Weathering and soils formation on different parent materials in Golestan Province,Northern Iran

Geochemical, mineralogical, and micromorphologieal characteristics of soils and their relevant parent rocks including loess, ignimbrite, sandstone and limestone were investigated to identify the soil-parent material uniformity and the weathering degree of soils in Golestan Province, northern Iran. Highly developed Caleixerolls and moderately developed Haploxerepts were formed on loess and limestone, respectively. In contrast, the soils formed on ignimbrite and sandstone were non- developed Entisols. Illite was the dominant clay mineral found in ignimbrite and sandstone in both the A horizon and parent material. In loess derived soils however, smectite was dominant especially in the Bt horizon compared to its parent material indicating partly to its pedogenic formation. In limestone, illite and vermiculite were dominant both in the A and C horizons. Ti/Zr ratio proved that the studied soils were closely related to their underlying parent materials geochemically. Chemical index of alteration （CIA）, micromorphological index of soil development （MISECA）, smectite/illite＋chlorite ratio and magnetic susceptibility were applied to investigate the degree of soil development. Results showed that the most and the least developed soils were those formed on loess deposits and limestone,respectively. Application of the different geochemical and pedogenetic approaches was proved to be useful in identifying the relevance of soils to their underlying parent materials and also their degree of development.

Chemical Weathering of New Pyroclastic Deposits from Mt. Merapi (Java), Indonesia

The Java Island, Indonesia with abundant amount of pyroclastic deposits is located in the very active and dynamic Pacific Ring of Fires. Studying the geochemical weathering indices of these pyroclastic deposits is important to get a clear picture about weathering profiles on deposits resulting from the eruption of Mt. Merapi. Immediately after the first phase of the eruption （March to June 2006）, moist and leached pyroclastic deposits were collected. These pyroclastic deposits were found to be composed of volcanic glass, plagioclase feldspar in various propoitions, orthopyroxene, clinopyroxene, olivine, amphibole and titanomagnetite. The total elemental composition of the bulk samples （including trace elements and heavy metals） was determined by wet chemical methods and X-ray fluorescence （XRF） analyses. Weathering of the pyroelastic deposits was studied using various weathering indices. The Ruxton ratio, weathering index of Parker, Vought resudual index and chemical index of weathering of moist pyroclastic deposits were lower than those of the leached samples, but the alteration indices （chemical and plagioclase） were slightly higher in the moist compared to the leached pyroelastic deposits.

Financial Innovation Way of Avoiding Risk of Climate Disasters in Food Production:Weather Index Insurance

Climate change will lead to a variety of climate disasters, and climate disasters have a greater impact on China＇s food production. Weather index insurance is a new financial way to avoid risk of climate disasters effectively in China＇s food production. Firstly, the relationship between weather index insurance and food production in China was elaborated, and then the development status, advantages and disadvantages of weather index insurance in China at present were analyzed. Finally, some countermeasures against the problems of weather index insurance in China were put forward.

Effects of astronomical orbital cycle and volcanic activity on organic carbon accumulation during Late Ordovician–Early Silurian in the Upper Yangtze area, South China

Based on field outcrop data,the effects of cyclic change of astronomical orbit and volcanic activity on organic carbon accumulation during the Late Ordovician-Early Silurian in the Upper Yangtze area were studied using cyclostratigraphic and geochemical methods.d13 C and chemical index of alteration(CIA)were used to filter the astronomical orbit parameters recorded in sediments.It is found that the climate change driven by orbital cycle controls the fluctuations of sea level at different scales,obliquity forcing climate changes drive thermohaline circulation(THC)of the ocean,and THC-induced bottom currents transport nutrient-laden water from high latitude regions to the surface water of low-latitude area.Hence,THC is the main dynamic mechanism of organic-carbon supply.The marine productivity indexes of Ba/Al and Ni/Al indicate that volcanic activities had limited effect on marine productivity but had great influences on organic carbon preservation efficiency in late Hirnantian(E4).Paleo-ocean redox environmental indicators Th/U,V/Cr and V/(V+Ni)show that there is a significant correlation between volcanism and oxygen content in Paleo-ocean,so it is inferred that volcanisms controlled the organic carbon preservation efficiency by regulating oxygen content in Paleo-ocean,and the difference in volcanism intensity in different areas is an important factor for the differential preservation efficiency of organic carbon.The organic carbon input driven by orbital cycle and the preservation efficiency affected by volcanisms worked together to control the enrichment of organic carbon in the Middle–Upper Yangtze region.

The impact of climate change on fire risk in Daxing'anling,China

Daxing’anling is a key region for forest fire prevention in China. Assessing changes in fire risk in the future under multiple climatic scenarios will contribute to our understanding of the influences of climate change for the region and provide a reference for applying adaptive measures for fire management. This study analyzed the changes in fire weather indices and the fire season under four climate scenarios (RCP2.6, RCP4.5, RCP6.0, RCP8.5) for 2021-2050 using data from five global climate models together with observation data. The results showed that the analog data could project the average state of the climate for a given period but were not effective for simulating extreme weather conditions. Compared with the baseline period (1971-2000), the period 2021-2050 was predicted to have an increase in average temperature of 2.02-2.65 °C and in annual precipitation 25.4-40.3 mm, while the fire weather index (FWI) was predicted to increase by 6.2-11.2% and seasonal severity rating (SSR) by 5.5-17.2%. The DMC (Duff moisture code), ISI (initial spread index), BUI (build-up index), FWI and SSR were predicted to increase significantly under scenarios RCP4.5, RCP6.0, and RCP8.5. Furthermore, days with high or higher fire danger rating were predicted to be prolonged by 3-6 days, with the change in the southern region being greater under scenarios RCP4.5, RCP6.0, and RCP8.5.

Spatiotemporal variation in forest fire danger from 1996 to 2010 in Jilin Province,China

We evaluated the spatial and temporal patterns of forest fires in two fire seasons (March to June and September to November) from 1996 to 2010 in Jilin Province, China, using the Canadian Forest Fire Weather Index System. Fire data were obtained from the Provincial Fire Agency, and historical climate records of daily weather observations were collected from 36 weather stations in Jilin and its neighboring provinces. A linear regression model was used to analyze linear trends between climate and fire weather indices with time treated as an independent variable. Correlation analysis was used to detect correlations between fire frequency, areas burned, and fire weather indices. A thin-plate smooth spline model was used to interpolate the point data of 36 weather stations to generate a surface covering the whole province. Our analyses indicated fire frequency and areas burned were significantly correlated with fire weather indices. Overall, the Canadian Forest Fire Weather Index System appeared to be work well for determining the fire danger rating in Jilin Province. Also, our analyses indicated that in the forthcoming decades, the overall fire danger in March and April should decrease across the province, but the chance of a large fire in these months would increase. The fire danger in the fall fire season would increase in the future, and the chance of large fire would also increase. Historically, because most fires have occurred in the spring in Jilin Province, such a shift in the future fire danger between the two fire seasons would be beneficial for the province's fire management.

Farmers' Risk Preferences and Agricultural Weather Index Insurance Uptake in Rural China

The purpose of this study is to investigate the effect of farmers' risk preferences on their decisions to purchase the agricultural weather index insurance based on the evidence from a household survey and field experiments conducted in Yongqiao District,Suzhou City of Anhui Province in China.Our empirical results show that farmers' risk aversion significantly increases the probability of their decision to buy weather index-based crop insurance.Other factors that significantly influence weather index insurance participation decisions include farmers' subjective beliefs on the probability of crop losses,farming experience,education level,farm size,and their household income.The empirical results of this study can provide helpful insights for policymakers and local insurers to further improve farmers' participation in weather indexbased crop insurance.

Performance of Temperature-Related Weather Index for Agricultural Insurance of Three Main Crops in China

In this study, two categories of weather index—absolute index and relative index—for chilling injury and heat damage of three main crops in China were assessed to identify insurable counties. First, correlations between selected weather indices and yield losses were examined for each county. If a correlation was significant, the county was categorized as ‘‘insurable'' for the corresponding hazard or index. Second, the spatial distribution of insurable counties was characterized and finally, their correlation coefficients were analyzed at various spatial scales.The results show that the spatial patterns of insurable areas varied by categories of weather indices, crops, and hazards.Moreover, the weather indices based on relative threshold of temperature were more suitable for chilling injury in most regions, whereas the indices based on absolute threshold were more suitable for heat damage. The findings could help the Chinese government and insurance companies to design effective insurance products.

Farmers’Demand for Informal Risk Management Strategy and Weather Index Insurance:Evidence from China

In the absence of formal risk management strategies,agricultural production in China is highly vulnerable to climate change.In this study,field experiments were conducted with 344 households in Heilongjiang(Northeast China)and Jiangsu(East China)Provinces.Probit and logistic models and independent sample T-test were used to explore farmers’demand for weather index insurance,in contrast to informal risk management strategies,and the main factors that affect demand.The results show that the farmers prefer weather index insurance to informal risk management strategies,and farmers’characteristics have significant impacts on their adoption of risk management strategies.The variables non-agricultural labor ratio,farmers’risk perception,education,and agricultural insurance purchase experience significantly affect farmers’weather index insurance demand.The regression results show that the farmers’weather index insurance demand and the influencing factors in the two provinces are different.Farmers in Heilongjiang Province have a higher participation rate than those in Jiangsu Province.The government should conduct more weather index insurance pilot programs to help farmers understand the mechanism,and insurance companies should provide more types of weather index insurance to meet farmers’diversified needs.

Structure of weathered clastic crust and its petroleum potential

Weathered clastic crust can be subdivided into weathered clay and leached zone in terms of variable weathering of different minerals and mobility of weathered products.On the basis of clastic outcrops and well cores in the Junggar Basin,the dark red Fe-rich weathered clay is formed in an arid environment,whereas the light blue Al-rich weathered clay under humid conditions.According to the geochemical analysis,a new weathering index for weathered clastic crust is built mainly on Fe and Al contents,accurately indicating the weathered clay,sandy leached zone,and muddy leached zone in the Junggar Basin.The breaking pressure of weathered clay is rather large,the same as that of normal muddy cap,effectively to seal oil or gas.The porosity of underlying leached zone is greatly enhanced by weathering and leaching,but its permeability is a function of clay mineral content,i.e.,the higher the clay content,the worse the permeability.Weathered crust provides effective sealing conditions for both top and bottom layers of a petroleum reservoir,and is important in the clastic hydrocarbon exploration.

cffdrs: an R package for the Canadian Forest Fire Danger Rating System

Introduction:The Canadian Forest Fire Danger Rating System(CFFDRS)is a globally known wildland fire risk assessment system,and two major components,the fire weather index system and the fire behavior prediction system,have been extensively used both nationally and internationally to aid operational wildland fire decision making.Methods:In this paper,we present an overview of an R package cffdrs,which is developed to calculate components of the CFFDRS,and highlight some of its functionality.In particular,we demonstrate how these functions could be used for large data analysis.Results and Discussion:With this cffdrs package,we provide a portal for not only a collection of R functions dealing with all available components in CFFDRS but also a platform for various additional developments that are useful for the understanding of fire occurrence and behavior.This is the first time that all relevant CFFDRS methods are incorporated into the same platform,which can be accessed by both the management and research communities.

Agricultural Risk Modeling Challenges in China:Probabilistic Modeling of Rice Losses in Hunan Province

This article summarizes a joint research projec undertaken under the Risk Management Solutions, Inc(RMS) banner to investigate some of the possible approaches for agricultural risk modeling in China. Two modeling approaches were investigated—the simulated weather crop index and the burn yield analysis approach. The study was limited to Hunan Province and a single crop—rice. Both modeling approaches were dealt with probabilistically and were able to produce probabilistic risk metrics. Illustrative model outputs are also presented. The article discusses the robustness of the modeling approaches and their dependence on the availability, access to, and quality of weather and yield data. We offer our perspective on the requirements for models and platforms for agricultural risk quantification in China in order to respond to the needs of all stakeholders in agricultural risk transfer.

Rainfall-Related Weather Indices for Three Main Crops in China

Rainfall-relatedhazards—deficitrainand excessive rain—inevitably stress crop production,and weather index insurance is one possible financial tool to mitigate such agro-metrological losses.In this study,we investigated where two rainfall-related weather indices—anomaly-based index(AI)and humidity-based index(HI)—could be best used for three main crops(rice,wheat,and maize)in China’s main agricultural zones.A county is defined as an“insurable county”if the correlation between a weather index and yield loss was significant.Among maize-cropping counties,both weather indices identified more insurable counties for deficit rain than for excessive rain(AI:172 vs 63;HI:182 vs 68);moreover,AI identified lower basis risk for deficit rain in most agricultural zones while HI for excessive rain.For rice,the number of AIinsurable counties was higher than the number of HI-insurable counties for deficit rain(274 vs 164),but lower for excessive rain(199 vs 272);basis risks calculated by two weather indices showed obvious difference only in Zone I.Finally,more wheat-insurable counties(AI:196 vs 71;HI:73 vs 59)and smaller basis risk indicate that both weather indices performed better for excessive rain in wheatplanting counties.In addition,most insurable counties showed independent yield loss,but did not necessarily result in effective risk pooling.This study is a primary evaluation of rainfall-related weather indices for the three main crops in China,which will be significantly helpful to the agricultural insurance market and governments’policy making.

Sedimentary and geochemical evidence of Eocene climate change in the Xining Basin, northeastern Tibetan Plateau

The northeastern Tibetan Plateau began to grow during the Eocene and it is important to understand the climatic history of Asia during this period of so-called ‘doubthouse' conditions. However, despite major advances in the last few decades,the evolutionary history and possible mechanisms of Eocene climate change in the northeastern Tibetan Plateau remain unclear.The Xining Basin in the northeastern Tibetan Plateau contains a continuous sequence of Early to Late Eocene non-marine sediments which provides the opportunity to resolve long-term climate changes during this period. In this study, we report the results of analyses of lithofacies, sediment color and geochemistry of bulk samples collected from the Xijigou section of the Xining Basin. An abrupt lithofacies change between the Early(~52–40 Ma) and Late Eocene(~40–34 Ma) indicates a change in the depositional environment from a shallow lake to a playa lake in response to a significant climatic shift. During ~52–40 Ma,higher values of sediment redness(a*), redness/lightness(a*/L*) and higher modified Chemical Index of Weathering(CIW′)indicate a relatively warm and humid climate, while from ~40–34 Ma the lower values of a*, a*/L*and lower CIW′ imply subhumid to semi-arid climatic conditions. The paleoclimatic records indicate a long-term(~52–34 Ma) trend of decreasing chemical weathering, consistent with global climate change. An abrupt sharp excursion of the proxy records during ~42–40 Ma suggests a relatively brief warm interval, corresponding to the Middle Eocene Climatic Optimum(MECO). We suggest that global cooling substantially reduced humidity in inner Asia, resulting in sub-humid to semi-arid climatic conditions after 40 Ma in the Xining Basin, which may have been responsible for the long-term trend of decreasing chemical weathering during the Eocene.