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Drought is a ubiquitous and reoccurring hazard that has wide ranging impacts on society, agriculture and the environment. Drought indices are vital for characterizing the nature and severity of drought hazards, and there have been extensive efforts to identify the most suitable drought indices for drought monitoring and risk assessments. However, to date, little effort has been made to explore which index(s) best represents drought impacts for various sectors in China. This is a critical knowledge gap, as impacts provide important ‘ground truth’ information. They can be used to demonstrate whether drought indices (used for monitoring or risk assessment) are relevant for identifying impacts, thus highlighting if an area is vulnerable to drought of a given severity. The aim of this study is to explore the link between drought indices and drought impacts, using Liaoning province (northeast China) as a case study due to its history of drought occurrence. To achieve this we use independent, but complementary, methods (correlation and random forest analysis). Using multiple drought indices – Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Soil Moisture (SoilM) and the Normalized Difference Vegetation Index (NDVI) – and drought impact data (on crop yield, livestock, rural people and the economy) correlation and random forest analysis were used to identify which indices link best to the recorded drought impacts for cities in Liaoning. The results show that the relationship varies between different categories of drought impacts and between cities. SPEI with a 6-month accumulation (SPEI6) had a strong correlation with all categories of drought impacts, while SPI12 had a weak correlation with drought impacts. Of the impact datasets, drought suffering area and drought impact area had a slightly strong relationship with all drought indices in Liaoning province, while population and number of livestock with difficulty in accessing drinking water had weak correlations with the indices. Based on the linkage, drought vulnerability was analyzed using various vulnerability factors. Crop cultivated area was positively correlated to the drought vulnerability for five out of the eight categories of drought impacts, while the total population had a strong negative relationship with drought vulnerability for half the drought impact categories. This study can support drought planning efforts in the region, and provides a methodology for application for other regions of China (and other countries) in the future, as well as providing context for the indices used in drought monitoring applications, so enabling improved preparedness for drought impacts.

Understanding of long-term climatic change prior to instrumental records necessitates reconstructions from documentary and palaeoclimate archives. In southern Africa, documentary-derived chronologies of nineteenth century rainfall variability and palaeoclimate records have permitted new insights into rainfall variability over past centuries. Rarely considered, however, is the climatic information within early colonial documentary records that emerge from the late fifteenth century onwards. This paper examines evidence for (multi-)seasonal dry and wet events within these earlier written records (c. 1550–1830 CE) from southeast Africa (Mozambique) and west-central Africa (Angola) in conjunction with palaeoclimate records from multiple proxies. Specifically, it aims to understand whether these sources agree in their signals of rainfall variability over a 280-year period covering the ‘main phase’ Little Ice Age (LIA) in southern Africa. The two source types generally, but do not always, show agreement within the two regions. This appears to reflect both the nature of rainfall variability and the context behind documentary recording. Both source types indicate that southeast and west-central Africa were distinct regions of rainfall variability over seasonal and longer timescales during the LIA, with southeast Africa being generally drier and west-central Africa generally wetter. However, the documentary records reveal considerable variability within these mean state climatic conditions, with multi-year droughts a recurrent feature in both regions. An analysis of long-term rainfall links with the El Niño–Southern Oscillation (ENSO) in southeast Africa suggests a complex and possibly non-stationary relationship. Overall, early colonial records provide valuable information for constraining hydroclimate variability where palaeoclimate records remain sparse.

Hydrological models can provide estimates of streamflow pre- and post-observations, which enable greater understanding of past hydrological behaviour, and potential futures. In this paper, a new multi-objective calibration method was derived and tested for 303 catchments in the UK, and the calibrations were used to reconstruct river flows back to 1891, in order to provide a much longer view of past hydrological variability, given the brevity of most UK river flow records which began post-1960. A Latin hypercube sample of 500 000 parameterisations for the GR4J model for each catchment were evaluated against six evaluation metrics covering all aspects of the flow regime from high, median, and low flows. The results of the top ranking model parameterisation (LHS1), and also the top 500 (LHS500), for each catchment were used to provide a deterministic result whilst also accounting for parameter uncertainty. The calibrations are generally good at capturing observed flows, with some exceptions in heavily groundwater-dominated catchments, and snowmelt and artificially influenced catchments across the country. Reconstructed flows were appraised over 30-year moving windows and were shown to provide good simulations of flow in the early parts of the record, in cases where observations were available. To consider the utility of the reconstructions for drought simulation, flow data for the 1975–1976 drought event were explored in detail in nine case study catchments. The model's performance in reproducing the drought events was found to vary by catchment, as did the level of uncertainty in the LHS500. The Standardised Streamflow Index (SSI) was used to assess the model simulations' ability to simulate extreme events. The peaks and troughs of the SSI time series were well represented despite slight over- or underestimations of past drought event magnitudes, while the accumulated deficits of the drought events extracted from the SSI time series verified that the model simulations were overall very good at simulating drought events. This paper provides three key contributions: (1) a robust multi-objective model calibration framework for calibrating catchment models for use in both general and extreme hydrology; (2) model calibrations for the 303 UK catchments that could be used in further research, and operational applications such as hydrological forecasting; and (3) ∼ 125 years of spatially and temporally consistent reconstructed flow data that will allow comprehensive quantitative assessments of past UK drought events, as well as long-term analyses of hydrological variability that have not been previously possible, thus enabling water resource managers to better plan for extreme events and build more resilient systems for the future.

In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in earth system models is currently oversimplified. As a result, there are large uncertainties in the current understanding of the past and current state of the earth system. In order to improve representation of the variety and scale of impacts that past land use had on the earth system, a global effort is underway to aggregate and synthesize archaeological and historical evidence of land use systems. Here we present a simple, hierarchical classification of land use systems designed to be used with archaeological and historical data at a global scale and a schema of codes that identify land use practices common to a range of systems, both implemented in a geospatial database. The classification scheme and database resulted from an extensive process of consultation with researchers worldwide. Our scheme is designed to deliver consistent, empirically robust data for the improvement of land use models, while simultaneously allowing for a comparative, detailed mapping of land use relevant to the needs of historical scholars. To illustrate the benefits of the classification scheme and methods for mapping historical land use, we apply it to Mesopotamia and Arabia at 6 kya (c. 4000 BCE). The scheme will be used to describe land use by the Past Global Changes (PAGES) LandCover6k working group, an international project comprised of archaeologists, historians, geographers, paleoecologists, and modelers. Beyond this, the scheme has a wide utility for creating a common language between research and policy communities, linking archaeologists with climate modelers, biodiversity conservation workers and initiatives. Fil: Morrison, Kathleen D.. University of Pennsylvania; Estados Unidos Fil: Hammer, Emily. University of Pennsylvania; Estados Unidos Fil: Boles, Oliver. University of Pennsylvania; Estados Unidos Fil: Madella, Marco. University of the Witwatersrand; Sudáfrica. Universitat Pompeu Fabra; España Fil: Whitehouse, Nicola. University of Glasgow; Reino Unido Fil: Gaillard, Marie-Jose. Linnaeus University; Suecia Fil: Bates, Jennifer. University of Pennsylvania; Estados Unidos Fil: Linden, Marc Vander. Bournemouth University; Sudáfrica Fil: Merlo, Stefania. University of the Witwatersrand; Sudáfrica Fil: Yao, Alice. University of Chicago; Estados Unidos Fil: Popova, Laura. Arizona State University; Estados Unidos Fil: Hill, Austin Chad. University of Pennsylvania; Estados Unidos Fil: Antolin, Ferran. Universiat Basel; Suiza Fil: Bauer, Andrew. University of Stanford; Estados Unidos Fil: Biagetti, Stefano. University of the Witwatersrand; Sudáfrica. Universitat Pompeu Fabra; España Fil: Bishop, Rosie R.. University of Stavanger; Noruega Fil: Buckland, Phillip. Universidad de Umea; Suecia Fil: Cruz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Unidad Ejecutora en Ciencias Sociales Regionales y Humanidades. Universidad Nacional de Jujuy. Unidad Ejecutora en Ciencias Sociales Regionales y Humanidades; Argentina Fil: Dreslerová, Dagmar. Institute Of Archaeology Of The Academy Of Sciences Of The Czech Republic; Hungría Fil: Dusseldorp, Gerrit. Leiden University; Países Bajos Fil: Ellis, Erle C.. University of Maryland; Estados Unidos. University Of Johannesburg; Sudáfrica Fil: Filipovich, Ruben Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina Fil: Foster, Thomas. University of Tulsa; Estados Unidos Fil: Hannaford, Matthew J.. Lincoln University.; Nueva Zelanda Fil: Harrison, Sandy P.. University of Reading; Reino Unido Fil: Hazarika, Manjil. Cotton University; India Fil: Herold, Hajnalka. University of Exeter; Reino Unido Fil: Hilpert, Johanna. Universitat zu Köln; Alemania Fil: Kaplan, Jed O.. The University Of Hong Kong; Hong Kong Fil: Kay, Andrea. Max Planck Institute For The Science Of Human History; Alemania Fil: Goldewijk, Kees Klein. Utrecht University; Países Bajos Fil: Kolár, Jan. Masaryk University; República Checa Fil: Kyazike, Elizabeth. Kyambogo University; Uganda Fil: Laabs, Julian. University of Bern; Suiza Fil: Lancelotti, Carla. Universitat Pompeu Fabra; España Fil: Lane, Paul. University of the Witwatersrand; Sudáfrica. University of Cambridge; Estados Unidos Fil: Lawrence, Dan. University of Durham; Reino Unido Fil: Lewis, Krista. University of Arkansas; Estados Unidos Fil: Lombardo, Umberto. University of Bern; Suiza Fil: Lucarini, Giulio. Consiglio Nazionale delle Ricerche; Italia. University of Naples; Italia Fil: Arroyo Kalin, Manuel. Colegio Universitario de Londres; Reino Unido Fil: Marchant, Rob. University of York; Reino Unido Fil: Mayle, Francis. University of Reading; Reino Unido Fil: McClatchie, Meriel. University College; Irlanda Fil: McLeester, Madeleine. Dartmouth College; Estados Unidos Fil: Mooney, Scott. Unsw Sydney; Australia Fil: Moskal-Del Hoyo, Magdalena. Wladyslaw Szafer Institute Of Botany Of The Polish Academy Of Sciences; Polonia Fil: Navarrete, Vanessa. Universitat Autònoma de Barcelona; España Fil: Ndiema, Emmanuel. National Museums Of Kenya; Kenia Fil: Neves, Eduardo Góes. Universidade de Sao Paulo; Brasil Fil: Nowak, Marek. Jagiellonian University; Polonia Fil: Out, Welmoed A.. Moesgaard Museum; Dinamarca Fil: Petrie, Cameron. Universitat Pompeu Fabra; España. University of Cambridge; Estados Unidos Fil: Phelps, Leanne N.. Royal Botanic Gardens; Reino Unido. University of Edinburgh; Reino Unido Fil: Szakonyi, Zsolt. Eötvös University; Hungría Fil: Rostain, Stéphen. Centre National de la Recherche Scientifique; Francia Fil: Russell, Thembi. University of the Witwatersrand; Sudáfrica Fil: Sluyter, Andrew. Louisiana State University; Estados Unidos Fil: Styring, Amy K.. University of Oxford; Reino Unido Fil: Tamanaha, Eduardo. The Mamirauá Sustainable Development Institute; Brasil Fil: Thomas, Evert. The Alliance of Bioversity International and CIAT; Perú Fil: Veerasamy, Selvakumar. Tamil University; India Fil: Welton, Lynn. University of the Witwatersrand; Sudáfrica Fil: Zanon, Marco. Institute of Pre- and Protohistoric Archaeology; Alemania

Geographic and socio-economic factors combined make China particularly vulnerable to droughts. Here we review academic literature to assess publication trends on the topics of drought monitoring and early warning in China, exploring the common themes and recent advances presented. Literature searches for the 1970–2017 period were made for a range of search terms relating to drought monitoring. It was found that publications on these topics started to appear sporadically in 1989 and have increased rapidly since the early 2000s, with the rate of publication increasing over the last eight years. The scope of studies varied, often with the spatial scale considered: at the national scale, studies focused on evaluating existing indices, while new indices were developed and tested at the regional scale – relating, in general, to monitoring agricultural and meteorological droughts. At the catchment scale, novel monitoring techniques were developed, often incorporating other data types such as modelled data or soil moisture measurements. National scale operational drought monitoring in China is currently being improved and updated. However, although operational systems are discussed in the literature, there is a still a disconnect between theory and practice with the most recent advances not yet operationalised. Here, we identify the methods and approaches which can be translated from the experimental case study scale to the national operational scale.

Climate has emerged as one of a number of themes in debates concerning the formation and disaggregation of African state structures before the colonial era. The proliferation of paleoclimatic data series from “natural archives” such as tree-rings has shed increasing light on changes in temperature and precipitation stretching back millennia. Such long-term climatic changes could have enduring effects on human livelihoods in agriculturally marginal areas. The apparent coincidence of periods of climatic change with major turning points in African history over the last millennium has therefore led to claims of causation, with early moves towards state formation in the Shashe–Limpopo basin (c. 1000–1220ce) and in KwaZulu-Natal (c. 1750–1800) linked to contemporaneous warm–wet conditions, and the decline, or “collapse,” of state structures, including Mapungubwe (c. 1300ce) and Great Zimbabwe (c. 1450ce), linked to a shift to cooler and drier regional climates. Recent literature from both within and outside of the southern African context has begun to question the veracity of climate-driven historical change. In the southern African case, there remains considerable uncertainty concerning the climate history of the region prior to 1800. The climatic signatures captured by some records are ambiguous in their representation of temperature or precipitation, while many long-duration climate records available for southern Africa are simply of insufficient temporal resolution to capture the short-term extremes in rainfall that have proved challenging to societies in more recent centuries. Even where there is robust evidence for the coincidence of wet or dry conditions with societal change, African farming communities were far from passive observers, but responded to environmental stress in a variety of ways. The relative length, continuity and richness of the historical record in Zimbabwe and Mozambique after. c. 1505 provides opportunities to look more closely at these relationships. From the early 16th century onwards, Portuguese observers left records of those droughts which most impacted societies. These short-term extremes—usually back-to-back years of deficient, irregular or delayed rainfall, sometimes coupled with locust plagues—had varying effects between and within societies as they were “filtered” through different levels of societal vulnerability and resilience, which in turn engendered divergent responses. Analysis of over three centuries of written records on the pre-colonial period suggest that climate-related stress alone, while sometimes leading to famine, was rarely enough to cut deeper into the political fabric of the region; yet, when combined with weak institutional capacity, warfare, or increasingly uneven distributions of power, extreme and protracted droughts could prove decisive and help bring about transformations in society. The Mutapa state and lower Zambezi valley during the late 16th and early 19th centuries, as well as the Zulu kingdom in the 1820s, serve as cases in point.

We present the first large-sample catchment hydrology dataset for Great Britain, CAMELS-GB (Catchment Attributes and MEteorology for Large-sample Studies). CAMELS-GB collates river flows, catchment attributes and catchment boundaries from the UK National River Flow Archive together with a suite of new meteorological time series and catchment attributes. These data are provided for 671 catchments that cover a wide range of climatic, hydrological, landscape, and human management characteristics across Great Britain. Daily time series covering 1970–2015 (a period including several hydrological extreme events) are provided for a range of hydro-meteorological variables including rainfall, potential evapotranspiration, temperature, radiation, humidity, and river flow. A comprehensive set of catchment attributes is quantified including topography, climate, hydrology, land cover, soils, and hydrogeology. Importantly, we also derive human management attributes (including attributes summarising abstractions, returns, and reservoir capacity in each catchment), as well as attributes describing the quality of the flow data including the first set of discharge uncertainty estimates (provided at multiple flow quantiles) for Great Britain. CAMELS-GB (Coxon et al., 2020; available at https://doi.org/10.5285/8344e4f3-d2ea-44f5-8afa-86d2987543a9) is intended for the community as a publicly available, easily accessible dataset to use in a wide range of environmental and modelling analyses.

The current work addresses one of the key building blocks towards an improved understanding of flood processes and associated changes in flood characteristics and regimes in Europe: the development of a comprehensive, extensive European flood database. The presented work results from ongoing cross-border research collaborations initiated with data collection and joint interpretation in mind. A detailed account of the current state, characteristics and spatial and temporal coverage of the European Flood Database, is presented. At this stage, the hydrological data collection is still growing and consists at this time of annual maximum and daily mean discharge series, from over 7000 hydrometric stations of various data series lengths. Moreover, the database currently comprises data from over 50 different data sources. The time series have been obtained from different national and regional data sources in a collaborative effort of a joint European flood research agreement based on the exchange of data, models and expertise, and from existing international data collections and open source websites. These ongoing efforts are contributing to advancing the understanding of regional flood processes beyond individual country boundaries and to a more coherent flood research in Europe.

Macroinvertebrates are used more often than any other groups of organisms when assessing the environmental quality of lotic systems. In this chapter we describe the many ways macroinvertebrates are used as indicators of environmental quality—from the molecular-through the community-level of biological organization. We highlight more recent advances in the use of DNA bar coding and species traits and then describe in detail the most commonly used macroinvertebrate-based methods for assessing the quality of streams and rivers. Two exercises are provided. The first can be completed as a full day project by students or volunteers and includes a laboratory-only option. The second provides the basic background and information for a college-level senior thesis, graduate study or governmental monitoring organization.

Climate variability has been causally linked to the transformation of society in pre‐industrial southeast Africa. A growing critique, however, challenges the simplicity of ideas that identify climate as an agent of past societal change; arguing instead that the value of historical climate–society research lies in understanding human vulnerability and resilience, as well as how past societies framed, responded and adapted to climatic phenomena. We work across this divide to present the first critical analysis of climate–society relationships in southeast Africa over the last millennium. To achieve this, we review the now considerable body of scholarship on the role of climate in regional societal transformation, and bring forward new perspectives on climate–society interactions across three areas and periods using the theoretical frameworks of vulnerability and resilience. We find that recent advances in paleoclimatology and archaeology give weight to the suggestion that responses to climate variability played an important part in early state formation in the Limpopo valley (1000–1300), though evidence remains insufficient to clarify similar debates concerning Great Zimbabwe (1300–1450/1520). Written and oral evidence from the Zambezi‐Save (1500–1830) and KwaZulu‐Natal areas (1760–1828) nevertheless reveals a plurality of past responses to climate variability. These were underpinned by the organization of food systems, the role of climate‐related ritual and political power, social networks, and livelihood assets and capabilities, as well as the nature of climate variability itself. To conclude, we identify new lines of research on climate, history and society, and discuss how these can more directly inform contemporary African climate adaptation challenges.

Atmospheric circulation in the oceans surrounding southern Africa plays an important role in determining its precipitation. This study uses wind information recorded in ships’ logbooks in order to statistically reconstruct summer and winter season precipitation at four southern African weather stations from 1796 to 1854. The reconstruction was obtained by first relating gridded 8° × 8° NCEP-DOE reanalysis seasonal mean wind vectors in the adjacent oceans to station precipitation. Over a 30-year calibration period (1979–2008), significant correlations between wind and precipitation at Cape Town, Mthatha and Royal National Park showed particular correspondence with those areas with the greatest concentration of logbook observations. Principal component regression was used to assess the potential of the dominant patterns of variability in the wind vectors as predictors to reconstruct precipitation. Cross-validation in the calibration period gave confidence that precipitation could be reconstructed at several stations across South Africa, meaning the regression relationships derived in the calibration period could be applied to the gridded seasonal mean logbook data to produce reconstructions of precipitation from 1796 to 1854. The reconstructions show a degree of correspondence with other regional data sets. For instance, the decade beginning in 1810 was the wettest of the period at Mthatha and Royal National Park, while the 1820s were the driest. At Cape Town, the 1820s were the wettest decade, with drier conditions observed in the 1830s. An index of west–east circulation in the summer season revealed correspondence with two documentary reconstructions of El Niño events and increased westerliness, although this did not always result in drier conditions. Attention is also drawn to the remaining 3000 yet to be digitised English East India Company logbooks which would provide a high-resolution picture of atmospheric circulation back to 1700 in the region under consideration.

Habitat assessments are an important component of most water quality evaluations in the USA. Habitat assessments are often based on an observer rating the habitat quality of a site by matching specific habitat features to written descriptions. We examined the effect that training has on reducing observer variability by using 2 separate groups of observers to assess the habitat quality at the same sites. One group received training on habitat assessments; the 2nd group conducted the assessment using the written descriptions but without training. The trained group's assessments were less variable than those of the untrained group of observers. We attribute this difference to a greater disparity among untrained observers in the interpretation of individual habitat features. However, after equal training and experience, variability of both groups' habitat assessments was not significantly different at a 2nd stream site. Finally, the variability of the habitat assessments at the 2 sites was not equal, indicati...

Variability of the United States Environmental Protection Agency's Rapid-Bioassessment Protocol III was examined by comparing the results of benthic macroinvertebrate surveys and habitat assessments conducted by 14 student groups on each of three distinct 2nd-order reaches of Strawberry Creek, on the Berkeley campus of the University of California: a reach that was recently restored to improve water quality and aquatic habitat; an unrestored tributary, which receives occasional inputs of organic pollution; and an unmodified reference site upstream of the restored site. Impact was assessed by comparison with the reference site using three different impairment thresholds: 83% similarity; 65% similarity; and the interquartile range of the reference-site data. A randomized block analysis of variance showed that taxa richness, the Family Biotic Index (FBI),% Ephemeroptera-Plecoptera-Trichoptera (EPT) abundance, EPT/Chironomidae abundance ratio, EPT/[Chironomidae+EPT],% contribution of dominant taxon, and% shre...