Decreasing Water Availability Research Articles

Water Security in the Context of the Piracicaba River Sub-Basin During the COVID-19 Pandemic

Objective: To analyze the challenges for water security in municipalities belonging to the Piracicaba River (SP) sub-basin, during the COVID-19 pandemic. Method: This is an exploratory and bibliographical research with a qualitative approach and case study and with a technical documentary procedure. The data sources were: Water Resources Situation Report; number of COVID-19 cases and deaths obtained from the Brazilian Ministry of Health website. In addition, a questionnaire on aspects related to water was administered to experts from the Technical Chamber for Conservation and Protection of Natural Resources of the Piracicaba, Capivari and Jundiaí River Basin Committees. Results and conclusions: The number of cases and deaths from the COVID-19 pandemic increased significantly in the 1st half of 2021 compared to the same period in 2020. The experts interviewed attributed high importance to prevention measures, the trend of decreasing water availability and the reduction of losses from water distribution systems. Research implications: The research presented theoretical reflections on the COVID-19 pandemic and water security. Water is an extremely important resource, especially in times of epidemics, as occurred with COVID-19. Water security affects the availability of water both to meet the needs of the population and to maintain ecosystems. Originality/value: The research carried out highlights the need for public policies regarding water and sanitation in order to achieve the protection of the population's health and sustainable development.

Impact of resilience policies on cape town's water-food nexus: A system dynamics approach

BackgroundClimate change is increasingly affecting the supply of resources such as water and food. From 2015 to 2018, Cape Town endured its most severe drought on record. Yet, resource management often occurs in isolation, which contrasts with the holistic perspective provided by the nexus concept that recognizes the interdependence of resource sectors. This study employs system dynamics modeling, to examine the City of Cape Town’s (CoCT) water-food trade-offs and interactions using qualitative and quantitative approaches. It assesses various policies proposed by the CoCT, to improve system resilience and to boost future water supplies, examining their efficacy and potential drawbacks. These policies are tested against future scenarios including population growth and climate change predictions of different severities.ResultsThe simulation results show an increase in food demand, which is mainly linked to population growth and a significant decrease in water availability. Without intervention, the CoCT is expected to experience serious water shortages within the 40-year simulation period.ConclusionsThe findings indicate that the CoCT’s strategies will effectively secure adequate water for its expanding population. However, a major concern was found to be the proposed intensification of aquifer exploitation. The model predicts that such an approach could lead to overabstraction of some aquifers, compromising their sustainability.

Global and regional hydrological impacts of global forest expansion

Abstract. Large-scale reforestation, afforestation, and forest restoration schemes have gained global support as climate change mitigation strategies due to their significant carbon dioxide removal (CDR) potential. However, there has been limited research into the unintended consequences of forestation from a biophysical perspective. In the Community Earth System Model version 2 (CESM2), we apply a global forestation scenario, within a Paris Agreement-compatible warming scenario, to investigate the land surface and hydroclimate response. Compared to a control scenario where land use is fixed to present-day levels, the forestation scenario is up to 2 °C cooler at low latitudes by 2100, driven by a 10 % increase in evaporative cooling in forested areas. However, afforested areas where grassland or shrubland are replaced lead to a doubling of plant water demand in some tropical regions, causing significant decreases in soil moisture (∼ 5 % globally, 5 %–10 % regionally) and water availability (∼ 10 % globally, 10 %–15 % regionally) in regions with increased forest cover. While there are some increases in low cloud and seasonal precipitation over the expanded tropical forests, with enhanced negative cloud radiative forcing, the impacts on large-scale precipitation and atmospheric circulation are limited. This contrasts with the precipitation response to simulated large-scale deforestation found in previous studies. The forestation scenario demonstrates local cooling benefits without major disruption to global hydrodynamics beyond those already projected to result from climate change, in addition to the cooling associated with CDR. However, the water demands of extensive forestation, especially afforestation, have implications for its viability, given the uncertainty in future precipitation changes.

Impact of Water Scarcity on the Growth of Golden Sweet Potato

In this review study, the effect of water scarcity on the growth of Golden Sweet Potatoes (Ipomoea batatas) is investigated. Particular emphasis is made to the morphological and biochemical responses of this significant crop to weather circumstances that are characterized by drought. One of the most important crops, the golden sweet potato is well-known for the remarkable nutritional benefits it has, including high levels of vitamins, minerals, and antioxidants. Water scarcity, which is made worse by climate change and expanding agricultural requirements, poses significant threats to its production and productivity. However, these threats are made worse by the fact that water is scarce. In order to achieve the objective of this study, which is to provide a comprehensive understanding of how the growth and physiological health of Golden Sweet Potato plants are influenced by decreased water availability, the data from prior studies will be synthesized. The study focuses on the key morphological changes that occur as a result of water scarcity. These changes include a decrease in plant height, leaf area, biomass production, and root architecture. When the plant is experiencing a drought, these alterations demonstrate that it is making an effort to save water and maintain critical physiological functions. Biological reactions, such as alterations in protein synthesis, glucose metabolism, antioxidant activity, and chlorophyll content, are also investigated in this research. Chlorophyll content regularly decreases in reaction to water scarcity, which in turn reduces the efficiency of photosynthetic processes and the overall amount of energy produced. Through the production of stress-responsive proteins and the accumulation of osmolytes, which are both essential adaptation processes, plants are able to control the process of dehydration and maintain the integrity of their cells. An further characteristic response that protects plants from the oxidative stress that is brought on by drought is an increase in the activity of antioxidants. For the purpose of summarizing, this article presents a comprehensive investigation of the ways in which water scarcity influences the growth of golden sweet potatoes. It also gives insights into the processes by which the plant adapts to drought and alternative approaches for improving drought resistance. When it comes to finding solutions to the issues that are brought about by climate change and water scarcity in agriculture, the findings highlight how urgently additional research and ingenuity are required.

Adjustment of storage capacity for non-structural carbohydrates in response to limited water availability in two temperate woody species.

Reserves of non-structural carbohydrates (NSC) stored in living cells are essential for drought tolerance of trees. However, little is known about the phenotypic plasticity of living storage compartments (SC) and their interactions with NSC reserves under changing water availability. Here, we examined adjustments of SC and NSC reserves in stems and roots of seedlings of two temperate tree species, Acer negundo L. and Betula pendula Roth., cultivated under different substrate water availability. We found that relative contents of soluble NSC, starch and total NSC increased with decreasing water availability in stems of both species, and similar tendencies were also observed in roots of A. negundo. In the roots of B. pendula, soluble NSC contents decreased along with the decreasing water availability, possibly due to phloem decoupling or NSC translocation to shoots. Despite the contrast in organ responses, NSC contents (namely starch) positively correlated with proportions of total organ SC. Individual types of SC showed markedly distinct plasticity upon decreasing water availability, suggesting that water availability changes the partitioning of organ storage capacity. We found an increasing contribution of parenchyma-rich bark to the total organ NSC storage capacity under decreasing water availability. However, xylem SC showed substantially greater plasticity than those in bark. Axial storage cells, namely living fibers in A. negundo, responded more sensitively to decreasing water availability than radial parenchyma. Our results demonstrate that drought-induced changes in carbon balance affect the organ storage capacity provided by living cells, whose proportions are sensitively coordinated along with changing NSC reserves.

Interface and mixing zone between soil waters arising from upward and downward seepage - Part II: Heterogeneous total density.

Freshwater lenses in otherwise saline environments contain an important source of fresh water for natural vegetation and agricultural crops. Such lenses are regularly found in areas where both upward seeping saline groundwater and downward infiltrating fresh recharge water occur simultaneously during part of the year, resulting in shallow freshwater lenses which are highly susceptible to changes in recharge or seepage. In a series of two papers, we consider the water – and solute transport in a 2D cross-section between two parallel outflow faces. In this second part of the series, we build upon expressions presented in the first part to consider a situation where the density of seepage water exceeds that of recharge water, as typical for many deltaic areas around the world. Analytical expressions and approximations are given to obtain the steady state position of the interface between the two types of water using a sharp interface approximation, with a focus on the position midway between two outflow faces. Results show that the effect of a heterogeneous density distribution is limited when the seepage flux exceeds the density difference induced flux, but increases rapidly for ratios of the seepage flux over the density flux falling below 1. The heterogeneous density distribution then results in a decrease in freshwater lens thickness and, correspondingly, a decrease in fresh water availability. We also consider time-variant, oscillatory boundary conditions, and show that for heterogeneous density distributions the interface approaches its equilibrium position faster than for a corresponding situation with a homogeneous density distribution, indicating a higher vulnerability for changing boundary conditions. We also demonstrate that heterogeneous density distributions have limited effect on the amplitude of the interface oscillations. Analytical results obtained with the simplified model are validated using the numerical code SUTRA, which solves the full model for a numerical grid.

Assessment of a downscaling using quantiles mapping with MIROC Model in Guadalquivir Basin, Bolivia

In this study historical and combined GS precipitation products were assessed versus climate change scenarios at Guadalquivir basin. The purpose of this study was to evaluate the downscaling procedure using Quantiles Downscaling Mapping (QDM). This scheme is based in statistical analysis where precipitation and temperature are adjusted using observed datasets. Moreover, simulated river discharge was obtained using HYDROBID tool. It was identified underestimation of combined GS precipitation product as well as simulated river discharge. Three climate change scenarios from MIROC CORDEX were used namely: RCP2.6, RCP4.5 and RCP8.5. The precipitation and temperature analyses were performed at daily time step. The results of QDM application showed more efficiency with RCP 8.5 and combined product GS for the 230 subbasins. About hydrological modeling using CORDEX variables, it was observed perturbed climate change using combined product GS with lower values against rain gauges. In this sense, precipitation and discharge were underestimated. Temperature showed the best performance at all cases. Finally, discharge series were integrated into volumes, where a decrease in water availability at the basins was noted as for near and far future. It is recommended to use perturbed scenarios with combined precipitation product since it is the most critical and takes into account the spatial variability with 230 syntactical rain gauges.

Analysis of Meteorological Drought for Selected Districts of Saurashtra Region of Gujarat

Drought, in particular, is a complex and recurring phenomenon triggered by insufficient precipitation or changes in its distribution, often resulting in decreased water availability. It evolves slowly, affecting large populations' access to food and water, disrupting the entire hydrological cycle, and causing long-term economic losses. The present study attempts a comprehensive analysis of meteorological drought characteristics for selected districts (Junagadh, Amreli, Jamnagar, and Rajkot) in the semi-arid Saurashtra region of Gujarat. The analysis of meteorological drought was performed using rainfall (RF), maximum temperature (Tmax), and minimum temperature (Tmin) data from four stations (each district has one station) for the 43 years duration (1981–2023). The Standardized Precipitation Evapotranspiration Index (SPEI) is utilized across multiple timescales to assess the number of drought affected years, occurrence of drought and drought parameters (total drought duration, magnitude, and intensity). The meteorological drought incidence varied significantly across Junagadh, Amreli, Jamnagar and Rajkot, with Junagadh experiencing droughts in 29% of years, Amreli in 32%, and higher rates in Jamnagar (37%) and Rajkot (36%). The most severe drought years in the four districts were 1987 and 2002, with additional major droughts occurred in 1985, 1986, 1987, 1993, 2002 and 2012. These districts also faced consecutive droughts from 1985 to 1987 and again from 1999 to 2002.Analysis of drought parameters in Junagadh, Amreli, Jamnagar and Rajkot districts showed that drought duration (DD) ranged from 29.46% (Junagadh) to 35.85% (Jamnagar) of months, drought magnitude (DM) varied between -37.58% (Jamnagar) and -34.10% (Junagadh), and drought intensity (DI) spanned from -1.17 (Rajkot) to -1.04 (Junagadh). The analysis of drought occurrence in all districts shows that mild and moderate droughts have been most frequent while severe and extreme droughts have been less common. The study's findings enhance water managers' understanding of how climate change influences drought patterns in the region, thereby assisting policymakers in conducting effective drought risk assessments.

Expansion of grasslands across glacial Sundaland caused by enhanced precipitation seasonality

The distribution of vegetation across glacial Sundaland and the underlying mechanisms have long been debated. We address this issue by comparing a compilation of vegetation reconstructions with climate simulations from the Community Earth System Model 2 (CESM2). A new n-alkane δ13C record derived from higher plants, covering the period from 21 to 5 cal ka BP in the southern South China Sea, is presented. This record, combined with previous pollen-based reconstructions, indicates that C3 forests dominated the outer-to-mid shelf regions of the northern Sundaland between the Last Glacial Maximum (LGM) and Heinrich Stadial 1, while open grasslands occupied the inner shelf region. A compilation of vegetation reconstructions shows a glacial contraction of lowland rainforests in longitudinal extent compared to the Holocene, especially in southern Sundaland. Furthermore, the previously proposed “savannah corridor” or “dry tropical forests” existed in the interior of Sundaland during the LGM, extending from the Malay Peninsula to the Lesser Sunda Islands. Modelling studies suggest that changes in the seasonality of precipitation, rather than mean annual rainfall, are more relevant to vegetation changes between the LGM and the Holocene. The glacial emergence of Sundaland caused an eastward shift of the ascending branch of the Walker Circulation and a substantial reduction in atmospheric convection activity over Southeast Asia, leading to a decrease in water availability during the dry season in both hemispheres. The enhanced water stress thus favors the expansion of open environments.

Water Management and Hydrological Characteristics of Paddy-Rice Fields under Alternate Wetting and Drying Irrigation Practice as Climate Smart Practice: A Review

Paddy-rice cultivation using the traditional continuous flooding method requires much water, up to 2500 L, to produce 1 kg of rice. Decreasing water availability is being exacerbated by climate dynamics, i.e., droughts and rainfall variability negatively affecting food security in developing regions, particularly Africa. Alternate wetting and drying (AWD) practice is a climate-smart water management strategy that, together with puddling (a critical field preparation process), significantly affects soil hydrological and physicochemical regimes, such as soil water dynamics and oxidation states in paddy fields. However, there are limited reviews on the effects and interaction of the AWD duration on hydrological conditions in the paddy-rice rhizosphere continuum under AWD practice at different rice growth stages. Our review synthesizes key scientific literature to examine water management and hydrological properties of paddy soils under AWD practice with climate change and sheds light on why farmers are skeptical in adopting the practice. To develop this paper, we reviewed scientific information from published journal articles, reliable reports, and our knowledge on paddy-rice cultivation and water management with climate change in Asia and Sub-Saharan Africa. Several studies confirm that AWD practice increases water–rice–crop productivity, yields, and reduces methane emissions. Limitations and challenges of AWD irrigation, including changes in soil structure that influence irrigation water application, variations in hydraulic conductivity caused by the duration and frequency of irrigation cycles, and frequent manual water level (WL) monitoring, are discussed. Opportunities to improve the integration of AWD strategies within government policies, irrigation schemes, and farmer acceptance due to skepticism, limited knowledge, and fear of unreliable water hindering adoption are highlighted. Future research suggestions include the following: (i) long-term measurement of water stress indices using infrared thermometers; (ii) seasonal suitability mapping using NDVI, GIS, and remote sensing; and (iii) application of smart sensors based on the Internet of Things (IoT) to address AWD challenges for precision water management in paddy fields with climate change.

Multivariate investigation of Moringa oleifera morpho-physiological and biochemical traits under various water regimes

BackgroundThe climatic changes crossing the world menace the green life through limitation of water availability. The goal of this study was to determine whether Moringa oleifera Lam. trees cultivated under Tunisian arid climate, retain their tolerance ability to tolerate accentuated environmental stress factors such as drought and salinity. For this reason, the seeds of M. oleifera tree planted in Bouhedma Park (Tunisian arid area), were collected, germinated, and grown in the research area at the National Institute of Research in Rural Engineering, Waters and Forests (INRGREF) of Tunis (Tunisia). The three years aged trees were exposed to four water-holding capacities (25, 50, 75, and 100%) for 60 days to realise this work.ResultsGrowth change was traduced by the reduction of several biometric parameters and fluorescence (Fv/Fm) under severe water restriction (25 and 50%). Whereas roots presented miraculous development in length face to the decrease of water availability (25 and 50%) in their rhizospheres. The sensitivity to drought-induced membrane damage (Malondialdehyde (MDA) content) and reactive oxygen species (ROS) liberation (hydrogen peroxide (H2O2) content) was highly correlated with ROS antiradical scavenging (ferric reducing antioxidant power (FRAP) and (2, 2’-diphenyl-1-picrylhydrazyle (DPPH)), phenolic components and osmolytes accumulation. The drought stress tolerance of M. oleifera trees was associated with a dramatic stimulation of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), ascorbate peroxidase (APX), and glutathione peroxidase (GPX) activities.ConclusionBased on the several strategies adopted, integrated M. oleifera can grow under drought stress as accentuated adverse environmental condition imposed by climate change.

Identification of drought tolerant inbred lines and assessment of combining ability in maize (Zea mays L.)

AbstractMaize is an important agricultural crop ensuring food and nutritional security throughout the globe. It is highly sensitive to many of the biotic and abiotic stresses, and among them, drought is the most severe abiotic stress limiting maize production. Climate change tends to worsen this scenario by changing precipitation patterns and decreasing water availability. Hence, the present study was undertaken to identify drought‐tolerant inbred lines under well‐irrigated and managed stress conditions in the field toward developing drought‐resilient maize hybrids. The initial in vitro screening of 65 agronomically elite maize inbred lines was undertaken at 15%, 20%, and 25% polyethylene glycol (PEG) concentrations. Subsequently, the 15 inbreds selected for their promising performance under varying concentrations of PEG were evaluated in the pot (100%, 60%, and 40% of field capacity [FC]) and managed field experiments (moisture stress). Various physiological, biochemical, and yield attributing traits were measured among the inbreds to assess their drought tolerance potential. The analysis of variance in the pot and field experiments indicated significant genotypic differences among the inbreds and genotype × treatment interaction for different traits considered. In the pot experiment, the phenotypic correlation analysis showed a significant positive association of shoot fresh weight with plant height (r = .71), number of leaves (r = .58), relative water content (r = .60), root fresh weight (r = .58), shoot dry weight (r = .60), and SPAD meter readings under (r = .71) moisture stress condition. In the field experiment, the grain yield had a significant positive association with plant height, relative water content, SPAD before stress, ear length, ear girth, kernel rows per ear, kernels per row, and per day productivity under stress. Proline accumulation in inbreds during stress was found to be higher compared to nonstress conditions. The inbred lines CML 505, CML 444, CML 451, CML 504, QM 11408, and MAI 214 were promising for most of the drought tolerance imparting traits. These six inbreds along with four inbreds having low DRI (SKV 50, MAI E2‐163, MAI 16, and MAI E2‐241) were crossed in half diallel manner, and crosses involving low × high or high × low DRI inbreds showed higher grain yield. The current study also revealed the need of combining various physiological and yield attributing traits in drought breeding programmes.

Application of RNN-LSTM in Predicting Drought Patterns in Pakistan: A Pathway to Sustainable Water Resource Management

Water is a fundamental and crucial natural resource for human survival. However, the global demand for water is increasing, leading to a subsequent decrease in water availability. This study addresses the critical need for improved water resource forecasting models amidst global water scarcity concerns exacerbated by climate change. This study uses the best weather and water resource forecasting model for sustainable development. Employing a Recurrent Neural Network–Long Short-Term Memory (RNN-LSTM) approach, the research enhances drought prediction capabilities by integrating secondary data of the rainfall, temperature, and ground and surface water supplies. The primary objective is to forecast water resources under changing climatic conditions, facilitating the development of early warning systems for vulnerable regions. The results from the LSTM model show an increased trend in temperature and rainfall patterns. However, a relatively unstable decrease in rainfall is observed. The best statistical analysis result was observed with the LSTM model; the model’s accuracy was 99%, showing that it was quite good at presenting the obtained precipitation, temperature, and water data. Meanwhile, the value of the root mean squared error (RMSE) was about 13, 15, and 20, respectively. Therefore, the study’s results highlight that the LSTM model was the most suitable among the artificial neural networks for forecasting the weather, rainfall, and water resources. This study will help weather forecasting, agriculture, and meteorological departments be effective for water resource forecasting.

Impacts of Climate Change and Adaptation Strategies for Rainfed Barley Production in the Almería Province, Spain

Mediterranean water-stressed areas face significant challenges from higher temperatures and increasingly severe droughts. We assess the effect of climate change on rainfed barley production in the aridity-prone province of Almería, Spain, using the FAO AquaCrop model. We focus on rainfed barley growth by the mid-century (2041–2070) and end-century (2071–2100) time periods, using three Shared Socio-economic Pathway (SSP)-based scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Using the paired t-test, Spearman and Pearson correlation coefficient, Root Mean Squared Error, and relative Root Mean Squared Error, we verified AquaCrop’s ability to capture local multi-year trends (9 or more years) using standard barley crop parameters, without local recalibration. Starting with a reference Initial Soil Water Content (ISWC), different soil water contents within barley rooting depth were modelled to account for decreases in soil water availability. We then evaluated the efficiency of different climate adaptation strategies: irrigation, mulching, and changing sowing dates. We show average yield changes of +14% to −44.8% (mid-century) and +12% to −55.1% (end-century), with ISWC being the main factor determining yields. Irrigation increases yields by 21.1%, utilizing just 3% of Almería’s superficial water resources. Mulches improve irrigated yield performances by 6.9% while reducing irrigation needs by 40%. Changing sowing dates does not consistently improve yields. We demonstrate that regardless of the scenario used, climate adaptation of field barley production in Almería should prioritize limiting soil water loss by combining irrigation with mulching. This would enable farmers in Almería’s northern communities to maintain their livelihoods, reducing the province’s reliance on horticulture while continuing to contribute to food security goals.

Declining Tradeoff Between Resistance and Resilience of Ecosystems to Drought

AbstractResistance and resilience are widely used to characterize ecosystem drought stability. Tradeoff between resistance and resilience have been reported, but its long‐term trends remain uncertain at global scale. Based on remotely sensed vegetation indices, we assessed the spatiotemporal dynamics of drought resistance and resilience. Result revealed that there was a significant decline in the tradeoff between resistance and resilience, corresponding to a substantial increase in the proportion of areas with high resistance‐high resilience or low resistance‐low resilience. In the South Sahel, South Africa and Central China, the increased precipitation and vegetation coverage contribute to enhanced drought stability constructed by resistance and resilience; while rising temperature, decreased water availability and deforestation lead to declined stability in northeastern North America, South America and the Congo region. Increases in the areas with low resistance‐low resilience resulting from declining tradeoffs warn of increased regional ecosystem vulnerability.

Functional diversity enhances dryland forest productivity under long-term climate change.

Short-term experimental studies provided evidence that plant diversity increases ecosystem resilience and resistance to drought events, suggesting diversity to serve as a nature-based solution to address climate change. However, it remains unclear whether the effects of diversity are momentary or still hold over the long term in natural forests to ensure that the sustainability of carbon sinks. By analyzing 57 years of inventory data from dryland forests in Canada, we show that productivity of dryland forests decreased at an average rate of 1.3% per decade, in concert with the temporally increasing temperature and decreasing water availability. Increasing functional trait diversity from its minimum (monocultures) to maximum value increased productivity by 13%. Our results demonstrate the potential role of tree functional trait diversity in alleviating climate change impacts on dryland forests. While recognizing that nature-based climate mitigation (e.g., planting trees) can only be partial solutions, their long-term (decadal) efficacy can be improved by enhancing functional trait diversity across the forest community.

Monitoring cotton water status with microtensiometers

Stem water potential (Ψstem) is a key indicator for assessing plant water status, which is crucial in understanding plant health and productivity. However, existing measurement methods for Ψstem, characterized by destructiveness and intermittency, limit its applicability. Microtensiometers, an emerging plant-based sensor, offer continuous monitoring capabilities and have shown success in certain vine and tree species. In this study, we investigate the efficacy of microtensiometers ability to monitor the Ψstem of cotton (Gossypium hirsutum L.) under three distinct irrigation treatments in Maricopa, Arizona, an extremely hot, arid environment. We analyze the diurnal dynamics of Ψstem across the irrigation regimes and compare these measurements with midday leaf water potentials (Ψleaf) obtained using a dewpoint potentiometer. Our results demonstrate that the microtensiometer-derived Ψstem closely follows known diurnal patterns of Ψleaf, tracking with vapor pressure deficit (VPD) and responding to variations in irrigation levels and soil moisture content. Time cross-correlation analysis reveals an 80-minute lag in Ψstem response to changing VPD under non-water limiting conditions, which shortens under water-limiting conditions. Additionally, we establish a robust linear relationship (R2adj = 0.82) between Ψstem and Ψleaf, with this relationship strengthening as water availability decreases. Notably, we observe mean gradients of 1.2 and 0.06 MPa between soil vs. stem and stem vs. leaf water potentials, respectively. Moreover, Ψstem data proves to be more sensitive in distinguishing between irrigation treatments earlier in the growing season compared to Ψleaf, leaf temperature and leaf gas exchange parameters. These findings highlight the utility of microtensiometers as valuable tools for monitoring water status in smaller-stemmed row crops such as cotton.

Learning from local knowledge on changes in tree-cover and water availability: the case of the contested agroforested landscape of the Mt. Elgon Water Tower, Uganda

Participatory Rural Appraisal was used to compare stakeholder perceptions of spatial and temporal variation in tree cover and water availability using Uganda’s Mt. Elgon Water Tower as a case study. This study was guided by the research question: How do multi-level stakeholders’ perceptions of changes in tree-cover and water availability vary across spatial and temporal scales of the water tower? Five Participatory Rural Appraisal tools were applied to understand multi-level stakeholders’ perspectives on the changes in tree-cover and water availability. Data was collected from farmers’ focus group discussions, key experts from local government offices and structured household interviews with local communities. This study focused on the upper and lower zones of the water tower, which differ in terms of proximity to Mt. Elgon National Forest Park, household water-use, elevation, and tree-cover. Results showed that there are both similarities and differences in perceptions of changes in tree cover and water availability among stakeholders. Farmers and key experts perceived a decrease in water availability and a decrease in overall tree cover for the period 1990–2020. There are differences in stakeholders’ perceptions of water availability across the zones and sub-catchments. For instance, more farmers in Sipi River Sub-catchment perceived a decrease in water availability during 2006–2020 compared to 1990–2005 period. There were notable contradictions in farmers’ and key experts’ perceptions on tree cover. Farmers’ perceptions of 1990–2020 precipitation were in agreement with trends in existing precipitation data. Declining trends of natural tree cover especially outside the Mt. Elgon national forest park pose great threat to water resources originating from forests. Changes in tree cover and water availability in the study area can be partly explained by the tree species grown. Local stakeholders’ perceptions complemented the existing data gaps in explaining the changes in tree cover and water availability. Participatory Rural Appraisal tools are helpful for documenting the perceptions of local communities. However, this cannot replace reliable data resulting from large-scale efforts for monitoring changes and variations in tree-cover and water availability. The findings of this paper can be valuable to inform strategies for community involvement in sustainable agroforested landscape management.

Drought potential index using Normalized Difference Drought Index (NDDI) method based on Geographical Information System (GIS) in Slogohimo, Wonogiri Indonesia

Climate change is an impact caused by global warming. The phenomenon due to climate change is El Nino, which affects a long dry season. Central Java is an area heavily affected by drought caused by El Nino, one of which is Wonogiri Regency, which has the potential to cause crop failures, forest fires, and decreased water availability, which can be detrimental. Drought potential analysis was carried out to estimate the distribution of the drought index in Slogohimo District, Wonogiri Regency. The method used is the Normalized Difference Drought Index (NDDI), which combines vegetation density and wetting level using Landsat imagery—the NDDI index transformation method on a scale ranging from very low to very high (severe). The results show that the distribution of drought potential in Slogohimo District, Wonogiri Regency, is classified as very low to very high class. Still, the broadest area is classified as low. The tendency for drought to occur in the Slogohimo area is spread from the east to the south. This research suggests the application of organic mulch for improvement to reduce the potential for drought. Apart from being an effort to modify soil temperature, organic mulch also functions as a soil conditioner, which impacts adding soil pores to increase water retention.

Hydroclimatic Vulnerability of Wetlands to Upwind Land Use Changes

AbstractDespite their importance, wetland ecosystems protected by the Ramsar Convention are under pressure from climate change and human activities. These drivers are altering water availability in these wetlands, changing water levels or surface water extent, in some cases, beyond historical variability. Attribution of the effects of human and climate activities is usually focused on changes within the wetlands or their upstream surface and groundwater inputs. However, the reliance of wetland water availability on upwind atmospheric moisture supply is less understood. Here, we assess the vulnerability of 40 Ramsar wetlands to precipitation changes caused by land use and hydroclimatic change occurring in their upwind moisture‐supplying regions. We use moisture flows from a Lagrangian tracking model, atmospheric reanalysis data, and historical land use change (LUC) data to assess and quantify these changes. Our analyses show that historical LUC has decreased precipitation and terrestrial moisture recycling in most wetland hydrological basins, decreasing surface water availability (precipitation minus evaporation). The most substantial effects on wetland water availability occurred in the tropic subtropical regions of Central Europe and Asia. Overall, we found wetlands in Central Asia and South America to be the most vulnerable by a combination of LUC‐driven effects on runoff, high terrestrial precipitation recycling, and recent decreases in surface water availability. This study stresses the need to incorporate upwind effects of land use changes in the restoration, management, and conservation of the world's wetlands.