858 research outputs found
Monitoring Oil Exploitation Infrastructure and Dirt Roads with Object-Based Image Analysis and Random Forest in the Eastern Mongolian Steppe
Information on the spatial distribution of human disturbance is important for assessing and monitoring land degradation. In the Eastern Mongolian Steppe Ecosystem, one of the major driving factors of human-induced land degradation is the expansion of road networks mainly due to intensifications of oil exploration and exploitation. So far, neither the extents of road networks nor the extent of surrounding grasslands affected by the oil industry are monitored which is generally labor consuming. This causes that no information on the changes in the area which is affected by those disturbance drivers is available. Consequently, the study aim is to provide a cost-effective methodology to classify infrastructure and oil exploitation areas from remotely sensed images using object-based classifications with Random Forest. By combining satellite data with different spatial and spectral resolutions (PlanetScope, RapidEye, and Landsat ETM+), the product delivers data since 2005. For the classification variables, segmentation, spectral characteristics, and indices were extracted from all above mentioned imagery and used as predictors. Results show that overall accuracies of land use maps ranged 73%â93% mainly depending on satellitesâ spatial resolution. Since 2005, the area of grassland disturbed by dirt roads and oil exploitation infrastructure increased by 88% with its highest expansion by 47% in the period 2005â2010. Settlements and croplands remained relatively constant throughout the 13 years. Comparison of multiscale classification suggests that, although high spatial resolutions are clearly beneficial, all datasets were useful to delineate linear features such as roads. Consequently, the results of this study provide an effective evaluation for the potential of Random Forest for extracting relatively narrow linear features such as roads from multiscale satellite images and map products that are possible to use for detailed land degradation assessments
Assessing responses of grasslands to grazing management using remote sensing approaches
Grazing caused grassland degradation has occurred worldwide in recent decades. In spite of numerous efforts that have been invested to explore the mechanism of grassland responses to grazing management, the major challenge remains monitoring the responses over large area. This research evaluates the synthetic use of remote sensing data and the Milchunas-Sala-Lauenroth (MSL) model for grazing impact assessment, aiming to explore the potential of remotely sensed data to investigate the responses of grasslands to various grazing intensities across different grassland types.
By combining field collected biophysical parameters, ground hyperspectral data and satellite imagery with different resolutions, this research concluded that 1) sampling scale played an important role in vegetation condition assessment. Adjusted transformed soil-adjusted vegetation index (ATSAVI) derived from remote sensing imagery with 10m or 20m spatial resolution was suitable for measuring leaf area index (LAI) changes in post-grazing treatment in the grazing experimental site; 2) canopy height and the ratio of photosynthetically to non-photosynthetically active vegetation cover were identified as the most sensitive biophysical parameters to reflect vegetation changes in mixed grasslands under light to moderate grazing intensities; 3) OSAVI (Optimised soil adjusted vegetation index) derived from Landsat Thematic Mapper (TM) image can be used for grassland production estimation under various grazing intensities in three types of grasslands in Inner Mongolia, China, with an accuracy of 76%; and 4) Grassland production predicted by NCI (Normalized canopy index) showed significant differences between grazed and ungrazed sites in years with above average and average growing season precipitation, but not in dry years, and 75% of the variation in production was explained by growing season precipitation (April-August) for both grazed and ungrazed sites
Effects of land-use change on grassland ecosystem services in Inner Mongolia and their implications for livelihoods and sustainable management
Grassland degradation has become a major challenge in many parts of the world, especially in arid or semi-arid areas, such as the Chinese Inner Mongolian Autonomous Region (IMAR). Previous studies of the grassland ecosystems in IMAR focused on climate change and its environmental consequences or on the land-use conflicts between agrarian communities and nomads. For better planning and management, a more integrated analysis of the consequences of land-use change for the livelihood dependence and other benefits (services) of the grasslands in IMAR is needed. Studies on ecosystem services of IMARâs grasslands are usually based on remote sensing data (TM images) to assess the total value of the grassland ecosystem services using benefit transfer. Thus far, to my knowledge no study collected original data on the detailed use of ecosystem services by pastoralists on the Mongolian Plateau or on their livelihood dependence on these services at the household level. Also, no data is available on the changes over time in contrasting situations for different grassland types (like meadow, steppe and desert steppe). I therefore aim to analyse the interactions between the people and the ecosystems in IMAR in an integrated manner, and especially focus on analysing the different utilization patterns of ecosystem services and the livelihood dependence of local herders and other stakeholders in selected study sites. The ultimate goal of my study is to contribute to sustainable management of the IMARâs ecosystems. To achieve the goal of my PhD study, the changes in land use, household consumption patterns and their impacts have been addressed and investigated for four selected study sites: Hulun Buir, Xilin Gol, Ordos and Alxa Right. These sites are in a âtransectâ from southwest to northeast to capture the gradient in use of ecosystem services in IMAR. The methodological framework of this research combines quantitative and qualitative tools to analyse ecosystem services. It specifies an integrative approach in specific spatial and temporal contexts to evaluate trade-offs between human activities, use of ecosystem services and human well-being. This framework enables to analyse the effects of multiple factors (e.g. policies or climate and geographic conditions) on utilization patterns of ecosystem services and the influence on society. The data used to apply the framework stems from a bottom-up approach by using household surveys and other local field data. The results show that the householdersâ intake comprised a low amount of crops, including staple foods, vegetables and fruit with a high amount of meat. However, more crops and less meat are increasingly preferred now. From 1995 to 2010, fuel consumption patterns changed from bio-fuels (especially dung) to mainly electricity and gas. Beside the influences of different environmental conditions and economic development, the grassland restoration policy measures changed grazing activities and basic household consumption patterns. Grazing activities were less affected by seasonal grazing and rotational grazing measures than other policy measures. However, when grazing was prohibited, immigration and livestock rearing control policy measures (e.g. in Xilin Gol and Ordos) fundamentally changed the basic household consumption patterns (especially for food and fuel). Livelihoodâs food-consumption highly links to potential water consumption. The results show that compared to the direct water consumption, the indirect water consumption through food production was a major share of total water consumption. From 1995 to 2010, indirect water consumption decreased in Xilin Gol and Ordos because meat consumption decreased and fruit and vegetable consumption increased. The grassland ecosystem degradation in IMAR leads to a shortage of meat production and this causes people to purchase food from outside, but the ability to purchase food also depends on income levels. The implementation of the grassland conservation policies significantly affected household livelihoods and this in turn, affected household use of natural assets (primarily the land), their agricultural assets (farming and grazing activities) and their financial assets (income and consumption). The households developed adaptation measures to account for the dependence of their livelihoods on local ecosystems by initializing strategies (e.g. seeking off-farm work, leasing pasture land, increasing purchases of fodder for stall-fed animals and altering their diet and fuel consumption) to compensate for their changing livelihoods. In general, the household dependence on local grasslands decreased. This indicates a transition from traditional pastoral grazing to control grazing, rising of modern dairy cattle (intensive animal husbandry), diversification of income sources and decreases in land-based employment and in the household food and fuel consumption. These changes increased the diversity of livelihoods, household resilience and environmental sustainability. Five grassland utilization patterns were identified, including no use (natural grasslands), light use, moderate use, intensive use and recovery sites (degraded sites protected from further use). The results show that light use generally provided higher levels of ecosystem services than intensive use and no use. Only supporting ecosystem services differed. Surprisingly, I found no consistently positive effects of the strict conservation activities across the sites, since the results varied spatially and with respect to differences in the land-use patterns. My results suggest that appropriate grassland-utilization patterns likely enhance the supply of ecosystem services and reduce negative effects on both household livelihoods and the environment. For example, in the Hulun Buir grasslands, the precipitation is 50% higher than in the other areas. Therefore the area tolerates a higher grazing intensity before degradation occurs and its grasslands provide more provisioning services but at the cost of decreased regulating and supporting services. After implementing grassland conservation policies, income from cultivation and animal grazing decreased, whereas income from compensation and off-farm activities increased. The herders preferred an annual payment of 99.2 US ha-1, resulting in an annual gap of 15.4 US$ ha-1. These currently too low payments probably lead some herders to expand their grazing into restricted grasslands or increase their number of animals, particularly if such payment program ends. To create an improved and sustainable payment scheme, solutions are needed that enable the herders to sustain their livelihood, while conserving the grasslands. My findings can help to establish appropriate grassland-utilization patterns and more effective payment schemes for the grasslands of IMAR and similar regions.</p
Land Quality and Landscape Processes
This monograph contains a selection of scientific papers presented on the conference on Land Quality and Landscape Processes, hold in Keszthely, Hungary. It covers topics related to various aspects of land quality including : concepts of assessment; evaluation of biomass productivity ; bioindicators of land quality ; quality assessment of degraded land ; land use related data processingJRC.H.5-Land Resources Managemen
"May They Live with Herds". Transformation of Mongolian Pastoralism in Inner Mongolia of China
This thesis is dedicated to a better understanding of Mongolian pastoralism transformation in the contemporary Inner Mongolia context. Such a comprehension requires both the knowledge of common resource management and a historical analytical approach. A multidisciplinary approach based on institutional theory is proposed, primarily because the research rationale on reflection of fieldwork information raises the hypothesis that outside forces are the main cause of Mongolian pastoralism transformation; also because the long-standing controversy over common resource management needs a comprehensive approach instead. Moreover, a historical dimension can be very well integrated in the institutional change theory. Hence, the transformation of Mongolian pastoralism is an imposed institutional change process in which external institutions constantly pushes internal institutions out of functions. The thesis is thus structured: From the presentation of internal institutions of traditional Mongolian pastoralism, to the explanation of external institution transformations, and to the observation of internal institutions adapting to the changing institutional environment. The discussion concentrates on the present change of Mongolian pastoralism under the Household Production Responsibility System and other related management policies. The appropriation of the present external management system is questioned through a cost-benefit evaluation, in which the vulnerabilities both of Mongolian pastoralism and the pastoralists are exposed. Therefore, the socio-economic, environmental and cultural predicaments faced by these people can actually be interpreted as the phenomena or outcome of institution maladjustments or institutional defects. New forms of cooperative usage of rangeland, as an expression of micro-level motive for âappropriateâ institutional arrangement in sustaining pastoral practices, are finally discussed to suggest the transformation prospect
Deserts and Desertification
A desert is an ecosystem in an arid zone in which sand dunes cover the land and sandstorms often occur. Although desert vegetation is sparse, it plays an important role in ecosystem structure and function. Desertification is one of the most severe environmental problems today. Land desertification can be controlled through many measures, such as eco-villages, eco-agriculture, biodiversity conservation, and the combination of engineering and biology. This edited volume provides new insights into the pattern of desert ecosystems and the progress of desertification control. It is a useful resource for researchers in ecology, forestry, and land desertification control
QUANTIFYING GRASSLAND NON-PHOTOSYNTHETIC VEGETATION BIOMASS USING REMOTE SENSING DATA
Non-photosynthetic vegetation (NPV) refers to vegetation that cannot perform a photosynthetic function. NPV, including standing dead vegetation and surface plant litter, plays a vital role in maintaining ecosystem function through controlling carbon, water and nutrient uptake as well as natural fire frequency and intensity in diverse ecosystems such as forest, savannah, wetland, cropland, and grassland. Due to its ecological importance, NPV has been selected as an indicator of grassland ecosystem health by the Alberta Public Lands Administration in Canada. The ecological importance of NPV has driven considerable research on quantifying NPV biomass with remote sensing approaches in various ecosystems. Although remote images, especially hyperspectral images, have demonstrated potential for use in NPV estimation, there has not been a way to quantify NPV biomass in semiarid grasslands where NPV biomass is affected by green vegetation (PV), bare soil and biological soil crust (BSC). The purpose of this research is to find a solution to quantitatively estimate NPV biomass with remote sensing approaches in semiarid mixed grasslands. Research was conducted in Grasslands National Park (GNP), a parcel of semiarid mixed prairie grassland in southern Saskatchewan, Canada. Multispectral images, including newly operational Landsat 8 Operational Land Imager (OLI) and Sentinel-2A Multi-spectral Instrument (MSIs) images and fine Quad-pol Radarsat-2 images were used for estimating NPV biomass in early, middle, and peak growing seasons via a simple linear regression approach. The results indicate that multispectral Landsat 8 OLI and Sentinel-2A MSIs have potential to quantify NPV biomass in peak and early senescence growing seasons. Radarsat-2 can also provide a solution for NPV biomass estimation. However, the performance of Radarsat-2 images is greatly affected by incidence angle of the image acquisition. This research filled a critical gap in applying remote sensing approaches to quantify NPV biomass in grassland ecosystems. NPV biomass estimates and approaches for estimating NPV biomass will contribute to grassland ecosystem health assessment (EHA) and natural resource (i.e. land, soil, water, plant, and animal) management
Long-term analysis and appropriate metrics of climate change in Mongolia
Department Head: N. LeRoy Poff.2010 Spring.Includes bibliographical references.This study addresses three important issues related to long-term climate change study in Mongolia. Mongolia is one of the biggest land-locked countries in Asia and 75-80 percent of the land is rangeland, which is highly vulnerable to climate change. Climate will affect many sectors critical to the country's economic, social, and ecological welfare. Therefore, it is regionally and globally important to evaluate climate change in Mongolia. Chapter 1 discusses the qualitative and descriptive study on exposure characteristics of the 17 Mongolian meteorological stations, which are part of the Global Climate Observing Network (GCON). The global average temperature anomalies are based in part on the GCON stations' meteorological data. To document the possible exposures surrounding the weather stations, the Mongolian meteorological stations were surveyed during July-August 2005. From the total 17 stations, 47 percent were determined strongly influenced by urban character landscape, 41 percent received some anthropogenic influences, and 12 percent had very little to no anthropogenic influences. Even though the Mongolian meteorological stations' exposure characteristics are better than the European and North American stations' the strict adherence in following WMO guidelines is important and urgently needed. Chapter 2 evaluates the long-term (1961-2005) trends in seasonal and annual surface mean, maximum, minimum temperatures and precipitation. Furthermore, this study compares the long-term mean temperature trends with decadal (1998-2007) trends. This chapter also discusses the extreme climate indices on spatial and temporal scales. According to the results, the long-term linear temperature trends show a clear increasing trend whereas the decadal trends show the decreasing trend mostly in winter and spring. The analysis of extreme indices (1961-2001) indicate that most of the stations frost and icing days are decreased and summer days, tropical nights, monthly maximum value of daily minimum, maximum temperatures and growing season length are increased. Precipitation indices varied substantially and there were no unified temporal and spatial pattern. In addition to that, I am suggesting effective temperature as an appropriate metric to evaluate surface heat change because it counts not only air temperature but also surface humidity. Chapter 3 discusses a case study of grazing intensity on surface energy budgets. To evaluate the land atmospheric interactions over the grassland area depending on the different grazing intensity I conducted the case study over the Shortgrass Steppe Long-Term Ecological Research site on Northern Great Plains of US to imply the findings in semiarid shortgrass steppe of Mongolia. The study site has much of similarities with Mongolian shortgrass steppe and has more frequent, high quality data. This study evaluates the impact of grazing on microclimate and energy budgets in a dry (163 mm) and two near-normal (262 and 260 mm) precipitation years based on continuously measured 20 minute interval data. This study helps to describe surface energy partitioning in semi-arid grasslands that has long history of grazing. The main finding of the study is grazing has a potential impact on the energy partitioning under conditions of higher water availability, but not during dry conditions
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