Wet Zone Research Articles

Constraints in Farmers’ Purchase Decisions of Agricultural Inputs in High Hills Temperate Wet Zone of Himachal Pradesh

"The study was conducted in the high hill temperate wet zone of Himachal Pradesh to investigate the information sources used and the constraints in farmers’ purchase of agricultural inputs. Multi-stage random sampling technique was used to select a sample size of 448 households in the study area. Multiple response analyses and Kendall’s coefficient of concordance were used for the study. The findings of the study revealed that timely non-availability of inputs in government stores, followed by the limited supply of inputs in government stores, high input prices, non-availability of the preferred package of inputs in markets, and fear of adulteration were the significant constraints experienced by the farmers in purchase of agricultural inputs. However, fellow/progressive farmers and private input dealers were the most commonly used source of information for purchased agricultural inputs. The results suggested that an increase in government funding for the development of input delivery systems can positively impact public awareness campaigns aimed at promoting better agricultural input u"

Structuring And Fostering Traditional Markets, Shopping Centers, And Modern Stores At The Community Income Level

The market is a medium for bartering between the needs of sellers and buyers where sellers expect profits while buyers expect efficiency at very affordable prices. The purpose of this study is to explore the changes in the arrangement and guidance as well as the impact on the income level of the community after the fire. This research used a qualitative method with a case study approach. Three data collection techniques were used including observation, interview, and documentation. The research findings show that the authorized parties in implementing the policy are only the Cirebon Regency Trade and Industry Office. In terms of structuring, it is divided based on 3 elements, namely dry, semi, and wet zones. Based on Public Policy, structuring, and coaching have been implemented in accordance with government policy and in accordance with existing data. Policy Stakeholders have been well implemented, but not optimal because the traders are still not orderly and consumer interest is more to the marketplace making it easier for them to shop and more efficient in terms of time and expenses. Policy Environment has been well implemented, because it makes it easier for traders and consumers when selling and shopping. The conclusion of the impact on the income of business actors decreased due to a lot of competitiveness.

RS-AAT for enhancing saturation and chloride resistance in unsaturated concrete: Experimental and numerical assessment

In this paper, the effect of RS-AAT (Reverse-seepage and Saturation based Active Anti-corrosion Technology) on chloride ion erosion and saturation of unsaturated concrete is studied. The design of partially opening of permeable pipes is proposed for partial purpose. The infiltration of chloride ions in cylindrical concrete by RS-AAT is experimentally and numerically analyzed. Based on the water vapor adsorption and adsorption isotherm test and chloride ion erosion test, a convection-diffusion model of chloride ions with varying saturation is established by using simultaneous V-G model and Richards' equation. It can be used for characterizing the effect of pore opening on saturation change and chloride ion erosion. The results show that the use of RS-AAT can accelerate the growth of concrete saturation in the alternating wet and dry zones, and keep the area in a saturated state, under the effect of reverse seepage and saturation, the durability of the structure is increased. Moreover, the opening size and spacing of the permeable pipe are especially investigated. The results recommend 8 mm opening diameter and 2 mm opening spacing, by which the opening spacing is reduced as much as possible, and the ability to resist chloride ion erosion for a long time can be improved s under the combined action of reverse seepage and saturation. The significance of these results is immense for the continued utilization of the novel anti-chloride attack technology in engineering applications.

Vulnerability of firn to hydrofracture: poromechanics modeling

Abstract On the Greenland Ice Sheet, hydrofracture connects the supraglacial and subglacial hydrologic systems, coupling surface runoff dynamics and ice velocity. In recent decades, the growth of low-permeability ice slabs in the wet snow zone has expanded Greenland's runoff zone, but observations suggest that surface-to-bed connections are rare, because meltwater drains through crevasses into the porous firn beneath ice slabs. However, there is little quantitative evidence confirming the absence of surface-to-bed fracture propagation. Here, we use poromechanics to investigate whether water-filled crevasses in ice slabs can propagate vertically through an underlying porous firn layer. Based on numerical simulations, we develop an analytical estimate of the water injection-induced effective stress in the firn given the water level in the crevasse, ice slab thickness, and firn properties. We find that the firn layer substantially reduces the system's vulnerability to hydrofracture because much of the hydrostatic stress is accommodated by a change in pore pressure, rather than being transmitted to the solid skeleton. This result suggests that surface-to-bed hydrofracture will not occur in ice slab regions until all pore space proximal to the initial flaw has been filled with solid ice.

A Systematic Review on Buffalo Breeds, Lactation Performance, and Buffalo Milk Production Characteristics in Sri Lanka

Purpose: The current study aimed to systematically review the publications originating from Sri Lanka on buffalo milk to identify potential dairy buffalo breeds and their lactation performances, milk composition, physicochemical properties, and products originating from buffalo milk.Research Method: Articles published over the last 6 decades were found through Scopus and Google Scholar databases using keywords. Original Research articles which are relevant and published in English were only selected. The six-step selection process in line with the Preferred Reporting Items for Systematic Reviews and Meta-analysis Approach (PRISMA) was adopted.Findings: The majority of the publications focused on product development aspects rather than buffalo milk production aspects. Pure breeds of the locals, Murrah, Surti, and Nili-Ravi, and their crossbreeds are frequently cited in the literature. The daily average milk yields of Murrah, Local, Surti, and Nili-Ravi pure breeds were 4.7±2.3, 3.1±1.3, 3.0±1.19, and 1.2 L, respectively. Daily milk yields of the crossbreeds ranged from 1.1 – 5.0 L. Average lactation lengths were largely dependent on the breed in which Murrah recorded the highest (341±100 days). The average lactation length of the local breed was exceptionally shorter (156±27 days) than that of the exotic breeds (>235 days). The calving interval of the Murrah and Local buffaloes was the same (636 d). Pure breeds of Surti and Nili-Ravi recorded calving intervals of 489 and 411 d, respectively. Whereas, it ranged from 417-477 d among crossbreeds. Studies focused on milk compositions and physicochemical properties were extremely rare. Curd and cheese were the most focused products originating from buffalo milk.Value: This study summarises the buffalo milk production aspects in Sri Lanka and identifies research gaps in the area. Current literature reflects a satisfactory level of information relevant to the buffaloes reared in the Dry-Zone. This study recommends more research in milk composition analysis and lactation performance of the breeds and buffalo production in the Low-Country Wet Zone and Up-Country regions.

Seasonal forecasting of Bactrocera dorsalis Hendel, 1912 (Diptera: Tephritidae) in bioclimatic zones of Sri Lanka using the SARIMA model

Bactrocera dorsalis Hendel is a severe fruit pest that causes significant economic losses globally. Despite B. dorsalis having been distributed mostly across Asia, studies on its current and future density variation in Sri Lanka are sparse to date. The present study was thus carried out to assess the contemporary density variation (2020–2022) and future density fluctuation (2023–2025) of B. dorsalis in bioclimatic zones of Sri Lanka. The density was assessed using the monthly-based fruit fly trap collection method from randomly selected 40 locations in all bioclimatic zones (wet, intermediate, dry, and arid). The SARIMA modelling technique was applied for delineating the best-fit model and for density forecasting in each bioclimatic zone. The density variations were depicted for the year and for the bioclimatic zone (2020–2025) by colour intensity maps using QGIS. According to the findings, B. dorsalis shows a seasonal component to its year-round density variation and an ascending trend in its density from 2020 to 2025. Density forecasting records a 20%, 30%, 26%, and 37% density increase in the wet, intermediate, dry, and arid zones, respectively, in 2025. In 2025, the highest predicted B. dorsalis density from the arid zone and the lowest predicted density from the wet zone were recorded. This study contains the first forecasting attempt for B. dorsalis density using the SARIMA approach as well as the application of colour-intensity depiction for its density variation in Sri Lanka, which leads decision makers and stakeholders in economic agriculture to plan the scientific management of B. dorsalis to avoid its current and potential future threat to the country’s fruit industry.

Consideration of Vadose Zone Moisture Dynamics in Remediation of PFAS‐Impacted Soils

AbstractOilfield brines are soluble, non‐volatile, and recalcitrant contaminants that are vulnerable to capillary effects and evapoconcentration and have been known to recontaminate clean fill soils emplaced after excavations. This problem may also occur for some poly‐ and perfluoroalkyl substances (PFAS) at PFAS sites. In this paper, we consider the soil moisture characteristic curve, wetting front dynamics, and the moisture redistribution cycle to understand the potential behavior of different PFAS in the vadose zone. Drawing on experience with remediation of soils impacted by brine spills, we provide recommendations on the design and implementation of soil excavation and cover remedies such as capillary barriers to prevent recontamination.

Long-term evaluation of pasture production, seasonality, and variability: An application of the DairyMod pasture model for three tropical species

Adoption of improved pastures coupled with intensified management provide quality pastures in adequate quantities and thus improve livestock productivity. While pasture modelling is imperative for exploring the performance of newer pastures, models are little used for long-term simulations of multiple tropical pastures (genotype), under varying soil, climate (environment) and pasture production systems (management). We applied the DairyMod, a biophysical model to simulate the long-term pasture production of Brachiaria ruziziensis x B. decumbens x B. brizantha ‘Brachiaria Mulato II’ (BM), Megathyrsus maximus ‘Gatton Panic’ (GP), and Chloris gayana ‘Rhodes grass cv. Reclaimer’ (RR) across major dairying regions of Sri Lanka under different management scenarios and characterize the long-term pasture growth, seasonality and spatial variability, and possible implications for dairying in Sri Lanka. Simulations of three pasture species were carried out for 16 locations (8 dry (DZ), 5 intermediate (IZ), and 3 wet zone (WZ)) over 30 years (1980–2010). Three pasture management scenarios simulated were; 1) potential pasture production system under non-limiting N and irrigation (Yp) 2) rainfed pasture production system under non-limiting N fertilizer (Yw), and 3) rainfed pasture production system under current nitrogen (N) fertilizer rate (Ya). Statistical techniques were used to identify the long-term growth rates, variability, and trends in pasture production. The long-term pasture production varied greatly among climate, species, and management scenarios. Overall, the Ya showed a seasonal cycle following the rainfall pattern, with a reduction in growth rates in dry seasons (May–September). Pasture growth rates were greater in GP at Ya, and BM at Yw and Yp while RR showed the lowest growth rate at all times. Variability of pasture growth was high in DZ (May–September) and RR has the lowest growth variability. The Yw increased the growth rate (doubled) while the Yp substantially increased (nearly tripled) the growth rate and growth pattern producing less variable pastures. Simulated growth rates suggest that GP in low-input and BM in high-input farming areas would be more suitable. Our study suggested that the BM, GP, and RR are edaphic-climatologically fit for major dairying regions in Sri Lanka and the appropriate fertilizer and irrigation management can greatly increase the herbage accumulation and availability of year-round pastures. While this study offers valuable insights, the species-specific growth pattern, growth variability, yield potential under different managements and the possible implications for herbage quality need to be sensibly considered when selecting the appropriate species.

The dominant pests (Coleoptera) of cereal crops, and population forecast for this

Goal. Create a forecast of the development of harmful organisms in cereal crops, to determine the economic feasibility of applying plant protection measures.
 Methods. Analysis of the phytosanitary state of cereal crops in Ukraine, where the main attention is paid to the dominant pest species. Analysis of the areas of distribution of these pests, population dynamics, their phenology and the state of populations in the context of natural and climatic zones (Steppe, Forest-steppe and Polissya). To assess the phytosanitary state of crops, and its dynamic changes, the following are used: — the results of phytosanitary monitoring of crops (according to generally accepted methods), which were carried out directly by the staff of the forecast laboratory of the Institute of Plant Protection of NAAS; — current reports of researchers from other laboratories of the Institute of Plant Protection of NAAS from the places of business trips; — materials of decadal reports of regional plant protection stations, as well as signaling and forecasting points; — information on the phytosanitary situation from regional state research stations and institutes of NAAS.
 Results. A study of the phytosanitary state of cereal crops on the territory of Ukraine was carried out, the dominant species of pests were identified, materials were prepared regarding the peculiarities of the phytosanitary state in the conditions of the year, and a long-term (annual) forecast of the development of pests for the next year was drawn up, based on the appropriate analysis of the data obtained.
 Conclusions. In recent years, climate change in Ukraine has manifested itself through an increase in the average annual temperature, and an increase in the sum of effective temperatures. A decrease in the zone of sufficient soil moisture was noted, its line shifted to the north. Under the influence of abiotic factors, pests constantly change the boundaries of their habitat and zones of damage, therefore reliable protection of crops is impossible without constant monitoring, constant clarification of the species composition of phytophages, and phytosanitary forecast. Improved methodological approaches for assessing the phytosanitary state of acrocyanoses and the promptness of obtaining relevant data will allow agricultural producers to make timely decisions on the economic feasibility of using certain plant protection products.

Niche partitioning association of fungal genera correlated with lower Fusarium and fumonisin-B1 levels in maize

Through partitioning of ecological niches, several fungi are able to coexist on the same host crop. In (partial) absence of niche partitioning, competitive exclusion among fungi can occur. Competitive exclusion is one of the bases for biocontrol. We investigated fungal correlations, in terms of relative abundance of the fungi, in pre-harvest maize, as a natural ecosystem model. Internal mycobiome fungal relative abundance of maize was used to establish correlations. The maize had been harvested from dry and wet agro-ecological zones of Zambia. The relative abundances of the fungal genera were determined using DNA amplicon sequencing. For this study, positive or absence of correlations between fungal genera signified good niche partitioning (co-existence), whereas negative correlations signified poor niche partitioning and potential for competitive exclusion. When species compete within one niche (competitive exclusion), we may expect to detect higher levels of mycotoxins—since mycotoxins are considered antagonistic agents aimed at defending or invading an ecological niche. To estimate the importance of mycotoxins in competitive exclusion, we measured the influence of the fungal correlations on levels of fumonisin-B1 (FB1) in the maize. FB1 data were derived from a previous study on the maize, determined by HPLC. Results showed that Sarocladium and Stenocarpella had the strongest significant negative correlation with Fusarium, suggesting poor niche partitioning and potential for antagonism of these genera with Fusarium. Furthermore, higher levels of Stenocarpella resonated with lower levels of FB1 and vice versa. It was also observed that, when Sarocladium was in low abundance (< 10%), the frequency of detection of higher levels of FB1 (> 100 µg kg−1) in the pre-harvest maize was highest.

Cultivar-Specific Growth and Yield of Mukunuwenna (&lt;em&gt;Alternanthera sessilis&lt;/em&gt;) in the Low Country Wet Zone, Sri Lanka

Joyweed/Mukunuwenna (Alternanthera sessile) is a globally significant leafy vegetable, yet its maximum yield potential remains largely unrealized due to the limited genetic diversity of existing varieties. Farmers frequently lack precise knowledge about the yield potential, growth characteristics, and quality of the produce. Few attempts of research attentions were given to assess its growth characteristics, susceptibility to diseases and pests, consumer acceptability, and yield potential. Therefore, this study aims to comprehensively evaluate growth and yield traits, sensory qualities and morphological features of eight carefully selected Mukunuwenna cultivars. Thus, identifying the most suitable Mukunuwenna cultivars for the Low Country Wet Zone, Sri Lanka. In this investigation, we assessed four Mukunuwenna selections, including one wild (red) variety, alongside three local Mukunuwenna cultivars, focusing on their growth, yield and morphological characteristics under upland field conditions at the Agriculture Research Station, Thelijjawila, Sri Lanka. The study followed a randomized complete block design (RCBD) with three replicates. Data were meticulously collected for eight growth parameters and two yield parameters including average internodal distance, average leaf length, average leaf width, average number of shoots per unit area, average number of leaves per stem, average number of flowers per stem, average shoot height, average chlorophyll content, average leaf to stem ratio, and average yield per plot. The results, analyzed through ANOVA and mean separation demonstrated significant differences (P&lt; 0.05) among Mukunuwenna cultivars across various attributes, To assess the diversity in growth and yield, a principle component analysis was conducted. A sensory evaluation was performed to assess the consumer preference. Notably, the Piliyandala selection exhibited the most promising growth and yield traits, particularly excelling leaf to stem ratio and gaining the highest consumer preference. Other notable performers were the Colombo selection, Weda Mukunuwenna and Cultivar M7 showing preferable growth and yield traits with strong consumer appeal. Considering these findings, we conclude that Piliyandala selection, Colombo selection, and Cultivar M7 exhibit preferable growth and yield traits for commercial cultivation, while Weda Mukunuwenna stands out as an ideal choice for home garden cultivation under upland conditions in the Low Country Wet Zone, following recommended agronomic practices. This study’s outcomes hold significant promise for further research endeavors, focusing on enhancing desirable growth and yield traits.

Impact of Organic and Chemical Fertilizer Combinations on Growth, Yield, and Soil Carbon in in Oil Palm Cultivation at Talgaswella Estate, Sri Lanka

The success of oil palm cultivation hinges on factors such as planting material quality, management practices, and the availability of essential macro and micro-nutrients. Insufficient nutrient supply adversely impacts both vegetative growth and the ultimate yield in terms of quantity and quality. To address this issue, an experiment was conducted at Talgaswella Estate, belonging to Elpitiya Plantations PLC., situated in the Low Country Wet Zone (LCWZ) of Sri Lanka. The objective was to enhance the productivity and profitability of marginal oil palm lands. A ten-year-old oil palm field was chosen as the experimental site, employing a Randomized Complete Block Design (RCBD) with eleven treatments and three replicates, including an absolute control. Each trial plot consisted of six palm trees, totaling 198 trees in the experiment. Treatments involved varying combinations of Empty Fruit Bunches (EFB), Palm Oil Mill Effluent (POME), and Poultry Litter (PL), with and without chemical fertilizer. Soil, plant, and yield parameters were measured, and the data were analyzed using the Minitab statistical tool. After three years, results indicated that 100% organic fertilizer-received plots (T11) and 100% chemical fertilizer-treated plots (T2) exhibited significant increases in average fresh fruit bunch weight (22.81 Kg and 21.82 Kg), soil organic carbon percentage (3.00 and 2.23), and leaf chlorophyll content (78.79 and 75.07) of the 17th frond compared to T11 and T2 treated plots. Intermediate results were observed in the remaining fertilizer combined plots (T3, T4, T5, T6, T7, T8, T9, T10). The findings suggest that the use of organic fertilizer in marginal oil palm lands not only improves crop and soil factors but also contributes to environmental sustainability through the recycling of oil palm waste products. It is recommended to periodically apply organic fertilizer, especially on marginal oil palm lands, to enhance overall crop productivity and land sustainability.

Efficiency of weed control in winter pea in the Right Bank Forest Steppe of Ukraine

Purpose. To analyze the features of weed control in winter pea in the Right Bank Forest Steppe of Ukraine. Methods. The research was conducted at the Salyvonky State Enterprise of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agrarian Sciences of Ukraine (Bila Tserkva district, Kyiv region) in 2020–2023. The agronomic practices used in the experiment were conventional for the zone of insufficient moisture of the Right Bank Forest Steppe of Ukraine, with the exception of the studied elements. Results. The development of the concept of autumn weed control for winter pea from requires a fairly competent selection of herbicides, taking into account weather forecasts, the specifics of the effect of active substances on weeds and cultivated plants, etc., as conditions for sowing winter pea do not allow to effectively apply conventional weed control system with the use of soil tillage and, if necessary, the limited application of herbicides during the vegetation season. This is explained by the fact that the terms for soil preparation and sowing are quite limited, and soil herbicides at high air temperatures work unpredictably and have limited efficiency in case of moisture deficit. Herbicide Corum, developed by combination of active substances bentazone (480 g/l) and imazomox (22 g/l), had better indicators in terms of total efficiency at an increased application rate (1.5 l/ha) – 92.9% in the BBCH 12 and 91.7% in the BBCH 14. At the same time, the efficiency of an application rate of 1.25 l/ha was within 80%. The latter is probably related not only to the autumn conditions of application of the [reparation, but also to the fact that such species as Fumaria officinalis, Sinapis arvensis, Solanum nigrum and thistles sprouted later, when the main mass of weeds was already in a development stage that was less sensitive to low rates of the herbicide. Conclusions. The application of Corum herbicide in the BBCH 12 at an application rate of 1.25 l/ha contributed to the destruction of 73.8% and an application rate of 1.5 l/ha resulted in 86.7% of weeds. When the herbicide was applied in BBCH 14, the total efficiency of crop treatment at an application rate of 1.25 l/ha was higher by 2.4% and at a rate of 1.5 l/ha it was higher by 1.2% compared to application in the BBCH 12. This is due to the fact that Chenopodium album, Amaranthus retroflexus, Polygonum convolvulus, Persicaria maculosa, Solanum nigrum, Polygonum lapathifolium and thistles sprouted in the pea crops, and the herbicide was highly effective against them. On the other hand, weed plants that sprouted earlier continued to vegetate and were already less sensitive even to increased application rates of herbicide. The application of the maximum recommended application rates was, for the most part, the most effective measure to reduce the number of weeds in winter pea crops. At the same time, such rates affected crop plants, causing stress, especially in the late periods of growth and development, which further affected the formation of pea yield. Therefore, the use of herbicides in the late phases of crop development should be avoided.

Distribution status and influence of climate change on patterns of distribution of hornbills in Sri Lanka

There is ample evidence for the impacts of recent climatic changes on ecology. Climate plays a major role in the population dynamic of birds. Hornbills are confined to Asia and Africa with only two species present in Sri Lanka. In this study, we utilized field observations and filtered e-bird records to generate current and future climatic models for the two hornbill species in Sri Lanka (Ocyceros gingalensis and Anthracoceros coronatus). Critical reduction of predicted ecological niches was observed in Anthracoceros coronatus throughout the period considered (2000–2100). Special conservation interventions are required for these two species. However, predicted suitable ecological niches for the Ocyceros gingalensis show little reduction towards the wet zone of Sri Lanka. This shift in species distribution boundaries coincides with periods of global warming suggesting a possible connection. This study provides supporting evidence for the possible influence of climate change on hornbill species distribution.

Are the stream macrobenthos impacted by the wastewater from rubber factories?

We assessed how the wastewater generated from raw rubber factories affected the water quality parameters and how such changes influenced the stream macrobenthic assemblages in some streams in the wet zone of Sri Lanka. For this assessment, water quality parameters viz. DO, COD, BOD5, conductivity, TDS, T, pH, and OMC in the sediment were measured, and the macrobenthic fauna were sampled during the dry season at six sampling sites established based on judgemental sampling technique viz. rubber factory wastewater effluent canal (site A), point of wastewater discharge in the stream (site B), 50 m upstream site from site B (site C), 50 m downstream site from site B (site D), 100 m downstream site from site B (site E), and 150 m downstream site from site B (site F) following standard field sampling techniques. Secondary research data (dry season) from two other streams subjected to rubber factory wastewater effluents, namely Rakwatte Ela (2001) and Gurugoda Oya (2011), were also used for this assessment. Results revealed that the COD, BOD5, OMC, conductivity, and TDS levels were elevated, and the DO level was reduced significantly in the highly polluted A and B sites in all three streams. Parallel to them, the macrobenthic diversity decreased significantly (p&lt;0.5; ANOVA) at these two sites. However, the complete opposite was observed at the furthermost downstream site F, where the water quality parameters and the microbenthic composition became almost the same as that in the upstream control site C. It is evident that the changes made to the stream water quality and the macrobenthic assemblages by the rubber factory wastewater are never permanent and disappear within a relatively short stretch of 150 m along the streams, most probably due to the dilution of wastewater along the stream. The pollution-tolerant tubificids and chironomids were bioindicator candidates to detect such changes where they became highly abundant at the highly polluted wastewater effluent canal (i.e., Site A) and point of wastewater discharge in the stream (i.e. Site B), but their abundance gradually decreased along the downstream sites probably due to wastewater dilution by the fresh water supply from the stream.

Human biomonitoring of trace metals from different altitudinal settings of Pakistan.

Human biomonitoring of toxic trace elements is of critical importance for public health protection. The current study aims to assess the levels of selected trace metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) into paired human nail and hair samples (n = 180 each) from different altitudinal setting along the Indus River, and which were measured by using inductively coupled plasma mass spectrometry (ICP-MS). The human samples (hair and nail) were collected from four different ecological zones of Pakistan which include frozen mountain zone (FMZ), wet mountain zone (WMZ), riverine delta zone (RDZ), and low-lying southern areas (LLZ). Our results showed the following occurrence trends into studied hair samples: higher values (ppm) of Zn (281), Co (0.136), and Mn (5.65) at FMZ; Cr (1.37), Mn (7.83), and Ni (1.22) at WMZ; Co (0.15), Mn (11.89), and Ni (0.99) at RDZ; and Mn (8.99) and Ni (0.90) at LLZ. While in the case of nails, the levels (ppm) of Mn (9.91) at FMZ and Mn (9.38, 24.1, and 12.5), Cr (1.84, 3.87, and 2.33), and Ni (10.69, 8.89, and 12.6) at WMZ, RDZ and LLZ, respectively, showed higher concentration. In general, among the studied trace elements, Mn and Ni in hair/nail samples were consistently higher and exceeded the WHO threshold/published reference values in most of the studied samples (> 50-60%) throughout the Indus basin. Similarly, hair/nail Pb values were also higher in few cases (2-10%) at all studied zones and exceeded the WHO threshold/published reference values. Our area-wise comparisons of studied metals exhibited altitudinal trends for Cd, Cr, Zn, and Mn (p < 0.05), and surprisingly, the values were increasing from south to north (at higher altitudes) and indicative of geogenic sources of the studied toxic elements, except Mn, which was higher at lower floodplain areas. Estimated daily intake (EDI) values showed that food and drinking water had the highest contribution towards Zn, Cu, Mn, and Ni and accumulation at all studied zones. Whereas, dust also acts as the main exposure route for Mn, Co, Cr, and Cd followed by the food, and water.

Drought susceptibility mapping in Iraq using GRACE/GRACE-FO, GLDAS, and machine learning algorithms

Drought susceptibility mapping is crucial for mitigating water scarcity and its cascading effects. This study utilizes machine learning (ML) and Gravity Recovery and Climate Experiment (GRACE) data to identify drought-prone areas in Iraq. Terrestrial water storage anomaly (TWSA) data derived from GRACE observations was utilized, in conjunction with various meteorological and topographical factors (temperature, precipitation, wind speed, potential evapotranspiration, aridity index, normalized difference vegetation index, groundwater storage, root zone moisture, elevation, and slope) sourced from diverse global datasets, primarily those comprising the Global Land Data Assimilation System (GLDAS). These combined datasets served as input for five machine learning models to identify the drought prone area of Iraq: linear discriminant analysis, classification and regression trees, support vector machine, random forest, and k-nearest neighbor. All models exhibited exceptional performance (>0.9 accuracy, >0.8 kappa values, >0.9 areas under the receiver operating characteristic curve) highlighting the effectiveness of the combined TWSA and multi-factor approach. The analysis identified five drought susceptibility zones across Iraq, ranging from very low to very high. An area of approximately 160,650 km2, primarily concentrated in the northeastern and Mesopotamian plains of central and southern Iraq, was identified as exhibiting high to very high drought susceptibility, highlighting the necessity for targeted mitigation strategies. This study pioneers the use of GRACE-derived TWSA and GLDAS data for drought susceptibility mapping in Iraq, paving the way for data-driven water management interventions.

Effects of agro-climatic zones, soil orders, and irrigation types on the exchangeable cadmium in paddy soils

Even though the concentrations of the total cadmium (Cd) in paddy soils from different countries have been reported, the exchangeable-Cd (Ex-Cd) concentrations in these soils are unknown despite its importance in agriculture. This study was conducted with a total of 5460 soil samples collected in Sri Lanka, representing six agro-climatic zones, six soil orders, and three irrigation types. The Ex-Cd concentrations in soil samples were extracted using 0.01 ​M CaCl2 and analyzed using an inductively coupled plasma-mass spectrophotometry. The Ex-Cd concentrations were <0.31–163 ​μg ​kg−1, with mean and median concentrations being 14.1 and 8.98 ​μg ​kg−1, respectively, which was affected by both agro-climatic and soil conditions. Samples from the Wet zone, particularly the Wet zone Low country, had higher Ex-Cd (24.1 ​μg ​kg−1) than those from the Dry zone Low country (11.6 ​μg ​kg−1). Among the soil orders, Histosols (21.3 ​μg ​kg−1) and Inceptisols (19.5 ​μg ​kg−1) had the highest Cd concentration while Vertisols had the lowest (6.3 ​ ​kg−1). The irrigation types only affected Ex-Cd concentrations in Dry zone Low country, but not in other agro-climatic zones. Overall, it is important to consider agro-climatic zones, soil orders, and irrigation types when implementing agronomic strategies to mitigate the risk associated with Cd accumulation in paddy fields.

An Analysis of Stream Flow and Flood Frequency: A Case Study from Downstream of Kelani River Basin, Sri Lanka

River floods in Sri Lanka are mainly associated with extreme rainfall events. The Kelani and Kalu rivers are recorded the highest flood frequencies and the accompanying flood damages among the river basins in wet zone (UNDP, 2011). Therefore, the specific objective of the study is to estimate the temporal probability of occurrence of flood events in downstream of Kelani river basin. Secondary data were used for the study. Daily discharges data were obtained from Hanwella gauging station for the period of 1990 to 2019 from the Department of Irrigation, Sri Lanka. Trend analysis, normal distribution and flood frequency analysis have been used. The results of the study revealed that there was a bi-modal pattern of discharges that occurred in June and October. The results also indicated that ten return periods were covered the total period of 30 years, and there was a 97 per cent probability of flood occurrence almost annually and 64 per cent probability of occurring once every two years. This study, therefore, was recommended to design flood control structures for mitigating flood risk; and to determine the economic value of flood control projects and the effect of encroachments on flood plain. Keywords: floods, frequency, downstream, return period, probability

Habitat Utilization and Behavioral Patterns of the Endemic Sri Lankan Green Pit Viper (Craspedocephalus trigonocephalus) in the Wet Zone of Sri Lanka

Behavioral patterns and habitat utilization of the endemic Green Pit Viper (GPV) Craspedocephalus trigonocephalus were studied in the wet zone of Sri Lanka. The region, which is covered by the wet zone, has no significant dry periods and a moderately high mean annual rainfall of over 2,500 mm. Data collection occurred between April 2021 and March 2022 with a total of 260 hours of standardized sampling effort distributed throughout the collection period. The method used was an active search which consists of a visual search of up to six meters from the central line along each side of the quadrate. Quadrats were placed in habitats, taking each GPV sighting as the center of a quadrate. At each GPV-occupied quadrat, ambient temperature, body surface temperature, prey availability, perch position and perch light level were recorded. The day was divided into six-time periods as; early morning, morning, mid-day, evening, late evening, and night. Activity level was determined considering the number of GPV that could be visually observed. A total of 49 GPV were examined during the study. Focal animal sampling was conducted, and an ethogram was developed. A strong positive relationship was observed between ambient temperature (Ta) and body surface temperature (Ts) of GPVs (Pearson correlation r=0.936). The highest number of individuals preferred filtered sun light (57.14%). C. trigonocephalus mostly preferred distal position on the branches followed by middle and apical. There was a significant difference in the percentage of individuals with different behaviors [ANOVA, F=3.64, p&lt;0.05]. Behavioral pattern of GPV varied in the temporal scale during the day. During the morning time slot, C. trigonocephalus spent most of the time ambushing (16.12%) and basking (6.42%) respectively. During the mid-day they spent most of their time basking (10.57%), followed by resting (7.15%). The evening, late evening, night, and early morning slots were spent mostly on ambushing. The highest average time of 239 min was spent on ambushing behavior. Feeding behavior (9.8 min) had relatively short time on average. Results of this study indicate that C. trigonocephalus is well adapted for the utilization of its preferred habitat in the wet zone, and that, it displayed behavioral patterns that vary within temporal scales, which results in more efficient and effective utilization of resources. Therefore, this study provides important insights for conservation and management of C. trigonocephalus by critically evaluating the requirements of this species. &#x0D; Keywords: Craspedocephalus trigonocephalus, Behavior, Endemic pit viper, Wet zone