Desertification

IPCC SPECIAL REPORT ON CLIMATE CHANGE AND LAND (SRCCL) Chapter 3: Climate Change and Land: An IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystem

Using Remote Sensing Techniques to Improve Hydrological Predictions in a Rapidly Changing World

Remotely sensed geophysical datasets are being produced at increasingly fast rates to monitor various aspects of the Earth system in a rapidly changing world. The efficient and innovative use of these datasets to understand hydrological processes in various climatic and vegetation regimes under anthropogenic impacts has become an important challenge, but with a wide range of research opportunities. The ten contributions in this Special Issue have addressed the following four research topics: (1) Evapotranspiration estimation; (2) rainfall monitoring and prediction; (3) flood simulations and predictions; and (4) monitoring of ecohydrological processes using remote sensing techniques. Moreover, the authors have provided broader discussions on how to capitalize on state-of-the-art remote sensing techniques to improve hydrological model simulations and predictions, to enhance their skills in reproducing processes for the fast-changing world

Ocena występowania susz oraz ich wpływu na środowisko w zlewni rzeki Udhaim w Iraku

AbstractThis research addresses selected key issues related to the occurrence of droughts and their impacts on the environment in the mesoscale basin of the Udhaim River, the left tributary of the Tigris River, Iraq. It highlights the importance of water resources, which are dependent on the climate and human activity, as well as exposed to drought hazard. The Standardized Precipitation-Evapotranspiration Index was applied to analyze drought development over the period 1980-2010. Trends in the SPEI time series in the years 1980-2010 were analyzed. Following this, the impacts of drought on land degradation, water discharge and water quality were investigated. The study results may help develop sustainable water management strategies important in mitigating water shortage.They can be used as a baseline for further research on improving water management in the region. The main contributions of this research include: (1) multi-year analysis of drought development of variable duration in the mesoscale basin; (2) extended understanding of drying trends explained by using the statistical tests; (3) broadened knowledge on the scale of land degradation, through remote sensing data sets and application of advanced GIS techniques; (4) improved understanding of water quality changes and their links with the magnitude of the revenue of water resources.StreszczenieNiniejsze badania dotyczą wybranych kluczowych zagadnień dotyczących występowania suszy i ich wpływu na środowisko w mezoskalowej zlewni rzeki Udhaim, lewym dopływie rzeki Tygrys, w Iraku. Praca dotyczy znaczenia zasobów wodnych, które są uzależnione od klimatu i działalności człowieka, a także są narażone na zagrożenie suszą. Zastosowano Standaryzowany Indeks Opadu i Ewapotranspiracji w celu analizy rozwoju suszy w okresie 1980-2010. Analizowano trendy w serii SPEI w latach 1980-2010. Następnie zbadano wpływ suszy na degradację środowiska, odpływ rzeczny i jakość wody. Wyniki badań mogą przyczynić się do opracowania trwałych strategii zarządzania zasobami wodnymi istotnych w łagodzeniu niedoboru wody. Mogą być wykorzystane jako podstawa do dalszych badań nad poprawą gospodarki wodnej w regionie. Główne osiągnięcia tych badań to: (1) wieloletnia analiza rozwoju suszu o zmiennym czasie trwania w zlewni mezoskalowej; (2) pogłębione zrozumienie trendów przesuszania środowiska wyjaśnione przy użyciu testów statystycznych; (3) poszerzona wiedza na temat skali degradacji lądu, uzyskana poprzez zastosowanie danych teledetekcyjnych i wykorzystanie zaawansowanych technik GIS; (4) lepsze zrozumienie zmian jakości wody i ich związku z wielkością odnawiania zasobów wodnych

Is there a solution to the spatial scale mismatch between ecological processes and agricultural management?

The major limit to develop robust landscape planning for biodiversity conservation is that the spatial levels of organization of landscape management by local actors rarely match with those of ecological processes. This problem, known as spatial scale mismatch, is recognized as a reason of lack of effectiveness of agri-environment schemes. We did a review to describe how authors identify the problem of spatial scale mismatch in the literature. The assumption is made that the solutions proposed in literature to conciliate agricultural management and conservation of biodiversity are based on theoretical frameworks that can be used to go towards an integration of management processes and ecological processes. Hierarchy Theory and Landscape Ecology are explicitly mobilized by authors who suggest multiscale and landscape scale approaches, respectively, to overcome the mismatch problem. Coordination in management is proposed by some authors but with no theoretical background explicitly mentioned. The theory of organization of biological systems and the theories of Social-Ecological Systems use the concept of coordination and integration as well as concepts of organization, adaptive capabilities and complexity of systems. These theories are useful to set up a new framework integrating ecological processes and agricultural management. Based on this review we made two hypotheses to explain difficulties to deal with spatial scale mismatch: (1) authors generally do not have an integrated approach since they consider separately ecological and management processes, and (2) an inaccurate use of terminology and theoretical frameworks partially explain the inadequacy of proposed solutions. We then specify some terms and highlight some ‘rules’ necessary to set up an integrative theoretical and methodological framework to deal with spatial scale mismatch.(Presentation des résumés n°186, p. 95-96, non paginé

Afforestation and Reforestation: Drivers, Dynamics, and Impacts

Afforestation/reforestation (or forestation) has been implemented worldwide as an effective measure towards sustainable ecosystem services and addresses global environmental problems such as climate change. The conversion of grasslands, croplands, shrublands, or bare lands to forests can dramatically alter forest water, energy, and carbon cycles and, thus, ecosystem services (e.g., carbon sequestration, soil erosion control, and water quality improvement). Large-scale afforestation/reforestation is typically driven by policies and, in turn, can also have substantial socioeconomic impacts. To enable success, forestation endeavors require novel approaches that involve a series of complex processes and interdisciplinary sciences. For example, exotic or fast-growing tree species are often used to improve soil conditions of degraded lands or maximize productivity, and it often takes a long time to understand and quantify the consequences of such practices at watershed or regional scales. Maintaining the sustainability of man-made forests is becoming increasingly challenging under a changing environment and disturbance regime changes such as wildland fires, urbanization, drought, air pollution, climate change, and socioeconomic change. Therefore, this Special Issue focuses on case studies of the drivers, dynamics, and impacts of afforestation/reforestation at regional, national, or global scales. These new studies provide an update on the scientific advances related to forestation. This information is urgently needed by land managers and policy makers to better manage forest resources in today’s rapidly changing environments

Climate Change and Environmental Sustainability- Volume 5

This volume of Climate Change and Environmental Sustainability covers topics on greenhouse gas emissions, climatic impacts, climate models and prediction, and analytical methods. Issues related to two major greenhouse gas emissions, namely of carbon dioxide and methane, particularly in wetlands and agriculture sector, and radiative energy flux variations along with cloudiness are explored in this volume. Further, climate change impacts such as rainfall, heavy lake-effect snowfall, extreme temperature, impacts on grassland phenology, impacts on wind and wave energy, and heat island effects are explored. A major focus of this volume is on climate models that are of significance to projection and to visualise future climate pathways and possible impacts and vulnerabilities. Such models are widely used by scientists and for the generation of mitigation and adaptation scenarios. However, dealing with uncertainties has always been a critical issue in climate modelling. Therefore, methods are explored for improving climate projection accuracy through addressing the stochastic properties of the distributions of climate variables, addressing variational problems with unknown weights, and improving grid resolution in climatic models. Results reported in this book are conducive to a better understanding of global warming mechanisms, climate-induced impacts, and forecasting models. We expect the book to benefit decision makers, practitioners, and researchers in different fields and contribute to climate change adaptation and mitigation