Mm Of Rain Research Articles

Pintando con acuarelas en el lugar más lluvioso del mundo

This work reflects the story of an artistic experience developed in Ecuador, specifically in the biogeographic zone of Choco, in the north of the country. This region, located on the western face of the Andes mountain range, is home to one of the most important biodiversity hotspots on the planet, and is also the region in the world with the highest rainfall records, trapping clouds from 800 meters and reaching between 3,000 and 10,000 mm of rain per year. The objective was none other than to record a sample of the enormous biodiversity of the Choco through notes from the natural in a field notebook. For this, a stay was made in the Mashpi Reserve, which has a laboratory, research center, hotel and network of trails, to take notes of the natural flora and fauna species present in the reserve, and carry out a larger work based on these notes made for use in environmental awareness and dissemination. A project that links science, art and direct experience in equal parts and that has involved a whole scientific, artistic and research community to achieve it. Work financially supported by the Doctoral School of the University of Jaen.

Geospatial analysis of Ae. aegypti foci in southern Brazil

Arboviruses have become a major public health problem in recent decades. Ae. aegypti has been the vector responsible for the greatest spread of these diseases. This study aims to identify outbreaks of Ae. aegypti, through the capture of egg traps installed in the City of Passo Fundo, in southern Brazil, to understand the geospatial dimensions aimed at mapping to control the proliferation of these mosquitoes. Methodologically, 20 points were selected for trap placement using an Irregular Triangular Network. Then, ovitrap traps were distributed at the sampled points, during all seasons in 2016 and 2017. From the collected eggs, a colony of wild Ae. aegypti mosquitos was established and stored for future testing. Using geotechnologies, the mapping of each trap was carried out with an accuracy of up to 50 cm. The greatest number of outbreaks occurred in the autumn and summer seasons, with an average temperature of 18 °C and 350 mm of rain, and 22 °C and 300 mm of rain, respectively. Spring and winter, when temperatures are lower, 16 °C and 17 °C, respectively, saw fewer outbreaks. The places that stood out in the study were the two most densely populated and least vegetated areas of the city, Bairro Vila Luiza and the Centro neighborhood. This demonstrates that vegetation suppression and high urban density rates contribute to the proliferation of Ae. aegypti on a global scale.

A numerical study to investigate the roles of former Hurricane Leslie, orography and evaporative cooling in the 2018 Aude heavy-precipitation event

Abstract. In south-eastern France, the Mediterranean coast is regularly affected by heavy-precipitation events. On 14–15 October 2018, in the Aude department, a back-building quasi-stationary mesoscale convective system produced up to about 300 mm of rain in 11 h. At synoptic scale, the former Hurricane Leslie was involved in the formation of a Mediterranean surface low that channelled conditionally unstable air towards the coast. At mesoscale, convective cells focused west of a decaying cold front that became quasi-stationary and downwind of the terrain. To investigate the roles of the moisture provided by Leslie, orography and evaporative cooling among the physical processes that led to the location and intensity of the observed rainfall, numerical simulations are run at 1 km and 500 m horizontal grid spacing and evaluated with independent near-surface analyses including novel crowd-sourced observations of personal weather stations. Simulations show that, in a first part of the event, low-level conditionally unstable air parcels found inside strong updraughts mainly originated from areas east of the Balearic Islands, over the Mediterranean Sea, whereas in a second part, an increasing number originated from Leslie's remnants. Air masses from areas east of the Balearic Islands appeared as the first supplier of moisture over the entire event. Still, Leslie contributed to substantially moistening mid-levels over the Aude department, diminishing evaporation processes. Thus, the evaporative cooling over the Aude department did not play any substantial role in the stationarity of the quasi-stationary front. Regarding lifting mechanisms, the advection of conditionally unstable air by a low-level jet towards the quasi-stationary front, confined to altitudes below 2 km, reactivated convection along and downwind of the front. Most of the air parcels found inside strong updraughts near the location of the maximum rainfall were lifted above the quasi-stationary front. Downwind of the Albera Massif, mountains bordering the Mediterranean Sea, cells formed by orographic lifting were maintained by low-level leeward convergence, mountain lee waves and a favourable directional wind shear; when terrain is flattened, rainfall is substantially reduced. The location of the exceptional precipitation was primarily driven by the location of the quasi-stationary front and secondarily by the location of convective bands downwind of orography.

Impacts of the addition of biochar, biosolid and aluminum silicate on the leaching and bioavailability of 2,4-D + picloram in soil

The use of herbicides in high-yield crops is increasing, and their fate in the environment has become a primary environmental concern. The aim of this study was to evaluate the impacts of the use of biosolid, biochar, and aluminum silicate on the leaching dynamics of a mixture of 2,4-D + picloram herbicides, which is widely used in agricultural and non-agricultural areas. Three experiments were carried out, one for each residue, using the same methodological procedure. The tests were designed in randomized blocks with four replicates and split plots. Different proportions of the residues were incorporated in the pots at 0%, 10%, 20%, 30%, and 40% referring to the column volume, allocated in the subplots at different depths in the soil column (0–5, 5–10, 10–15, 15–20, 20–25, 25–30, 30–35, 35–40, and 40–45 cm). After the application of 2,4-D + picloram, 40 mm of rain was simulated in all columns. The plant bioindicator, Cucumis sativus , was sown in the profile. The increase in the biochar dose intensified 2,4-D + picloram leaching and grew C. sativus biomass in deeper layers of the soil profile. Regarding biosolids, an increased dose reduced the 2,4-D + picloram movement in soil and stimulated the growth of C. sativus . The addition of aluminum silicate to the soil did not influence the leaching of 2,4-D + picloram. However, it increased the biomass of C. sativus plants in the deeper layers of the soil profile. The addition of biosolids reduced the leaching of 2,4-D + picloram in the soil profile. However, the incorporation of biochar and aluminum silicate did not decrease the risk of contamination of the deeper layers of soil. • The addition of residues in soil versus the leaching 2,4-D + picloram was evaluated. • Bioassay carried out used on soil columns, with Cucumis sativus as the bioindicator. • Biosolid reduces herbicide leaching in the soil profile and environmental risk. • Biochar increases herbicide leaching and availability in deeper soil layers. • Aluminum silicate behaves as inert for the herbicide movement and availability.

Thunderstorms and extreme rainfall in south Norfolk, 16 August 2020: meteorological analysis

A multicell thunderstorm cluster affected parts of the Breckland region in south Norfolk on the afternoon of 16 August 2020, producing as much as 240mm of rain. A detailed mesoanalysis is constructed to analyse the meteorological conditions present using conventional observations, reanalysis and privately owned automatic weather station observations. While the instantaneous rain rates observed are not unprecedented, when maintained over several hours result in this event ranking as the highest August daily rainfall on record in the United Kingdom.

Warm and Wet Autumns Favour Yield Losses of Oilseed Rape Caused by Phoma Stem Canker

Winter oilseed rape (Brassica napus L.) is the main source of domestic oil in central and northern Europe, bringing profits to farmers, but the plants are often damaged by stem canker, caused by two fungal species belonging to the genus Leptosphaeria. Due to environmental concerns, the benefits of fungicide applications must outweigh disadvantages. The aim of this work was to determine the effect of stem canker on seed yield and its quality and find out the best timing of fungicide application. The multi-year field experiments were done at two sites in south-west Poland, where the disease is regarded as a serious problem. The fungicide treatments with the azole-containing preparation followed the same scheme each year; a single application was made at one-week intervals, starting in late September through mid-November for a total of eight treatments. Seed yield, oil and protein content, mass of thousand seeds as well as indole-and alkenyl-glucosinolate contents in seeds were statistically unrelated with the incidence and severity of phoma leaf spotting and stem canker symptoms. The significant decrease of the seed yield was observed in three (site × year combinations) of eight, in which phoma leaf spotting and stem canker were severe. Yield loss was noted only in years with warm and wet autumns, when cumulative mean temperatures between BBCH14 and BBCH19 plant growth stages exceeded 60 °C and precipitation in this period exceeded 110 mm of rain. Under these conditions, fungicide treatments were highly effective when they were done between BBCH15–BBC16 growth stages (5–6 true leaves).

Coexistence without conflict, the recovery of Ireland\u2019s endangered wild grey partridge Perdix perdix

By 1995, Ireland’s wild grey partridge (Perdix perdix) was extinct nationally as a breeding species on farmland. The two populations remaining were confined to Ireland’s industrial cutaway peat bogs. One of these populations was deemed viable. In 1996, the National Parks and Wildlife Service of Ireland and the Irish Grey Partridge Conservation Trust established a conservation project to prevent the extirpation of this population. In this paper, we explore the impact of each management factor on two key demographic response variables: chick survival rates and the number of breeding pairs. The numbers of linear metres of nesting strips had the most significantly positive effect on spring pairs, followed by the total number of supplementary food hoppers and the total hectares of brood-rearing and over-winter cover. Counterintuitively, encounters with Hen Harriers (Circus cyaneus) did not negatively affect chick survival or the number of spring pairs. While we cannot rule out the contribution of each explanatory variable, none had a statistically significant effect on chick survival, suggesting there may be locally confounding factors that our model could not capture. The weather conditions during the peak hatching period had a significant influence on chick survival, with the average maximum temperature observed in June having the strongest positive association with an increase of 1 °C in the average maximum temperature in June associated with an increase in chick survival of 9.4% on average. Conversely, for every additional 1 mm of rain in June, there was a 0.23% drop in chick survival on average.

The 2019/2020 floods in the UK: a hydrological appraisal

The 2019/2020 floods in the <scp>UK</scp>: a hydrological appraisal

Rainfall-induced attenuation correction for two operational dual-polarization C-band radars in the Netherlands

AbstractThe Royal Netherlands Meteorological Institute (KNMI) operates two operational dual-polarization C-band weather radars providing 2-D radar rainfall products. Attenuation can result in severe underestimation of rainfall amounts, particularly in convective situations that are known to have high impact on society. In order to improve the radar-based precipitation estimates, two attenuation correction methods are evaluated and compared: 1) Modified Kraemer (MK) method, i.e. Hitschfeld-Bordan where parameters of the power-law Zh–kh relation are adjusted such that reflectivities in the entire dataset do not exceed 59 dBZh and attenuation correction is limited to 10 dB; 2) using two-way path-integrated attenuation computed from the dual-polarization moment specific differential phase Kdp (Kdp method). In both cases the open-source Python library wradlib is employed for the actual attenuation correction. A radar voxel only contributes to the computed path-integrated attenuation if its height is below the forecasted freezing level height from the numerical weather prediction model HARMONIE-AROME. The methods are effective in improving hourly and daily quantitative precipitation estimation (QPE), where the Kdp method performs best. The verification against rain gauge data shows that the underestimation diminishes from 55% to 37% for hourly rainfall for the Kdp method when the gauge indicates more than 10 mm of rain in that hour. The improvement for the MK method is less pronounced, with a resulting underestimation of 40%. The stability of the MK method holds a promise for application to data archives from single-polarization radars.

Debris flow magnitude, frequency, and precipitation threshold in the eastern North Cascades, Washington, USA

We examine the magnitude, frequency, and precipitation threshold of the extreme flood hazard on 37 low-order streams in the lower Stehekin River Valley on the arid eastern slope of the North Cascades. Key morphometric variables identify the magnitude of the hazard by differentiating debris flood from debris flow systems. Thirty-two debris flow systems are fed by basins 10°. Five debris flood systems have larger drainage areas and debris fans with slopes 7–10°. The debris flood systems have Melton ruggedness ratios from 0.42–0.64 compared to 0.78–3.80 for debris flow basins. We record stratigraphy at seven sites where soil surfaces buried by successive debris flows limit the age of events spanning 6000 years. Eighteen radiocarbon ages from the soils are the basis for estimates of a 200 to1500-year range in recurrence interval for larger debris flows and a 450 ± 50-year average. Smaller events occur approximately every 100 years. Fifteen debris flows occurred in nine drainage systems in the last 15 years, including multiple flows on three streams. Summer storms in 2010 and 2013 with peak rainfall intensities of 7–9 mm/h sustained for 8–11 h triggered all but one flow; the fall 2015 event on Canyon Creek occurred after 170 mm of rain in 78 h. A direct link between fires and debris flows is unclear because several recent debris flows occurred in basins that did not burn or burned at low intensity, and basins that burned at high intensity did not carry debris flows. All but one of the recent flows and fires occurred on the valley’s southwest-facing wall. We conclude that fires and debris flows are linked by aspect at the landscape scale, where the sunny valley wall has flashy runoff due to sparse vegetation from frequent fires.

Geomorphic effects caused by heavy rainfall in the Corigliano-Rossano area (NE Calabria, Italy) on 12 August 2015

ABSTRACT The surroundings of Corigliano and Rossano (NE Calabria) were damaged by a short-lasting and localized rainstorm on 12 August 2015, when more than 230 mm of rain in sixteen hours caused damage exceeding 100 million euros. In the Map, shallow landslides triggered by the event are shown at 1:50,000 scale, together with areas affected by soil erosion and flooding, and most damaged sites; historical landslides are also mapped. The main slope-stability controlling factors are mapped at 1:200,000 scale, and an event-based geomorphological landslide inventory of the most damaged sector (Citrea basin) is provided at 1:10,000 scale. Isohyets (cumulative over 16 h), as obtained by interpolating rain-gauge and weather-radar data by Kriging techniques, are shown together with the density of event landslides. Estimated rain maxima (ca. 506 mm in 16 h) by far overcome measured ones, and ground effects well fit the sectors heavily stricken by the storm.

Rainfall-Runoff Simulation and Modelling Using HEC-HMS and HEC-RAS Models: Case Study Tabuk, Saudi Arabia

Flooding regimes in arid regions are heavily influenced by climate change, water shortage, water regulations, and increased water demands. The low amount of annual precipitation due to the desert climate may lead to false estimations of flooding hazards. This study analyzed flash floods caused by short-intense rainstorms. The objective of this study was to determine flood risk related to identified precipitation depths. The project quantized the runoff corresponding to different design storms and used hydraulics and geospatial data to determine flood elevations. The study constructed hydrologic and hydraulic models to quantify flood hazards in the adjacent area of Wadi Abu Nashayfah. Peak discharges for the wadi were computed by using observed rainfall data, and the output of this process was applied to compute water surface elevations within the flow channel. At upstream, there is a high potential of flooding when Wadi Abu Nashayfah receives a minimum of 25 mm of rain which generates 40.60 m3/s of peak discharge, thus, at this point the stream will overtop its banks and risking the adjacent area. In the second case, flow will overtop its banks when the channel receives at least 35 mm of rain and peak discharge level to 67.20 m3/s. While flow will reach bank full point if wadi Abu Nashayfah receives 10.00 mm of rain and generates 14.80 m3/s of streams downstream. The depth of precipitation at which the channel was overtopped was determined in several locations. The predicted overtopping was compared to historic events with good agreement.

The spring bread wheat ‘Ekstra’

The current study was carried out in order to create an early-ripening variety of spring bread wheat with productivity at the level of middle-early or higher, the most adapted to the specific conditions of the Middle Urals. The estimation of the breeding material was carried out in the fields, the soils of which are typical for the Sverdlovsk region and Permsky Krai. During the years of the study, the agroclimatic conditions differed along the growing season. There have been established the dry year of 2016 (90 mm of rain, GTC 0.6) and the moisture years of 2014, 2015, 2017–2019 (with precipitation amount of 247–448 mm, GTC 2.0–3.2). The crossings were carried out between the middle-ripening variety ‘Omskaya 35’ (mother) and the early- ripening variety ‘Iren’ (father). There has been developed the variety that combined high productivity and early maturity. The average productivity of the new variety ‘Ekstra’ in the Competitive Variety Testing in 2014–2019 was 4.07 t/ha, which is on 0.55 t/ha higher than the standard variety ‘Iren’, the maximum productivity was 5.0–6.1 t/ha (2019). The new variety has exceeded the values of the standard variety in such yield structure elements as “seed weight per head”, “1000 grain weight”, “grain content per head”; the accumulation of seeds per day of growing season was 14.2% and at 1 mm of precipitation the value improved till 15.2%. In the ecological testing the variety ‘Ekstra’ exceeded the varieties ‘Iren’, ‘Irgina’ from the State List of Breeding Achievements in the Volga-Vyatka region on 0.56–0.80 t/ha and the middle-early ripening varieties ‘Gornouralskaya’, ‘Bazhenka’, ‘Svecha’, ‘Zlata’ on 0.44–0, 55 t/ha. The variety ‘Ekstra’ is characterized by better energy efficiency parameters than ‘Irgina’, ‘Iren’, ‘Gornouralskaya’, ‘Zlata’. The excess was 9.2–21.9% in terms of total energy in the harvest per hectare, 16.0–40.6% in net energy income, and 4.7–13.1% in bioenergy ratio. The variety reduced energy consumption for the production of 1 ton of grain by 9.5–11.5%. There has been determined a significant advantage of the variety ‘Ekstra’ in terms of the general adaptability, stability, and breeding value of the genotype. In 2020 the variety was included into the State List of Breeding Achievements in the Volga-Vyatka region, Ural, West Siberian regions of the Russian Federation. The variety ‘Ekstra’ has the same parameters of productivity, yield structure elements, adaptability, the accumulation of seeds per day of growing season and per 1 mm of precipitation, energy efficiency of cultivation, as the middle-early ripening standard variety ‘Ekaterina’.

Impact of heavy rainfall events and shading on the temperature of sea turtle nests

While most studies assessing the ecological impacts of climate change have examined impacts from warming temperatures, less attention has been given to other parameters such as increased rainfall events. At a nesting rookery in the northern Great Barrier Reef, Australia, we used data loggers to examine the impact of heavy rainfall and shade on the nest temperatures for green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles clutches, which have temperature-dependent sex determination. In the middle of the nesting season (December–March), on 21 January 2019, 125 mm of rain fell over two days, causing the temperature to initially decrease by an average of ~ 3.6 °C in hawksbill turtle nests (n = 18) and ~ 3.5 °C in green turtle nests (n = 9). For shaded clutches during the 20-day cooling period after the rainfall event, we report average nest temperatures of ~ 27.9 °C and ~ 28.2 °C for hawksbill and green turtle clutches respectively, falling well into the male-producing range for sex determination. This was profoundly cooler than the average nest temperatures of clutches without shade and prior to the heavy rainfall, which was ~ 31.3 °C for both species. Extreme rainfall events are predicted to increase around Australia due to climate change but may help counteract impacts of atmospheric warming on sea turtle offspring sex-ratios. Our results also show the potential for artificially cooling nests by applying a combination of shade and irrigation, to counter the expected increases in the feminisation of sea turtle hatchling production worldwide.

Late Pleistocene and Early Holocene aeolian deposits of Tasmania and their climatic implications

AbstractLate Pleistocene and Early Holocene aeolian deposits in Tasmania are extensive in the present subhumid climate zone but also occur in areas receiving &gt;1000 mm of rain annually. Thermoluminescence, optically stimulated luminescence, and radiocarbon ages indicate that most of the deposits formed during periods of cold climate. Some dunes are remnants of longitudinal desert dunes sourced from now-inundated continental shelves which were previously semi-arid. Others formed near source, often in the form of lunettes east of seasonally-dry lagoons in the previously semi-arid Midlands and southeast of Tasmania, or as accumulations close to floodplains of major rivers, or as sandsheets in exposed areas. Burning of vegetation by the Aboriginal population after 40 ka is likely to have influenced sediment supply. A key site for determining climate variability in southern Tasmania is Maynes Junction which records three periods of aeolian deposition (at ca. 90, 32 and 20 ka), interspersed with periods of hillslope instability. Whether wind speeds were higher than at present during the last glacial period is uncertain, but shells in the Mary Ann Bay sandsheet near Hobart and particle size analysis of the Ainslie dunes in northeast Tasmania suggest stronger winds during the last glacial period than at present.

EFFICIENCY OF THE USE OF THE PREPARATION ROSTMOMENT ON SUNFLOWER CROPS IN THE CONDITIONS OF THE FOREST-STEPPE OF THE RIGHT-BANK

The results of the use of a yeast preparation on sunflower crops for 2016-2017 have been presented. A positive effect of the researched preparation on the growth and development of sunflower crops of the Neoma hybrid has been established. The preparation Rostmoment increased the height of sunflower plants with a single treatment by 6 cm, and with a two-time treatment of crops by 11 cm, the diameter of the baskets increased by 2.0 cm and 6.3 cm, respectively, against untreated crops. The mass of thousand achenes has been increased by 0.7 g with a single treatment and 2.2 g with a double treatment. The oil content during one-time processing in the basket formation phase was 50.7%, when used twice in the phase of flowering, 51.9%, while in the control its content was 49.2%. Weather conditions in the years of the study significantly affected the productivity of the sunflower of Neom hybrid, especially in terms of moisture supply, and the best conditions for the study of the crop were in 2016, where 209 mm fell during the growing season. precipitation with a uniform distribution. The temperature regime of air on average over the period of sunflower vegetation was 16.5 ºС. The weather conditions of 2017 significantly differed in the amount of precipitation, their distribution and temperature regime, versus 2016. Thus, in 2017, 374 mm of rain fell in the form of prolonged and heavy rainfall, which were unevenly distributed over the decades and months. Such weather conditions caused alternation of excessive moisture and drought during certain periods of growth and development of sunflower plants of the Neoma hybrid, while the average air temperature was 16.2° C. Under such extreme conditions of vegetation periods in the years of research, on average for two years, the yield of sunflower seeds on an untreated experiment was 3.32 t / ha and oil yield 1.64 t / ha. The 2016 yield was slightly higher, 3.43 t / ha and an oil yield of 1.43 t / ha. The use of Rostmoment during a one-time treatment in the basket formation phase led to an increase in yield over two years, which amounted to 3.63 t / ha, and in 2016 - 3.82 t / ha. The use of the studied drug even in the phase of the beginning of flowering contributed to an increase in the yield of seeds in two years to 3.89 t / ha, and in a more favourable 2016 - 4.02 t / ha. The average oil yield per hectare over two years for a one-time treatment of plants was 1.87 t / ha, and for a two-time treatment it was 2.02 t / ha, whereas in 2016 these figures were respectively 1.96 and 2.11 t / ha. The research having been conducted for two years indicated the positive effect of the yeast preparation Rostmoment on sunflower crops, which positively influenced the growth and development of the crops and increased the productivity of the Neoma hybrid in the conditions of the Right-Bank Forest-Steppe. The obtained results are of practical value and can be used by producers in the development and application of technologies for the cultivation of sunflower for increasing the productivity of crops and the ecological state of the agroecosystem. The preparation Rostmoment must be introduced into vegetation plants in the basket formation phase and in the phase of the beginning of the sunflowers’ blossoming, normally 4 kg per 300 l of water per 1 ha of sowing. Key words: sunflower, hybrid, Rostmoment, plant height, basket diameter, oil content, yield, weight of 1000 seeds, oil yield.

Interceptação em uma floresta ripária secundária urbana em Santarém- PA, Amazônia, Brasil

The interception of rain by riparian forest trees plays an important role in the urban Amazon ecosystem. It affects all hydrological processes, as well as the spatial and temporal redistribution of moisture. The aim of this study was to evaluate rainfall interception in an area of urban riparian forest at the source of the Irurá stream, Santarém-PA. The monitoring of precipitation in the open area and precipitation in the internal area occurred with the use of Ville de Paris type rain gauges and gutters. Runoff through the trunk was monitored within a 10 m x 10 m plot. During the study period, 2,659.6 mm of rain was accounted for rainfall above the canopy, 89.3% reached the forest floor as internal precipitation and only 0.5% as runoff through the tree trunk. The trees of the urban secondary riparian forest from the source of the Irurá stream intercepted 272 mm, that is, 10.2% of the total precipitation, representing an important role for the hydrology of the area, both because it allows a high volume of water to return to the atmosphere, as by minimizing the increase in urban runoff. In this study it was possible to quantify and qualify the important role of the components for the recharge of groundwater from the urban spring.

Modeling the physiological responses of a desert shrub to rainfall pulses in an arid environment in northwestern China

A physically-based model for soil-plant-atmosphere continuum (SPAC) is parameterized and evaluated against field-measured physiological responses of a desert shrub, Haloxylon Ammodendron (HA), to rainfall pulses in a desert environment in northwestern China. Despite its simplicity, the model was successfully employed to assess the complexity and uncertainty involved in the physiological responses of HA following pulsed rainfall events. Through modelling efforts, we report a systematic evaluation of the non-linear relationship between the physiological responses of HA and pulse magnitude or antecedent moisture. The results show that following the rainfall pulses, the modeled daily transpiration and assimilation rates either stayed the same or decreased monotonically with water stress. However, the stomatal conductance (gs) and photosynthetic rate (An) responses were relatively weaker when compared to the increase in water potential. We found that rainfall events with <5 mm cannot induce any substantial response of An (Δ < 4 μmol m−2s−1), and at least 13 mm of rain is required to increase An by 10 μmol m−2s−1. Significant responses of water use efficiency (WUE) were not even discernible from viewing the simulation. Our analysis reproduced the judgements with a certain uncertainty that HA is basically a kind of drought resistant species, it tends to have a more conservative water-use strategy and thus a safer photosynthetic behavior. The inverse–texture hypothesis is much more clearly supported by the modeling experiments, suggesting that soil texture drives differences in the effects of pulses on the magnitude and sensitivity of the physiological responses of plants, and the interaction between rainfall and soil texture may lead to the preferred acquisition and use of pulsed precipitation by HA. The modelling work and findings in this study is likely to shed light on the quantitative understanding of the physiological behavior of other plants in water-limited environments.

The Role of Snowmelt on the Spatio-Temporal Variability of Spring Recharge in a Dolomitic Mountain Group, Italian Alps

Springs play a key role in the hydrology of mountain catchments and their water supply has a considerable impact on regional livelihood, biodiversity, tourism, and power generation. However, there is still limited knowledge of how rain and snow contribute to the recharge of Alpine springs. This study presents a four-year investigation of stable isotopes in precipitation and spring water at the scale of a 240 km2 wide dolomitic massif (Dolomites, Italian Alps) with the aim of determining the proportions of snowmelt and rain in spring water and to provide insights on the variability of these contributions in space and time. Four precipitation sampling devices were installed along a strong elevation gradient (from 725 to 2660 m a.s.l.) and nine major springs were monitored seasonally. The monitoring period comprised three extreme weather conditions, i.e., an exceptional snowpack melting period following the highest snowfall in 30 years, an intense precipitation event (386.4 mm of rain in 48 h), and one of the driest periods ever observed in the region. Isotope-based mixing analysis revealed that rain and snowmelt contributions to spring water were noticeably variable, with two main recharge time windows: a late spring–summer snowmelt recharge period with an average snowmelt fraction in spring water up to 94 ± 9%, and a late autumn–early winter period with a rain fraction in spring water up to 68 ± 17%. Overall, during the monitoring period, snowmelt produced high-flow conditions and sustained baseflow more than rain. We argue that the seasonal variability of the snowmelt and rain fractions during the monitoring period reflects the relatively rapid and climate-dependent storage processes occurring in the aquifer. Our results also showed that snowmelt fractions in spring water vary in space around the mountain group as a function of the elevation of their recharge areas. High-altitude recharge areas, above 2500 m a.s.l., are characterized by a predominance of the snowmelt fraction (72% ± 29%) over the rain contribution. Recharge altitudes of approximately 2400 m a.s.l. also show a snow predominance (65 ± 31%), while springs recharged below 2000 m a.s.l. are recharged mostly from rain (snowmelt fraction of 46 ± 26%). Results from this study may be used to develop more accurate water management strategies in mountain catchments and to cope with future climate-change predictions that indicate a decline in the snow volume and duration in Alpine regions.

Case study for estimating the potential evaporation in tunnel farming in Central Japan

In this research, a method was proposed to estimate the potential evaporation in polytunnel fields. In order to calculate the potential evaporation by the Penman method, as part of an irrigation plan, the climatic conditions inside the tunnels needed to be accurately estimated by adjusting the climatic conditions outside the tunnels. Measurements taken in two polytunnels of watermelon plants from April to June of 2005 and 2006, respectively, revealed that the climatic conditions inside the tunnels differed from those in open fields outside the tunnels. The air temperature inside the tunnels was 2.0 to 4.5 °C higher than that in the open fields, the air saturation deficiency was equivalent to that in the open fields, and there was more or less no wind. The net radiation inside the tunnels was estimated by an equation that uses the transmission factor and shielding factor values. In this study, the crop coefficient of watermelon was assumed to be the ratio of the water consumption to the potential evaporation value estimated by the Penman method, which was almost identical to the design standard value used in irrigation planning in Japan. Furthermore, this study showed that rainfall outside the approximately 1.5-m-wide tunnels did not affect the soil moisture within the tunnels, because the soil moisture inside the tunnels did not increase in response to the 100 mm of rain that fell over two days. Thus, the potential evaporation inside a polytunnel can be estimated with the Penman method and then adjusted with respect to the climatic factor values from neighboring open fields. In irrigation planning, such tunnels should be reclassified as greenhouses, rather than open field sites, due to their lack of access to rainfall.