High Rainfall Amounts Research Articles

Investigating high altitude platform stations communication in Tanzania under heavy rain conditions

AbstractHigh altitude platform station (HAPS) is one of the promising solutions to many of the developing and less developed countries. To a great extent, HAPS is relatively cost‐effective and can be easily moved on demand while observing the required quality of service. For tropical countries, rain attenuation is the main factor that affects HAPS performance. This study investigated HAPS performance in Tanzania under heavy rain conditions. Rain rate, rain attenuation, and carrier‐to‐noise ratio were used to quantify the system's performance. In this study, the rain rate exceeds by 0.01% of an average, was obtained using the Chebil model. Based on Tanzania Meteorological Agency data, the registered a high amount of rainfall for the five selected regions: Dar es Salaam, Kagera, Tanga, Unguja, and Pemba. By using ITU‐R model, rain attenuation for the downlink was predicted, assuming horizontal polarisation, for 31.0–31.3 GHz. Finally, the HAPS link budget was analysed with a platform altitude of 22 km at frequency of 31.0–31.3 GHz for different elevation angles. Results showed that the performance of the system was promising in the given rainfall scenarios.

An Investigation on Microphysical Characteristics of Early‐, Late‐, and Post‐Mei‐yu Season Rainfall Over Taiwan

AbstractOver Taiwan, Mei‐yu season (May and June), which is primarily linked to frontal systems, is the transition period between winter and summer. Using the Global Precipitation Measurement Mission dual‐frequency precipitation radar (GPM DPR), the current study examined the rain and microphysical characteristics of the Mei‐yu season in Taiwan. In order to examine the areal and intra‐seasonal aspects, May and June months are divided into three sub‐seasons: early‐Mei‐yu, late‐Mei‐yu, and post‐Mei‐yu. The three sub‐seasons exhibited differences in rainfall and raindrop size distributions, with abundance of large drops in the post‐Mei‐yu. Additionally, there were noticeable variations in the raindrop size distributions among the south, central, north, and eastern parts of Taiwan, with more large drops in central Taiwan. To comprehend the microphysical progressions causing the regional and intra‐seasonal fluctuations, CFADs (contoured frequency by altitude diagrams) of rain parameters are utilized. Compared to other two sub‐seasons, the early‐Mei‐yu season exhibited weaker convection. Dominance of stratiform precipitation in late‐Mei‐yu season, and convective precipitation in post‐Mei‐yu season resulted in higher rainfall amounts in these two sub‐seasons (more particularly in post‐Mei‐yu) than the early‐Mei‐yu season. Examination of warm rain microphysical processes (below 5 km height) among these sub‐seasons revealed that the early‐Mei‐yu season is dominated with break‐up process, late‐Mei‐yu season with breakup and coalescence balance, and post‐Mei‐yu with coalescence, size‐sorting and evaporation processes.

A Study on Rainfall Rate, Temperature and Rain Attenuation of Ka-Band Satellite signal

This research paper is studied rainfall, temperature and rain attenuation of Ka-Band satellite signal by using rainfall and temperature data in 2023. Department of Electronics and Telecommunications Engineering, Faculty of Engineering is where the station is housed. Therefore, this paper aims to investigate the relationship between rainfall values, temperature and rain attenuation in Vientiane Capital using advanced technologies to facilitate and monitor the data in real time. A rain gauge Tipping Bucket 0.1mm/Tip is used to detect the amount of rain, and a DHT22 sensor is used to monitor the temperature. The research procedure entails analyzing temperature and rainfall, designing and setting up measurement sites, setting up a central monitoring station and using the Internet of Things to collect temperature and rainfall data. The analysis showed that the high precipitation amount of the actual rainfall and actual daily data contains two maximum values from August 15, 2023 at 85.3mm/hr with 26°C and September 7, 2023 at 110mm/hr with 25.1°C. ITU-R model is used to analyze the rain attenuation by applying the abovementioned rainfall values. As a result, the rain attenuation of Ka-Band Satellite Signal is 85.3mm/hr the rain attenuation is 11.63 dB and 110mm/hr the rain attenuation is 10.58 dB, respectively, which showed the interlinkage between rainfall amount and temperature while it is raining. The temperature change will not affect the rain attenuation as much as the increase of rainfall amount.

Urbanization signature on hourly rainfall extremes of Kuala Lumpur

This study uses high-resolution satellite data to investigate the impact of urbanization on the local climate of Kuala Lumpur, Malaysia. Nonparametric statistical methods, including trend test, spatial correlation, and quantile regression, were employed to quantify interrelationships between satellite nighttime light (NTL), Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST), and Global Satellite Mapping of Precipitation (GSMaP) extreme rainfall events. The results revealed that urbanization increased Kuala Lumpur's LST by 3.8 to 4.1 °C and the 99th percentile rainfall by 10 to 43 % compared to surrounding areas. The correlation analysis showed an association (r = 0.62) between the trends in LST and rainfall extremes, with a significance level of p < 0.05. The NTL trend analysis showed a rapid expansion of the city, particularly in the west, and thus, an expansion of high LST areas and extreme rainfall amounts. Quantile regression results confirmed the influence of increased LST on rainfall extremes. The trends for hourly rainfall revealed increases mainly between 2pm and 9pm in the city, which is attributed to the intensification of convective rainfall caused by increased LST. The study highlights the importance of mitigating urban LST to reduce climatic extremes and promote sustainable urban development.

Influence of changes in solar activity on Nigerian Rainfall

This paper focuses on the impact of solar activity changes on rainfall in Nigeria. Rainfall data were got from Gridded Time Series (CRU TS v4) of the University of East Anglia, United Kingdom. Various statistical tools like Pearson rank correlation coefficient, regression analysis, covariance, skewness, and kurtosis are employed in the study. The results show that there are generally weak correlations between rainfall and solar activity in most seasons. However, low correlation coefficients (0.0424 and 0.1040, respectively for sunspot numbers and F10.7 mean a very weak positive relationship between early rainfall, main rainfall and annual rainfall and negative for dry season rainfall and Harmattan rainfall. Also, there is a negative time-series relationship between the rainfall amount in dry and Harmattan seasons, with the highest rainfall amount during low solar activity and vice versa. Therefore, it can be concluded that solar activity has little effect on Nigeria's annual and main season rainfall. However, during the dry season and Harmattan, heavy rainfall appears to be associated with low solar activity, while high solar activity appears to be associated with low rainfall. This study will be beneficial to farmers in Nigeria, majority of whom are peasant farmers that practice rain-fed farming.

Correlation between flood couplet-based sediment yield and rainfall patterns in a small watershed on the Chinese Loess Plateau

Understanding how rainfall patterns impact sediment yields during rainfall events is important to explore soil erosion changes and to prevent watershed flood disasters. However, few studies identified sediment yields variation affected by rainfall patterns at continuous deposited flood couplet scale. This study analyzed sediment yields under different rainfall patterns and correlated particle depositional features on the condition that the erosive environment was obviously changed by anthropogenic activities in a check dam-controlled small watershed on the Chinese Loess Plateau. Results showed that erosive rainfall events, having formed 40 flood couplets behind the check dam between 1978 and 2010, can be grouped into three rainfall patterns (i.e., rainfall patterns I, II, and III) according to changes in rainfall amount, erosivity, and duration. Rainfall pattern III, characterized by high rainfall amount and erosivity within a short duration (i.e., rainstorm) accounted for only 15.0 % of erosive rainfall events while yielding 44.7 % of the total sediment. Conversely, rainfall pattern I (the most common, 55.0 %), characterized by its long duration and relatively low rainfall amount and erosivity, only contributed 25.3 % of the total sediment. Both sediment yields and thickness proportions of coarse particle layer in flood couplets exhibited a decreasing trend under all three rainfall patterns. Meanwhile, the main factor that impacted sediment yields changed from rainfall in the 1980s and 1990s to the “Grain for Green” program dominated anthropogenic activities since 1999. For a small watershed with a few terraces and only one check dam at the outlet, artificial vegetation restoration significantly reduced coarse soil particle loss and sediment yield. Findings showed that sediment yield and deposition feature variations in flood couplets under different rainfall patterns are helpful in improving watershed soil and water conservation measures against flood disasters, particularly under rainstorms.

Trend analysis of extreme rainfall indices from CHIRPS precipitation estimates over the Lake Tana sub-basin, Abbay Basin of Ethiopia.

Ethiopia is among the African nations most susceptible to climate change because of its frequent droughts and heavy rainfall. Therefore, hydrological and water management problems require an investigation of regional variability and extreme rainfall patterns. This study analyzed the spatiotemporal trends of extreme rainfall in the Lake Tana sub-basin (LTSB) of Ethiopia's upper Blue Nile basin (UBNB) between 1981 and 2019. The trend and geographic patterns of ten extreme rainfall indices are evaluated using high-resolution data from Climate Hazards Group InfraRed Precipitation Stations (CHIRPS). The researcher used RClimDex, an R software tool, to analyze the ten severe rainfall indices. The variability of the extreme rain indices was also assessed by applying the standard anomaly index (SAI). The trend analysis shows that the majority of rainfall indices decreased in the majority of station locations. Among the rainfall locations, the decreasing trend was only significant in 40% consecutive wet days (CWD), 13.33% (R95p and R99p), and 6.66% highest rainfall amount in a 1-day period (RX1day). In contrast, significant positive patterns were revealed in the incidence of rainfall events of number of heavy precipitation days (R10mm), annual total wet day rainfall (PRCPTOT), and consecutive dry days (CDD), with significant positive trends of 26.66% (R10mm) and 40% (PRCPTOT). Furthermore, a spatial distribution result of extreme rainfall trends reveals considerable variations between stations location. Thus, these findings point to the necessity of creating adaptation and mitigation plans for climate change variability within the sub-basin.

Water Erosion Response to Rainfall Type on Typical Land Use Slopes in the Red Soil Region of Southern China

Land use and rainfall are two important factors affecting soil erosion processes. The red soil region of southern China is a representative region with high rainfall amounts and rapidly changing land use patterns where the water erosion process is sensitive to changes in land use and rainfall. To comprehensively understand the water erosion response to land use and rainfall in this region, a 6-year in situ experiment based on eight plots (bare land and seven typical land uses) was conducted from 2015 to 2020. The 320 rainfall events were divided into 4 types, and there were 3 main rainfall types. The runoff of different rainfall types was primarily determined by the rainfall amount, while the soil erosion of different rainfall types was primarily determined by the rainfall intensity. High-intensity rainfall contributed the most to both total runoff and soil erosion. Compared with bare land, the seven typical land uses reduced runoff and soil erosion by more than 75%. Grassland, cropland, and forest with low vegetation coverage experienced high runoff and soil erosion, while shrubland most effectively reduced runoff and soil erosion. The combination of land use and rainfall type significantly affected the annual average runoff depth, soil erosion modulus, and soil loss coefficient. Rainfall types can change the relationship between runoff and soil erosion for different land uses. The runoff and soil erosion of bare land were highly correlated with rainfall characteristics, while vegetation weakened this relationship under short- or moderate-duration rainfall. To effectively reduce water erosion, high-intensity rainfall should receive special attention, and all land uses should ensure that vegetation is well developed, especially understory vegetation.

Morphometric Analysis Using Geographical Information System and the Relationship with Precipitation Quantiles of Major Dam Basins in South Korea

Geographic information system (GIS) and remote sensing (RS) technologies are potent tools for evaluating various aspects of basin hydrology. This study conducted a morphological analysis using GIS tools on seven major dam basins in Korea. Additionally, long-term RS-based precipitation data were obtained, the probability of precipitation was estimated, and their relationship was examined. The findings are summarized as follows. It was observed that most major dam basins in Korea, which were the focus of this study, had a broad radial shape, and due to the mountainous topography, there was a notable presence of numerous river branches. Through the estimation of probability precipitation and its comparison with morphological indices, it was noted that wider basins tend to have higher rainfall amounts and a relatively uniform spatial distribution. Furthermore, it was found that the more uniform the spatial distribution, the simpler the river network. This trend becomes more pronounced in relation to basin size for longer durations, and in spatial dispersion for shorter durations. However, it is crucial to acknowledge that the complexity of these relationships is also affected by other factors such as climate, altitude, and local geographical conditions.

The Jurassic climate change in the northwest Gondwana (External Rif, Morocco): Evidence from geochemistry and implication for paleoclimate evolution

The present work deals with Jurassic deposits belonging to the External Rif chain. It is well known that the Jurassic time was a crucial period in the earth's history as witness of significant climate changes. This work aims to provide a preliminary reconstruction of the regional Jurassic paleoclimate of the northwest Gondwana hinterland and its global paleogeographic context. We used diverse geochemical proxies to unravel paleoclimate of the Jurassic sediments accumulated in the Atlantic and Tethysian hyperextended passive margins bordering the northwest Gondwana. We reconstituted their paleo-humidity, paleo-precipitation, paleo-weathering, paleo-productivity, paleo-floral landscape distribution in the Gondwanaland, the paleo-redox, paleo-oxygenation and paleosalinity of the bordering oceanic sinks. The obtained results indicate that the early Jurassic climate was cool with low rainfall and productivity, while the middle Jurassic was characterized by a semi-moist warm climate with high chemical weathering and subsequent seaward terrigenous supply. The Uppermost Jurassic climate was warm, semi-moist to moist with a return to an arid cold climate marked by high rainfall amount which yielded more terrigenous material to the bordering Tethysian and Atlantic hyperextended passive margins around the northwest Gondwana hinterland. The result of this research reveals, among others, the control of the first-order geodynamic processes on the Jurassic mid-latitude climate change, such as plate tectonics reorganization, oceanic seafloor spreading, and subsequent volcanic activity. The latter may triggered a climate shift from early Jurassic dry “cool” to middle-late Jurassic wet warm “greenhouse” climate conditions around the northwest Gondwanaland. Besides, the Jurassic climate change may have been also controlled by successive mega-monsoons that occurred through the Inter-Tropical Convergence Zone (ICZ) over margins and oceanic realms bordering the northwest Gondwanaland.

Response of Sap Flow Trends of Conifer and Broad-Leaved Trees to Rainfall Types in Sub-Humid Climate Region of China

Sap flow is one of the most important physiological water transport processes of trees, and the characteristics of sap flow are greatly affected by the spatial and temporal distribution of water in the SPAC (soil–plant–atmosphere continuum). However, different precipitation characteristics have great influence on the water environment of forest trees, which causes considerable differences in sap flow. Therefore, researching the response of sap flow to precipitation type is the key to accurately determining plant transpiration in semi-arid areas. We used K-means clustering analysis to divide the rainfall during the study period into three rainfall types (the highest rainfall amount and intensity (types I), medium rainfall amount and intensity, with a long duration (types II); and the lowest rainfall amount and intensity (types III)) based on the rainfall amount and intensity in order to compare the differences in the response of sap flow trends and influencing factors of Pinus tabulaeformis and Robinia pseudoacacia under different rainfall types. The results showed that, under the daily scale average sap flow of P. tabulaeformis and R. pseudoacacia, rainfall type II decreased significantly relatively to rainfall types I and III (p &lt; 0.05). In rainfall type II, The sap flow characteristics of R. pseudoacacia were positively correlated with solar radiation (p &lt; 0.05), while those of P. tabulaeformis were positively correlated with temperature, solar radiation, and VPD (p &lt; 0.01). The sap flow of P. tabulaeformis and R. pseudoacacia were significantly positively correlated with temperature, solar radiation, VPD, and soil moisture content (p &lt; 0.01) and negatively correlated with relative humidity (p &lt; 0.05) in rainfall type III. The hourly sap flow of P. tabulaeformis and R. pseudoacacia on rainfall days was higher than before the rainfall. Rainfall type I promoted the daily sap flow of both species, and the proportion of the sap flow in daytime was also higher. On rainy days, the sap flow rates of rainfall type I and III showed a “midday depression”. In type I rainfall events, the sap flow “midday depression” after rainfall occurred an hour ahead compared to the sap flow “midday depression” before rainfall. In type II rainfall events, the daytime sap flow rates of P. tabulaeformis and R. pseudoacacia were obviously inhibited, but the nighttime sap flow rate increased. In type III rainfall events, the sap flow before rainfall presented a unimodal curve versus time. The daily average sap flow of R. pseudoacacia was more susceptible to rainfall type II, while P. tabulaeformis was more susceptible to rainfall types I and III. The sap flow rate of R. pseudoacacia decreased on rainy days. The results show that the effects of different rainfall types on the sap flow trends of P. tabulaeformis and R. pseudoacacia were different. They revealed the responses of their sap flow trends to meteorological factors under different rainfall types, which provided basic data and theoretical support for further predicting the sap flow trends on rainy days, clarifying the effects of rainfall amount, rainfall duration, and rainfall intensity on sap flow trends and accurately estimating the transpiration water consumption of typical tree species in the sub-humid climate regions of China.

Spatiotemporal Variability of Rainfall as an Evidence of Changing Climate over the Nigerian Niger Delta

This study assesses the spatial and temporal variability of rainfall over the Niger Delta area (Benin, Calabar, Port Harcourt and Uyo) in Nigeria between 1990 and 2020. The daily rainfall data used for this study were obtained through secondary source from NASA’s POWER (Prediction of Worldwide Energy Resources). Coefficient of variation, standardized anomaly index (SAI), precipitation concentration index (PCI) and seasonality index (SI) were used to evaluate rainfall variability and seasonality. The results of temporal analysis of annual rainfall indicated that Benin had the highest annual rainfall amount in 2000 and lowest in 1999 while Calabar and Port Harcourt had their highest rainfall amount in 2007 with the lowest occurring in 1991 and 2014 respectively. Uyo had the highest in 2000 and lowest in 2014. SAI also witnessed the presence of interannual variability of rainfall with negative and positive anomalies in 59.46% and 40.54% of the analyzed years, respectively. PCI and SI results implied that the Niger Delta area had strong irregular rainfall distribution. The results confirm the meteorological sensitivity to locations and provide support for the implementation of station and regional meteorological hazards prevention and to support the mitigation of hazards and improve the management practices of environment system in Niger Delta area.

Potential Erosion in Mining, Oil Palm Plantations, and Watersheds Reforestation Areas

Erosion forecasting is a complex issue generated by numerous causes, the extent of which varies based on the unique area and conditions. Changes in rainfall, land cover, and watershed function are the primary causes of increased erosion. This study aims to scrutinize the actual and potential erosion in the mining area (MA), oil palm plantations (OPP), and watersheds reforestation (WR) in Asoloe, South Konawe, Indonesia. We utilized qualitative research methods and surveys with the USLE model. MA shares the highest actual erosion with 332.30 tons/ha/year, with an average erosion of 27.69 tons/ha/year from 2011 to 2022. Meanwhile, the potential erosion is 4747.19 tons/ha/year, with an average of 395.60 tons/ha/year. In terms of current conditions, 44.6% of rainfall engenders erosion with more than 0.5 t/ha and 33.9% with more than 1 t/ha. This study successfully demonstrates that for given location and area characteristics, high amounts of rainfall and changes in land function eminently affect soil erosion and that the potential erosion changes that occur in the Asoloe watershed every year are exceptionally influenced by changes in land use and land function. Therefore, some mitigation strategies and policies must be taken to reduce the risk of future erosion. Doi: 10.28991/CEJ-2023-09-09-07 Full Text: PDF

Diabatic Heat Effects on the Generation of Energy for Evolution of a SACZ Event: A Perspective from the Lorenz Energy Cycle

Abstract Here we used meteorological datasets from ERA5 to study the dynamic and thermodynamic characteristics of a SACZ event that occurred between 12 and 26 December 2013. This is an atypical SACZ episode with considerable variations in cloudiness band positioning and high rainfall amounts, causing enormous problems for society. We study this case through the Lorenz energy cycle (LEC), focusing mainly on the role of diabatic heating in energy generation and consequently in circulation aspects, analyzing the event in three stages (formation, development, and dissipation), and discussing it according to the convection localization pattern. The diabatic heat rate has a large impact on the energy generation of SACZ events at midlevels south of 24°S and below 900 hPa in the tropics. In LEC, the generation terms in the SACZ area were larger at the beginning (12–15 December) and smaller at the ending periods (23–26 December), with means of 21.23 and −7.62 W m−2, respectively. The conversion terms follow the LEC directions, except for barotropic instability [C(KE, KM) &lt; 0] that dominates throughout the analyzed periods. The convection area expansion to the north between 16 and 22 December was reflected by the most intense heating in the tropics and weaker barotropic instability. The friction term did not favor the event decay; therefore, we concluded that the cooling through a negative covariance between Q and T contributed to the event decay. We find that these results were largely influenced by a midlatitude wave train configuration that acted to favor the persistence, expansion, and decay of the event.

Microclimatic Variation in Miri Region (NW Borneo): Inference from Rainfall and Temperature Trends, Isotopic Signature and Air Mass Movement

Trend analysis is frequently utilised to identify the changes in meteorological and hydrologic time series data, such as rainfall and temperature. The variations in the intensity, rainfall pattern and temperature have gradually changed globally. Hence, in this study, an attempt was made to analyse the decadal rainfall and surface air temperature data to understand the microclimatic variations in the Miri coastal region of NW Borneo. A data series of records for daily total rainfall amount and daily surface temperature of 11 years from 2010 to 2021 was studied and analysed. In addition, representative rainwater and groundwater samples were collected and analysed for hydrochemical parameters and oxygen and hydrogen isotopes. A detailed literature review was carried out on rainfall patterns in Malaysia, which was used for the comparative study. Interpretation of results shows that the northeast monsoon (NEM) contributed a higher total rainfall rate with lower daily mean surface air temperature over the years compared to the southwest monsoon (SWM). The recorded data for rainfall amounts in SWM for the month of May, July, August and September were higher, particularly for the years 2010 and 2020. During NEM, a higher rainfall amount was recorded in the month of January for several years. February month has always been among the driest month in NEM, and September has been the wettest month throughout the year during SWM. The isotopic values of rainwater indicate a similar moisture source to the regional precipitation trend. Groundwater isotopes reveal the low water-rock ratio of retrograde exchange between water and primary silicate minerals in the aquifer. The moisture source of the precipitation was contributed from both oceanic and continent, affecting the rainfall intensity in this region. This study is a crucial outcome to determine the potential impacts of microclimatic variations on the rainfall patterns in the Miri coastal region.

Soil moisture observations and machine learning reveal preferential flow mechanisms in the Qilian Mountains

The complexity of the spatial distribution and temporal occurrence of preferential flow (PF) makes it challenging to understand the mechanisms of PF. This study aims to identify the spatial and temporal patterns of PF occurrence using machine learning (Classification and Regression Trees and Random Forests) in the Qilian Mountains, Northwest China. Our results show that detected PF events transport much more rainfall down to the subsoil than non-PF events. Different vegetation types exhibit variations in the main soil layers where PF occurs, which is closely related to the distribution of roots. The PF proportion varies significantly both vertically and horizontally. Based on the Random Forests, we found that the spatial distribution of the PF proportion is mainly controlled by the saturated hydraulic conductivity and residual soil moisture, which cannot be identified by conventional correlation analysis methods. With these soil properties, the spatial distribution of the PF proportion can be estimated with reasonable performance. Using the Classification and Regression Trees method, we identified the temporal occurrence pattern of the PF for different vegetation types and all observation stations. Results indicate that the dominant factors controlling the temporal occurrence of the PF varied for different vegetation types. The thresholds at which these factors initiate the PF also varied. Finally, we found that the PF occurs particularly under wet conditions (except for hydrophobic soils), under denser vegetation, and under conditions of high rainfall amount and intensity, regardless of vegetation type. Our study confirms that both site factors (e.g., soil properties and vegetation) and temporal factors (e.g., initial soil moisture and rainfall characteristics) control the occurrence of the PF in mountainous regions such as the Qilian Mountains and that the Classification and Regression Trees has great potential to study the temporal occurrence of the PF.

Insight into the pollution characteristics of road and roof runoff in Changsha, China

Non-point source pollution from rainwater runoff presents a serious challenge for urban water management in many cities undergoing urbanization and experiencing climate change. To alleviate water resource conflicts in Changsha, China, this study comprehensively evaluated the pollution characteristics and first flush effect (FFE) of runoff from asphalt roads and colored steel plate roofs under seven rainfall events in April-May 2022. The runoff was collected and purified using bioretention ponds. The results showed that the peak runoff pollutant concentrations occurred within the first 20min of runoff generation and then decreased to relatively stable levels, with maximum total suspended solids (TSS) concentration and chemical oxygen demand (CODCr) reaching 873.5 and 207.32mg/L, respectively, for road runoff and 162 and 73.31mg/L for roof runoff, respectively. The main pollutants were TSS and CODCr, followed by ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3--N), total phosphorus (TP), and nitrite nitrogen (NO2--N). Concentrations of pollutants and FFE for roof runoff were lower than those for road runoff. Road runoff had a more obvious FFE for TP and NH4+-N, whereas the roof runoff showed the presence of TP and NO3--N. An important implication is that treating the first 30% of surface runoff from rainfall events with long antecedent dry days or high rainfall amounts is necessary to improve water quality before discharge or utilization. The study also found that road and roof runoff, after treatment with bioretention ponds, exhibit good water quality, thus, allowing their use as reclaimed water or for miscellaneous purposes in urban areas. Overall, this study provides useful information for designing management measures to mitigate runoff pollution and reuse in Changsha.

Emission Source Areas of Fine Particulate Matter (PM2.5) in Ho Chi Minh City, Vietnam

This study aims to determine emission source areas of fine particulate matter (PM2.5) in Ho Chi Minh (HCM) City, Vietnam, using a conditional bivariate probability function (CBPF) and hybrid receptor models, including three-dimensional potential source contribution function (3D-PSCF) and concentration-weighted trajectory (3D-CWT), considering latitudes, longitudes, and height of trajectory segments. Uncertainties of the CBPF and 3D-PSCF/3D-CWT were evaluated based on the 95th confidence intervals and 95% confidence levels, respectively. For the local scale, PM2.5 in HCM City was primarily emitted from shallow or common ground sources (e.g., vehicle emissions) throughout the year. Regarding non-local source areas, PM2.5 in HCM City is contributed by those originated from the East Sea (e.g., shipping emissions) and southeastern Vietnam (e.g., Binh Duong and Dong Nai provinces) having several industrial zones with PM2.5 emission sources, especially in the dry season (December to April of the following year). In the rainy season (May–November), PM2.5 derived from emission sources in the Mekong Delta (e.g., biomass burning) might be transported to HCM City. However, contribution of the non-local sources to PM2.5 pollution in HCM City during the rainy season is less important because of PM2.5 deposition stemmed from the high rainfall amount in this season.

The Extent to Which Rainfall Variability has Affected Small Scale Dairy Farmers in Uasin-Gishu County, Kenya

Dairy farming in Kenya remains among the key wheelers to the Nations GDP contributor at about 6- 8%. Majority of the farmers in this sector, are small scale who mostly have no knowledge and capacity to handle challenges posed by rainfall variability that causes frequent droughts, impacting on water and pasture supply to their animals. Objective of study was: To assess the extent to which rainfall variability had affected small scale dairy farming in Uasin-Gishu County in Kenya between years 2010-2020. Rainfall data was collected from the Kenya Meteorological Department (KMD), Eldoret. While milk produce data was obtained from Ministry of Agriculture Uasin-Gishu County. Structured Questionnaires were used to collect data from farmers with few key respondents interviewed on the same . The questionnaire was administered to small scale dairy farmers who were sampled in a stratified manner based on their sub counties, then randomly within the Sub County. In total about 368 small scale dairy farmers were sampled out of which 300 (82%) of administered questionnaire were fully responded to. Analysis of objective one was done by Pearson correlation to establish the relationship between various rainfall characteristics and milk produce. Total annual rainfall with total annual milk had correlation of r= 0.532, number of rainy days in a year to the amount of milk with Pearson correlation of r =0.375, P&gt;0.05. Onset and cessation periods had Pearson correlation of r=0.305 and r=0,019 respectively. Average monthly rainfall to milk had Pearson correlation indicating a negative relationship of r= -0.424, P= 0.169, meaning months with high rainfall amounts had lower milk produced while dry ones had higher milk produced. The researcher therefore failed to accept the null hypothesis and adopted the alternative one that rainfall variability has had significant impact on small scale dairy farming in Uasin –Gishu County. Research recommended that farmers should keep more of cross breed animals which cope with climate variability unlike exotic ones. There was also need for farmers to join and strengthen cooperative societies to assist them adapt, this is besides use of digital methods of sharing challenges and solutions to rainfall variability

Long‐Term High‐Resolution Gauge Adjusted Satellite Rainfall Product Over India

AbstractThis study aims to create a 21‐year, high spatiotemporal resolution Global Satellite Mapping of Precipitation (GSMaP) rainfall product adjusted by rain gauge measurements over the Indian mainland and highlighted the importance of the Indian Meteorological Department (IMD) daily gridded rainfall to generate gauge adjusted GSMaP rainfall products over Indian landmass. The targeted resolutions of the GSMaP are hourly and 0.1° × 0.1°. The National Oceanic and Atmospheric Administration Climate Prediction Center daily gauge analysis (0.5° × 0.5°) and IMD daily gridded rainfall (0.25° × 0.25°) were utilized to generate long‐term rainfall products, GSMaP_CPC and GSMaP_IMD rainfall, respectively. After preliminary verification of the GSMaP_CPC and GSMaP_IMD rainfalls with IMD gauges, these rainfall products are evaluated for the Indian Summer Monsoon periods of 2000–2020 with comparisons of other gauge adjusted rainfall products such as the Integrated Multi‐satellitE Retrievals for Global Precipitation Measurement final‐run. The results suggest GSMaP_IMD has a smaller root‐mean‐square difference (RMSD) and higher correlation than GSMaP_CPC, evaluated against independent rainfall products. In the 3‐hour mean analysis with spaceborne precipitation radar data, it is found that the value of RMSD decreases in GSMaP_IMD with respect to GSMaP_CPC throughout the day. The statistics against the hourly dense gauge network suggests that the GSMaP_IMD is more effective in capturing large spatiotemporal rainfall variation. Thus, validation results with the independent sources suggest that GSMaP_IMD rainfall generally improved over GSMaP_CPC rainfall. These improvements are significant in orographic regions with high rainfall amounts, mainly the western Ghats and northeastern parts of India.