Variable Water Supply Research Articles

Health and Drinking Water Supply Vulnerabilities to Climate Variability in Coastal and Drought-Prone Areas of Bangladesh

The objectives of the study are to understand the relationship among climate variability, waterborne disease, and the drinking water supply vulnerabilities in coastal and drought-prone areas of Bangladesh. The study used both qualitative and quantitative approaches. Qualitative data were collected by conducting stakeholder interviews and focus group discussion. Quantitative data were collected using survey and from hospital records. The study was conducted in three sites, one in a drought-prone area and two in coastal areas. Correlation analysis provided the relationship among climate variables, health outcomes, and water supply system. The regression analysis was used to determine the health vulnerabilities of the communities with time. Temperature, rainfall, humidity, and hot and cold days per year adversely affected the groundwater table and functionality of water technologies in both coastal and drought-prone sites, which in turn affects the accessibility and quality of water and health. Diarrhea, dysentery, and stomachaches and skin diseases were found in all sites more than the usual number, whereas, jaundice and typhoid are distinct in drought-prone areas only. Strong correlations of these health outcomes with different climatic and water supply variables were observed with different magnitude. Regression analysis forecasts annual increases of 5% diarrhea, 3% stomachache, 5% skin diseases cases in coastal sites and 5% diarrhea, 3% skin disease, 3% stomachache, and 2% jaundice cases in drought-prone sites annually over the next decade. The level of significance of linear association was found to be high only for diarrheal cases. Communities are becoming more vulnerable due to climate-change-related increases in waterborne diseases and impacts on water supply. Interventions are recommended to increase the resilience of water supply systems and to reduce vulnerabilities.

Efficient Water Allocation When Climate Is Changing: An Interdisciplinary Approach

This study analyzes the effects of rising water supply variability provoked by climate change on the welfare of a society whose economy heavily depends on water availability. Several studies recommend that communities should impose policies that ensure a minimum level of water allocation for human consumption. We compare two contracts, one where society allocates to the firm a fixed proportion of the annual water-runoff; and the other one, where due to the uncertainties of climate change, the community instead allocates to human consumption a fixed annual amount of water-runoff. We consider a risk-averse community. We show that, unless water supply is absolutely fixed, a higher variability and scarcity of water supply does not necessarily imply that society is better off choosing a contract that assures a minimum water for human consumption. Depending on the characteristics of water supply frequency distribution, particularly the third moment, it is possible that society would not benefit by switching to the fixed allocation contract for human consumption. We illustrate the main analytical results using data and runoff climate change projections from a water basin located in the central region of Chile, showing that in this case the community is better-off sticking to the current contract.

Roles of Bank Material in Setting Bankfull Hydraulic Geometry as Informed by the Selenga River Delta, Russia

AbstractA semi‐empirical bankfull Shields number relation as a function of slope, bed, and bank sediment grain size is obtained based on a field data set that includes the delta of the Selenga River, Russia, and other rivers from around the globe. The new Shields number relation is used in conjunction with continuity, flow resistance, and sediment transport equations to deduce predictive relations for bankfull width, depth, and slope of sand‐bed rivers. In addition, hydraulic geometry relations are obtained specifically for the Selenga River delta. Key results of this study are as follows: (1) bankfull width is strongly dependent on water discharge and is directly related to bank sediment size; (2) bankfull shear velocity is weakly dependent on bed sediment size and is inversely related to bank sediment size; (3) sand‐bed deltas with multiple distributary channels maintain smaller bankfull Shields numbers than is typical of alluvial rivers. This analysis is the first of its kind to include bank sediment size into a predictive bankfull Shields number relation to obtain relations for bankfull hydraulic geometry. The relations presented here can be utilized in morphodynamic models that explore how fluvial and deltaic systems respond to a range of imposed conditions, such as variable base level, sediment, and water supply.

Study on Energy Saving through Partial Variable Temperature Water Supply System

Study on Energy Saving through Partial Variable Temperature Water Supply System

At-Site Assessment of a Regional Design Criterium for Water-Demand Peak Factor Evaluation

In this study an analysis of the water supply variability for three towns in Puglia (Southern Italy), Roccaforzata, Palagianello and Palagiano, was carried out, based on time series continuously recorded over two years. The towns’ population ranges between 1800 and 16,000 inhabitants and the flow data, collected with time steps of 10 min, are referred to drinking water in an urban environment. The frequency analysis was conducted on the hourly and instantaneous peak factors and confirmed that the Gumbel distribution is able to represent the stochastic behavior of the peak water demand. A physically based formulation of the distribution parameters was exploited in order to investigate the regional distribution of the peak factor for towns with a different population.

High lipid perennial ryegrass growth under variable nitrogen, water and carbon dioxide supply

A novel strategy to increase the metabolisable energy content of pasture species has been the development of a GM technology (‘High metabolisable energy’ or HME), which when expressed in the leaves of perennial ryegrass, increases leaf lipids up to 6-7% of DW (approximately double ‘normal’ levels). Remarkably, increased rates of photosynthesis and growth also occur in these plants. The industry strategy is to perform field trials overseas to establish the value proposition for New Zealand. Here, results are presented from preliminary growth-chamber pot trials which reveal the influence of the HME technology on perennial ryegrass growth under different levels of N, H2O and CO2 supply. HME increased perennial ryegrass growth under high N supply, limiting and non-limiting H2O supply, and with ambient and elevated CO2 supply. Possible HME growth mechanisms and their practical implications are discussed. Progress on the 2017 field trial in the USA using offspring from the HME crossing programme is also discussed.

Below-ground hydraulic constraints during drought-induced decline in Scots pine

Below-crown hydraulic resistance, a proxy for below-ground hydraulic resistance, increased during drought in Scots pine, but larger increases were not associated to drought-induced defoliation. Accounting for variable below-ground hydraulic conductance in response to drought may be needed for accurate predictions of forest water fluxes and drought responses in xeric forests. Hydraulic deterioration is an important trigger of drought-induced tree mortality. However, the role of below-ground hydraulic constraints remains largely unknown. We investigated the association between drought-induced defoliation and seasonal dynamics of below-crown hydraulic resistance (a proxy for below-ground hydraulic resistance), associated to variations in water supply and demand in a field population of Scots pine (Pinus sylvestris L.) Below-crown hydraulic resistance (rbc) of defoliated and non-defoliated pines was obtained from the relationship between maximum leaf-specific sap flow rates and maximum stem pressure difference estimated from xylem radius variations. The percent contribution of rbc to whole-tree hydraulic resistance (%rbc) was calculated by comparing stem water potential variations with the water potential difference between the leaves and the soil. rbc and %rbc increased with drought in both defoliated and non-defoliated pines. However, non-defoliated trees showed larger increases in rbc between spring and summer. The difference between defoliation classes is unexplained by differences in root embolism, and it is possibly related to seasonal changes in other properties of the roots and the soil-root interface. Our results highlight the importance of increasing below-ground hydraulic constraints during summer drought but do not clearly link drought-induced defoliation with severe below-ground hydraulic impairment in Scots pine.

Root length and root lipid composition contribute to drought tolerance of winter and spring wheat

Mechanisms of drought tolerance based on root architecture and lipid composition in wheat are poorly understood. We quantified the differences in root morphological traits and phospholipids and galactolipids levels between winter and spring wheat genotypes at variable water supply amounts (drought stress). Experiments were conducted using seven winter and four spring wheat (Triticum aestivum) genotypes. In the first experiment, solid agar medium was used to quantify seminal root angles. In the second experiment, the plants were grown in 150-cm columns in a greenhouse under full and deficit water supply for 65 days to record root architecture. The root tips (2-cm-long) were used for quantifying polar lipids. Drought stress at vegetative stage decreased plant height (14%), total dry matter production (48%), maximum root length (25%), root length:shoot length ratio (11%), and other root traits. Winter wheat genotypes had ~1.5 times higher maximum root length than spring wheat genotypes. Significant differences in molar percentages of root phospholipids and galactolipids, molecular species, and double bond index of galactolipids were observed among spring wheat but not winter wheat genotypes. Based on the genotypes studied, the drought tolerant mechanism of winter wheat was associated with deep root system, and in spring wheat it was well branched (albeit shallow) root system with more unsaturated membrane lipids.

Seasonal evaporation cycle in oxbow lakes formed along the Tisza River in Hungary for flood control

AbstractAs a result of water regulation, dykes (i.e., embankments against floods) were constructed along the Tisza River and meanders were cut to control the floods in the region. These cut‐off meanders resulted in oxbow lakes that are important locations for nature conservation. We collected water samples over 5 years in 7 campaigns to measure the δ18O (‰) and δ2H (‰) ratios in 45 oxbow lakes from the Upper Tisza Region (NE‐Hungary). We applied Random Forest Regression involving climatic data to reveal the connection with the stable isotopes. We determined that isotope ratios changed as a function of time, due to evaporation and a varying water supply (precipitation and groundwater). The average difference in the isotopic ratios for the river and oxbows increased from spring to winter, but decreased between the oxbows on both sides of the dyke. We found that isotope ratios were determined by the maximum monthly temperature in the case of oxbows in the active floodplain, whereas in case of oxbows on the reclaimed side, this was also influenced by the maximum monthly temperature, and the cumulative evaporation. As direct measurement of evaporation is difficult to evaluate, stable isotope measurements provided an effective quantitative alternative to estimate evaporation. Measuring the seasonality of the δ18O and δ2H is important to interpret the results and these data are useful to water management experts to identify the lakes at risk of running dry.

Water security at local government level in South Africa: a qualitative interview-based analysis

BackgroundAs one of the 40 driest countries in the world with an annual average rainfall of 497 mm, South Africa is a water-scarce country. Additionally, South Africa's rate of economic development is closely linked to its water security. Thus, increasing water stress, supply variability, flooding, and water pollution levels and inadequate access to safe drinking water and sanitation are slowing economic growth. Despite the high premium placed on South Africa's water resources, no commonly shared understanding of water security exists. The aim of this study was to research, using qualitative social scientific methods, how people in two South African localities understand water security. MethodsWe used interviews and qualitative analyses to establish and compare how people from different lifestyles perceive water security in the Greater Sekhukhune District and the eThekwini Metropolitan Municipalities of South Africa. The inland Sekhukhune has a drier climate and more rural socioeconomic profile than the coastal, urbanised eThekwini with its complex economy and diverse socioeconomic structure. We did face-to-face structured interviews with a diverse stakeholder group consisting of community members, traditional leaders, municipal officials, researchers, business people, and farmers in each municipality and focus groups in two communities of each municipality: Leeuwfontein and Motetema (Sekhukhune) and Inanda and Ntshongweni (eThekwini). Each interview lasted 40–60 min, and focus group discussions lasted 90–120 min. We asked the respondents about their understanding of the concept of water security and whether they believe that, at the local and national level, the authorities had achieved water security for all. FindingsFollowing a qualitative analysis, we found that water security is a state of mind based on context-specific (ie, localised and individualised) perceptions held by an individual of water-related threats and how it influences individuals and their natural surroundings. We discovered that perceptions depend on many different factors. First, the changing state of the natural environment a person lives in—eg, one respondent from eThekwini said “When it rains in summer a lot of stuff gets washed down into the storm water drains and into the sea. The main concern here is pathogens.” Second, socioeconomic status is important—one community member in Ntshongweni noted that only some community members have the financial means to buy water tanks for rain harvesting to enhance their household water security. Third, experiences relating to various interactions with local governments and members of the community can also affect perceptions—eg, some respondents were unsatisfied with responses to problems by local authorities. A respondent from eThekwini said “Sometimes when we report water leakages it takes a long time for them to get fixed”, and a respondent from Sekhukhune said “Sometimes we have asked the authorities about the problem of water supply cuts, they told us about a stolen water pump and gave us inconsistent answers”. Therefore, a changing natural environment, like flooding and drought, is not the only variable that influences water security perceptions; such conceptualisations also depend to varying degrees on interpersonal relationships (eg, with local authorities) and practices (eg, collecting rainwater), which are directly or indirectly related to water security enhancement. InterpretationHow people perceive water security has policy implications at the local government level in South Africa and further afield in other low-income and middle-income countries where data collection is unreliable. We established that people from diverse lifestyles hold various understandings and interpretations of water security relating mainly to the availability, access, and quality of water resources. Understanding how people perceive water security in specific localities could aid policy makers and health practitioners to develop more nuanced responses to ameliorate water insecurity and its negative effects on people's wellbeing. FundingWe received funding for this project from the Department of Science and Technology, South Africa, through a Parliamentary Grant, the National Research Foundation, South Africa, the Water Research Commission, South Africa, and the European Union's KnowHow Marie Curie International Staff Exchange Scheme.

Epiphytic bromeliads in a changing world: the effect of elevated CO2 and varying water supply on growth and nutrient relations.

Global climate change is likely to impact all plant life. Vascular epiphytes represent a life form that may be affected more than any other by possible changes in precipitation leading to water shortage, but negative effects of drought may be mitigated through increasing levels of atmospheric CO2 . We studied the response of three epiphytic Aechmea species to different CO2 and watering levels in a full-factorial climate chamber study over 100days. All species use crassulacean acid metabolism (CAM). Response variables were relative growth rate (RGR), nocturnal acidification and foliar nutrient levels (N, P, K, Mg). Both elevated CO2 and increased water supply stimulated RGR, but the interaction of the two factors was not significant. Nocturnal acidification was not affected by these factors, indicating that the increase in growth in these CAM species was due to higher assimilation in the light. Mass-based foliar nutrient contents were consistently lower under elevated CO2 , but most differences disappeared when expressed on an area basis. Compared to previous studies with epiphytes, in which doubling of CO2 increased RGR, on average, by only 14%, these Aechmea species showed a relatively strong growth stimulation of up to +61%. Consistent with earlier findings with other bromeliads, elevated CO2 did not mitigate the effect of water shortage.

Quantifying persimmon tree responses to water and nutrients for designing efficient and sustainable fertirrigation protocols

Persimmon cultivation is gaining importance in many semi-arid areas of the world. This is the case of eastern Spain, where the rainfall regime is well below the crop water needs, and drip irrigation is typically used to control the water and nutrient supplies. This review is a summary of the current information in the literature on persimmon water and nutrient requirements. Crop responses to variable irrigation regimes and mild to severe water stress are also analyzed. It is concluded that persimmon water needs can be particularly high during summer, when the crop coefficient can reach values close or even above 1.0. In order to cope with water scarcity, regulated deficit irrigation (RDI) has been shown as a useful technique for reducing fruit drop in persimmon trees. RDI strategies during fruit ripening can accelerate fruit color development, resulting in earlier harvesting but with lower fruit weight. Information on nutrients requirement of astringent and non-astringent varieties of persimmon is also provided. Finally, new research for continuing plant-water relations studies on persimmon trees, such as the need to quantify the optimum nutrition plans under conditions of variable water supply, will be proposed.

Response of lentil to high temperature under variable water supply and carbon dioxide enrichment

Lentil (Lens culinaris Medik.) production in arable, Mediterranean-type climates is limited by heat waves and unreliable rainfall. Under climate change scenarios, increased atmospheric carbon dioxide (CO2) concentration will increase plant growth; however, the net effect of increasing occurrence and intensity of heat waves and drought is unclear. This study tested the response of combined acute high temperature (>32°C) at the early pod-filling stage and (i) crop-available soil water, and (ii) elevated CO2 on three lentil genotypes in two experiments. The three lentil genotypes selected were commercial cultivar PBA Bolt and two landraces sourced from the Australian Grains Genebank, AGG 71457 and AGG 73838. High soil-water availability (0.42 Mg m–3) throughout the growing season increased yield by 28% compared with low soil-water availability (0.35 Mg m–3). Across contrasting water treatments, there was no difference in patterns of crop response to high temperature during the early pod-filling phase (5 days at 42°C daytime, 25°C night), where yields were reduced by 45%. A significant interaction between high temperature response and genotype was observed, where reduction in grain number was higher for AGG 73838 (0.20% per degree-hour >32°C) than for AGG 71457 (0.07% per degree-hour >32°C) or PBA Bolt (0.10% per degree-hour >32°C). For heat and CO2 effects, there was no significant interaction between high temperature (3 days at 38°C daytime, ambient night temperature) and CO2 treatment on yield components. There was, however, an overall trend of increased biomass, grain number and yield due to elevated CO2. Although non-limiting soil water did not reduce the impact of high temperature in this study, the range in response across genotypes to high temperature supports opportunity for increased adaptation of lentil toward increasing yield stability under effects of climate change.

Hydroclimatology of the Missouri River Basin

Abstract Despite the importance of the Missouri River for navigation, recreation, habitat, hydroelectric power, and agriculture, relatively little is known about the basic hydroclimatology of the Missouri River basin (MRB). This is of particular concern given the droughts and floods that have occurred over the past several decades and the potential future exacerbation of these extremes by climate change. Here, observed and modeled hydroclimatic data and estimated natural flow records in the MRB are used to 1) assess the major source regions of MRB flow, 2) describe the climatic controls on streamflow in the upper and lower basins , and 3) investigate trends over the instrumental period. Analyses indicate that 72% of MRB runoff is generated by the headwaters in the upper basin and by the lowest portion of the basin near the mouth. Spring precipitation and temperature and winter precipitation impacted by changes in zonal versus meridional flow from the Pacific Ocean play key roles in surface water supply variability in the upper basin. Lower basin flow is significantly correlated with precipitation in late spring and early summer, indicative of Atlantic-influenced circulation variability affecting the flow of moisture from the Gulf of Mexico. Although increases in precipitation in the lower basin are currently overriding the effects of warming temperatures on total MRB flow, the upper basin’s long-term trend toward decreasing flows, reduction in snow versus rain fraction, and warming spring temperatures suggest that the upper basin may less often provide important flow supplements to the lower basin in the future.

Responding to a Groundwater Crisis: The Effects of Self-Imposed Economic Incentives

Many globally important groundwater aquifers are under considerable stress as withdrawals, predominantly for irrigation, outpace recharge. Meanwhile, groundwater policy to address the common-pool resource losses remains in its nascent stage. This study analyzes a recent and unique bottom-up effort to self-impose a groundwater pumping fee in San Luis Valley, Colorado. Utilizing a difference-in-difference econometric framework, our results bring new and direct empirical evidence to the debate on the use of economic incentives in groundwater policy. We find that the price intervention has been effective, leading to a 33% reduction in groundwater use, predominantly through reduced irrigation intensity. We also find, to a more limited extent, movement away from water-thirsty crops and reduced overall irrigated acreage. Given that financial incentives can produce substantial conservation within a groundwater commons in duress, price-based policies warrant further consideration as irrigators address diminishing and variable water supplies.

Mediterranean California's water use future under multiple scenarios of developed and agricultural land use change.

With growing demand and highly variable inter-annual water supplies, California’s water use future is fraught with uncertainty. Climate change projections, anticipated population growth, and continued agricultural intensification, will likely stress existing water supplies in coming decades. Using a state-and-transition simulation modeling approach, we examine a broad suite of spatially explicit future land use scenarios and their associated county-level water use demand out to 2062. We examined a range of potential water demand futures sampled from a 20-year record of historical (1992–2012) data to develop a suite of potential future land change scenarios, including low/high change scenarios for urbanization and agriculture as well as “lowest of the low” and “highest of the high” anthropogenic use. Future water demand decreased 8.3 billion cubic meters (Bm3) in the lowest of the low scenario and decreased 0.8 Bm3 in the low agriculture scenario. The greatest increased water demand was projected for the highest of the high land use scenario (+9.4 Bm3), high agricultural expansion (+4.6 Bm3), and high urbanization (+2.1 Bm3) scenarios. Overall, these scenarios show agricultural land use decisions will likely drive future demand more than increasing municipal and industrial uses, yet improved efficiencies across all sectors could lead to potential water use savings. Results provide water managers with information on diverging land use and water use futures, based on historical, observed land change trends and water use histories.

Adapting to Variable Water Supply in the Truckee-Carson River System, Western USA

In snow-fed inland river systems in the western United States, water supply depends upon timing, form, and amount of precipitation. In recent years, this region has experienced unprecedented drought conditions due to decreased snowpack, exacerbated by exceptionally warmer winter temperatures averaging 3–4 °C above normal. In the snow-fed Truckee-Carson River System, two sets of interviews were conducted as part of a larger collaborative modeling case study with local water managers to examine local adaptation to current drought conditions. A comparative analysis of these primary qualitative data, collected during the fourth and fifth consecutive years of continued warmer drought conditions, identifies shifts in adaptation strategies and emergent adaptation barriers. That is, under continuous exposure to climate stressors, managers shifted their adaptation focus from short-term efforts to manage water demand toward long-term efforts to enhance water supply. Managers described the need to: improve forecasts and scientific assessments of snowmelt timing, groundwater levels, and soil moisture content; increase flexibility of prior appropriation water allocation rules based on historical snowpack and streamflow timing; and foster collaboration and communication among water managers across the river system. While water scarcity and insufficient water delivery infrastructure remain significant impediments in this arid region, climate uncertainty emerged as a barrier surrounding adaptation to variable water supply. Existing prior appropriation based water institutions were also described as an adaptation barrier, meriting objective evaluation to assess how to best modify these historical institutions to support dynamic adaptation to climate-induced water supply variability. This study contributes to a growing body of research that assesses drought adaptation in snow-fed inland river systems, and contributes a unique report concerning how adaptation strategies and barriers encountered by local water managers change over time under continuous exposure to climate stressors. These locally identified adaptation strategies forward a larger collaborative modeling case study by informing alternative water management scenarios simulated through a suite of hydrologic and operations models tailored to this river system.

Projected Hydroclimatic Changes in Two Major River Basins at the Canadian West Coast Based on High-Resolution Regional Climate Simulations

Abstract The impact of anthropogenic climate change on water resources and flood and drought risk is of great interest for impact modeling and to inform adaptation strategies. Here an analysis of hydroclimatic changes in the Fraser and Athabasca River basins in western Canada is presented, based on an ensemble of climate projections, which have been dynamically downscaled to 10-km resolution using the Weather Research and Forecasting Model in two configurations. The GCM ensemble comprises four independent integrations of the Community Earth System Model under the representative concentration pathway 8.5. Basin-integrated changes in the seasonal cycle of hydroclimatic variables, and the variability of water supply and flood and drought risk, are considered. It is found that fall and winter precipitation generally increase by 20%–30% toward the end of the century, while changes in summer precipitation are smaller and associated with high model uncertainty. Furthermore, a reduction in snowfall and an increase in evapotranspiration are projected. However, projected impacts on water resources east and west of the Rocky Mountains are quite different: in basins closer to the coast (west of the Rocky Mountains) higher temperatures lead to a transition from predominantly solid to liquid precipitation and a significantly weaker spring freshet, followed by drier summers. In the lee of the Rocky Mountains the spring freshet remains largely unaffected and in summer the increase in evapotranspiration (ET) is compensated by increasing precipitation, so that water balance changes appear to be small. It is further found that a shift in runoff seasonality near the coast may lead to significantly increased flood risk in fall.

Association between water supply and early childhood development in Palestine: a descriptive analysis of demographic and health survey data

BackgroundThe proportion of the Palestinian children who are not on track in their early development is higher than that among their peers in neighboring countries. This study aimed to assess and explain the association between unimproved water supply and early childhood development, and examine its implication for policy and programmes in Palestine. MethodsDemographic and health data obtained from nationally representative surveys were merged and analysed. Descriptive analysis was used to investigate the magnitude and patterns of inadequate access to domestic water supply (running water from household tap) and its association with early childhood development in Palestine. A causal mediation model was used to assess the pathways through which access to domestic water supply interacts with poverty and affects early childhood development. Data were analysed using the structural sequential method and the potential outcome framework, while confounders (such as age, sex, and mother's education) were controlled for using bootstrapping and propensity matching tests. Ecological data about multidimensional socioeconomic, health, and environmental conditions in 52 communities in the West Bank, Jerusalem, and Gaza were gathered. Data were analysed using Z score (level of dispersion) to develop a single summary measure capturing the multidimensional influence of water supply on children's wellbeing and development at the community level. FindingsFor one standard deviation increase in the access to unimproved water supply, a 0·308 increase was predicted for child underdevelopment due to indirect effect mediated by poverty, and a 0·084 increase due to direct effect. The ecological data indicated that the average Z score of unimproved water supply variables in the target communities could be indicative of possible low scores of early childhood development. InterpretationInadequate water supply might exacerbate the negative effects of poverty and inadequate family care on early childhood health and development. These findings suggest that holistic perspectives are needed in systems and interventions to monitor child wellbeing and development. FundingNone.

Dynamic analysis of nonlinear variable frequency water supply system with time delay

In this paper, we study the mathematical model about variable frequency water supply system in the process of applying glue to particleboard. Based on the original linear ordinary differential model, the effects of time delay and the nonlinear factor are considered. Then, we obtain the delayed nonlinear differential equation associated with variable frequency water supply system. Further, we consider the existence and stability of the equilibria and the existence of several types of bifurcations in this functional differential equation. Next, we derive the normal forms of Hopf bifurcation and Bogdanov–Takens bifurcation by using the multiple time scales method and the center manifold reduction method, respectively, and analyze the classifications of local dynamics. Finally, by using Matlab software, we obtain numerical simulations with estimated values of parameters and show the existence of stable equilibrium, stable periodic-1, periodic-2, and periodic-4 solutions, and a complex chaotic attractor from a sequence of period-doubling bifurcations.