An evaluation of targeting as a strategy for attaining objectives of conservation and water quality in the North Fork Forked Deer Watershed

Renewed concern regarding the problem of soil erosion from agricultural land has led to a serious re-evaluation of federal soil erosion control policy in the United States. The objective of reducing off-site water quality impacts of soil erosion has gained in prominence relative to that of maintaining on-site productivity. Recognition that most federal cost sharing supports implementation of best management practices (BMPs) on land with only slight to moderate erosion problems has led to proposals for targeting efforts to more highly erosive land. Cost effectiveness of soil erosion control efforts can be defined in terms of maximizing erosion reduction per dollar of federal expenditure when off-site water quality impact is considered the dominant objective. The purpose of this study was to evaluate (a) the extent to which the cost effectiveness of soil erosion control efforts was or could be increased by targeting to and within a critically eroding area, the North Fork Forked Deer (NFFD) Watershed of West Tennessee. The NFFD Watershed was an excellent case study area due to the severity of its erosion problem and an extensive base of collected data. A special Agricultural Conservation Program (ACP) water quality project on the NFFD provided 75% cost sharing for application of BMPs sufficient to bring every field\u27s erosion rate down to soil loss tolerance. In Chapter III summarization of the set of BMPs planned under this project was developed so as to be as comparable as possible with the findings of the National Summary Evaluation of the Agricultural Conservation Program, Phase I (NSE-ACP-I). BMPs included were establishment of permanent vegetative cover, improvement of permanent vegetative cover, terraces, diversions, winter cover, critical area treatment and conservation tillage. Comparison on the basis of the distribution of BMPs by pre-practice erosion rate class and cost per ton of erosion reduction indicated that targeting funds to a critical watershed increased cost effectiveness. This was apparently due primarily to the more highly erosive land base in the NFFD Watershed, rather than any targeting accomplished within the context of the project itself. This set of BMPs was viewed too in light of the pre-project situation in terms of acreage in various pre-practice erosion rate classes and compared to the recommended treatment goals in the project application. The conclusion was drawn that significant potential exists for targeting to highly erosive land within a watershed and more cost-effective BMPs in order to increase cost effectiveness. Based on the development of the equi-marginal principle of cost efficiency for application to the soil erosion control problem at hand in Chapter II, an LP model of the NFFD Watershed was constructed and employed as reported in Chapter IV. The basic LP model had as its objective maximization of erosion reduction subject to a constraint on available cost sharing funds. The activities in the LP model were BMPs applicable to fields on eight farms synthesized to represent the land and owner-operator characteristics in the NFFD Watershed. Deviation of an optimal BMP set from the LP model served to emphasize the conclusion regarding potential for targeting to land within watershed and particular BMPs to increase cost effectiveness. Policy implications outlined in Chapter V included support for further shifting of funds to critical watershed or areas but also the need to re-evaluate particular aspects of the current approach to include BMP implementation within a project or regular county program. The whole-farm requirement may limit cost effectiveness to the extent that treatment of slight erosive fields is mandated in addition to treatment of highly erosive fields. Possible modifications of the voluntary, first come-first served soil loss tolerance, and uniform cost-sharing aspects of the current approach merit consideration to allow for increased cost effectiveness. Of course, concern for the on-site productivity objective of soil erosion control may influence the advisability of some of these possible changes

Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

BackgroundEstimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period.Methods22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution.FindingsGlobal all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations.InterpretationGlobal adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic