Mean Annual Rainfall Research Articles

Greenhouse gas emissions and environmental drivers in different natural wetland regions of China

Wetlands sequestrate carbon at the highest rate than any other ecosystems on Earth. However, the spatial and temporal dynamics of GHGs emissions from the wetland ecosystems in China are still elusive. We synthesized 166 publications that contain 462 in situ measurements of GHGs emissions from the natural wetlands in China, and further analyzed the variability and the drivers of GHGs emissions in eight subdivisions of China's wetlands. The results show that the current studies are mainly concentrated in the estuaries, Sanjiang Plain, and Zoige wetlands. The average CO2 emissions, CH4 fluxes and N2O fluxes from Chinese wetlands were 218.84 mg·m−2·h−1, 1.95 mg·m−2·h−1 and 5.8 × 10−2 mg·m−2·h−1, respectively. The global warming potential (GWP) of China's wetlands was estimated to be 1881.36 TgCO2-eq·yr−1, with CO2 emissions contributing more than 65% to the GWP value. The combined GWP values of Qinghai-Tibet Plateau wetlands, coastal wetlands and northeastern wetlands account for 84.8% of GWP of China's wetlands. Correlation analysis showed that CO2 emissions increased with the increasing mean annual temperature, elevation, annual rainfall, and wetland water level, but decreased with soil pH. CH4 fluxes increased with the mean annual temperature and soil water content but decreased with the redox potential. This study analyzed the drivers of GHGs emissions from wetland ecosystems at the national scale, and GWP values of eight wetland subregions of China were comprehensively assessed. Our results are potentially useful for the global GHGs inventory, and can help assess the response of GHGs emissions of wetland ecosystem to environmental and climate change.

Analysis of Spatio-temporal Variation of Fractional Vegetation Coverage and Influence Factors in Qinghai, China

The fractional vegetation coverage (FVC) can visually represent ecological changes in a region. Based on MDO12A1 data to calculate FVC, we investigated the spatial and temporal variations of FVC in Qinghai Province from 2001 to 2015 and performed correlation analysis with the annual mean temperature and annual rainfall. The results indicate that the spatial changes in FVC in Qinghai Province increase gradually from northwest to southeast and are discontinuous due to topographic variations. In Qinghai Province, the area of higher FVC decreased by 0.69% over the past 15 years, while the area of medium FVC increased by 5.75%, and the area of lower FVC decreased by 5.06%. Changes in FVC in Qinghai Province are influenced by changes in rainfall and temperature. The average partial correlation coefficients of FVC with rainfall and temperature are 0.031 and 0.117, respectively, indicating that rainfall has a more significant influence on vegetation growth when the temperature remains constant.

The Trends and Effects of Flood Occurrences in the Shire River Basin in Chikwawa District of Malawi: A Historical Perspective (1980 - 2019)

Purpose: The purpose of this study was to examine historical trends in flooding in Malawi’s Shire River Basin (SRB). The basin is prone to severe flooding and most affected in the country. For many years, flooding has posed a significant threat to communities in and around the basin. Therefore, the main objective of the study was to document the historical perspective of flood occurrences in terms of frequency and impact in the Shire River Basin of Chikwawa District, Malawi, from 1980 to 2019. 
 Methodology: A mixed survey design was used for the study. Both random and purposive sampling were used to identify participants. A total of 384 respondents took part in the study. The study collected both primary and secondary data. Primary sources of data were collected using household surveys, interviews with key informants, and focus group discussions, while secondary sources of data were collected using documents from both non-governmental and Malawian governmental departments and agencies (MDAs) as well as existing literature. Data from focus group discussions (FGDs), interviews with community elders (CEIs), and key informant interviews (KIIs) were recorded in Chichewa with a voice recorder, transcribed in Chichewa, and then translated into English. Household survey data were processed using Statistical Package for Social Scientists (SPSS) version 25 and secondary data were converted to time series data and then analysed using STATA software to produce charts and graphs. 
 Findings: The results showed that all three hydrometeorological extremes (mean annual temperature, average rainfall and baseflow index) increased, suggesting that both the intensity and frequency of flooding in the Shire River Basin of Chikwawa District were also increasing in absolute terms. People’s perceptions of flooding showed that the Shire River Basin in Chikwawa District experienced excessive flooding every 5 years. This 5-year cycle was, among other factors the result of climate change and forest loss in the study area, leading to an increase in river sedimentation.
 Recommendations: This article found that the local people in the Shire River Basin of Chikwawa District will always live with increasing levels of flooding. Therefore, they should be proactive in flood management and understand the process as an ongoing activity for future risk assessment. Analysing the history of river basin flooding is important as it helps the Malawi's Department of Disaster Management Affairs (DoDMA) officials to be alert and estimate the time frame for the next flood in the Shire River Basin of Chikwawa District to strengthen the flood forecasting accuracy.

Improving satellite-based global rainfall erosivity estimates through merging with gauge data

Rainfall erosivity is a key factor that influences soil erosion by water. Rain-gauge measurements are commonly used to estimate rainfall erosivity. However, long-term gauge records with sub-hourly resolutions are lacking in large parts of the world. Satellite observations provide spatially continuous estimates of rainfall, but they are subject to biases that affect estimates of rainfall erosivity. We employed a novel approach to map global rainfall erosivity based on a high-temporal-resolution (30-min), long-term (2001–2020) satellite-based precipitation product—the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM-IMERG)—and mean annual rainfall erosivity from the Global Rainfall Erosivity Database (GloREDa) stations (n = 3286). We used a residual-based merging scheme to integrate GPM-IMERG-based rainfall erosivity with GloREDa using Geographically Weighted Regression (GWR). The accuracy of the GWR-based merging scheme was evaluated with a 10-fold cross-validation against GloREDa stations. Based on GPM-IMERG-only, the global mean annual rainfall erosivity was estimated to be 1173 MJ mm ha−1 h−1 yr−1 with a standard deviation of 1736 MJ mm ha−1 h−1 yr−1. The mean value estimated via GPM-IMERG merged with GloREDa was 2020 MJ mm ha−1 h−1 yr−1 with a standard deviation of 3415 MJ mm ha−1 h−1 yr−1. Overall, GPM-IMERG-only estimates underestimated rainfall erosivity. The underestimations were greatest in areas of high rainfall erosivity. The accuracy of rainfall erosivity estimates from GPM-IMERG merged with GloREDa substantially improved (Nash-Sutcliffe efficiency = 0.83, percent bias = −2.4%, and root mean square error = 1122 MJ mm ha−1 h−1 yr−1) compared to estimates by GPM-IMERG-only (Nash-Sutcliffe efficiency = 0.51, percent bias = 27.8%, and root mean square error = 1730 MJ mm ha−1 h−1 yr−1). Improving satellite-based global rainfall erosivity estimates through integrating with gauge data is relevant as it can contribute to enhancing soil erosion modeling and, in turn, support land degradation neutrality programs.

Environmental controls on the hydrogen isotopic composition of volcanic glass from the Southern Afar rift, eastern Ethiopia

Hydrogen stable isotope values of hydrated volcanic glass as a proxy for the isotopic composition of past meteoric waters provide an opportunity for reconstructing past climates. Here we present new hydrogen stable isotope values from 63 individual tuffs from the Afar region in the lower Awash Valley of eastern Ethiopia. The hydrogen isotopic results from volcanic glass spanning the last 6.4 Ma show a wide distribution with values ranging between −89 and − 32 ‰ (VSMOW). The variability is consistent with the observed paleo-depositional setting (i.e., lower values for fluvial settings while higher values are recorded in lacustrine settings). The reconstructed hydrogen isotopic values of parent waters are considerably lower than those of modern meteoric waters, suggesting a bias toward lower values during the hydration of volcanic glass.Reconstructed hydrogen stable isotope values of water derived from volcanic glass differ from other proxies of regional climate in northeast Africa, pointing to the controls of local meteoric waters on the hydrogen isotopic composition of volcanic glass. There is agreement between the reconstructed isotopic composition of parent waters and the lowest hydrogen isotopic values of modern precipitation in the Awash catchment that correspond to periods of large rainfall. This correspondence probably indicates that volcanic glass is preferentially hydrated during the wettest seasons. To test this idea, we compared the isotopic results from volcanic glass with the reconstructed isotopic composition of surface waters from soil carbonates deposited during the Pliocene and Pleistocene in the lower Awash Valley. The comparison reveals a considerable difference between proxies, with volcanic glass recording lower isotopic values than soil carbonates. Evaporative isotopic enrichment of water in shallow (<1 m) soil profiles probably accounts for the elevated values in soil carbonates. In contrast, the presence of smectite-rich vertisols above volcanic deposits appears to retard infiltration of meteoric waters deep into the subsurface. During rainfall events, vertisols swell and prevent all but the largest rainfall events from penetrating deep (>1 m) into the profiles and promoting the hydration of volcanic glass that display systematically lower isotopic values of meteoric waters than the mean annual rainfall.

Rainfall and Temperature Variations in a Dry Tropical Environment of Nigeria

This study examines long-term rainfall and temperature variations over a dry tropical environment in Nigeria. An assessment of the variations of these weather variables showcases the extent of climate change limits and corresponding effects on the biotic environment. Rainfall and temperature data were obtained from Nigerian Meteorological Agency for a period of 31 years (1991-2020) for Kano and Katsina States. Descriptive statistics were used to determine the degree of variability of the weather variables across spatial domains. Results showed that there is a sharp contrast in mean annual rainfall amounts of 1154.1 mm and 569.6 mm for Kano and Katsina located in the dry continental and semi-arid climate zones of Nigeria respectively. It is revealed that the month of August had the highest mean monthly rainfall for both areas i.e. 359 mm and 194 mm with little or no trace during the dry season. The sharp difference in rainfall amount across spatial domains of the near similar climate zones shows that the Inter-tropical Discontinuity (ITD) does not completely overwhelm the northern band of Nigeria in August. The least variable monthly rainfall was in August and July with coefficient variations (CV) of 40% and 47% for Kano and Katsina. The months of February and March had the highest CV of 557% and 273% for the respective areas. In the examined areas the wet and dry seasons are from June-September and October-May respectively. The index of rainfall variability and drought intensity for the areas ranged from 0.85-0.95 and 45% indicating moderate variability and drought respectively. Mean annual temperature values are 33.4 °C and 33.8 °C for Kano and Katsina. The study recommends a proper climate observing scheme, most especially for agrarian practices so as to ensure profitable outputs for human sustainability.

A regional scale impact and uncertainty assessment of climate change in the Western Ghats in India.

The general circulation models (GCMs) and emission scenarios (RCP 4.5 and 8.5) have proven to be significantly functional in evaluating the impacts of climate change (CC) on hydrology, although their performance and accuracy varies on a regional scale. The objective of the present study is to evaluate the performance of five CMIP5 GCMs (CanESM2, BNU-ESM, CNRM-CM5, MPI-ESM-LR and MPI-ESM-MR) on a regional scale in the West Flowing River Basins-2 (WFRB-2) in India to model the impact of CC and its scenario uncertainty using reliability ensemble average (REA) method. For quantifying the results, the upper, middle and lower regions of WFRB-2 are separately analysed. The MPIMR and MPILR GCM model shows highest reliability factor range (0.3-0.6) in predicting the annual mean and annual maximum rainfall for most of the grids in the region. The GCM-simulated runoff using VIC (variable infiltration capacity) model is evaluated using statistical parameters such as root mean square error (RMSE), percentage bias (Pbias) and standard deviation (Std). The annual mean (maximum) runoff obtained using REA ensemble shows least RMSE, Pbias and Std values, i.e. 21.08%, 9.10mm and 8.9mm (6%, 39.1mm, 39.1mm), respectively for the middle region, which demonstrates higher reliability of GCM outputs in the flood-prone regions of WFRB-2. Furthermore, the future projection of annual maximum rainfall/runoff shows an increase of 50mm/15mm in the near future (2011-2040) for lower and 20mm/6mm for middle regions, which may cause flooding activities in the lower and middle region of WFRB-2.

Variation Characteristics of Temperature and Rainfall and Their Relationship with Geographical Factors in the Qinling Mountains

The Qinling Mountains (QMs) are considered to be the division in geology, geochemistry, and physical geography between northern China and southern China. They have crucial effects on regional climate, especially on rainfall and temperature, and have shown great scientific relevance to climate change research in China. Using the observational daily and monthly rainfall and temperature data derived from meteorological and regional automatic stations—as well as the methods of correlation analysis, climate trend analysis, and Mann–Kendal and t tests—we revealed the spatiotemporal change characteristics of temperature and rainfall and their correlation with elevation, longitude, and latitude. The results show that the annual mean temperature (AMT) underwent a significant increasing trend in the QMs. The maximum AMT increase occurred in spring, and the minimum occurred in summer. Positive anomalies of annual mean rainfall amount (AMRA) occurred in the 1960s, 1980s, and 2010s, and negative anomalies occurred in the 1970s, 1990s, and 2000s. In the QMs, the amount of moderate rainfall (MR) occupied the maximum proportion and accounted for 27.9% of the AMRA, whereas the torrential rainfall (TR) occupied the minimum proportion and accounted for 12.8%. The AMRA amount significantly decreased by 130.1 mm from the 1980s to the 1990s and accounted for 13.5% of the measure in the 1980s. The AMT and AMRA showed consistent change trends with increases in elevation and latitude and showed the opposite trend as the longitude increased. The results offer a further understanding of the meteorological background of the QMs, helping us in further investigating the potential physical mechanisms that influence the spatiotemporal distribution characteristics of temperature and rainfall in the QMs. This study will provide a scientific basis for rainfall and temperature forecasts, with relevance to local ecosystems, agriculture, soil erosion, and the prevention and mitigation of floods in the future.

Spatial Interpolations of Annual Rainfall in Ethiopia Using Simple and Universal Kriging Techniques

The study of spatial distribution of precipitation is an important aspect of water-related research like, hydrological modeling, disaster prediction and watershed management. But, spatial interpolations of annual average rainfall in Ethiopia using Simple and Universal Kriging type through different models has not yet investigated. This study was focused on to select the best fit semivarogram model for annual rainfall interpolation and to map the spatial distribution of rainfall of Ethiopia. In this study, long term mean annual rainfall which was collected from 931 meteorological stations were interpolated using different mathematical variogram models of Kriging to select the best fit variogram model useful to predict continuous surface values of annual average rainfall in Ethiopia. Spherical model was found to be the best fitted variogram model and most accurate model for interpolation using both Simple and Universal Kriging with the value of ME (0.005), RMSE (1.21) and MSDR (121.32) and ME (0.001), RMSE (0.88) and MSDR (144.11), respectively. Since the kriging results of spherical model indicate good model efficacy for this study, it may be useful to map spatial pattern of annual rainfall in Basin level in Ethiopia.

Unrecognised Ant Megadiversity in Monsoonal Australia: The Tetramorium spininode Bolton Group in the Northern Territory

We document unrecognised diversity within the Tetramorium spininode Bolton group of the Australian monsoonal tropics, which has a single described species. At the time of its description, T. spininode was known from just two collections, but there have since been hundreds of collections from throughout monsoonal Australia. We document morphological and genetic (CO1) variation within the group’s fauna of the Northern Territory (NT), in the centre of its range, where collection intensity has been highest. We recognise 20 species among 124 CO1-sequenced specimens, and 32 species in total from the NT. A key to these species is provided. The most intensively sampled regions within the NT are the mesic (&gt;1000 mm mean annual rainfall) Top End in the far north (with 14 species) and the semi-arid (500–900 mm) Sturt Plateau region to its south (13 species). Only one species is known from both regions. Given such high regional turnover and highly patchy sampling, we estimate that at least 40 species of the T. spininode group occur in the NT. Similar diversity appears to occur in Western Australia, especially in the Kimberley region, but less in Queensland. Our findings suggest that the total number of species in the T. spininode group is likely to be around 100. Our study provides further evidence that monsoonal Australia is an unrecognised global centre of ant diversity.

Contributions of hypolithic communities to surface soil organic carbon across a hyperarid-to-arid climate gradient

Carbon (C) in soils accounts for a substantial and dynamic portion of the global C cycle, with concentrations of soil organic carbon (SOC) typically closely linked to vascular plant productivity. However, C fixed by non-vascular photosynthetic organisms may account for a sizeable proportion of SOC in locations where vascular plants are not abundant. In the hyperarid Namib Desert, vascular plant growth is very limited and largely ephemeral. Extreme abiotic conditions even limit establishment of cyanobacterial soil crusts, with photoautotrophic cyanobacteria largely restricted to the undersides of translucent quartz clasts that buffer environmental extremes. The importance of these ‘hypoliths’ in enhancing SOC pools, and how this may vary with climate and clast physical characteristics, remains unknown. We worked across a rainfall and fog gradient in the central Namib to assess quartz clast size and distribution, factors affecting the probability of hypolithic colonization, and the landscape-level influence of hypoliths on surface SOC pools. Clast colonization increased with clast thickness and with increasing mean annual rainfall. SOC and chlorophyll a (a proxy for cyanobacterial biomass) concentrations were greater under colonized quartz clasts than under non-quartz clasts or in bare soil. Landscape-level SOC, estimated by combining SOC concentration with the distribution and colonization of quartz clasts, was greatest at the site with the highest rainfall and lowest at a mid-gradient site with moderate rainfall and fog. Climate change scenarios that promote quartz colonization have the potential to double SOC pools at the mid-gradient site, although SOC changes would be more muted at other sites. Low vascular plant and biocrust cover in the Namib Desert allows hypolithic communities to play an outsized role in SOC pools; a loss of all hypolithic cyanobacteria would lead to 10–20% declines in surface SOC pools. Future climate change has the potential to shift surface SOC if it alters cyanobacterial colonization of quartz.

Variation characteristics of rainfall erosivity in tropical China and its impact on river sediment load

Rainfall erosivity is one of the important factors leading to soil and water erosion, affecting the intensity of soil erosion and the variation of river sediment load. This work aimed to explore the distribution and variation characteristics of rainfall erosivity in the Nandu River Basin in tropical China and to clarify the effect of rainfall erosivity on sediment load variation. The daily rainfall data of 13 meteorological stations in the Nandu River Basin during 1971–2020 were used to calculate the rainfall erosivity of the river basin by using the rainfall erosivity model based on the daily rainfall. The analyses were conducted using the Mann-Kendall non-parametric trend/abrupt test, wavelet analysis, inverse distance weighted interpolation and other research methods to determine the temporal and spatial fluctuation patterns of rainfall erosivity and sediment load. The annual mean rainfall erosivity in the Nandu River Basin during 1971–2020 was 16,497.67 MJ mm·ha−1·h−1, which showed an upward trend. The distribution of rainfall erosivity was concentrated from July to September. Except spring, the variation of rainfall erosivity in summer, autumn and winter showed an upward trend. Spatially, rainfall erosivity showed a decreasing trend from south to north. The variation coefficient of each meteorological station ranged from 0.24 to 0.43, showing high regional variability. The correlation between rainfall erosivity and erosive rainfall in the basin was the highest, followed by altitude and latitude. From 1980 to 2020, the sediment load in the Nandu River Basin showed an overall upward trend, with obvious periodic changes. The main change period was 25 years, and the sediment load had a large inter-annual variation. Taking the period before the inflection point of the double accumulation curve of sediment load and rainfall erosivity as the base period, since 2009, the river sediment load increased by 46.36% compared with the base period. The influence of the variation of rainfall erosivity on sediment load is −22.23%, and that of human activities on sediment load is 122.23%. These findings can provide a scientific reference for soil erosion model prediction, soil and water conservation and environmental management in tropical basins of China.

Drought assessment and rainfall trend analysis in southwestern Nigeria

AbstractProlonged instability and insufficiency of rainfall resulting in drought, extreme weather events, and food insecurity are climate change‐related challenges bedeviling humanity. This study assessed drought conditions and rainfall trends in southwestern Nigeria, using the 1984–2014 rainfall dataset from the Nigerian Meteorological Agency (NIMET). The coefficient of variation (CV), long‐term standardized precipitation index (SPI), serial correlation test, Mann–Kendall trend analysis, Sens's slope estimation, and Pettit test were carried out using various R programming packages. Long‐term mean annual rainfall ranged between 1224.7 and 1537.1 mm. The highest variation (17.3%) was observed for Abeokuta and Ikeja. SPI analysis revealed Ibadan and Oshogbo as the driest and wettest stations, respectively. There was no serial autocorrelation in the dataset. The Mann–Kendall trend showed an upward rainfall trend for Abeokuta, Ibadan, and Ikeja and a downward trend for Akure and Oshogbo. Sen's slope annual rates of change in mm for Abeokuta, Akure, Ibadan, Ikeja, and Oshogbo are 6.69, −2.36, 2.07, 7.82, and 1.42 respectively. The Pettit test revealed change points that are not statistically significant. The drought assessment largely showed a cyclical SPI pattern with greater years of dryness. Given the increasing impact of climate change, future studies are needed to simulate the local drivers of drought severity and frequency and the changing rainfall pattern in rapidly urbanizing cities. There is also the need to incorporate climate‐related adaptive strategies in existing water management policies.

Climate change alters slug abundance but not herbivory in a temperate grassland.

Climate change will significantly impact the world's ecosystems, in part by altering species interactions and ecological processes, such as herbivory and plant community dynamics, which may impact forage quality and ecosystem production. Yet relatively few field experimental manipulations assessing all of these parameters have been performed to date. To help fill this knowledge gap, we evaluated the effects of increased temperature (+3°C day and night, year-round) and precipitation (+30% of mean annual rainfall) on slug herbivory and abundance and plant community dynamics biweekly in a pasture located in central Kentucky, U.S.A. Warming increased slug abundance once during the winter, likely due to improving conditions for foraging, whereas warming reduced slug abundance at times in late spring, mid-summer, and early fall (from 62-95% reduction depending on month). We found that warming and increased precipitation did not significantly modify slug herbivory at our site, despite altering slug abundance and affecting plant community composition and forage quality. Climate change will alter seasonal patterns of slug abundance through both direct effects on slug biology and indirect effects mediated by changes in the plant community, suggesting that pasture management practices may have to adapt.

Divergent patterns of intraspecific trait variation among floral and vegetative characters in the hyperdominant dioecious Neotropical treeVirola sebifera(Myristicaceae)

AbstractMany Neotropical tree species are widespread at continental and even inter-continental scales, but phenotypic variation across their respective ranges has rarely been quantified. We measured traits in the widespread, unisexual Neotropical tree Virola sebifera (Myristicaceae) across its continental-scale range, and predicted that, given its hyperdominant status, generalist-pollinated flower type, high dispersal capacity and wide ecological amplitude there would be: (1) a weak relationship among and within reproductive and vegetative characters with environmental, spatial and biome correlates; (2) undetectable canalization of reproductive traits; and (3) high phenotypic variation of vegetative characters. We measured five foliar and seven floral traits from 187 male-expressing individuals of V. sebifera in specimens collected from Central to South America. Spatial regression models were employed to test for the importance of distance, elevation, mean annual rainfall and temperature on phenotypic variation. Pairwise correlations of vegetative and reproductive characters were calculated to examine intraspecific trait variation among and within these two classes. We found that most phenotypic variation was weakly explained by spatial predictors such as certain major South American domains like the Andes Cordillera and the Amazon Basin. Within-class comparisons of floral characters were no different than among-class (floral-foliar) correlates, suggesting the absence of canalization of reproductive structures. Greater phenotypic variation in flowers relative to leaves may be due to the generalist pollinator regime and high dispersal capacity thus relaxing divergences in the evolutionary process of its floral morphology. The results of these morphometric analyses (e.g. weak signals of isolation by distance) in combination with the biology of this Neotropical tree suggest that V. sebifera operates as a well-dispersed metapopulation across most of its range.

Statistical Analyses of Rainfall Distribution: A Check on Climatic Shift

The study Statistical Analyse of Rainfall Distribution: A check on Climate Shift is concerned with using table values and graph to visually compare rainfall distribution over different climatic cycles. To achieve this, rainfall data from Nigeria Meteorological Agency archive was extracted for analysis. The study observed that only two months had mean rainfall less than 51mm. It was also observed that rainfall occurrence decreases over the years, as indicated by the negative trend line. The study among other things discovered that the double maxima as a result of August dry spell has reduced significantly, thereby increasing run-off. This paper observed that the time of the years is significantly related to rainfall occurrence. The month of August had more improved rainfall throughout the period of study. The rate of dispersion of mean annual rainfall from the station mean is an indication of the reliability of rainfall or otherwise. This work opined that change in climate will lead to a complete shift in RF distributions; therefore, the activities that were influenced by RF will be affected positively or in a negative way in the future. This work recommends that agriculture calendar of the study area need to be changed therefore farmers need to adopt new farming techniques as RF distribution change. There agricultural calendar needs to also change.

Development of Automatic Fish Feeding Machine for Integrated Floating Cage Aquageoponic System

Aims: The objective of this work was to develop and evaluate the performance of an automatic fish feeder- to enhance aquacultural practices and farmponds&#x0D; Place and Duration of Study: The research study was conducted at Madakasira, (Latitude: 13°56ʹ55.96″ N and Longitude: 77°18ʹ45.38″ E) which is located in Anantapur district of Andhra Pradesh, India. The mean annual temperature and annual rainfall of the study area are 27.6°C and 532 mm, respectively. Most of the rainfall (~80%) is received during South-West monsoon. The experiment study was conducted from March‒June, 2018.&#x0D; Methodology: Automatic fish feeder includes both electrical and mechanical mechanism. The materials includes for the development of the feeder was cone shape hopper, top covering lid, base, 12V DC motor, 12V 7Ah Rechargeable Lead Acid Battery, Arduino Uno, Bluetooth HC-05 module, 5v Relay, DC-DC step-down converter. The developed feeder was operated with the help of mobile app by using Bluetooth HC-05 module. The spreading distance and amount of feed spread, opening angles of the feeder were evaluated during the research period.&#x0D; Results: Our results showed that the amount of feed spread was maximum (140 g m-1) with 1.0 m height and was minimum (101 g m-1) at 0.2 m height. This results clearly shows that the fish feeder has to be kept at maximum height so that it covers maximum spreading distance with minimum loss of fish feed by drift. With increase in height of the machine from ground surface, the spreading distance of the fish feed from the feeding machine was also increased.&#x0D; Conclusion: Farmers were satisfied with this new technology which helps to avoid manual feeding and provides the clean environment.

Impacts of Climate Change on Area and Production Under Different Crops in Bhandara District: Central India

Abstract: The present study Impacts of Climate Change on Area and production under different crops in Bhandara district, Central India. The hydrological parameters such as rainfall, drainage analysis, topographic parameters, and land-use patterns were evaluated and interpreted for district management of the area. This has been done using the sofware of the Arc map module in Arc GIS 9.3 and ERDAS Imagine 9.2 satellite image analysis. The hydrological investigation shows that the climate of the basin is characterized by hot summer from March to May followed by a rainy season from June to September. The postmonsoon season is also observed in the month of October. The annual mean rainfall range varies from 1,000 to 1,400 mm. The temperature rises rapidly from March to May. The monthly average maximum temperature rises to 47.50 Celsius in the month of May. In summer, the nights are cool compared to the scorching heat of the day. Bhandara district receives more rainfall than other districts of Maharashtra. The main crop here is paddy (rice). And 70% of agriculture is rain dependent. Total average rainfall for five years in seven districts of Bhandara district was recorded. Considering the total average rainfall in 5 years, Lakhandur taluka has the highest rainfall while Tumsar taluka has the lowest

Effect of seasonal variation on yield and leaf quality of tea clone (Camellia sinensis (L.) O. Kuntze) in South West Ethiopia

The tea plant is widely cultivated in southwest Ethiopia. But the impact of seasonal variation on monthly yield, leaf quality, and the long-term yield response potential of clones has not been studied. The objective of the study is to determine the impact of seasonal change and climate variables on the yield and leaf quality of tea plants in southwest Ethiopia. The experiment consisted of five clones and four seasons under a split-plot design and was replicated three times. The results indicated that the yield and leaf quality showed significant variation in the different seasons at P < 0.05. The highest peak yields of 12.68, 12.59, and 11.3 kg plot−1 were recorded in May, June, and April, respectively, and the yield suddenly dropped by 5.1% in July. Then the soft banjhi increased by 5–10% in July. The yield response potential of clones is highly affected by monthly climate variation at P < 0.05. Clone BB-35 recorded the highest (18.8 kg plot−1) yield in June, followed by clones 11/4 (18.3) in May, 11/56 (14.7) in November, 6/8 (11.7) in December, and 12/38 (5.78 kg plot−1) in June. The lowest mean green leaf and a longer shoot replacement cycle were created due to a decrease in rainfall to 760 mm/month and rising temperatures above 26.35 °C in winter. The leaf phenological response of tea clones is strongly governed by the monthly temperature and suitable precipitation pattern of a season. The highlands have two harvesting seasons, i.e., a dry and a wet harvesting season. The dry harvesting season, which exists between the middle of December and March, accounts for 18.3–24.3% of the total annual yield. The wet harvesting season is subdivided further into two peak harvesting seasons. The first harvest is characterized by a short plucking round, and the highest peak yield occurs in April, May, and June, accounting for 40.22–42.2% of the total annual yield. The second wet harvesting season begins in September and ends in the middle of December, contributing to 35.5–40% of the annual yield. Seasonal variation has a direct impact on leaf quality and clone yielding potential. Clones show higher yield and shorter plucking rounds at maximum temperatures above 23.03 °C and below 26.35 °C, but temperatures above 28.34 °C and below 10.38 °C have a negative effect on leaf quality and yield. Over the last two decades, rainfall, maximum, and mean temperatures all increased by 16.09 mm y-1, 0.127 °C, and 0.0566 °C y−1, respectively, and the tea plant showed a strong correlation with maximum temperature (76%), whereas mean temperature (44.6%) and annual rainfall (32.8%) correlated weakly. Green leaf production is well explained by around 85.4% of the observed climate variance, with an increase of 1287.18 tonnes y−1, and highland tea production will exhibit a positive net benefit from expected climate change in the future.

Spatio-Temporal Differentiation and Driving Factors of Carbon Storage in Cultivated Land-Use Transition

Revealing the response of carbon storage to cultivated land-use transition (CLUT) and identifying its driving factors are of great significance for maintaining ecosystem stability and promoting regional carbon peak and carbon neutrality goals. Given the knowledge gap regarding the driving factors of carbon storage in CLUT, this study takes the Songhua River Basin in the black soil region of China as the case study area. The study aimed to reveal the spatial–temporal heterogeneity of carbon storage in CLUT based on the grid element method and carbon storage density. In addition, the driving factors were demonstrated using the geodetector model. The results show that the cultivated land area gradually decreased from 1990 to 2020, and the transition between cultivated and construction land was the most significant. The carbon storage in cultivated land-use transitions showed a substantial decreasing trend. The conversion of cultivated land to construction land resulted in the loss of 130,443,200 tons of carbon reserves. Moreover, the transformation from unused land to cultivated land led the highest increase in carbon storage, which increased by 29,334,600 tons. The gravity center of carbon storage was stable, moving 28.77 km to the northeast between 1990 and 2020. Conversely, the spatial structure of carbon storage showed a transformation trend from multicore fragmentation to mononuclear agglomeration, with obvious regional accumulation, a weakened degree of fragmentation, and uniform distribution. Carbon reserves increased by 388,600 tons from 1990 to 2000, and carbon reserves lost 60,121,700 tons from 2010 to 2020, nearly 155.700 times. The mean annual rainfall was the main carbon storage factor. The interaction between mean annual rainfall and land-use intensity had strong explanatory power, and the spatial heterogeneity of carbon storage resulted from multiple factors.