rise in sea level due to global warming would pose the biggest threat to mangroves, thereby affecting nature's contributions to people especially in Bangladesh, Philippines, New Zealand, Viet Nam and China (well established) {3.2.3.1; 3.2.3.2; 3.3.4}. There has been a steady increase in the number, abundance and impacts of invasive alien species in the Asia-Pacific region, negatively affecting native biodiversity, ecosystem functioning and socio-cultural environments (well established). The total annual loss caused by invasive alien species has been estimated at US35.5billioninSEAsiaandUS35.5 billion in SE Asia and US9B in Australia. Costs to agriculture due to invasive alien species are likewise immense in the region {3.2.1.1; 3.2.1.2; 3.2.1.4; 3.2.1.5; 3.2.1.6; 3.2.1.7; 3.2.2.1; 3.2.2.2; 3.2.2.3; 3.2.3.6; 3.3.5}. There has been a nearly 30 per cent decline in biocultural diversity in the Asia-Pacific region since the 1970s (well established). Decline of linguistic diversity has been catastrophic in the indigenous Australian and Trans-New Guinean families, as a result of a shifting away from small indigenous languages towards larger, national or regional languages (well established). Linguistic and biological diversity often coincide in the Asia-Pacific region and parallel strategies need to be developed for their conservation. National conservation priorities should take into consideration the bioculturally rich areas that are facing great threats {3.2.5; 3.2.5.2; 3.2.5.4; 3.4}. Protected Area coverage in the Asia-Pacific region has increased substantially since last three decades. Despite this progress, however, at least 75 per cent of Key Biodiversity Areas remain unprotected, suggesting that the region is not on track to conserve areas of particular importance for biodiversity, as called for under Aichi Target 11 (well established). Oceania has the highest overall Protected Area coverage in the region. North-East Asia has the highest proportion of Key Biodiversity Areas covered by Protected Areas, but only 1 per cent of its marine area is protected (well established) {3.2.5.6; 3.2.6; 3.2.6.1}. The Asia-Pacific region has high levels of endemism, and some 25 per cent of the region’s endemic species are facing high extinction risks as per the IUCN Red List. Endemic species in some subregions face an extinction risk as high as 46 per cent of endemic species threatened in South Asia (well established). South-East Asia has the greatest number of threatened species and the fastest increases in extinction risk (Red List Index) in the Asia-Pacific region. North Asian endemic species extinction risk is also higher than the regional average; the high percentage of Data Deficient species (36 per cent) indicates that more research and conservation action are needed for endemic species in this subregion (well established) {3.2.1; 3.2.2; 3.2.6.2; 3.3.4}. Some aspects of biodiversity have recently started to recover in several countries in the Asia-Pacific region (established but incomplete). This recovery has resulted from various changes, including population concentration in cities, increased agricultural production per unit area, increasing conservation awareness among citizens, and the enabling policies of the governments. Future trends of biodiversity in the Asia-Pacific region will largely depend on whether other countries will follow this recovering trajectory by stabilizing land/sea use change, manage their natural resources sustainably, and cooperating with each other in meeting the Aichi Targets and the Sustainable Development Goals {3.2.1.5; 3.2.3.5; 3.3.1; 3.3.3; 3.3.6}. Given that the scientific information on the status and trends of biodiversity and nature's contributions to people is not available uniformly across all ecosystems and habitats in the region, the national governments are encouraged to initiate systematic documentation and monitoring of health of ecosystems and ecosystem flows (established but incomplete). Saving terrestrial fauna especially big mammals and other fauna that require large roaming areas such as Orangutans, proboscis monkey, hornbills, tigers, Sumatran rhinoceros, gaurs and Asian elephants can be done by connecting large tracts of forests with wildlife corridors or through rehabilitation projects; the same goes for coastal and marine, freshwater and other ecosystems in the region {3.2.1.1; 3.2.2.4; 3.3.4; 3.4}
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