Risk perception and decision-making: do farmers consider risks from climate change?   总被引：2，自引：0，他引：2  

Anton Eitzinger  Claudia R. Binder  Markus A. Meyer 《Climatic change》2018,147(3-4):507-521

This paper provides one of the first empirical studies that examine the impact of climate change adaptation practices on technical efficiency (TE) among smallholder farmers in Nepal. An adaptation index is used to explore the impact of farmers’ adaptation on TE using the stochastic frontier analysis framework. Data for six districts of Nepal representing all three agro-ecological regions (terai, hill, and mountain) were collected from a focus group discussion, a stakeholder workshop and a household survey. The survey shows that about 91% of the farming households have adopted at least one practice to minimize the adverse impacts of climate change. Empirical results reveal that adaptation is an important factor explaining efficiency differentials among farming households. Those adopting a greater number of adaptation practices on a larger scale are, on average, found to be 13% more technically efficient than those adopting fewer practices on smaller scale. The empirical results also show that average TE is only 0.72, indicating that there are opportunities for farming households in Nepal to further improve productive efficiency, on average by 28%. Other important factors that explain variations in the productive efficiency across farming households include farmer’s education level, irrigation facilities, market access, and social capital such as farmer’s participations in relevant agricultural organizations and clubs. This study provides empirical evidence to policy makers that small scale adjustments made by farmers in response to climate change impacts are effective in improving farmers’ efficiency in agriculture production. This indicates a need for farmers’ involvement in climate change adaptation planning.  相似文献   

Erratum to: The Quadrennial Ozone Symposium 2016     

Sophie GODIN-BEEKMANN  Irina PETROPAVLOSKIKH  Stefan REIS  Paul NEWMAN  Wolfgang STEINBRECHT  Markus REX  Michelle L. SANTEE  Richard S. ECKMAN  Xiangdong ZHENG  Matthew B. TULLY  David S. STEVENSON  Paul YOUNG  John PYLE  Mark WEBER  Johanna TAMMINEN  Gina MILLS  Alkiviadis F. BAIS  Clare HEAVISIDE  Christos ZEREFOS 《大气科学进展》2018,35(3):368-369

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Arsenic speciation and turnover in intact organic soil mesocosms during experimental drought and rewetting   总被引：1，自引：0，他引：1  

Christian Blodau  Beate Fulda  Markus Bauer  Klaus-Holger Knorr 《Geochimica et cosmochimica acta》2008,72(16):3991-4007

Wetlands are significant sources and sinks for arsenic (As), yet the geochemical conditions and processes causing a release of dissolved arsenic and its association with the solid phase of wetland soils are poorly known. Here we present experiments in which arsenic speciation was determined in peatland mesocosms in high spatiotemporal resolution over 10 months. The experiment included a drought/rewetting treatment, a permanently wet, and a defoliated treatment. Soil water content was determined by the TDR technique, and arsenic, iron and sulfate turnover from mass balancing stocks and fluxes in the peat, and solid phase contents by sequential extractions. Arsenic content ranged from 5 to 25 mg kg⁻¹ and dissolved concentrations from 10 to 300 μg L⁻¹, mainly in form of As(III), and secondarily of As(V) and dimethylated arsenic (DMA). Total arsenic was mainly associated with amorphous iron hydroxides (R² > 0.95, α < 0.01) and deeper into the peat with an unidentified residual fraction. Arsenic release was linked to ferrous iron release and primarily occurred in the intensely rooted uppermost soil. Volumetric air contents of 2-13 % during drought eliminated DMA from the porewater and suppressed its release after rewetting for >30 d. Dissolved As(III) was oxidized and immobilized as As(V) at rates of up to 0.015 mmol m⁻³ d⁻¹. Rewetting mobilized As(III) at rates of up to 0.018 mmol m⁻³ d⁻¹ within days. Concurrently, Fe(II) was released at depth integrated rates of up 20 mmol m⁻³ d⁻¹. The redox half systems of arsenic, iron, and sulfur were in persistent disequilibrium, with H₂S being a thermodynamically viable reductant for As(V) to As(III). The study suggests that rewetting can lead to a rapid release of arsenic in iron-rich peatlands and that methylation is of lesser importance than co-release with iron reduction, which was largely driven by root activity.  相似文献   

Model-based quantification of runoff generation processes at high spatial and temporal resolution     

Andreas Steinbrich  Hannes Leistert  Markus Weiler 《Environmental Earth Sciences》2016,75(21):1423

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Extraordinary heat during the 1930s US Dust Bowl and associated large-scale conditions     

Markus G. Donat  Andrew D. King  Jonathan T. Overpeck  Lisa V. Alexander  Imke Durre  David J. Karoly 《Climate Dynamics》2016,46(1-2):413-426

Unusually hot summer conditions occurred during the 1930s over the central United States and undoubtedly contributed to the severity of the Dust Bowl drought. We investigate local and large-scale conditions in association with the extraordinary heat and drought events, making use of novel datasets of observed climate extremes and climate reanalysis covering the past century. We show that the unprecedented summer heat during the Dust Bowl years was likely exacerbated by land-surface feedbacks associated with springtime precipitation deficits. The reanalysis results indicate that these deficits were associated with the coincidence of anomalously warm North Atlantic and Northeast Pacific surface waters and a shift in atmospheric pressure patterns leading to reduced flow of moist air into the central US. Thus, the combination of springtime ocean temperatures and atmospheric flow anomalies, leading to reduced precipitation, also holds potential for enhanced predictability of summer heat events. The results suggest that hot drought, more severe than experienced during the most recent 2011 and 2012 heat waves, is to be expected when ocean temperature anomalies like those observed in the 1930s occur in a world that has seen significant mean warming.  相似文献   

Some long period variations of microseismic activity     

Mr. Markus Bath 《Pure and Applied Geophysics》1948,12(3-4):121-126

Summary The microseisms recorded at Uppsala have been studied for the time 1907–1947 with regard to long period variations. There is clear evidence of an 11 year variation and slight indications of a 28 month variation. The 11 year variation is from 1923 negatively correlated to the sunspot frequency and is explained by corresponding meridional displacements of the dominant cyclonic tracks.

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Zusammenfassung Die in Uppsala registrierte Bodenunruhe ist für die Zeit 1907–1947 betreffs langperiodischen Schwankungen untersucht worden. Eine 11-j?hrige Variation wird festgestellt und es gibt weiter Anzeichnungen einer Variation von 28 Monaten. Die 11-j?hrige Variation ist seit 1923 zur Sonnenflecken-frequenz negativ korreliert und ist durch entsprechende meridionale Verschiebungen der am meisten betretenen Zyklonenbahnen, erkl?rt.

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Riassunto L'agitazione microsismica registrata a Uppsala nel quarantennio 1907–1947 venne esaminata in vista di determinare le oscillazioni di lungo periodo. Si è accertata una oscillazione undecennale, trovandosi altresi indizi per una oscillazione di 28 mesi. Dal 1923 l'oscillazione undecennale manifesta una correlazione negativa con la frequenza delle macchie solari e viene spiegata con i corrispondenti spostamenti meridionali delle rotte cicloniche dominanti.

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Arsenic in seawater and brown algae of the Baltic and the North Sea     

Markus Stoeppler  Mechthild Burow  Friedrich Backhaus  Winfried Schramm  Hans Wolfgang Nürnberg   《Marine Chemistry》1986,18(2-4)

A long-term study within the pilot environmental specimen bank programme of the Federal Republic of Germany on arsenic levels in coastal and open seawater and their reflection in the brown seaweed (Fucus vesiculosus) has been performed. Dissolved arsenic was on average 0.76 (range 0.45–1.11) μgl⁻¹ for 17 sampling stations in the Baltic Sea, whereas contents of dissolved arsenic are somewhat higher in shallow waters of the coastal zone of the North Sea. Total arsenic levels in algae ranged up to 40 mg kg⁻¹ (dry weight) and showed for the four locations studied obvious seasonal variations for comparatively nonpolluted or nondisturbed locations only. However, probably due to biological influences, the results obtained so far indicate that composite samples integrating a one year period are supposed to be the best strategy for future environmental specimen banking. Using a new efficient speciation technique the percentage of chemically stable organoarsenic compounds in the investigated algae has been found to be 95% of the total arsenic content and thus somewhat lower than in teleost fish. For comparison, typical data for a few other algae species from the Baltic and the Mediterranean Sea are also shown.  相似文献   

Evidence of central Alpine glacier advances during the Younger Dryas–early Holocene transition period          下载免费PDF全文

Andrew P. Moran  Susan Ivy‐Ochs  Michael Schuh  Markus Christl  Hanns Kerschner 《Boreas: An International Journal of Quaternary Research》2016,45(3):398-410

The transition phase from Lateglacial to Holocene climate conditions was accompanied by a pronounced reorganization of climate patterns in the Northern Hemisphere. Evidence of Alpine palaeoglaciers provides a basis for understanding climate downturns during a time of generally warming conditions. In this context a series of well‐preserved and previously undated moraines were investigated in the small Falgin cirque located in the central Alpine Langtaufers Valley (South Tyrol, Italy) and in the neighbouring Hinteres Bergle cirque of the Radurschl Valley (North Tyrol, Austria). Both localities are situated in the driest area of the eastern Alps. They lie well above prominent moraines associated with the Younger Dryas (YD) cold phase and represent the first moraines below Little Ice Age (LIA) positions. The corresponding equilibrium line altitude of the palaeoglaciers in both cirques was 100–120 m lower than during the LIA. Surface exposure dating (¹⁰Be) of the inner Falgin moraines shows a mean stabilization age of 11.2±0.9 ka, which is similar to the deglaciation age of 10.9±0.8 ka for the Hinteres Bergle cirque. The ages indicate glacier activity most likely during the earliest Holocene or the YD/Holocene transition. These findings point to a climate with mean summer temperatures about 1.5 °C lower than during the 20th century in the Alps.  相似文献   

Ionospheric corrections for single-frequency tracking of GNSS satellites by VLBI based on co-located GNSS   总被引：1，自引：1，他引：0  

Benjamin Männel  Markus Rothacher 《Journal of Geodesy》2016,90(2):189-203

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Erratum to “Can old analogue sidescan sonar data still be useful? An example of a sonograph mosaic geo-coded by the DECCA navigation system”: [Continental Shelf Res. 26 (2006) 1858–1867]     

Adam Kubicki  Markus Diesing 《Continental Shelf Research》2007

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