Promise and reality of market-based environmental policy in China: Empirical analyses of the ecological restoration program on the Qinghai-Tibetan Plateau     

《Global Environmental Change》2016

Environmental conservation programs in China have increasingly emphasized integration of market-based logic into regulatory programs. But the realization of market logic and the effectiveness of such efforts are widely questioned by scientists and policy analysts. We empirically analyze the design, implementation, and outcomes of the ecological restoration program in the Three-Rivers Headwater Region in China, a large-scale conservation scheme aimed at restoring degraded grasslands and improving local livelihoods. Results indicate that the market mechanisms emphasized in the design of the policy were not realized in practice due to inadequate use of scientific measurements, lack of accountability, and poor monitoring and enforcement. Moreover, because enrollment was not voluntary, as is generally expected in market-based programs, there were negative impacts on herders. A household survey (n = 202) of local herders shows that if conservation incentives were properly designed and implemented, 67% would voluntarily participate in the program. Variance recorded in ecological and socioeconomic conditions points to opportunities to use market-based policy instruments to integrate local information into decision making regarding targeting of land conservation and land retirement. The potential of market-based environmental policies can be expanded through commitments to scientific measurement, voluntary participation, and outcome-based payments.  相似文献   

Stable chlorine isotopes in arid non-marine basins: Instances and possible fractionation mechanisms     

《Applied Geochemistry》2016

Stable chlorine isotopes are useful geochemical tracers in processes involving the formation and evolution of evaporitic halite. Halite and dissolved chloride in groundwater that has interacted with halite in arid non-marine basins has a δ³⁷Cl range of 0 ± 3‰, far greater than the range for marine evaporites. Basins characterized by high positive (+1 to +3‰), near-0‰, and negative (−0.3 to −2.6‰) are documented. Halite in weathered crusts of sedimentary rocks has δ³⁷Cl values as high as +5.6‰. Salt-excluding halophyte plants excrete salt with a δ³⁷Cl range of −2.1 to −0.8‰. Differentiated rock chloride sources exist, e.g. in granitoid micas, but cannot provide sufficient chloride to account for the observed data. Single-pass application of known fractionating mechanisms, equilibrium salt-crystal interaction and disequilibrium diffusive transport, cannot account for the large ranges of δ³⁷Cl. Cumulative fractionation as a result of multiple wetting-drying cycles in vadose playas that produce halite crusts can produce observed positive δ³⁷Cl values in hundreds to thousands of cycles. Diffusive isotope fractionation as a result of multiple wetting-drying cycles operating at a spatial scale of 1–10 cm can produce high δ³⁷Cl values in residual halite. Chloride in rainwater is subject to complex fractionation, but develops negative δ³⁷Cl values in certain situations; such may explain halite deposits with bulk negative δ³⁷Cl values. Future field studies will benefit from a better understanding of hydrology and rainwater chemistry, and systematic collection of data for both Cl and Br.  相似文献   

Assessing groundwater recharge in an Andean closed basin using isotopic characterization and a rainfall-runoff model: Salar del Huasco basin,Chile   总被引：1，自引：0，他引：1  

Javier Uribe  José F. Muñoz  Jorge Gironás  Ricardo Oyarzún  Evelyn Aguirre  Ramón Aravena 《Hydrogeology Journal》2015,23(7):1535-1551

  相似文献   

Limiting superluminal electron and neutrino velocities using the 2010 Crab Nebula flare and the IceCube PeV neutrino events     

《Astroparticle Physics》2014

  相似文献   

On the stability of a class of radiating viscous self-gravitating stars with axial symmetry     

《Astroparticle Physics》2014

This study investigates the stability of a class of radiating viscous self-gravitating stars with axial symmetry having anisotropic pressure. We use perturbation technique to establish the perturbed form of the Einstein field equations and dynamical equations. The instability range in the Newtonian and post-Newtonian eras has been analyzed by constructing the collapse equation. It is found that the adiabatic index has a key role in the discussion of instability ranges which depends upon the physical parameters, i.e., energy density, anisotropic pressure and shear viscosity of the fluid and heat flux. We conclude that the shear viscosity decreases the instability range and makes the system more stable.  相似文献   

Distribution and type of sticky spots at the centre of a deglacial streamlined lobe in northeastern Manitoba,Canada     

Michelle S. Trommelen  Martin Ross 《Boreas: An International Journal of Quaternary Research》2014,43(3):557-576

The distribution of basal drag zones (sticky spots) underneath palaeo‐ice streams or lobes is largely unknown. We investigated the centre of the large (300 km long and up to 400 km wide) deglacial Hayes Lobe in NE Manitoba, Canada, by focusing on surficial till and its composition to get insights into dispersal patterns and their potential relationships to areas of basal drag. Subglacial bed roughness is a good criterion to identify areas of basal drag, but till composition may provide important insights across smoother beds. The onset zone of the Hayes Lobe overlies Palaeozoic Carbonate Platform rocks, whereas the majority of the lobe overlies the low‐lying Canadian Shield. We show that, within a 3500‐km² central area of this lobe, calcareous detritus within the till has been transported over 100 km within subglacial environments of reduced ice‐bed coupling and fast ice flow. Six per cent of samples (n = 782), however, outline 0.2 to 4 km wide spots with a dominantly local composition. The glacial history and composition indicate that the till within these spots contains high inheritance from a pre‐Late Wisconsinan ice‐flow phase, which we suggest was protected beneath sticky spots (low erosion, high strength) during transport of substantial calcareous detritus to the area. Furthermore, our findings show that local till spots are present within streamlined landforms, as well as till blankets or veneers over bedrock. This diverse geomorphology indicates that the process of drumlinization within the deglacial Hayes Lobe does not appear to have been responsible for significant sediment transport or deposition across the study area. The overall record thus indicates potentially complex spatiotemporal shifts between calcareous till deposition, sticky conditions, erosion and drumlinization – which supports the subglacial bed mosaic model.  相似文献   

Corrigendum to “Temperature and precipitation history of the Arctic” [Quat. Sci. Rev. 29 (2010) 1679–1715]     

G.H. Miller  J. Brigham-Grette  R.B. Alley  L. Anderson  H.A. Bauch  M.S.V. Douglas  M.E. Edwards  S.A. Elias  B.P. Finney  J.J. Fitzpatrick  S.V. Funder  T.D. Herbert  L.D. Hinzman  D.S. Kaufman  G.M. MacDonald  L. Polyak  A. Robock  M.C. Serreze  J.P. Smol  R. Spielhagen  E.W. Wolff 《Quaternary Science Reviews》2011,30(19-20):2841-2843

  相似文献   

Atmospheric circulation controls on precipitation isotope–climate relations in western Canada     

By S. J. BIRKS  T. W. D. EDWARDS 《Tellus. Series B, Chemical and physical meteorology》2009,61(3):566-576

  相似文献   

The effect of dock length on harbour siltation     

Dirk Sebastiaan van Maren  Johan C. Winterwerp  Marc Sas  Joris Vanlede 《Continental Shelf Research》2009,29(11-12):1410-1425

Density-driven exchange flows between estuaries and harbour docks are influenced by the length of the dock. As a result, increasing dock size through its lengthening, not necessarily results in an increase in sedimentation rates. The propagation of a low-salinity surface patch into the dock is blocked at the head of a relatively short dock, resulting in a reversal of density-driven flows, and a reduction of the hydrostatic pressure gradients in the entrance of the dock. A reduced hydrostatic pressure in the dock, in turn, promotes near-bed inflow. When this increased near-bed inflow coincides with a high sediment supply on the adjacent river, the sediment transport into the dock increases. This has been tested with an extensively validated high-resolution numerical model developed for the Deurganckdok in the Port of Antwerp. In the Deurganckdok, siltation rates are expected to decrease when the dock is fully excavated compared to the present half-opened dock.Whether exchange flows between estuaries and harbour docks are influenced by the length of the dock, depends on the tidal variation in salinity. For small tidal density variations (around 0.5 kg/m³), the dock length is expected to influence exchange flows in a short dock (approximately 1 km), whereas the dock should be much longer (4 km) when the tidal density variation is higher (around 5 kg/m³). Whether these changing exchange flow result in a lowering or increase of sediment import, depends on the phase difference between sediment concentration peaks on the adjacent river/estuary and the salinity variation, and on the vertical distribution of sediment.  相似文献   

Surface vegetation controls on evapotranspiration from a sub‐humid Western Boreal Plain wetland     

S. M. Brown  R. M. Petrone  C. Mendoza  K. J. Devito 《水文研究》2010,24(8):1072-1085

  相似文献