Indicator Of Water Availability Research Articles

POTENSI SPESIES DI SEKITAR MATA AIR BENA SEBAGAI INDIKATOR KETERSEDIAAN AIR DI DESA NIBAAF KABUPATEN TIMOR TENGAH UTARA

Nibaaf Village is one of the areas in Noemuti District, North Central Timor Regency. This village has a spring called Bena spring. Bena Spring is one of the natural springs located in the production forest area of ​​Nibaaf Village, North Central Timor Regency. This research aims to determine the type of vegetation, species that have potential as indicators of water availability, and the influence of vegetation on water availability, as well as to determine the efforts made by the Nibaaf Village community to protect and preserve Bena springs as a production forest area. This research was carried out from December 2023 to February 2024 at the Bena springs in Nibaaf Village, Noemuti District, North Central Timor Regency. The method used in this research is the quadratic plot method which is carried out by making 7 plots measuring 20 m x 20 m. The research results showed that there were 19 types of species distributed in tree growth forms, poles, saplings and seedlings. Consisting of 97 individuals for growth from trees, 70 individuals for growth from poles, 144 individuals for growth from saplings, and 430 individuals for growth from seedlings. The results of the highest INP data analysis for growth from trees were Eucaliptus alba with an INP of 181.27%. The highest INP for growth from poles is Swietenia mahagoni with an INP of 158.51%. The highest INP for growth from saplings is Syzgium aqueum with an INP of 242.08%. The highest INP for growth from seedlings was Sweitenia mahagoni with an INP of 64.17%. The Shannon Winner Diversity Index is in the medium category, the Evennes/Evenness Index is in the high category, and the Dominance Index is in the medium category. Types of plants that have potential as indicators of water availability around the Bena spring are Swietenia mahagoni, Syzygium aqueum, and Ficus benjamina. The existence of vegetation around the Bena spring has a big influence on water availability because it can conserve water. Therefore, this vegetation needs to be maintained and preserved or reforested in order to maintain the stability of water discharge during the dry season. Efforts made by the Nibaaf Village community to protect and preserve the Bena spring as a production forest area include: not cutting down trees carelessly, not throwing away rubbish, and carrying out reforestation to maintain soil fertility so that the spring does not dry out.

The complex relationship between precipitation and productivity in drylands

Abstract Drylands provide multiple essential services to human society, and dryland vegetation is one of the foundations of these services. There is a paradox, however, in the vegetation productivity–precipitation relationship in drylands. Although water is the most limiting resource in these systems, a strong relationship between precipitation and productivity does not always occur. Such a paradox affects our understanding of dryland vegetation dynamics and hinders our capacity to predict dryland vegetation responses under future climates. In this perspective, we examine the possible causes of the dryland precipitation–productivity paradox. We argue that the underlying reasons depend on the location and scale of the study. Sometimes multiple factors may interact, resulting in a less significant relationship between vegetation growth and water availability. This means that when we observe a poor correlation between vegetation growth and water availability, there are potentially missing sources of water input or a lack of consideration of other important processes. The paradox could also be related to the inaccurate measurement of vegetation productivity and water availability indicators. Incorporating these complexities into predictive models will help us better understand the complex relationship between water availability and dryland ecosystem processes and improve our ability to predict how these ecosystems will respond to the multiple facets of climate change.

Interannual dynamics and controlling factors of the ratio of actual to potential evapotranspiration across typical ecosystems within the Heihe River Basin

AbstractThe ratio of actual to potential evapotranspiration (AET/PET) represents the water supply of terrestrial ecosystems and can be used to assess the water stress level of plants or ecosystems. This study quantified the control of meteorological, hydrological, and biological factors on AET/PET variations using variance partitioning analysis and path analysis. A soil–plant–atmosphere continuum model was validated and used to simulate AET and PET, as well as the interannual dynamics of AET/PET in typical ecosystems in the upper, middle, and downstream reaches of the Heihe River Basin from 2014 to 2016. The good agreement between measurements and simulations indicates that the model accurately represents the water/heat transfer process in various ecosystems within the Heihe River Basin. The study found that the alpine meadow ecosystem had the highest annual average AET/PET (0.89 ± 0.12), followed by the Populus euphratica ecosystem (0.72 ± 0.17) and cropland ecosystem (0.65 ± 0.15). AET/PET variation characteristics were comparable across the three ecosystems, showing apparent seasonality and interannual fluctuations. Plant transpiration stress was found to be a dominant indicator of ecosystem water availability. Changes in AET/PET were attributed to diverse environmental conditions in the three distinct ecosystems. While the relationship between soil water (SW) content and AET/PET weakened in cropland ecosystems with low water stress, the study demonstrates that SW content remains the most important factor governing AET/PET. The leaf are index and vapour pressure deficiency had significant indirect effects on AET/PET by influencing SW content. Overall, this study provides scientific support for optimizing water resource management in the Heihe River Basin by revealing the interannual variations and controlling factors of AET/PET in typical ecosystems.

Defining the Multiscalar Index Timescale—Soil Water Depth Continuum for the Southwestern United States

AbstractThe lack of long‐term reliable in‐situ soil moisture data sets creates unique drought monitoring challenges for the semi‐arid Southwestern United States (“Southwest”). Land managers use multiscalar meteorological drought indices, like the Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI), as proxies for soil water availability; however, objectively identifying the index and timescale that best represents soil water availability in semi‐arid environments remains a significant gap for applying available climate information to land management action. Here, we couple site‐specific soil modeling with high resolution, spatially continuous meteorological data sets to define the relationship between index timescale length and soil water availability of different depths. By creating new matric potential indices (MPI) from 0 to 200 cm, we correlate MPI time series with the SPI and SPEI at different timescale lengths to identify the best index‐timescale combination for each depth. Results indicate the general relationship between highest correlating index‐timescale and MPI‐depth operates roughly on a 1‐month:5 cm step progression at shallow depths (<80 cm). Analysis by soil texture class shows that soils with higher clay content produce shallower sloped relationships (>1‐month:5 cm) than sandy soils (<1‐month:5 cm). Overall, the SPI produced higher correlations and less error with the MPI compared to the SPEI across all texture classes and depths. Thus, the SPI is a good indicator of soil water availability at shallow depths (<80 cm) and should be considered for soil drought monitoring on Southwestern drylands. However, land managers should consult local soils information, if available, given the impacts of texture class on timescale‐depth relationships.

Combining resilience and resistance with threat‐based approaches for prioritizing management actions in sagebrush ecosystems

AbstractThe sagebrush biome is a dryland region in the western United States experiencing rapid transformations to novel ecological states. Threat‐based approaches for managing anthropogenic and ecosystem threats have recently become prominent, but successfully mitigating threats depends on the ecological resilience of ecosystems. We used a spatially explicit approach for prioritizing management actions that combined a threat‐based model with models of resilience to disturbance and resistance to annual grass invasion. The threat‐based model assessed geographic patterns in sagebrush ecological integrity (SEI) to identify core sagebrush, growth opportunity, and other rangeland areas. The resilience and resistance model identified ecologically relevant climate and soil water availability indicators from process‐based ecohydrological models. The SEI areas and resilience and resistance indicators were consistent—the resilience and resistance indicators showed generally positive relationships with the SEI areas. They also were complementary—SEI areas provided information on intact sagebrush areas and threats, while resilience and resistance provided information on responses to disturbances and management actions. The SEI index and resilience and resistance indicators provide the basis for prioritizing conservation and restoration actions and determining appropriate strategies. The difficulty and time required to conserve or restore SEI areas increase as threats increases and resilience and resistance decrease.

Apparent contradiction in the projected climatic water balance for Austria: wetter conditions on average versus higher probability of meteorological droughts

Abstract. In this paper future changes of surface water availability in Austria are investigated. We use an ensemble of downscaled and bias-corrected regional climate model simulations of the EURO-CORDEX initiative under moderate mitigation (RCP4.5) and Paris Agreement (RCP2.6) emission scenarios. The climatic water balance and its components (rainfall, snow melt, glacier melt and atmospheric evaporative demand) are used as indicators of surface water availability, and we focus on different altitudinal classes (lowland, mountainous and high alpine) to depict a variety of processes in complex terrain. Apart from analysing the mean changes of these components, we also pursue a hazard risk approach by estimating future changes in return periods of meteorological drought events of a given magnitude as observed in the reference period. The results show, in general, wetter conditions over the course of the 21st century over Austria on an annual basis compared to the reference period 1981–2010 (e.g. RCP4.5 +107 mm, RCP2.6 +63 mm for the period 2071–2100). Considering seasonal differences, winter and spring are getting wetter due to an increase in precipitation and a higher fraction of rainfall as a consequence of rising temperatures. In summer only little changes in the mean of the climatic water balance conditions are visible across the model ensemble (e.g. RCP4.5 ±0 mm, RCP2.6 −2 mm for the period 2071–2100). On the contrary, by analysing changes in return periods of drought events, an increasing risk of moderate and extreme drought events during summer is apparent, a signal emerging within the climate system along with increasing warming.

Extent of intraspecific trait variability in ecologically central and marginal populations of a dominant alpine plant across European mountains.

Studying trait variability and restricted gene flow between populations of species can reveal species dynamics. Peripheral populations commonly exhibit lower genetic diversity and trait variability due to isolation and ecological marginality, unlike central populations experiencing gene flow and optimal conditions. This study focused on Carex curvula, the dominant species in alpine acidic meadows of European mountain regions. The species is sparser in dry areas such as the Pyrenees and Balkans, compared to the Central-Eastern Alps and Carpathians. We hypothesized that distinct population groups could be identified based on their mean functional trait values and their correlation with the environment; we predicted that ecologically marginal populations would have stronger trait correlations, lower within-population trait variability (intraspecific trait variability, ITV) and lower genetic diversity than populations of optimal habitats. Sampling was conducted in 34 populations that spanned the entire distribution range of C. curvula. We used hierarchical clustering to identify emergent functional groups of populations, defined by combinations of multiple traits associated with nutrient economy and drought tolerance (e.g. specific leaf area, anatomy). We contrasted the geographical distribution of these groups in relation to environment and genetic structure. We compared pairwise trait relationships, within-population trait variation (ITV) and neutral genetic diversity between groups. Our study identified emergent functional groups of populations. Those in the southernmost ranges, specifically the Pyrenees and Balkan region, showed drought-tolerant trait syndromes and correlated with indicators of limited water availability. While we noted a decline in population genetic diversity, we did not observe any significant changes in ITV in ecologically marginal (peripheral) populations. Our research exemplifies the relationship between ecological marginality and geographical peripherality, which in this case study is linked to genetic depauperation but not to reduced ITV. Understanding these relationships is crucial for understanding the biogeographical factors shaping trait variation.

The Effect of Increasing Irrigation Rates on the Carbon Isotope Discrimination of Apple Leaves

13C discrimination (Δ13C) has been used in research as an indicator of water availability in crops; however, few data are available concerning fruit trees. The aim of this study was to examine the effect of irrigation on the Δ13C values of apple leaves. We assumed that Δ13C would increase with irrigation intensity. The Δ13C of apple trees (Malus domestica) cv. ‘Red Jonaprince’ was determined in the years 2019–2022. Leaf samples were collected in spring, in June, at the beginning of the irrigation campaign, and in autumn, in September, following the harvest. The irrigation doses were applied to replenish the water consumption, 0% (ET0), 50% (ET50), 75% (ET75), and 100% (ET100), of the calculated evapotranspiration (ET) levels. In November, the leaves collected from different positions on the shoots were sampled, assuming the Δ13C signature would reflect the changes occurring in the water supply during their growth. The irrigation rates had a significant effect on the Δ13C of the leaves when the data for the spring and summer months were pooled. On average, Δ13C increased from 20.77‰ and 20.73‰ for ET0 and ET50, respectively, to 20.80‰ and 20.95‰ for ET75 and ET100, respectively. When the data obtained for the spring and summer months were analysed separately, the effect of irrigation was weak (p < 0.043). The Δ13C value was always higher for treatment ET100 than treatment ET0, for individual experimental years and terms; however, the differences were minor and mostly insignificant. The leaf position had a strong significant effect on Δ13C; the values gradually decreased from the leaves growing from two-years-old branches (22.50‰) to the youngest leaves growing at the top of the current year’s shoots (21.07‰). This order was similar for all the experimental years. The results of the experiment suggest that 13C discrimination in apples is affected not only by water availability during growth, but also by the use of C absorbed in previous years.

Effect of Low Water Availability on Seed Yield and Seed Quality of Basil (Ocimum basilicum).

Basil (Ocimum basilicum L.) is an aromatic and medicinal plant with important properties and is used as an alternative crop in many countries of the world because of its medicinal, economic, industrial, and nutritional importance. The objective of the present study was to determine the effect of low water availability on seed production and seed quality of five cultivars of basil (Mrs Burns, Cinnamon, Sweet, Red Rubin, and Thai). Irrigation levels and cultivars affected seed yield and thousand seed weight. In addition, plants that were exposed to low water availability produced seeds that germinated in a greater percentage. Additionally, root length was increased as the PEG concentration was increased in the germination solution and was affected by the low water availability of the mother plants. The length of the shoot, the length of the root and the seed vigor could not be used as indicators of low water availability on the mother plants, but these characteristics and especially the seed vigor could be used as indicators of low water availability of the seed. Furthermore, the root length and the seed vigor indicated that there is a possibility of an epigenetic effect of water availability on the seed produced under low water availability, though more work is needed.

Phytoliths as indicators of plant water availability: The case of millets cultivation in the Indus Valley civilization

The interpretation of crop water management practices has been central to the archeological debate on agricultural strategies and is crucial where the type of water strategy can provide fundamental explanations for the adoption and use of specific crops. Traces of water administration are difficult to detect and are mostly indirect, in the form of water harvesting or distribution structures. Attempts have been made to infer plant water availability directly from archaeobotanical remains. Current evidence suggests that the ratio of sensitive to fixed phytolith morphotypes can be used as a proxy for water availability in C₃ crops, as well as in sorghum and maize. Nevertheless, the controversy on whether genetically and environmentally controlled mechanisms of biosilica deposition are directly connected to water availability in C₄ crops is open, and several species remain to be tested for their phytolith production in relation to water levels. This research aims at clarifying whether leaf phytolith assemblages and concentration, silica skeleton size and ratio of sensitive to fixed morphotypes can be related to different water regimes in Eleusine coracana Gaertn., Pennisetum glaucum (L.) R. Br., and Sorghum bicolor (L.) Moench. We cultivated 5 traditional landraces for each species in lysimeters, under different watering conditions and analyzed their phytolith content/production in leaves. Results show higher proportions of long cells, bulliforms and stomata produced in well watered conditions. The model built on the basis of phytolith composition has been then applied to interpret archeological phytolith assemblages recovered from a single phase at four different sites of the Indus Civilisation: Harappa, Kanmer, Shikarpur and Alamgirpur. The results show that most probably C4 crops grew under water stress conditions, providing new data on the interpretation of ancient agricultural management in the Indus Valley.

A Central Asia hydrologic monitoring dataset for food and water security applications in Afghanistan

Abstract. From the Hindu Kush mountains to the Registan Desert, Afghanistan is a diverse landscape where droughts, floods, conflict, and economic market accessibility pose challenges for agricultural livelihoods and food security. The ability to remotely monitor environmental conditions is critical to support decision making for humanitarian assistance. The Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS) global and Central Asia data streams provide information on hydrologic states for routine integrated food security analysis. While developed for a specific project, these data are publicly available and useful for other applications that require hydrologic estimates of the water and energy balance. These two data streams are unique because of their suitability for routine monitoring, as well as for being a historical record for computing relative indicators of water availability. The global stream is available at ∼ 1-month latency, and monthly average outputs are on a 10 km grid from 1982–present. The second data stream, Central Asia (21–56∘ N, 30–100∘ E), at ∼ 1 d latency, provides daily average outputs on a 1 km grid from 2000–present. This paper describes the configuration of the two FLDAS data streams, background on the software modeling framework, selected meteorological inputs and parameters, and results from previous evaluation studies. We also provide additional analysis of precipitation and snow cover over Afghanistan. We conclude with an example of how these data are used in integrated food security analysis. For use in new and innovative studies that will improve understanding of this region, these data are hosted by U.S. Geological Survey data portals and the National Aeronautics and Space Administration (NASA). The Central Asia data described in this paper can be accessed via the NASA repository at https://doi.org/10.5067/VQ4CD3Y9YC0R (Jacob and Slinski, 2021), and the global data described in this paper can be accessed via the NASA repository at https://doi.org/10.5067/5NHC22T9375G (McNally, 2018).

АНАЛИЗ ЭКОЛОГИЧЕСКОЙ УСТОЙЧИВОСТИ И СТАБИЛЬНОСТИ ЛАНДШАФТА В ЦЕЛЯХ РАЦИОНАЛИЗАЦИИ ЗЕМЛЕПОЛЬЗОВАНИЯ

The article presents an analysis of the environmental sustainability and stability of the territory of the Omsk region using GIS technologies. The structure of the land fund of the region is dominated by agricultural land and forest land (respectively 53.8% and 41.9% of the total area). The share of the lands of settlements is slightly less than 2%. Industrial and other special purpose lands, specially protected territories and facilities, water resources and reserves amount to 2.6% of the territory of the region. Omsk region is divided into four natural and agricultural zones, differing in the structure of land categories (steppe, southern forest-steppe, northern forest-steppe and northern). In the steppe zone, the largest share is occupied by agricultural land, in the northern zone – the lands of the forest fund. The natural features of the zones have left their mark on the agricultural development of the territory. When moving from the north to the south of the region, there is an increase in the development of land. In general, in the Omsk region, the land fund is characterized by a high degree of development (63.4%) and plowing (44.3%). The high ploughing of the steppe zone (reaches 90.7%) enhances the processes of soil degradation here and worsens the hydrological regime, reduces the ability of natural landscapes to self-regulation. The indicator of water availability in the region (characterizes the ecological stability of agricultural landscapes) varies from 0.3% in the southern forest-steppe to 7.7% in the northern forest-steppe. In the steppe natural and agricultural zone of the Omsk region, the territory is mainly with unstable and unstable landscapes, in the zone of the southern forest-steppe unstable and unstable territory, in the zone of the northern forest – steppe - conditionally stable and medium-stable, in the northern zone pronounced ecological stability and stability of landscapes. The southern part of the Omsk region, where the agricultural sector is more developed, is experiencing significant overload when using land.

Nitrogen deposition shows no consistent negative nor positive effect on the response of forest productivity to drought across European FLUXNET forest sites

Atmospheric reactive nitrogen (N) deposition is an important driver of carbon (C) sequestration in forest ecosystems. Previous studies have focused on N-C interactions in various ecosystems; however, relatively little is known about the impact of N deposition on ecosystem C cycling during climate extremes such as droughts. With the occurrence and severity of droughts likely to be exacerbated by climate change, N deposition—drought interactions remain one of the key uncertainties in process-based models to date. This study aims to contribute to the understanding of N deposition-drought dynamics on gross primary production (GPP) in European forest ecosystems. To do so, different soil water availability indicators (Standardized Precipitation Evapotranspiration Index (SPEI), soil volumetric water) and GPP measurements from European FLUXNET forest sites were used to quantify the response of forest GPP to drought. The computed drought responses of the forest GPP to drought were linked to modelled N deposition estimates for varying edaphic, physiological, and climatic conditions. Our result showed a differential response of forest ecosystems to the drought indicators. Although all FLUXNET forest sites showed a coherent dependence of GPP on N deposition, no consistent or significant N deposition effect on the response of forest GPP to drought could be isolated. The mean response of forest GPP to drought could be predicted for forests with Pinus trees as dominant species (R 2 = 0.85, RMSE = 8.1). After extracting the influence of the most prominent parameters (mean annual temperature and precipitation, forest age), however, the variability remained too large to significantly substantiate hypothesized N deposition effects. These results suggest that, while N deposition clearly affects forest productivity, N deposition is not a major nor consistent driver of forest productivity responses to drought in European forest ecosystems.

Groundwater quality and availability assessment: A case study of District Jhelum in the Upper Indus, Pakistan

People's well-being and their economic development are linked to the availability and accessibility of water. The Pind Dadan Khan tehsil located on the right bank of River Jhelum is a classic example of water stressed confronting water quality and quantity issues. To evaluate usable potential and qualitative variations of groundwater, an integrated approach involving geophysical, water quality and risk assessment techniques was used. Accordingly, groundwater potential zones were categorized. A small shallow fresh groundwater pocket with acceptable water quality (<1.5 dS/m) for a depth between 15 m to 50 m exists in the eastern part of the study area. The groundwater of remaining tehsil was highly saline (TDS: 3852.23±5091.54 mg/L with maximum level up to 23164.03 mg/L). The quality of domestic wells at these 82 sites was unsafe (90%) due to salts, bacteriological contamination (71%), fluoride (45%), arsenic (5%), and nitrate (4%). Compared to these, public water supply schemes show comparatively lower salts (total dissolved solids of 144-2690 mg/L). However, arsenic was found beyond the WHO Drinking water guidelines (10 µg/L) in 65% sources which may pose serious cancer risks for 2 to 5 persons (maximum 12 persons) per 10,000 population.The study reveals that the freshwater in the study area is scarce and of vulnerable quality and require integrated water quantity and quality management. Our results also suggest that in arid to semi-arid regions, scoring factors based on salinity levels and relative size of the saline zone should be incorporated into indicators of water access and availability.

Changing Causes of Drought in the Urmia Lake Basin—Increasing Influence of Evaporation and Disappearing Snow Cover

The water level of the Urmia Lake Basin (ULB), located in the northwest of Iran, started to decline dramatically about two decades ago. As a result, the area has become the focus of increasing scientific research. In order to improve understanding of the connections between declining lake level and changing local drought conditions, three common drought indices are employed to analyze the period 1981–2018: The Standard Precipitation Index (SPI), the Standard Precipitation-Evaporation Index (SPEI), and the Standardized Snow Melt and Rain Index (SMRI). Although rainfall is a significant indicator of water availability, temperature is also a key factor since it determines rates of evapotranspiration and snowmelt. These different processes are captured by the three drought indices mentioned above to describe drought in the catchment. Therefore, the main objective of this paper is to provide a comparative analysis of drought over the ULB by incorporating different drought indices. Since there is not enough long-term observational data of sufficiently high density for the ULB region, ECMWF Reanalysis data version 5(ERA5) has been used to estimate SPI, SPEI, and SMRI drought indicators. These are shown to work well, with AUC-ROC &gt; 0.9, in capturing different classes of basin drought characteristics. The results show a downward trend for SPEI and SMRI (but not for SPI), suggesting that both evaporation and lack of snowmelt exacerbate droughts. Owing to the increasing temperatures in the basin and the decrease in snowfall, drought events have become particularly pronounced in the SPEI and SMRI time series since 1995. No significant SMRI drought was detected prior to 1995, thus indicating that sufficient snowfall was available at the beginning of the study period. The study results also reveal that the decrease in lake water level from 2010 to 2018 was not only caused by changes in the water balance components, but also by unsustainable water management.

Soil health indicators for Central Washington orchards.

Soil health assessment can be a critical soil testing tool that includes biological and physical indicators of soil function related to crop and environmental health. Soil health indicator minimum data sets should be regional and management goal specific. The objective of this study was to initiate the steps to develop a soil assessment tool for irrigated orchard soils in Central Washington, United States including defining objectives, gathering baseline data and selecting target indicators. This study measured twenty-one biological, physical and chemical properties of soils in irrigated Central Washington apple orchards including indicators of water availability, root health, fertility, and biological activity. Soil factors were related to fruit yield and quality. Principal components and nonlinear Bayesian modeling were used to explore the relationship between soil health indicators and yield. Soil indicators measurements in Washington state orchards varied widely but generally had lower organic matter, available water capacity, wet aggregate stability and higher percent sand than in other regions. Linear mixed effects models for available water capacity and percent sand showed significant effects on yield, and models for root health ratings and Pratylenchus nematodes had moderate effects. The minimum dataset of soil health indicators for Central Washington orchards should include measurements of water availability (available water capacity, percent sand) and of root health (bean root health rating, Pratylenchus nematodes) in addition to standard fertility indicators to meet stakeholder management goals.

Relationship between TIR and NIR-SWIR as Indicator of Vegetation Water Availability

Water availability for vegetation use has been associated with the relative amount of water in the plant and is a key factor for modeling variables related to the soil-plant system (e.g., net primary production, drought effects on vegetation). To the best of our knowledge, the integration of spectral proxies of vegetation water content (near-infrared (NIR), shortwave-infrared (SWIR) bands) and land surface temperature (LST) for estimation, not only of vegetation water content but also soil water available for the evapotranspiration process requires more analysis. This study aims to assess the relationship between NIR, SWIR reflectance, and LST data as indicators of water availability for crop use. For this purpose, vegetation water content, LST, and spectral reflectance over soybean, corn, and barley were measured in the field and the laboratory. Based on the consistency of satellite data from Moderate-Resolution Imaging Spectroradiometer (MODIS/Aqua) in relation to such measurements, a model is proposed, which can be parameterized from remotely sensed NIR-SWIR/LST scatterplots. The obtained results were tested in the Argentine Pampas, showing coherence with surface processes at regional scale associated with soil water availability. The comparison with soil moisture at different depths (R2 &gt; 0.7) showed that the method is sensitive to variations in root zone water availability. Given the reliance of the index on just satellite data, it can be pointed that the potential not only for vegetation water stress analyses but also in the context of hydrological modeling as an input of water availability.

Assessment of the ability of the standardized precipitation evapotranspiration index (SPEI) to model historical streamflow in watersheds of Western Canada

Knowledge of present-day spatial and temporal distribution of water resources is vital for successful water management and policies for planned adaptation to climate change. Measured quantities of hydroclimatic variables, including precipitation, evapotranspiration, streamflow, etc., are the primary indicators of water availability, and indices derived using several such primary variables provide a means to express water availability across a range of spatio-temporal scales. In this study, the ability of one such multi-scalar index, the Standardized Precipitation Evapotranspiration Index (SPEI), computed at a range of time scales, was examined to see how well it could model historically observed warm season monthly and annual streamflow in 24 natural-flowing watersheds of western Canada. The empirical relationships between the SPEI, computed at 1-, 3-, 6-, 9-, 12- and 24-month time scales, and monthly and annual streamflow were analyzed, showing significant correlations for all watersheds. The time scale of the SPEI with the strongest correlations varied seasonally. Based on these results, SPEI-based principal component regression (PCR) equations were calculated to model warm season monthly and annual historical streamflow. These PCR equations are able to adequately capture historical streamflow in these watersheds. Annual streamflow variability was better captured (mean = 0.46) than monthly variability (mean = 0.30 over March–October). Summer and fall streamflow variability was better captured (mean = 0.42 over June–September) than spring variability (mean = 0.15 over March–April).

FUNDAMENTALS OF WATER USE IN THE CATCHMENT AREAS OF THE ILI RIVER BASIN

Based on the long-term information and analytical materials «Balkhash-Alakol Basin Inspectorate for Regulation of Use and Protection of Water Resources» of the Committee for Water Resources of the Ministry of Agriculture of the Republic of Kazakhstan, the environmental indicator of specific water availability, which availability high water availability, ensuring sustainable development of economic sectors, but not ensuring the natural and environmental sustainability and safety of functioning of Lake Balkhash, as a geographic water body. The location in the arid and semi-arid zones, as well as the features of the formation of hydrological flow in the catchment areas of the Ili River basin, which determines the environment-forming system with socio-economic conditions and natural and technogenic objects that determine the level of water supply for water management sites, require the need for coordination of water management in order to prevent possible negative changes in watercourses and reservoirs that perform important environmental functions in the Ili-Balkhash basin, that is, to ensure natural and environmental sustainability and safe functioning of Lake Balkhash as a geographic water body.

Assessing the effect of water scarcity on crop selection and spatial pattern of croplands in central Iran

Farming and food production for the increasing world’s population require proper preparation of a diverse range of environmental parameters especially water availability and accessibility. This study investigated the effect of water scarcity on crop selection and spatial pattern of croplands in an agricultural landscape in central Iran. Towards this aim, the main crops including wheat, alfalfa, potato, fruit trees, rice and vegetables were mapped using a combination of decision tree and object-based classifiers and four Landsat 8 images acquired from March 2015 to June 2015 with Kappa Coefficient and Overall Accuracy of 80.16 and 85.37 percent, respectively. Groundwater depth as an indicator of water availability was mapped by interpolating over 13 thousand wells and, according to the ability of farmers and available technologies to extract water, classified into four groundwater level areas (GLA). Finally, spatial pattern of crops in each GLA was investigated using four landscape-level metrics including Mean Patch Size (MPS), Mean Nearest-Neighbor distance (MNN), Contagion index (CONTAG) and Shannon's diversity (SHDI). The results of this study showed that cropping system in drier areas has shifted towards monoculture (crops with fewer water requirements such as wheat) and led to a fragmented and homogeneous landscape with large and low dispersed agricultural units. It was finally concluded that changes in crop selection and spatial pattern of croplands could be considered and applied as a precise and fast indicator of determining water availability and accessibility over large geographical regions in Iran.