Sustainable Management of Water Resources in Arid Environments—Innovative Approaches

Dear Colleagues,

Arid lands cover about 41% of the earth’s surface and sustain over 900 million people. These regions are faced with persistent issues such as water scarcity, frequent droughts, high climatic variability, and degradation in the form of desertification and biodiversity loss. Many inhabitants of arid and semi-arid regions are poor and rely on agriculture and natural resources to survive. However, issues such as a lack of water, intense heat, frequent droughts, bare and marginal soil, topography that is sensitive to natural disasters, and wind and rain erosion significantly impact agriculture in these areas.

Crop yields in these regions are low due to infertile soils with weak structure, frequent droughts, and low and unpredictable rainfall, and the typical yearly rainfall cannot meet farmers’ minimum water needs. Crops in these areas frequently experience acute water stress during sensitive and vulnerable stages of growth, such as flowering and grain filling, which has a disastrous impact on agricultural yields. Droughts are another frequent occurrence in these areas, severely impacting almost all of Somalia, Eritrea, Djibouti, Ethiopia, Kenya, and Sudan.

Studies have shown that the agriculture industry is extremely susceptible to droughts because it depends on water availability. In addition to the impacts of variables such as pests, frost, floods, and other natural catastrophes, crop yields may be negatively impacted by drought. When a mild drought turns severe, the danger of yield loss quickly increases. It has been noted that a severe drought could result in crop losses of more than 70% for soybean and maize, and up to 68% and 64% for wheat and rice, respectively.

Several factors can impact the quality, quantity, availability, and distribution of water in arid and semi-arid areas. For instance, these areas rely heavily on rainfall, which varies in terms of its timing, location, volume, and duration. In semi-arid lands, major crop failure is caused by a lack of rainfall or by brief intervals of rainfall during the various stages of crop production. The most frequent crop production constraints in arid and semi-arid regions are the delayed onset of rainfall or long dry spells after early sowing; long gaps between two successive rain showers in the vegetative stages; the early cessation of rainfall; and crop water stress in the mature stage. Droughts and frequent dry spells increase crop failure, which contributes to food insecurity and poverty.

Rainwater in these areas is often of little use for crop plants because it either does not penetrate the soil deeply enough, moves swiftly through porous sandy soils, or immediately runs off. In semi-arid environments, fast flooding is exacerbated by short-lived, high-intensity rainstorms with little surface vegetation cover. Additionally, rivers, lakes, and wells in dry and semi-arid areas may be of poor quality, particularly if there are too many minerals present. Using these water sources for irrigation could result in salt accumulation.

Salt accumulation in the soil could cause salinity or alkalinity in water used for irrigation, leading to restricted agricultural growth. The majority of salt-affected lands are dry, arid, or semi-arid lowland regions with insufficient or unreliable rainfall, hindering sustained agricultural production. The rapid rate of evaporation in these areas concentrates the mineral components in the irrigation water, which might increase the effects of alkalinity or salinity. Short-season heavy rainfall may also cause significant erosion and the annual loss of productive soil. Large surface runoff causes poor crop root condition in early crop stages and high soil loss and precipitation during high-intensity storms. The resulting decrease in crop yields and income make it difficult for farmers to make a living.

Scientific studies have been published and cultural practices updated to maintain agricultural output in the affected locations, and successful farming practices have been identified, including soil and water conservation, rainwater gathering and supplemental irrigation, the adoption of crops that can withstand stress, and the integration of various farming systems. However, agricultural constraints must still be addressed and management actions designed to resolve such persistent problems in agriculture. Affordable and practical solutions are imperative for the development of resilient and adaptive techniques to minimize the effects of drought on crop yields.

There is still a significant knowledge gap to be filled by scientists, and researchers, and academics in order for information to be exchanged among stakeholders.

1. The aim of this Special Issue is to compile the experiences of scientists, researchers, and academics to facilitate the achievement of sustainable yields in arid and semi-arid regions.
2. We hope that the information collected in this Special Issue will close the knowledge gap and act as a foundation for achieving sustainability, ensuring food security, and enhancing the standard of living of underprivileged people.
3. We hope that this Special Issue will serve as a source of information for policy makers, planners, scientists, researchers, academics, students, extension workers, and innovative farmers.

We welcome original research and reviews, with possible research areas including:

Water Resources

• Innovative methods for rain and runoff water modelling.
• Assessment and control of radioactive contamination in groundwater.
• Innovative methods for water production from non-traditional water resources.
• Remote sensing and GIS applications for water resource management.
• Water harvesting and groundwater recharge.

Water Conservation

• Water conservation in the agricultural, industrial, and municipal sectors.
• New technologies and methods for water conservation.

Arid Environments

• Pollution of desert environments.
• Climate change and its impact on desert environments.
• Plant cover in arid environments.
• Conservation of biodiversity in arid environments.
• Strategies for combating desertification.

Utilization of New Technologies in the Study of Arid Environments and their Natural Resources

• Remote sensing (systems and techniques).
• Geographical information systems (GIS) and global positioning systems (GPS).
• Modern measuring systems and devices.
• Utilization of sustainable energy in water resource development.

We look forward to receiving your contributions.

Prof. Dr. Mirza Barjees Baig
Dr. Mohamed Behnassi
Prof. Dr. Shahbaz Khan
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sustainability is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• arid environments
• water resources
• technologies
• crops
• irrigation
• water harvesting
• GIS and remote sensing
• salinity
• enhancing WUE