Rehabilitation planning in an oilfield in the Monte Austral: Mapping sand-sized sediment availability and assessing its effect on microtopography rehabilitation

In drylands, the microtopography is formed by mound-shaped dunes of eolian deposition that occur around shrubs or other vegetation in clumps. These mounds are characteristic of the Monte Austral, which covers 20% of Argentina (approximately 50 million ha), has a strong water deficit and is subjected to land degradation by the oil industry. Considering the biogeomorphological approach, oilfield rehabilitation should begin with regeneration of the mounds as they provide safe sites for vegetation. Since rehabilitation success may be influenced by sand-sized sediment availability, we addressed two objectives: mapping the sediment availability in an oilfield and evaluating its effect on microtopography rehabilitation. We used a Sentinel-2 MSI scene and assessed three approaches to map the sediments: two expressions of the Normalized Difference Sand Index and the feature Brightness of the Tasselled Cap Transformation. We validated the three maps using a geomorphological map. Two maps showed the highest agreement with the geomorphological map and errors were associated with the detection of bright lithified or cohesive material not available for sediment transportation. Then, we evaluated the effect of sediments on microtopography rehabilitation. We compared the morphometric traits of mounds (height, maximum and minimum length) located in areas of low and high sediment availability, in both natural and scarified areas. We considered the time since scarification was applied (8–13, 4–8, or <4 years ago). The mounds in the natural areas were larger than the mounds in the scarified areas, so complete microtopography rehabilitation is not achieved 13 years after scarification. The mounds in high-sediment-availability areas were different from the initial condition 4 years after scarification, whereas differences took 8 years to become evident with low sediment availability. Sediment availability must be considered when designing rehabilitation techniques to ensure the success and sustainability of the project. Our results have implications for the development of a biogeomorphological model to guide rehabilitation planning.Fil: Ciancio, Matías Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimonides. Area de Invest.biomédicas y Biotecnológicas. Cent.d/est.biomedic.,biotecn.,ambient.y Diagnost.. Departamento de Ecología y Cs.ambientales; Argentina. BfU de Argentina S.A.; ArgentinaFil: Guida Johnson, Bárbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Zuleta, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimonides. Area de Invest.biomédicas y Biotecnológicas. Cent.d/est.biomedic.,biotecn.,ambient.y Diagnost.. Departamento de Ecología y Cs.ambientales; Argentin

LANDSCAPE IMPACT ASSESSMENT OF SDG2 DEVELOPMENT PROJECTS USING REMOTE SENSING AND UNSUPERVISED CONTROL SITE SELECTION

As part of its objective to achieve Zero Hunger under SDG2 the United Nations World Food Programme, in partnership with Governments, NGOs and other UN agencies, supports food insecure communities to increase natural resource availability and improve their management. This is done mostly through the building and rehabilitation of soil and water conservation assets (e.g., small dams, weirs, landscape restoration) and structures that increase productivity (e.g., vegetable gardens, irrigation canals). To adequately monitor these activities around the globe simultaneously, remote sensing was found to be an adequate tool. This study introduces the use of high-resolution satellite imagery, and more specifically NDVI derived from the Landsat series to verify and quantify the impact of such development projects. In total 121 projects in 10 countries and six different climate zones were analyzed using a pre- and post-implementation comparison and a Before-After Control Impact (BACI) study considering randomly selected control sites. Both approaches were found to show robust results throughout the different countries, project types and climate zones. 67% of all projects showed significant improvements in vegetation conditions during the wet seasons only three years after the implementation. Using the proposed workflow based on Python scripting and cloud computing of satellite data, fast and robust analyses can be achieved, while assuring constant data quality

Desertification in Europe: mitigation strategies, land use planning: Proceedings of the advanced study course held in Alghero, Sardinia, Italy from 31 May to 10 June 1999

The present volume is based on lectures given at the course held in Alghero, Sardinia, Italy, from 31 May to 10 June 1999 on ‘Desertification in Europe: Mitigation Strategies, Land Use Planning’. It also contains presentations, given by the participating students, on their own research activities and interests. With the adoption of the International Convention to Combat Desertification, which represents a follow up of the Rio recommendations, this publication is timely. It highlights the specific situation of the Southern European regions and provides a comprehensive and state-of-the-art review of this complex issue

Restoring Degraded Landscapes through An Integrated Approach Using Geospatial Technologies in the Context of the Humanitarian Crisis in Cox’s Bazar, Bangladesh

The influx of nearly a million refugees from Myanmar's Rakhine state to Cox's Bazar, Bangladesh, in August 2017 put significant pressure on the regional landscape leading to land degradation due to biomass removal to provide shelter and fuel energy and posed critical challenges for both host and displaced population. This article emphasizes geospatial applications at different stages of addressing land degradation in Cox’s Bazar. A wide range of data and methods were used to delineate land tenure, estimate wood fuel demand and supply, assess land degradation, evaluate land restoration suitability, and monitor restoration activities. The quantitative and spatially explicit information from these geospatial assessments integrated with the technical guidelines for sustainable land management and an adaptive management strategy was critical in enabling a collaborative, multi-disciplinary and evidence-based approach to successfully restoring degraded landscapes in a displacement setting

Rangeland Systems: Processes, Management and Challenges

environmental management; environmental law; ecojustice; ecolog

Multi-scale targeting of land degradation in northern Uzbekistan using satellite remote sensing

Advancing land degradation (LD) in the irrigated agro-ecosystems of Uzbekistan hinders sustainable development of this predominantly agricultural country. Until now, only sparse and out-of-date information on current land conditions of the irrigated cropland has been available. An improved understanding of this phenomenon as well as operational tools for LD monitoring is therefore a pre-requisite for multi-scale targeting of land rehabilitation practices and sustainable land management. This research aimed to enhance spatial knowledge on the cropland degradation in the irrigated agro-ecosystems in northern Uzbekistan to support policy interventions on land rehabilitation measures. At the regional level, the study combines linear trend analysis, spatial relational analysis, and logistic regression modeling to expose the LD trend and to analyze the causes. Time series of 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI), summed over the growing seasons of 2000-2010, were used to determine areas with an apparent negative vegetation trend; this was interpreted as an indicator of LD. The assessment revealed a significant decline in cropland productivity across 23% (94,835 ha) of the arable area. The results of the logistic modeling indicate that the spatial pattern of the observed trend is mainly associated with the level of the groundwater table, land-use intensity, low soil quality, slope, and salinity of the groundwater. To quantify the extent of the cropland degradation at the local level, this research combines object-based change detection and spectral mixture analysis for vegetation cover decline mapping based on multitemporal Landsat TM images from 1998 and 2009. Spatial distribution of fields with decreased vegetation cover is mainly associated with abandoned cropland and land with inherently low-fertility soils located on the outreaches of the irrigation system and bordering natural sandy deserts. The comparison of the Landsat-based map with the LD trend map yielded an overall agreement of 93%. The proposed methodological approach is a useful supplement to the commonly applied trend analysis for detecting LD in cases when plot-specific data are needed but satellite time series of high spatial resolution are not available. To contribute to land rehabilitation options, a GIS-based multi-criteria decision-making approach is elaborated for assessing suitability of degraded irrigated cropland for establishing Elaeagnus angustifolia L. plantations while considering the specific environmental setting of the irrigated agro-ecosystems. The approach utilizes expert knowledge, fuzzy logic, and weighted linear combination to produce a suitability map for the degraded irrigated land. The results reveal that degraded cropland has higher than average suitability potential for afforestation with E. angustifolia. The assessment allows improved understanding of the spatial variability of suitability of degraded irrigated cropland for E. angustifolia and, subsequently, for better-informed spatial planning decisions on land restoration. The results of this research can serve as decision-making support for agricultural planners and policy makers, and can also be used for operational monitoring of cropland degradation in irrigated lowlands in northern Uzbekistan. The elaborated approach can also serve as a basis for LD assessments in similar irrigated agro-ecosystems in Central Asia and elsewhere.Multisclare Bewertung der Landdegradation in Nord-Uzbekistan unter der Verwendung von Satellitenfernerkundung Die zunehmende Landdegradation (LD) in den bewässerten Agrarökosystemen in Usbekistan behindert die nachhaltige Entwicklung dieses vorwiegend landwirtschaftlich geprägten Landes. Bis heute sind nur wenige und veraltete Informationen über die aktuellen Bodenbedingungen der bewässerten Anbauflächen verfügbar. Ein besseres Verständnis dieses Phänomens sowie operationelle Werkzeuge für LD-Monitoring sind daher Voraussetzung für ein nachhaltiges Landmanagement sowie für Landrehabilitationsmaßnahmen. Ziel dieser Studie war es, das räumliche Verständnis der Degradierung von Anbaugebieten in den bewässerten Agrarökosystemsn des nördlichen Usbekistans zu verbessern, um staatliche Interventionen in Bezug auf Landrehabilitationsmaßnahmen zu unterstützen Auf der regionalen Ebene kombiniert die Studie lineare Trendanalyse, räumliche relationale Analyse sowie logistischer Regressionsmodellierung, um den LD-Trend darzustellen und Gründe zu analysieren. Zeitreihen von 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) Bildern wurden für den Zeitraum der Anbauperioden zwischen 2000-2010 untersucht, um Bereiche mit einem offensichtlich negativen Vegetationstrend zu ermitteln. Dieser negative Trend kann als Indikator für LD interpretiert werden. Die Untersuchung ergab eine signifikante Abnahme der Bodenproduktivität auf 23% (94,835 ha) der Anbaufläche. Zudem deuten die Ergebnisse der logistischen Modellierung darauf hin, dass das räumliche Muster des beobachteten Trends überwiegend mit der Höhe des Grundwasserspiegels, der Landnutzungsintensität, der geringen Bodenqualität, der Hangneigung sowie der Grundwasserversalzung zusammenhängt. Um das Ausmaß der Degradation der Anbauflächen auf der lokalen Ebene zu quantifizieren, kombiniert diese Studie objektbasierte Erkennung von Veränderungen und spektrale Mischungsanalyse für die Abnahme der Vegetationsbedeckung auf der Grundlage von multitemporalen Landsat-TM-Bildern im Zeitraum von 1998 bis 2009. Die räumliche Verteilung der Felder mit abnehmender Vegetationsbedeckung hängt überwiegend mit verlassenen Anbauflächen sowie mit nährstoffarmen Böden in den Randbereichen des Bewässerungssystems und an den Grenzen zu natürlichen Sandwüsten zusammen. Ein Vergleich mit der Karte des LD-Trends ergab insgesamt eine Übereinstimmung von 93%. Der vorgeschlagene Ansatz ist eine nützliche Ergänzung zu der häufig angewendeten Trendanalyse für die Ermittlung von LD in Regionen, für die keine Satellitenbildzeitreihen mit hoher Auflösung verfügbar sind. Als Beitrag zu Landrehabilitationsmöglichkeiten, wird ein GIS-basierter Multi-Kriterien-Ansatz zur Einschätzung der Eignung von degradierten bewässerten Anbauflächen für Elaeagnus angustifolia L. Plantagen beschrieben, der gleichzeitig die spezifischen Umweltbedingungen der bewässerten Agrarökosysteme berücksichtigt. Dieser Ansatz beinhaltet Expertenwissen, Fuzzy-Logik und gewichtete lineare Kombination, um eine Eignungskarte für die bewässerten degradierten Anbauflächen herzustellen. Die Ergebnisse zeigen, dass diese Flächen ein überdurchschnittliches Eignungspotenzial für die Aufforstung mit E. angustifolia aufweisen. Diese Studie trägt zu einem verbesserten Verständnis der räumlichen Variabilität der Eignung von solchen Flächen für E. angustifolia bei. Die Ergebnisse dieser Studie können als Entscheidungshilfe für landwirtschaftliche Planer und politische Entscheidungsträger sowie für verbesserte Landrehabilitationsmaßnahmen und operationelles Monitoring der Degradation von Anbauflächen im nördlichen Usbekistan eingesetzt werden. Zudem kann der beschriebene Ansatz als Grundlage für LD-Untersuchungen in ähnlichen bewässerten Agrarökosystemen in Zentralasien und anderswo dienen

Agroenvironmental transformation in the Sahel: Another kind of “Green Revolution"

millions fed, food security, Sahel, Zai, Stone bunds, Agroforestry, Soil management,

Assessing land degradation through land use/land cover change and socio-ecological analysis in the rural semiarid area of the greater Sekhukhune District Municipality, South Africa.

Masters Degree. University of KwaZulu-Natal, Pietermaritzburg.Abstract available in PDF