bluuebunny/crossref_metadata_2025 huggingface dataset:
Individualists
Authors: Fagan Brian
Published: November 2020

The French-speaking Swiss traveler Ella Maillart (1903–1997) was a remarkable personality. By age thirty, she had taught French in a Welsh school, sailed in the Olympics for the Swiss team, acted on the Parisian stage, captained the Swiss women’s field hockey team, assisted on an excavation in Crete, studied film production in Moscow, published a book about a north-south walk through the Caucasus, and ridden a camel across the Kizil Kum Desert in present-day Kazakhstan and Uzbekistan, southeast of the Aral Sea—in midwinter. No one knows why she had such a penchant for adventure and variety: perhaps she was rebelling against the staid and thoroughly conventional family life of her childhood. The freedom and self-assertion taken for granted by many women today could then be achieved only by being unconventional and heading off into the unknown. At the age of twenty-eight, Maillart gazed on China for the first time. “In 1932, having gone east from Moscow, I climbed a mountain nearly 17,000 feet high on foot, and succeeded in reaching the eastern frontier of Russian Turkestan. There, at least, from the heights of the Celestial Mountains I could decry, on a plain far away and still further to the east, the yellow dust of the Takla Makan desert. It was China, the fabulous country of which, since my childhood, I had dreamed. There the caravan trails that were as old as the world, still wound. Long ago, Marco Polo followed them as far as Peking.”1 But she was unable to obtain a visa to enter Chinese Turkestan, which, like Outer Mongolia, was virtually isolated from the world by political turmoil. “Sadly,” she wrote, “I retraced my steps, turning my back on the limitless unknown that beckoned.” Maillart traveled in romantic lands whose very names evoke adventure— Pingliang, Yarkand, Kashgar. For centuries, the Silk Road was synonymous with danger, mystery, and high adventure beyond the frontiers of the Western world. The men and women who explored this remote and unfamiliar realm had no illusions about the dangers and political disorder that awaited them, but they would have been quietly horrified to hear their travels described as adventures.
Natural Dust and Pneumoconiosis in High Asia
Authors: Derbyshire Edward
Published: November 2020

High Asia, defined here as that great tract of land from the Himalaya- Karakoram in the south to the Tian Shan in the north and the Pamir in the west to the Qinling Mountains in the east, is a very dusty place. Whole communities of people in this region are exposed to the adverse effects of natural (aerosolic) dusts at exposure levels reaching those encountered in some high-risk industries. Outdooor workers are at particular risk. However, few data are available on the magnitude of the dust impact on human health. The effect of such far-travelled particles on the health of the human population in the Loess Plateau, and including major Chinese cities, has received relatively little attention to date. A combination of the highest known uplift rates, rapid river incision (up to 12 mm/yr: Burbank et al. 1996), unstable slopes, glaciation and widespread rock breakup by crystal growth during freezing (frost action), and by hydration of salts (salt weathering) makes the High Asia region the world’s most efficient producer of silty (defined as between 2 and 63 μm) debris. The earliest written records of the dust hazard come from China, most notably in the “Yu Gong” by Gu Ban (ca 200 BC) (Wang and Song 1983). Here, deposits of wind-blown silt (known as ‘loess’) cover the landscape in a drape that is locally 500 m thick. In North China, the loess covers an area of over 600,000 km², most of it in the Loess Plateau, situated in the middle reaches of the Huang He (Yellow River). The characteristic properties of loess include high porosity and collapsibility on wetting (Derbyshire et al. 1995, Derbyshire and Meng 2000).Thus, it is readily reworked and redistributed by water. This process concentrates silts in large alluvial fans (up to 50 x 50 km) in the piedmont zones of 6,000 m high glacier- and snow-covered mountain ranges of western China, including the Altai Shan (‘shan’ = mountains), Tian Shan, Kunlun Shan, Qilian Shan, and Karakoram. These zones are loci for human populations, and also a major source of wind-blown dust.
Mercury, a Toxic Metal, and Dental Amalgam Removal
Authors: Carlmark B. , Lindvall A.
Published: November 2020

Mercury is an element with unique physical and chemical properties whose deleterious effects on various organ systems have been known for centuries. The metal (Hg°) mercury is the only element liquid at ambient temperatures and has an extremely high vapor pressure. Natural degassing of the earth’s crust by volcanoes and emissions from soils and waters are estimated to contribute on the order of 2700 to 30,000 tons per year (Nriagu 1989, Lindqvist 1991). A second source of mercury is anthropogenic from burning of coal or petroleum. The total input into the atmosphere may be up to 150,000 tons per year, with natural emissions accounting for the major input (Berlin 1986). However, estimations of contributions from different sources vary. Aristotle wrote about mercury as liquid silver (hydrargyrum) with the metallic mercury extracted in ancient times, as today, from the sulphide mineral cinnabar (HgS). Although technical developments have brought about more sophisticated methods of distilling mercury, all processes create mercury vapor, which is a potential hazard. Mercury mines pose environmental concern, due to mine tailings and waste rock contributing mercury-enriched sediment to watersheds (Rytuba 2000) such as in the California Coast Ranges (Rytuba 2000), the Idria mine in Slovenia (Hines et al. 2000), in Slovakia (Svoboda et al. 2000), and, perhaps most conspicuously, the mine tailings in Aznacollar, Spain, that caused a recent accident (Grimalt et al. 1999). Any industrial sites that utilize mercury during production may also produce contamination of the environment (Sunderland and Chmura 2000). The possible sources of mercury exposure are presented in Table 10.1. Amalgamation with mercury has been used as a method for beneficiation of gold and silver since Roman times. The total global release of mercury into the environment from these activities before 1930 was estimated as over 260,000 tons. Thereafter, with the introduction of cyanidation processing technology, the emissions declined (Lacerda and Solomons 1998). However, small-scale artisanal gold mining continues and is a serious hazard to largely unskilled persons in rural areas over the world.
Navigating Uncertain Waters : Geographies of Water and Conflict, Shifting Terms and Debates
Authors: Harris Leila M.
Published: November 2020

The debate over whether or not future water scarcities will contribute to heightened conflict and violent war is far from over. In the past decade, there has been a proliferation of books with titles such as Water Wars: Coming Conflicts in the Middle East, Rivers of Discord: International Water Disputes in the Middle East, and Rivers of Fire: The Conflict over Water in the Middle East, with many more undoubtedly planned or in press. This chapter serves as a critical assessment of some of the major themes of this literature and also contributes several concepts and case study examples in order to shift and reframe some of the common bases and assumptions of ongoing discussions. In particular, the concept of scale is used to argue for a broadened notion of “sociopolitical conflict” associated with water resources to overcome weaknesses inherent to dichotomous state-centered understandings of “war” and “peace.” Given the changing nature of contemporary conflicts, “peace” cannot justifiably be understood as the absence of war. Many people, livelihoods, places, and economies are marked by diffuse and persistent conflict. Whether disruptions take the form of gang warfare in cities, the frequency of preventable deaths caused by lack of access to basic needs, or conflict over access to and sharing of critical resources, times of “peace” are notably marked by political instability, death, vulnerability, and other features commonly associated with warfare. Further, given interconnections between environments, people, and places, conflicts at specific sites cannot be abstracted from situations and conditions at other locations and scales. Even if a state is not at “war,” situations of resource use or access may still be marked in important ways by sociopolitical conflict, either past conflicts or ongoing conflicts across other sites and scales. In short, narrow attention to stateto- state warfare detracts from the complexity of relationships between the changing geographies of water resources and sociopolitical conflicts. A multiscalar perspective that highlights manifold and interrelated geographies of “water and conflict” across historical and geographical scales and among multiple sites and actors brings this into relief.
Introduction to Quality in the Analytical Chemistry Laboratory
Authors: Hibbert D. Brynn
Published: November 2020

To understand quality of chemical measurements, one needs to understand something about measurement itself. The present edition of the International Vocabulary of Basic and General Terms in Metrology (ISO 1993, term 2.1) defines a measurement as a “set of operations having the object of determining a value of a quantity.” Quantity is defined as an “attribute of a phenomenon, body or substance that may be distinguished qualitatively and determined quantitatively” (ISO 1993, term 1.1). Typical quantities that a chemist might be interested in are mass (not weight), length, volume, concentration, amount of substance (not number of moles), current, and voltage. A curse of chemistry is that there is only one unit for amount of substance, the mole, and perhaps because “amount of substance” is verbally unwieldy and its contraction “amount” is in common nonscientific usage, the solecism “number of moles” is ubiquitous and has led to general confusion between quantities and units. The term “measurand,” which might be new to some readers, is the quantity intended to be measured, so it is correct to say of a numerical result that it is the value of the measurand. Do not confuse measurand with analyte. A test material is composed of the analyte and the matrix, and so the measurand is physically embodied in the analyte. For example, if the measurand is the mass fraction of dioxin in a sample of pig liver, the dioxin is the analyte and the liver is the matrix. A more rigorous approach of defining a quantity in terms of, System – Component; kind of quantity, has been under discussion in clinical medicine for some time. This concept of specifying a quantity has recently been put on a sound ontological footing by Dybkaer (2004). A measurement result typically has three components: a number and an uncertainty with appropriate units (which may be 1 and therefore conventionally omitted). For example, an amount concentration of copper might be 3.2 ± 0.4 μmol L-1. Chapter 6 explains the need to qualify an uncertainty statement to describe what is meant by plus or minus (e.g., a 95% confidence interval), and the measurand must also be clearly defined, including speciation, or isomeric form. Sometimes the measurement is defined by the procedure, such as “pH 8 extractable organics.”
Conclusions: Bringing It All Together
Authors: Hibbert D. Brynn
Published: November 2020

If you have read this book, whether a few pages at a time, by jumping back and forth, or meticulously from beginning to end, the aim of this chapter is to draw together the methods, concepts, and ideas to help you answer the question, how do I make a good analytical measurement? If nothing else, you will have discovered, like the answers to the greater questions of life, that there is not a simple prescription for quality assurance that if followed leads to success. Even knowing if you have the right answer is not always vouchsafed; is customer satisfaction sufficient? Does the continuing solvency of your business say that something must be going well? Does staying within ± 2σ in interlaboratory studies cause you happiness? The best laboratories do all of this and more. At the heart of a good laboratory is an excellent manager who has recruited good staff, set up a culture of quality, and who understands the science and business of chemical analysis and the requirements of his or her clients. I do not believe laboratories can be run by people with only managerial skills; at some point a chemical analyst is going to have to take responsibility for the product. In this reprise of the book’s contents I revisit the six principles of valid analytical measurement (VAM) so cleverly enunciated by the Laboratory of the Government Chemist. But first some words about clients and samples. As has been stressed throughout this book, many problems can be solved by chemical analysis, and the point of chemical analysis is therefore not to do chemistry for its own sake, but to contribute to the solution of those problems. Clients, or customers as now found in ISO/IEC 17025, come in many shapes and sizes, from people who gladly admit no scientific knowledge at all to fellow professionals who can discuss the analysis as equals. The first kind are more difficult to work with than the latter, although colleagues who meddle are never totally welcome. An apparently simple request to analyze something might require extensive negotiation about exactly what is needed.
Monitoring Agricultural Drought Using El Niño and Southern Oscillation Data
Authors: Naranjo Díaz Lino
Published: November 2020

Almost all the studies performed during the past century have shown that drought is not the result of a single cause. Instead, it is the result of many factors varying in nature and scales. For this reason, researchers have been focusing their studies on the components of the climate system to explain a link between patterns (regional and global) of climatic variability and drought. Some drought patterns tend to recur frequently, particularly in the tropics. One such pattern is the El Niño and Southern Oscillation (ENSO). This chapter explains the main characteristics of the ENSO and its data forms, and how this phenomenon is related to the occurrence of drought in the world regions. Originally, the name El Niño was coined in the late 1800s by fishermen along the coast of Peru to refer to a seasonal invasion of south-flowing warm currents of the ocean that displaced the north-flowing cold currents in which they normally fished. The invasion of warm water disrupts both the marine food chain and the economies of coastal communities that are based on fishing and related industries. Because the phenomenon peaks around the Christmas season, the fishermen who first observed it named it “El Niño” (“the Christ Child”). In recent decades, scientists have recognized that El Niño is linked with other shifts in global weather patterns (Bjerknes, 1969; Wyrtki, 1975; Alexander, 1992; Trenberth, 1995; Nicholson and Kim, 1997). The recurring period of El Niño varies from two to seven years. The intensity and duration of the event vary too and are hard to predict. Typically, the duration of El Niño ranges from 14 to 22 months, but it can also be much longer or shorter. El Niño often begins early in the year and peaks in the following boreal winter. Although most El Niño events have many features in common, no two events are exactly the same. The presence of El Niño events during historical periods can be detected using climatic data interpreted from the tree ring analysis, sediment or ice cores, coral reef samples, and even historical accounts from early settlers.
Techniques to Predict Agricultural Droughts
Authors: Şen Zekai
Published: November 2020

In general, the techniques to predict drought include statistical regression, time series, stochastic (or probabilistic), and, lately, pattern recognition techniques. All of these techniques require that a quantitative variable be identified to define drought, with which to begin the process of prediction. In the case of agricultural drought, such a variable can be the yield (production per unit area) of the major crop in a region (Kumar, 1998; Boken, 2000). The crop yield in a year can be compared with its long-term average, and drought intensity can be classified as nil, mild, moderate, severe, or disastrous, based on the difference between the current yield and the average yield. Regression techniques estimate crop yields using yield-affecting variables. A comprehensive list of possible variables that affect yield is provided in chapter 1. Usually, the weather variables routinely available for a historical period that significantly affect the yield are included in a regression analysis. Regression techniques using weather data during a growing season produce short-term estimates (e.g., Sakamoto, 1978; Idso et al., 1979; Slabbers and Dunin, 1981; Diaz et al., 1983; Cordery and Graham, 1989; Walker, 1989; Toure et al., 1995; Kumar, 1998). Various researchers in different parts of the world (see other chapters) have developed drought indices that can also be included along with the weather variables to estimate crop yield. For example, Boken and Shaykewich (2002) modifed the Western Canada Wheat Yield Model (Walker, 1989) drought index using daily temperature and precipitation data and advanced very high resolution radiometer (AVHRR) satellite data. The modified model improved the predictive power of the wheat yield model significantly. Some satellite data-based variables that can be used to predict crop yield are described in chapters 5, 6, 9, 13, 19, and 28. The short-term estimates are available just before or around harvest time. But many times long-term estimates are required to predict drought for next year, so that long-term planning for dealing with the effects of drought can be initiated in time.
Active Microwave Systems for Monitoring Drought Stress
Authors: Smith Anne M.
Published: November 2020

Remote sensing can provide timely and economical monitoring of large areas. It provides the ability to generate information on a variety of spatial and temporal scales. Generally, remote sensing is divided into passive and active depending on the sensor system. The majority of remote-sensing studies concerned with drought monitoring have involved visible–infrared sensor systems, which are passive and depend on the sun’s illumination. Radar (radio detection and ranging) is an active sensor system that transmits energy in the microwave region of the electromagnetic spectrum and measures the energy reflected back from the landscape target. The energy reflected back is called backscatter. The attraction of radar over visible– infrared remote sensing (chapters 5 and 6) is its independence from the sun, enabling day/night operations, as well as its ability to penetrate cloud and obtain data under most weather conditions. Thus, unlike visible–infrared sensors, radar offers the opportunity to acquire uninterrupted information relevant to drought such as soil moisture and vegetation stress. Drought conditions manifest in multiple and complex ways. Accordingly, a large number of drought indices have been defined to signal abnormally dry conditions and their effects on crop growth, river flow, groundwater, and so on (Tate and Gustard, 2000). In the field of radar remote sensing, much work has been devoted to developing algorithms to retrieve geophysical parameters such as soil moisture, crop biomass, and vegetation water content. In principle, these parameters would be highly relevant for monitoring agricultural drought. However, despite the existence of a number of radar satellite systems, progress in the use of radar in environmental monitoring, particularly in respect to agriculture, has been slower than anticipated. This may be attributed to the complex nature of radar interactions with agricultural targets and the suboptimal configuration of the satellite sensors available in the 1990s (Ulaby, 1998; Bouman et al., 1999). Because most attention is still devoted to the problem of deriving high-quality soil moisture and vegetation products, there have been few investigations on how to combine such radar products with other data and models to obtain value-added agricultural drought products.
Monitoring Agricultural Drought in Russia
Authors: Kleschenko Alexander D. , Zoidze Erodi K.
Published: November 2020

Drought has been posing serious problems for agricultural production in Russia. A well-known Russian scientist, Vavilov (1931), noted that droughts characterize Russian farming. Recently, in some Russian Federation regions, there has been a high probability of severe or extremely severe droughts (Pasechnyuk et al., 1977; ARRIAM, 2000; Kleschenko, 2000; Ulanova and Strashnaya, 2000; Zoidze and Khomyakova, 2000; table 15.1). Numerous definitions of drought are available in the Russian literature (Bova, 1946; Alpatiev and Ivanova, 1958; David, 1965; Kalinin, 1981; Polevoy, 1992; Khomyakova and Zoidze, 2001). However, Kleschenko (2000) noted that all definitions are similar. Droughts are most frequently observed in Russia (Povolzhie, North Caucasus, Central-Chernozem regions, Ural, West and East Siberia) as well as in other Commonwealth of Independent States (CIS) countries: Ukraine, Moldova, Kazakhstan, Uzbekistan, Turkmenistan, Georgia, and Armenia. The Povolzhie, North-Caucasus, and Central-Chernozem regions contribute significantly to the Russian economy because these regions have fertile chernozems soils and produce most (about two-thirds) of the food grains—wheat and rye during the winter season and wheat, maize, and barley during the spring season. In recent moisture-favorable or nondrought years (1978, 1990 and 2001), the total grain production was 130 million tons, while during drought years (1975, 1981, 1995 and 1998), the production declined by half (Ulanova and Strashnaya, 2000). Decline in food grain yields was observed from 1917 to 1990 in the former USSR, and since 1990 in the post-Soviet Russia. Rudenko (1958) reported that Ukraine experienced severe droughts during 1875, 1889, 1918, and 1921, when the spring wheat yield was 70% of the mean yield. A sudden depression in the winter rye yield was observed in Povolzhie region during severe droughts of 1890, 1898, and 1911, when the yield was less than 60%, and during 1906, when the yield was only 25% of the mean yield. During severe droughts in Russia during 1972, 1975, 1979, 1984, and 1995, the crop yield deviated by an average of 17–42% in Russia as a whole, up to 19–91% in the Central-Chernozem regions, up to 45–100% in Povolzhie region, 27–36% in the North-Caucasus region, and 21–100% in the Ural region.
Monitoring Agricultural Drought in the Near East
Authors: Pauw Eddy De
Published: November 2020

The countries of North Africa and West Asia, hereafter referred to as the “Near East,” cover a large part of the world (more than 7,200,000 km2). This region is characterized by diverse but generally dry climates, in which evaporation exceeds precipitation. The level of aridity is indicated by the aridity index, the ratio of annual precipitation to annual potential evapotranspiration, calculated by the Penman method (UNESCO, 1979). The degree of aridity is shown spatially in figure 16.1 and summarized per country in table 16.1. These data show that the region is characterized by humid, subhumid, semiarid, and arid to hyperarid moisture regimes. In addition, temperature regimes vary considerably, particularly due to the differences in altitudes and, to a lesser extent, due to the oceanic/continental influences. For most of the region, the precipitation generally occurs during the October–April period and thus is concentrated over the winter season. Table 16.1 shows that, with more than 90% of the land area in hyperarid, arid, or semiarid moisture regimes, aridity is very significant in the Near East. Turkey is better endowed with surface and groundwater resources due to the orographic capture of Atlantic cyclonal precipitation, but much of the interior is semiarid. If one excludes the hyperarid zones, which cover the driest deserts and have no potential for agricultural use, nearly 34% of the region, or about 2,460,000 km2, is dryland (i.e., the area with arid or semiarid moisture regime). These are the areas with some potential for either dryland farming (in semiarid zones) or for extensive rangeland (in arid zones). In the Near East countries, agriculture contributes about 10–20% to the gross domestic product and is therefore a major pillar of their economies. However, the indirect importance of agriculture is larger because it provides the primary goods that constitute the majority of merchandise exports and because of the relatively high number of people employed in agriculture. Because of the high degree of aridity in large parts of the region, agriculture in the Near East is particularly vulnerable to drought. Most of the agricultural systems depend on rainfall.
Drought Monitoring Techniques for Famine Early Warning Systems in Africa
Authors: Rowland James , Verdin James
Published: November 2020

Hundreds of millions of people in the world today do not enjoy food security—they do not have “access . . . at all times to enough food for an active and healthy life” (World Bank, 1986). Many of these individuals are among the quarter-billion people living in the climatically vulnerable drylands of sub-Saharan Africa (UNSO/UNDP, 1997). The drought of the early 1970s was responsible for 100,000 deaths in the Sahel and 200,000 deaths in Ethiopia (Sen, 1981) and was soon followed by another drought during 1983–85 that was responsible for 400,000 to 1 million deaths (Walker, 1989). Famine is the most extreme food security emergency that occurs in the vulnerable areas of Africa. A practical definition of famine, offered by Cox, states that it is “the regional failure of food production or distribution systems, leading to sharply increased mortality due to starvation and associated disease” (quoted in Field, 1993). Famine’s underlying cause is crop failure brought about by bad weather, armed conflict, or both (Mellor and Gavian, 1987). Famine is a slow-onset disaster, the culmination of physical and social processes occurring over two or more growing seasons. Thus, observation and detection of events leading up to famine can yield information needed to trigger preparation for famine and prevention of its worst effects. Even so, early warning of famine can come none too soon because “the time needed to get food to famine-stricken areas after an appeal for aid can stretch to six months or more” (Ulrich, 1993). Furthermore, early warning does not guarantee early response. The decision by relief organizations to commit large amounts of resources ordinarily demands clear evidence that, unfortunately, is often difficult to assemble in the early stages of the famine process. Prevention of famine in vulnerable regions of Africa, then, requires early and unambiguous identification of unfolding food security problems so that mitigating action can be taken. Complicating the task is the fact that, over the years, the identities and numbers of those who are food insecure can shift in time and space. Relevant physical, social, and political forces are ever changing.
Monitoring Agricultural Drought in Southern Africa
Authors: Unganai Leonard S.
Published: November 2020

Southern Africa lies between 0°S to 35°S latitude and 10°E to 41°E longitude. In this region, annual rainfall ranges from below 20 mm along the western coastal areas of Namibia to as high as 3000 mm in some highland areas of Malawi. Rainfall generally increases from south to north in response to topography and the main rain-bearing systems affecting the subregion. In the southwest sections of the sub-region, annual rainfall averages below 400 mm, whereas the high-altitude areas receive up to 3000 mm due to orographic enhancement. Two important features that control the climate of southern Africa are the semipermanent subtropical high-pressure cells centered in the southeast Atlantic and the southwest Indian Ocean. These subtropical high pressure cells are associated with widespread and persistent subsidence (Lockwood, 1979). Part of southern Africa is under the downward leg of the Hadley Cell, superposed on the zonal Walker cell. The complex interaction of these cells, particularly during warm El Niño/Southern Oscillation (ENSO) episodes, is usually associated with drier than normal austral summers over much of southern Africa. Much of southern Africa is therefore semiarid and prone to recurrent droughts. In South Africa, for operational purposes, a drought is broadly defined as occurring when the seasonal rainfall is 70% or less of the long-term average (Bruwer, 1990; Du Pisani, 1990). It becomes a disaster or severe drought when two or more consecutive rainfall seasons experience drought. Drought affects some part of southern Africa virtually every year. Southern Africa has suffered recurrent droughts since record keeping began (Nicholson, 1989; Unganai, 1993). Severe drought periods included 1800– 30, 1840–50, 1870–90, 1910–15, 1921–25, 1930–50, 1965–75, and 1980–95. During some of these drought periods, rivers, swamps, and wells dried up and well-watered plains turned into barren lands. For Zimbabwe, the worst drought years were 1911–12, 1923–24, 1946–47, 1972–73, 1981–82, 1982–83, 1986–87, and 1991–92 (Zimbabwe Department of Meteorological Services, personal communication, 2002). During the severe and recurrent droughts of the 1980s and 1990s, the impact on vulnerable communities and the environment was catastrophic.
A Drought Warning System for Thailand
Authors: Eiumnoh Apisit , Shrestha Rajendra P.
Published: November 2020

Thailand is located between 5°30' and 20°30'N latitudes and between 97°30' and 105°30'E longitudes. Geographically, the country can be divided into northern, northeastern, central, and southern regions. Most of the country experiences distinct wet and dry climates, except some parts of the southern region, which experience a wet and humid climate. Of the country’s total area (514,000 km2), 41% is under agricultural use (Office of Agricultural Economics, 1999) with 92% of it being rainfed. Drought normally occurs during the hot season (March–April) and sometimes during dry season (November–April) due to inadequate rains. In recent times, the occurrence of drought has increased in Thailand, threatening sustainability of agricultural production. According to Department of Local Administration (1998), droughts of varying intensity occur in 67 out of 76 provinces of Thailand almost every year. During the period from 1987 to 1997, drought impacted a total of 5.44 million ha of agricultural land, causing $1.4 billion in losses. Droughts of varying intensity or severity occur in different regions of Thailand. A drought is categorized as severe, moderate, slight, or none drought using a radiative index (RI) determined during the rainy season (May– October). The RI for a region is determined using the number of rainy days, percentage of irrigated area, groundwater availability, topography, land use, soil, drainage density, and watershed size. If RI ranges from 1.0 to 1.2 for 15 consecutive days for a region or area, the region is said to be affected by slight drought. If RI exceeds 1.2 for 30 consecutive days, the region is considered to be affected by moderate drought, and if RI exceeds 1.0 for more than 30 consecutive days, severe drought is said to have occurred in the region. Using these criteria, the percentage of area affected by different drought categories has been determined in Thailand. It can be observed from table 25.1 that the northeastern region is the most droughtprone in Thailand. A drought index, D, is also used to monitor drought conditions in Thailand.
International Activities Related to Dryland Degradation Assessment and Drought Early Warning
Authors: Singh Ashbindu
Published: November 2020

Land degradation usually occurs on drylands (arid, semiarid, and dry subhumid areas). According to the United Nations Convention to Combat Desertification held in Paris in 1994 (UNCCD, 1999), drylands are defined as those lands (other than polar and subpolar regions) where the ratio of annual precipitation to potential evapotranspiration falls within the range of 0.05–0.65. Land degradation causes reduction in the biological or economic productivity of those lands that may support cropland, rangelands, forest, and woodlands. Land degradation threatens culturally unique agropastoral and silvopastoral farming systems and nomadic and transhumance systems. The consequences of land degradation are widespread poverty, hunger, migration, and creation of a potential cycle of debt for the affected populations. Historical awareness of the land degradation was cited, mainly at the local and regional scales, by Plato in the 4th century B.C in the Mediterranean region, and in Mesopotamia and China (WRI, 2001). The occurrence of the “dust bowl” in the United States during the 1930s affected farms and agricultural productivity, and several famines and mass migrations, especially in Africa during the 1970s, were important landmarks of land degradation in the 20th century. It is estimated that more than 33% of the earth’s land surface and 2.6 billion people are affected by land degradation and desertification in more than 100 countries. About 73% of rangelands in dryland areas and 47% of marginal rain-fed croplands, together with a significant percentage of irrigated croplands, are currently degraded (WRI, 2001). In sub-Saharan Africa, land degradation is widespread (20–50% of the land) and affects some 200 million people. This region experiences poverty and frequent droughts on a scale not known anywhere else in the world. Land degradation is also severe and widespread in Asia, Latin America, as well as other regions of the globe. Continuous land degradation is accelerating the loss of agricultural productivity and food production in the world. Over the next 50 years, food production needs to triple in order to provide a nutritionally adequate diet for the world’s growing population. This will be difficult to achieve even under favorable circumstances.
The Impact of Environmental Dynamics on Cultural Emergence
Authors: Reynolds Robert G. , Saleem Salah
Published: November 2020

Holland describes emergence in rule-governed systems as "the recognizable features and patterns" that derive from the operation of systems for which we have "useful descriptions in terms of rules or laws" [8, p. 3-4]. He says that, "Emergent phenomena also occur in domains for which we presently have few accepted rules; ethical systems, the evolution of nations, and the spread of ideas come to mind. Most of the ideas developed here have relevance for such systems, but precise application to such systems will require better conjectures about the laws (if any) that govern their development" [8, p. 3]. Our goal in this chapter is to extend the notions of emergence proposed by Holland to allow for the study of emergent properties in the development of this latter class of systems. In particular, we are interested in the investigation of the laws that underlie the development of cultural systems. One thing that all cultures have in common is that they can change. Murdoch has stated that, "culture changes; and the process of change appears to be an adaptive one, comparable to evolution in the organic realm but of a different order. Cultures tend, through periods of time, to become adjusted to the geographic environment, as the anthro-geographers have shown, although environmental influences are no longer conceived as determinative of cultural development" [11, p. 51]. The question that we are interested in is how is this adaptive task reflected in the knowledge needed within a given culture? The "laws of cultural change" that will be of interest here are those that govern the knowledge used to adapt a culture to changes in its environment. That is, how do environmental dynamics impact the types of knowledge used by problem-solving agents in an environment. Holland has shown that binary schematic knowledge can play an important role in problem solving via the schema theorem. In that theorem he only addressed the utilization of one knowledge type, binary schemata. Here, we allow problem-solving knowledge to be stored explicitly in terms of several different types of schemata, each of which can be viewed as an extension of the binary approach.
John Holland and the Evolution of Economics
Authors: Arrow Kenneth J.
Published: November 2020

John Holland's work has combined what appears to be a complicated but technical contribution to giving approximate solutions for a class of difficult problems with a deepening of our understanding of the way we all do induction, of how the experience of the world modifies and improves our behavior and our decisions. Such a comprehension necessarily alters the viewpoint of the behavioral sciences. In this chapter, I want to concentrate on some of the already apparent ways in which he has altered our understanding of the complex dynamic system that constitutes the economic world. Of course, the genetic algorithm can be and has been used as a means of solving hard problems in economic analysis, as in any other field. That is, it is an aid to the analyst, and a powerful one. I want, however, to emphasize the second aspect of Holland's work, the implications of the genetic algorithm as a description of human problem-solving behavior in a complicated world. The economic world is complicated partly because it depends on the physical and biological world which governs the techniques of production. More interestingly, though, the economic world is complicated because the individuals in it are interacting through markets. It is an old observation among economists, going back to Adam Smith's observation of the invisible hand, that economic events are the results of human actions but are not necessarily an achievement of human intentions. In the murk of the economic world, individuals have to act. They have to make choices as to what they will consume, how much they will save, what goods they will produce and how they will produce them, and then what investments they will make. They make these choices with a view to their consequences, personal satisfaction today or in their future or the satisfaction of their heirs, the profits to be made now or in the future by producing goods, and the returns on their investments. These choices have an important time dimension; people and many of the things they buy, make, or sell last, and the outcomes of current decisions depend on events which will occur in the future. The life of the decisionmaker is uncertain, so is his or her health.
Nature of Soils and Soil Development
Authors: Alexander Earl B. , Coleman Roger G. , Keeler-Wolfe Todd , Harrison Susan P.
Published: November 2020

We walk on soils frequently, but we seldom observe them. Soils are massive, even though they are porous. Soil 1m (40 inches) deep over an area of 1 hectare (2.5 acres) might weigh 10,000–15,000 metric tons. It is teeming with life. There are trillions, or quadrillions, of living organisms (mostly microorganisms), representing thousands of species, in each square meter of soil (Metting 1993). In fact, species diversity, or number of species, may be greater below ground than above ground. We seldom see these organisms because we seldom look below ground or dig into it. The many worms and insects one finds digging in a garden are a small fraction of the species in soils because the greatest diversity of soil-dwelling species exists among microscopic insects, mites, roundworms (or nematodes), and fungi. Even though individual organisms in soils are mostly very small or microscopic, the total mass of living organisms in a hectare of soil, excluding plant roots, may be 1–5 or 10 metric tons. More than one-half of that biomass is bacteria and fungi. Living microorganism biomass generally accounts for about 1%–5% of the organic carbon and about 2%–6% of the nitrogen in soils (Lavelle and Spain 2001). The upper limit of soil is the ground surface of the earth. The lower limit is bedrock for engineers, or the depth of root penetration for edaphologists. Unconsolidated material that engineers call soil can be called “regolith” (Merrill 1897, Jackson 1997) to distinguish it from the soil of pedologists and edaphologists. Regolith may consist of disintegrated bedrock, gravel, sand, clay, or other materials that have not been consolidated to form rock. Pedologists investigate the upper part of regolith, where changes are effected by exchanges of gases between soil and aboveground atmosphere and by biological activity. This soil of pedologists may coincide with that of edaphologists or include more regolith. In fact, the lower limit of soil that pedologists investigate is arbitrary, unless this limit is a contact with bedrock that is practically impenetrable with pick and shovel.
Baja California, Domain 1
Authors: Alexander Earl B. , Coleman Roger G. , Keeler-Wolfe Todd , Harrison Susan P.
Published: November 2020

Ophiolites occur in Baja California along the outer coast from San Benito and Cedros Islands through the Vizcaíno Peninsula to Magdalena and Santa Margarita Islands. This is a mountainous region with altitudes up to 920 m (3018 ft) on the Vizcaíno Peninsula, >300 m (∼1000 ft.) on Magdalena Island, and about 550 m (∼1800 ft) on Santa Margarita Island. The ophiolite of Calmalli, which is geologically distinct from ophiolites on the outer coast, is in low hills (mostly <500 m, or 1640 ft) near El Arco, about midway from Guerrero Negro to the Gulf of California. Ophiolites of the outer coast are in the Cochimí terrane, whereas the ophiolite of Calmalli is in the Alisitos terrane (Sedlock et al. 1993, Sedlock 2003). Mafic rocks of the Peninsular Ranges batholith that extends from California into Baja California are included in this domain. A major feature of the Peninsular Ranges is this batholith with plutons that range in composition from granite to gabbro, with tonalite the most common composition. Also, gabbro is common in the “western zone” of the batholith (Sedlock 2003). This zone is mostly southwest of the Elsinore fault zone in the California and north of the Agua Blanca fault in Baja California. All the ophiolites are in desert areas. Mean annual temperatures are about 20°C, and mean annual precipitation is about 10 cm on Cedros Island and along the outer coast of Baja California Sur and about 15 cm in the ophiolite of Calmalli locality (Hastings and Turner 1965). The precipitation falls mostly in winter in the Cedros Island and Puerto Nuevo localities, in September in the Magdalena–Margarita locality, and in both September and in winter in the Calmalli locality. Fog and dew are common along the outer coast around Santa Margarita and Magdalena Islands. Drought persists for most of each year at all the localities (Hastings and Humphrey 1969; fig 13-3). The gabbro belt in the northern part of the Peninsular Ranges has been added to this domain. Descriptions of the geology, climate, soils, and vegetation of the gabbroic plutons are given in section 13.8, describing the Los Pinos locality.
Northern California Coast Ranges, Domain 4
Authors: Alexander Earl B. , Coleman Roger G. , Keeler-Wolfe Todd , Harrison Susan P.
Published: November 2020

The Northern California Coast Ranges domain is in a mountainous region in which most of the mountain ranges are aligned north–south, or more precisely north, northwest– south southeast, curving around the Klamath Mountains into Oregon where the domain branches to north–south and northeast–southwest trends on the northwest side of the Klamath Mountains. It extends about 600km from the Golden Gate at the entrance to San Francisco Bay north to about the Coquille River in Coos County and nearly to the North Umqua River in Douglas County, Oregon. The domain corresponds to a physiographic region that is bounded by the Pacific Ocean on the west, the Coast Range of Oregon and Washington (Orr and Orr 1996) on the north, the Klamath Mountains on the northeast, the Great Valley of California on the southeast, and on the south by the drainage outlet of the Sacramento and San Joaquin rivers through the Carquinas Straight and San Pablo Bay. Serpentine is scattered in relatively small ultramafic bodies throughout the Northern California Coast Ranges and is concentrated along some of the major faults. For 200 or 300 km south from the Klamath Mountains, the Northern California Coast Ranges region is a rectangular strip 90–110 km wide between the Ocean and the Great Valley of California. The Klamath Mountains crowd the region to a narrow strip only 10 or 12 km wide in Del Norte County. Most of the mountain ranges have approximately concordant summits that are tilted up toward the east–northeast. Therefore, the highest altitudes are on the east, just south of the Klamath Mountains. North Yolla Bolly at 2397 m (7865 feet) and South Yolla Bolly at 2466 m (8092 feet) have the highest summits. Both of these and some neighboring mountains have cirques and moraines indicative of glaciation on their north slopes. There is no evidence of glaciation in any areas with serpentine rocks. Only the Rogue and Klamath rivers cut from east to west all of the way across the Northern California Coast Ranges, except for a few smaller streams such as the Chetco and Smith rivers that have headwaters in the Klamath Mountains.
Synthesis and Future Directions
Authors: Alexander Earl B. , Coleman Roger G. , Keeler-Wolfe Todd , Harrison Susan P.
Published: November 2020

Ultramafic rocks come from deep within the earth. Most rocks on the surface of the earth are quite different from them. Unique rocks make unique soils and support special plants. Exploring the links and interactions among these unique rocks, soils, and vegetation is an interdisciplinary endeavor that has been accomplished by experts in three areas. It has helped elucidate serpentine rock–soil–plant relationships and provide a rationale for the unusual soil properties and vegetation associated with ultramafic rocks. Examples from arctic tundra to temperate rainforest and hot desert in western North America provide a framework for the investigation of serpentine geoecosystems around the world. The unusual character of most serpentine vegetation is readily apparent even to an untrained eye. Although a vast number of rock and soil types make up the earth’s surface, few have as dramatic and visible effects on ecosystems as do ultramafic, or serpentine materials. Most ultramafic rocks in western North America have been derived from the mantle of earth via ocean crust. Magnesium is highly concentrated in the mantle and calcium, potassium, and phosphorous are relatively low. Calcium and potassium are further depleted from peridotite in the partial melting of ultramafic rock at the base of the ocean crust. As oceanic plates drift from spreading centers, most of the ocean crust is subducted and returns to the mantle (chapter 2). Only relatively small fragments of ocean crust are added to the continents. Because eukaryotic organisms, from protozoa to plants and animals, have evolved on continental crust, they are adapted to soils with higher concentrations of calcium, potassium, and phosphorus (elements with higher concentrations in continental crust than in ultramafic rocks from the base of the ocean crust) and much lower concentrations of magnesium. Having evolved on continents, plants depend on relatively high ratios of calcium and potassium to magnesium, elements that they use for a wide range of physiological functions. Although there has been a long history of evolutionary adaptation to the chemistry of the continental crust, special adaptations have allowed some plants to colonize the atypical conditions of serpentine.