Water Management Development Research Articles

Water Management for Sustainable Development of World Heritage Properties

As climate change and water-related threats like floods and droughts intensify, water management must become a key component of World Heritage management plans. Currently, these plans are not required to address water management even though an increasing number of sites are encountering water-related challenges. A lack of comprehensive data and knowledge sharing hampers efforts to collectively address these issues, posing a risk to the preservation of their Outstanding Universal Value. This article examines the significance of water management for World Heritage Sites, including sites directly connected to water and those facing water-related threats. It presents three examples from Germany to illustrate these challenges and underscores the need for improved knowledge sharing and integration between World Heritage properties and their surrounding environments.

Coupled simulation of percolation and evapotranspiration in semi-mobile and semi-fixed dunes

Accurately describing the important components of the water balance, such as precipitation (P), deep percolation (D), and evapotranspiration (ET) and their relationships is crucial for understanding the water cycle and eco-hydrological processes in arid and semi-arid regions. This study coupled the dual crop coefficient model (Dualkc) with the HYDRUS-1D model to simulate D and ET processes in the semi-mobile and semi-fixed dune ecosystem in China’s Horqin Sandy Land during the growing seasons from 2015 to 2022. The results indicated that the improved HYDRUS-1D model achieved high simulation accuracy at a daily scale, with the R2 of 0.83, RMSE of 0.392, NSE of 0.714, and b of 0.828, representing increases of 15.27%, 20.16%, 16.01%, and 5.6%, respectively, compared to the original model. ET and D constituted the primary water dissipation processes in semi-mobile and semi-fixed dunes, accounting for 97% to 99% of P during the growing season. The evaporative ratio (ET/P) ranged from 46.7% to 79.3%, averaging 65.67% over multiple years, and the deep percolation ratio (D/P) varied between 16.1% and 53%, averaging 31.02%. The distribution of precipitation events, soil water content, and vegetation conditions are critical factors affecting ET and D in arid and semi-arid dune ecosystems. This study is of great significance for a deep understanding of the eco-hydrological processes in the dune ecosystem, and it can provide important support in developing water management strategies in the desertification region.

Evaluation of stakeholder knowledge and practices of water use management strategy: Observations from a questionnaire survey in Southern India

Freshwater resources remain unequally distributed in time and space around the world. Water resource frameworks should be designed, planned, and overseen in order to fully meet current and future social and economic objectives. The difficulties grow as the system gets bigger and more complex, with varying spatial distribution of water and insufficient resources, making water re-distribution more difficult. The current study fills such gaps by evaluating several factors influencing conjunctive management. In the current study, an effort has been made to compile the best data on water use, agricultural practises, socioeconomic status, and so on through field surveys in order to comprehend the reality on the ground. Additionally, investigations are being conducted into the causes and barriers that are most likely to have slowed the implementation of conjunctive use of available water resources. Two comprehensive socioeconomic surveys were conducted using the quantitative research methodology in a river basin in Southern India, and the results clearly show that stakeholders are unaware of the most effective agricultural water management techniques and the rationale behind modern irrigation systems. Over ninety-five percent of the total respondents were farmers, with only five percent having basic knowledge of watershed development and conjunctive use water management. The identified gaps and the inference made in the study are in the context of conjunctive water management of agricultural water. The current work may provide useful information on the baseline scenarios for upcoming agricultural water management plans, as well as a useful tool for achieving significant milestones in the agricultural sector. Furthermore, the prepared questionnaire and the data gathered for the study may also be helpful to decision-makers.

Water, Wastewater and Waste Management for Sustainable Development

Water, Wastewater and Waste Management for Sustainable Development

Integration of Artificial Intelligence into Sustainable Development Goals in India

In the pursuit of sustainable development, the fusion of artificial intelligence (AI) with legal mechanisms emerges as a potent force for transformative change. This paper delves into the intricate interplay between AI technologies and the legal framework, elucidating their collective capacity to address multifaceted challenges and propel progress towards the Sustainable Development Goals (SDGs). At the forefront of environmental stewardship, AI-driven solutions offer unprecedented capabilities in pollution monitoring, waste management, and climate change adaptation. From predictive analytics for air quality assessment to real-time monitoring of deforestation patterns, AI empowers stakeholders with actionable insights to mitigate environmental degradation and foster resilience. Simultaneously, AI applications hold promise in addressing socio-economic inequities through innovative approaches to poverty alleviation, financial inclusion, and inclusive growth strategies. By leveraging predictive modelling and data analytics, AI facilitates targeted interventions tailored to the unique needs of marginalized communities, thereby fostering sustainable development trajectories. However, the ethical and regulatory dimensions of AI deployment necessitate careful consideration within the legal framework. Ensuring data privacy, algorithmic transparency, and equitable access emerges as imperatives in harnessing the full potential of AI for societal benefit. Through the formulation of robust regulatory frameworks and ethical guidelines, the legal system plays a pivotal role in safeguarding against potential risks and maximizing the societal dividends of AI innovation. Moreover, interdisciplinary collaboration and stakeholder engagement are paramount in navigating the evolving landscape of AI governance, fostering dialogue, and consensus-building among diverse stakeholders. Thus, this paper advocates for a holistic approach to sustainable development, synergizing the transformative potential of AI with the protective mechanisms of the legal system. By fostering innovation, inclusivity, and accountability, this symbiotic relationship serves as a catalyst for advancing the global agenda towards a more equitable, resilient, and sustainable future. Keywords: Artificial Intelligence, Climate Change Adaptation, Deforestation, Education, Healthcare, Legal System, Pollution, Poverty, Sustainable Development Goals, Water and Waste Management.

A systematic review on the role of nature-based solutions (NbS) in housing delivery in Africa

Purpose The study aims to examine the potential benefits of integrating nature-based solutions (NbS) in the housing sector. Design/methodology/approach The approach adopted was a systematic literature review aided by the Preferred Reporting Items for Systematic Reviews criteria and the VOSviewer software. Abductive reasoning was used to analyze the collected data, which was then subjected to content analysis through an iterative read-and-review procedure. Findings The study identified green walls, indoor greenery, porous pavement and landscaping, rainwater harvesting and water purification and green roofs as elements of buildings where NbS should be incorporated. Although nature-based research on integrated greenery facades and roof applications was noted, rainwater harvesting and water purification-oriented research remained dominant. These findings demonstrate the advantages of implementing NbS in the housing sector, including energy efficiency, environmental development, flood prevention and sustainable water management. Integrating NbS into housing designs can considerably contribute to the creation of more resilient, eco-friendly and comfortable living environments. However, the adoption of NbS faces hurdles, including a lack of awareness, limited policy support and economic constraints. Practical implications This study recommends that NbS be mainstreamed into housing development and knowledge exchange opportunities between sub-Saharan Africa and Europe, as well as other regions, to promote the adoption of NbS through research and collaborations. Also, it contributes to the discourse of sustainable affordable housing in the Global South while addressing United Nations Sustainable Development Goals 11, 12, 13 and 15. This study offers valuable guidance to stakeholders, thereby fostering the development of more sustainable and resilient housing practices and policies. Originality/value The study used VOSviewer software visualization to identify structural patterns and track prominent research frontiers, allowing for a more thorough yet concise mapping and capture of a scientific knowledge domain.

Assessment of Changes in Hydrometeorological Indicators and Intra-Annual River Runoff in the Ile River Basin

Water management strategies in the Ile River basin (Republic of Kazakhstan) have traditionally relied on historical data without fully considering the potential impacts of climate change. This gap can lead to underestimating the changes in temperature, precipitation patterns, and runoff, hindering effective water resource management. This study aimed to analyze how a changing climate is affecting the Ile River basin’s water regime. Specifically, it investigated trends in temperature, precipitation, and runoff within the basin, emphasizing the importance of incorporating these intra-annual variations when planning water management strategies and hydraulic structures. A detailed analysis of the long-term data was conducted, focusing on changes in meteorological indicators. This included average air temperatures and annual precipitation for elevations above and below 1500 m during cold and warm periods. The analysis aimed to identify and quantify trends of increase or decrease. Meteorological stations were strategically chosen to represent both arid and humid areas within the basin, accounting for the region’s significant altitude variations. The investigation revealed several key findings. Rising average annual air temperatures are leading to a larger area experiencing snowmelt and a longer warm period within the runoff formation zone. This directly impacts the water balance of the basin. Additionally, an increase in total annual precipitation, particularly during the cold season within the runoff formation zone, suggests a potential for future water resource growth, assuming that these trends persist. This study highlights the importance of considering intra-annual variations in water regimes when developing water management strategies. The observed changes in temperature and precipitation patterns within the Ile River basin necessitate adjustments to existing plans to ensure sustainable water resource management in a changing climate.

A meta-model for understanding ‘green-red loop’ social-water interactions at a global scale

Within the coupled human and natural systems (CHANS), social-water interactions exhibit the ‘green-loop’ and ‘red-loop’ patterns, where social development is dependent on the local and external environment for resource provision, respectively. Sustainable management requires coordinating the interactions between water and the other socio-environmental systems, which we term ‘systems water management (SYWM)’. To understand the generic social-water interactions and obtain management implications for green-red loop systems, we develop a SYWM meta-model that conceptualises high-level social-environmental components and formulates their interactions into casual loops. This meta-model is evaluated via structural equation modelling using global datasets. Red- and green-loop scenarios are constructed to investigate the SYWM differences, and mediation analysis is conducted to quantify the reciprocal effects through the loops. Results show a critically weak causal link (0.22) from environmental state to quality of life, implying that the current water management performances have not been successfully incorporated for guiding further social development. Green- and red-loop systems have different direct causal effects in each link, which drives the corresponding behaviour. Red-loop systems have stronger total effects in causal links within the human system, depicting their strengths in socio-economic and water management decision-making. In contrast, green-loop systems have stronger total effects within the natural system, which symbolises receiving more environmental feedback. A sustainable SYWM that enhances both decision-making and feedback is recommended for green-red loop systems. The meta-model provides a platform for interdisciplinary collaborations and practical tools development that implements systems thinking in water management for sustainable development.

Integrated Environmental Management: Achieving Sustainable Development through the Lens of Water, Air and Waste

This paper explores the global status, primary issues, challenges, and implications of water, air, and waste management for sustainable development. Water management is crucial to achieving sustainable development goals. Currently, half of the global population faces severe water shortages annually, and a quarter faces "extremely high" water stress. Air management is closely tied to energy consumption, urbanization, and industrialization, with air pollution causing millions of premature deaths each year, especially in low- and middle-income countries. Waste management faces challenges from plastic pollution, electronic waste, and food waste, urgently requiring global improvements in infrastructure and regulations. The paper emphasizes the importance of an integrated approach to water, air, and waste management, as they are interconnected and impact the environment, health, and the economy. It calls for policy innovation, technological advancements, and societal behavior change, and emphasizes global cooperation and local action to achieve sustainable development goals.

Engaging stakeholders to address a complex water resource management issue in the Western Cape, South Africa

Engaging water users when developing water management plans is increasingly being embraced by a wide range of scientists in the water sector as imperative for dealing with present-day water resources challenges. However, the complexity presented by unique catchment situations makes it difficult to prescribe a ‘one size fits all’ solution to localised water resource challenges. South Africa is well-known for its population heterogeneity, which spreads into catchments, layering complexity in terms of water user types, needs and interests. This research presents a novel conjunctive use of classical and newly developed tools within a stakeholder engagement framework. This application of a suite of tools responds to the complex conflict of water user needs and interests in the Koue Bokkeveld catchment in the Western Cape Province of South Africa. We implement the Adaptive Planning Process, and the Actors, Resources, Dynamics, and Interactions approaches to unite conflicting stakeholders and develop a shared vision as the foundation for co-developing and negotiating a shared water management plan. We present the outcomes of a series of participatory workshops in which stakeholders developed a shared catchment vision. Stakeholders united around the vision and actively engaged in participatory Agent-based Model co-development with the research team. Increased attendance and active participation in the latter workshops demonstrate a positive progression in the engagement process. Outcomes of the stakeholder feedback evaluation validate increased participant satisfaction with the process. We then reflect on the practicalities of stakeholder engagement based on our experience. Learnings from this conjunctive application of approaches suggest that providing a conducive engagement platform, facilitation, and appropriate tools can enable conflicting water users to develop shared solutions collaboratively.

Integrated Environmental Management: Achieving Sustainable Development through the Lens of Water, Air and Waste

This paper explores the global status, primary issues, challenges, and implications of water, air, and waste management for sustainable development. Water management is crucial to achieving sustainable development goals. Currently, half of the global population faces severe water shortages annually, and a quarter faces "extremely high" water stress. Air management is closely tied to energy consumption, urbanization, and industrialization, with air pollution causing millions of premature deaths each year, especially in low- and middle-income countries. Waste management faces challenges from plastic pollution, electronic waste, and food waste, urgently requiring global improvements in infrastructure and regulations. The paper emphasizes the importance of an integrated approach to water, air, and waste management, as they are interconnected and impact the environment, health, and the economy. It calls for policy innovation, technological advancements, and societal behavior change, and emphasizes global cooperation and local action to achieve sustainable development goals.

Hydro‐modeling the ecosystem impact of wastewater reuse under climate change: A case study in upper Red River basin, Oklahoma

AbstractWater reuse, as a viable option for water supply, must be implemented to minimize the adverse impacts on stream ecosystems that previously received this wastewater effluent. In the State of Oklahoma (OK), USA, local communities have implemented wastewater reuse, and many seek to expand the reuse programs. This study presents a hydro‐modeling analysis based on the Coupled Routing and Excess STorage with VECtor routing (CREST‐VEC) model focusing on the potential ecosystem impacts and societal benefits of wastewater reuse under climate change in the OK portion of the Red River basin. First, a CREST‐VEC model is established for the upper Red River basin and validated against observed streamflow for a 30‐year historical period (1990–2020). Based on the established model, we then assess the sensitivity of ecosystem impact to various climate change scenarios and hypothetical wastewater reuse scenarios. Results show that dominant effects of climate change cause the annual time below environmental flow to increase in the next 30 years, which constrains the room to implement wastewater reuse. However, at sub‐catchment scale, the analyses identify viable locations for allocating wastewater reuse while maintaining ecosystem health. The results also reveal that wastewater reuse brings about the most societal water benefits at minimal cost of ecosystem health under representative concentration pathway (RCP) 2.6 followed by RCP 4.5 and then RCP 8.5. Overall, the study demonstrates capabilities of the hydro‐modeling framework in developing water management plans facing the changing climate.

Spatiotemporal patterns of groundwater over South Korea

Understanding the large-scale spatiotemporal pattern of multi-depth groundwater levels is critical to develop water management plans and policies for sustainable ecological and social prosperity, which are still lacking. Here, we investigate three major spatiotemporal modes of groundwater levels from ∼200 groundwater monitoring stations over the southern Korean Peninsula (2009–2020), using the Cyclostationary empirical orthogonal function analysis. The first two major modes are associated with the seasonality of recharge and discharge and groundwater use during the 2016/17 drought, which explained half of the total variance. The third major mode indicated a decreasing trend of deep groundwater levels over the western Korean Peninsula, where key administrative and authority offices have been relocated via balanced national land development policies. Furthermore, at least three million Koreans over this region likely experience groundwater depletion by the 2080s. Observational evidence of emerging groundwater depletion suggests a window of opportunity for pre-emptive groundwater management plans.

Model of Surface Water Management Based on the Potency of Water Balance

Purpose: This research intends to build the simulation model of surface water management in the Kali Lamong watershed based on each water district for maintaining in order to be able to fulfill the sustainable water demand Theoretical reference: Management of surface water is one of the very important issues nowadays. By the climate and land use change, it is adding the water resources problem in the future. Kali Lamong watershed is one of water sources for Surabaya city and the other cities. Water availability in Lamong watershed becomes very important to be known, and how is the condition in the future on short term (2050), medium term (2075), and long term (2100) by using the three scenarios for facing the uncertainty. Method: The methodology consists of developing the model of water management based on the water district by integrating the simulation result into the solutions for developing water management for reaching the water safety in the Kali Lamong watershed. Result and Conclusion: The simulation result shows that on the condition of scenario A, there is needed the reservoir capacity in short term (2050) in Lamong Hulu and Kalitemu that is 18 and 8 million m3; for medium term (2075) is 35 and 19 million m3; and for long term (2100) is 62 and 34 million m3. For scenario B, there is needed the reservoir capacity for short term (2050) in Lamong Hulu and Kalitemu is 23 and 10 million m3, for medium term (2075) is 35 and 15 million m3, and for long term (2100) is 50 and 26 million m3. However, for scenario C is needed the reservoir capacity for short term (2050) in Lamong hulu and Kalitemu is 26 and 11 miliion m3, for medium term (2075) is 45 and 21 million m3, and for long term (2100) is 80 and 38 million m3. Implication of research: Based on the prediction result of rainfall and land cover change, there is obtained the dependable discharge (Q-80%) in each water district with 3 scenarios including the projection of water demand. The potency of water balance in each water district produces 3 water districts which experience water deficit in Lamong Hulu, Sabeng, and Kalitemu Water District. To fulfill the water deficit in water district, there is carried out by building reservoir in the watershed downstream in two locations that are Lamong Hulu and Kalitemu water districts and it is integrated in the water management model. Originality/ value: To build a simulation model of surface water management.

The hydraulic network of the pre-Hispanic city of Tiwanaku (Bolivia): New insights from the integration of canal morphology, hydrogeological and palaeoenvironmental data

Water management enabled the development of ancient societies allowing them to ensure agropastoral production and manufacturing activities. In the Andes, near the shore of Lake Titicaca, the city of Tiwanaku (Bolivia) is one of the largest pre-Hispanic urban centres in South America. Abrupt climate changes in the high-altitude Altiplano during the late Holocene likely forced the population to develop water management strategies. So far, knowledge concerning the existence of a water network around the city of Tiwanaku is limited to hypotheses derived from surface and aerial observations. In this study, geoscience techniques (morphology, geophysics, sedimentology and chronostratigraphy) helped to reconstruct the canals' morphology and their flow dynamics, along with their chronology of operation in a context of hydroclimatic change. Two ca. 30 m large canals bypassing the monumental core and supplied by a shallow water table and multiple tributaries, connected the agricultural and the urban areas. The structure and organization of the network testify to an elaborate knowledge of the local hydrology by the former builders of the city. It ensured water supply and flood management in relation to the extreme intra- and inter-annual variability of precipitations in the central Andes. The palaeogeographical and landscape reconstruction demonstrates that canals were set from natural features during the early Late Formative period (200 BCE to 200 CE) during a wet period likely for water resource management needs. During the Tiwanaku state (before 800 CE), the filling of the canal network with soil and sediment suggests a major change in its use, and possibly its partial abandonment, during a major restructuration of the site, in a period of increased regional precipitation.

Water management and irrigation for bulb onion (Allium cepa L.) growth and development in the Papua New Guinea Highlands

Water is crucial for nutrient intake, transportation, temperature regulation, and photosynthesis in bulb onion (Allium cepa L.) growth and development. Water scarcity, caused by climate variability and particularly during prolonged dry periods, has proved to be an obstacle to cultivating bulb onions in the Papua New Guinea (PNG) Highlands. Farmers have a limited grasp of the interdependence of soil, water, and plants. They have traditionally depended on precipitation, and water from streams and rivers, to irrigate their bulb onion crops. The main method for providing irrigation support is manual irrigation, with agricultural organisations assisting with basic irrigation technologies. Despite farmers and organisations efforts to improve irrigation practices, the prolonged dry season still raises labour demands for bulb onion farms. Farmers’ lack of knowledge about irrigation technology and soil water conservation contributes to this issue. Moreover, the lack of irrigation suppliers worsens the issue of limited soil water in onion farms. This paper gives an overview of onion production in PNG, focusing on irrigation practices and constraints in the Highlands region. It aims to stress irrigation’s importance in crop growth and explore PNG’s irrigation methods and soil moisture conservation practices. There is a need for a sustainable irrigation and soil water conservation system that is easy to use and incorporates crop water requirements. This system is vital for watering onions and conserving soil moisture, promoting their growth and yield. In this context, the use of mulch and irrigation systems can preserve and enhance soil moisture during prolonged dry phases.

Mapping large-scale aquaculture ponds in Jiangsu Province, China: An automatic extraction framework based on Sentinel-1 time-series imagery

Aquaculture holds significant importance in supporting food security, economic development, resource conservation, and ecological balance. However, the rapid expansion of aquaculture ponds has caused many environmental problems. Studies on the trends and spatial distribution of aquaculture ponds in Jiangsu province, China, are limited, and there is a lack of aquaculture datasets with a 10-m resolution. This study aimed to develop a novel assessment framework for mapping aquaculture ponds using the Google Earth Engine (GEE) platform and Sentinel-1 time-series images. We integrated multi-threshold segmentation and object-oriented classification to extract spatial data on aquaculture ponds from 2017 to 2021 in Jiangsu Province. Results showed that (1) local adaptive threshold methods could extract data about water bodies more effectively. Based on the time series of each image element, calculating its water frequency could effectively exclude seasonal water. (2) This method could effectively map aquaculture ponds in Jiangsu Province. The overall identification accuracy was higher than 93%, and the Kappa coefficient was higher than 0.87. These results are in accordance with those in the statistical yearbook. (3) The total aquaculture pond area was largest in 2017 (3404.00 km2) and smallest in 2021 (2939.51 km2). The aquaculture pond area in Jiangsu Province showed a slight downward trend over the five-year period. Aquaculture ponds were mainly distributed in central and southern Jiangsu and the coastal areas, with the highest density at the junction of Yangzhou, Taizhou, and Yancheng. (4) From 2017 to 2021, Aquaculture ponds spanning 104.65 km2 (accounting for 55.28% of the total reduced area) were transformed into wetlands. In the coastal zone. Our results substantiate that aquaculture pond removal can accelerate wetland restoration. This study maximised the identification of aquaculture ponds as independent targets. Taken together, these results can provide a reference for aquaculture green development and tail water management in Jiangsu Province.

Developing a sustainable water conservation strategy for Saudi Arabian cities

Water scarcity is a global issue posing significant challenges for sustainable water management. Saudi Arabia, due to its arid conditions, limited freshwater resources, and high evapotranspiration rates, faces water scarcity. Factors such as rapid population growth, urban expansion, industrial development, and unsustainable water management practices contribute to increased municipal water demand and per capita water consumption. This trend is evident in the Jubail Industrial City (JIC), the largest industrial city in the Middle East. Although JIC heavily relies on desalination and groundwater extraction to meet growing water needs, it lacks a strategic vision for water conservation. The objective of this paper is to identify the causes of water scarcity, assess the sustainability of current water management practices, and develop a sustainable water conservation strategy using JIC as a case study. The study adopts a mixed-method approach, involving a comprehensive review of literature and official documents, along with an analysis of successful case studies of water conservation practices in arid regions worldwide. The proposed strategy encompasses demand management, adoption of water-efficient technologies, water reuse and recycling, public awareness and education, and policy and governance frameworks. Strategic water conservation, optimization and reuse hold significant relevance to industry settings. The study’s findings can contribute to the enhancement of the municipal water supply sector and support decision-makers in achieving the sustainable water resource management goals outlined in Saudi Vision 2030.

Spatial and Temporal Variability of Rainfall in South-central Senegal: Example of the Fatick and Kaolack Regions

One of the manifestations of climate change in the Sahel is a decrease in rainfall, which has led to a sharp decline in water potential in the south-central Senegal. The objective of this study is to understand the changes in rainfall through time and space, in the south-central Senegal (Fatick and Kaolack regions), to better plan water management for sustainable development. The rainfall data used ranges from 1961 to 2020 for the sites of Gossas, Foundiougne, Guinguineo and Nioro, and from 1951 to 2020 for the sites of Fatick and Kaolack. Pettitt and Buishand break tests were used to detect changes in rainfall patterns, Hubert segmentation was used to highlight sub-periods within the time series, and Standardized Precipitation Indices (SPI) were used to highlight deficits and surpluses. The results of break tests and Hubert segmentation show a decrease in average rainfall between the 1960s and 1970s, and an increase between the 1990s and 2000s, for some of the sites. The decrease in the 1960s and 1970s was early in sites in the Fatick region (Gossas, Fatick and Foundiougne) and late or absent in the Kaolack region (Guinguineo, Kaolack and Nioro). As for the increase in the 1990s and 2000s, it was first observed in the south and center of the study area in the 1990s (Nioro and Kaolack). In the 2000s, the increase was observed further north (Fatick and Gossas). The Standardized Precipitation Index shows reduced rainfall for 1971-2000 compared to the surrounding periods. Coefficient of variation values show that dispersion is lowest in the wetter years 1950 for two sites (Fatick and Kaolack), 1990 and 2000 for four sites (Gossas, Foundiougne, Guinguineo and Nioro). The highest coefficients of variation were detected in the drought years 1960, 1970 and 1980 for these four sites (Gossas, Foundiougne, Guinguineo and Nioro). This is not the case at the Fatick site, where the coefficients of variation for the 1970s, 1980s and 1990s are higher than those for 2000 and 2010. Coefficients of variation increase in the 2010s at five sites (Kaolack, Gossas, Foundiougne, Guinguineo and Nioro). The highest coefficients of variation were recorded in 2010 in Gossas, Guinguineo and Nioro. The decrease in average rainfall from the 1960s to the 1990s, and the increase in the 1990s and 2000s detected in most of the study sites, corroborates results of other studies from West and Central Africa.

Effects of conservation tillage with straw mulching on annual yield and water utilization in a winter wheat‐summer maize cropping system on the North China Plain

AbstractUnderstanding the combination of conservation tillage and straw mulching on water utilization is important for developing water management strategies in arid and semiarid areas. Few studies have investigated the effects of different tillage treatments on precipitation efficiency in winter wheat (Triticum aestivum L.)‐summer maize (Zea mays L.) cropping systems. A 3‐year field experiment with five treatments, that is, conventional tillage (CT), no‐tillage, no‐tillage with straw mulching (NT + S), subsoiling tillage, and subsoiling tillage with straw mulching (ST + S), was conducted. The objective was to investigate how conservation tillage with straw mulching affected soil water storage (SWC), precipitation storage efficiency (PSE), water consumption, grain yield, water use efficiency (WUE), and precipitation use efficiency (PUE) in a winter wheat‐summer maize cropping system. The results indicated that the ST + S treatment increased SWC by 10.1% and 8.3% in 2014–2015 and 2015–2016, respectively. The average PSE over the 3 years under the ST + S treatment was significantly higher, by 9.1% and 6.6%, than that under the CT treatment during the respective wheat and maize seasons. Compared with CT, the average annual yield under the NT + S treatment and ST + S treatment increased by 8.5% and 14.4%, respectively. In the winter wheat‐summer maize system, the NT + S and ST + S treatments significantly increased the annual WUE and PUE. The annual average PUE under the ST + S treatment was significantly higher, by 14.1%, than that under CT over the 3 years. Therefore, the ST + S treatment was more beneficial than the other treatments for increasing yield, WUE and PUE in sandy loam soil on the North China Plain.