High Rainwater Research Articles

Evolution and determinants of precipitation chemistry in a plateau city, China: Insight from the pollutants source identification and environmental effect

Rainfall-related chemical ions deposition processes have important environment effects on earth-surface, which is also a vital sink of urban air pollutants. Therefore, identifying the rainwater chemical evolution and determinants, and source is essential. The daily-based rainwater samples during 2022– 2023 and the historical rainwater data in a typical plateau city (Kunming) were investigated. The Ca2+ and NH4+, SO42− and NO3− dominated the rainwater cations and anions, with the cationic and anionic percentages of 78% and 10%, 50% and 33%. The historical variations in ions percentages revealed the achievement of environmental protection. The precipitation amount and the seasonal changes of source emission were critical determinants for the variations of rainwater chemistry. Using the stoichiometry and receptor model, the contributions of potential origins to rainwater chemicals were assessed. 86% of NO3− and 40% SO42− were from combustion-related anthropogenic source, volatilization-related source contributed 85% of NH4+ (e.g., agricultural/municipal wastes emissions), whereas marine input was the main contributor of Cl− (59%) and Na+ (52%). Mg2+ (58%) and Ca2+ (41%) were primary from terrestrial input source. The risk of wet deposition-caused acidification was limited due to the high rainwater neutralization level, whereas the impact of nitrogen-related deposition on gross primary productivity (GPP) was non-negligible and further attention was need. Overall, the present study clarified the rainfall chemical features of plateau city region and further provided decision support for more effective urban air environmental management programs.

COMPARISON STUDY OF INSTALLATION COSTS OF CONCRETE CULVERT TO MODULAR WELLS FROM POLYPROPYLENE PANEL

Pontianak City has a low ground elevation and a reasonably high groundwater level. The distribution of clean water from regional companies tends to be less than optimal, and there is high rainwater runoff, causing the channel discharge to increase along with the growth of land converted into residential and business areas. Therefore, houses often use fresh water storage, both raw and rainwater, to meet clean water needs. One type that is often used is concrete culverts. However, concrete culverts have gaps in the joints that have the potential to contaminate storage water. The development of modular wells can be an option that is superior in various aspects to concrete culverts. The results showed that installing polypropylene modular wells costs less than concrete culvert wells. In addition, the use of modular wells also has advantages in terms of ease of installation and maintenance, as well as efficiency in land use. Endurance strength Modular wells can carry a load of up to 24 tons/m2. Thus, the results of this study are expected to provide alternative methods of storing clean water in Pontianak City that are more effective and efficient in terms of cost and quality by considering technical and environmental factors.

Enhancing Oil Palm FFB Yields by Water Management: Sumber Tani Agung Resources’ Experiences

Oil palms (Elaeis guineensis) are generally able to grow economically on various soil types, especially across the regions of Malaysia and Indonesia. However, Fresh Fruit Bunche (FFB) production was lesser in flood-prone areas. In Sumber Tani Agung Resources (STAR), two estates namely (i) Seret Ayon (4289 ha) and (ii) Lembah Bawang (2511 ha) were facing problems of frequent flooding. Annual rainfall of these two estates would fall within 3500 mm - 4000 mm. Out of this, almost 30-40% of the total annual rainfall was recorded in the period of October-December. Furthermore, during the same period, high rainwater from the Forest Reserve of Bengkayang resulted from high water volume in the streams/rivers running across these estates. This caused high incidences of flooding. Therefore, a yield improvement program was embarked on to arise the existing height of riverbanks, literally speaking an ‘embankment or bund management’ on both banks of the river. A survey should be conducted first to demarcate areas that are prone to flooding incidences. Based on the survey results, areas that need improvement by ‘embankment’ would be identified and actions such as construction of flap-gates, building of embankments, and construction of drainage/reservoirs can be made. Outlet drains were desilted and thus, improved the water flow for smooth removal of excess water during the high pour and flooding seasons. FFB yields were satisfactorily increased from 11-14 mt/ha/yr during 2017-2018 to 25-33 mt/ha/yr in 2022. Besides improving FFB yields, palm growth also satisfactorily improved in frequently flooding areas, especially after three years of water management by embankment. In this paper, the commercial FFB yield of Seret Ayon Estate and Lembah Bawang Estate was collected and compared to those from before and after the implementation of efficient water management by embankment.

Optimized tillage can enhance crop tolerance to extreme weather events: Evidence from field experiments and meta-analysis

The frequency of droughts and floods has increased due to climate change and human activities, leading to adverse impacts on agricultural production. Conventional tillage exacerbates the vulnerability of crops to extreme weather. Optimized tillage practices can maintain crop yield stability by increasing soil water-holding capacity during dry seasons and improving crop lodging resistance during heavy rainfall events. The effects of tillage practice under different rainfall types on the productivity of summer maize were studied by combining a five-year field experiment and a meta-analysis. The study tested four tillage treatments: conventional tillage (CT), no-tillage (NT), ridge cultivation with no-tillage (RNT), and winter wheat conventional tillage followed by summer maize no-tillage (NC). Normal rainfall years (2018, 2019 and 2021), a wet year (2020), and a drought year (2022) were experienced during the experiment. Compared to CT, NC significantly increased available soil water storage during the dry season by an average of 19.7 % (P < 0.05). NC and RNT had lower lodging rates during the wet year than CT, and over the five years, NC had a higher average maize yield (9.8 t ha−1) than RNT, while RNT had a higher yield during the wet year (10.7 t ha−1). NC also had significantly higher yield stability than CT. Furthermore, NC and RNT had higher rainwater use efficiencies (RUE) (23.9 and 23.0 kg ha−1 mm−1, respectively) than NT and CT (22.9 and 21.6 kg ha−1 mm−1, respectively). A meta-analysis showed that the crop yield under combined tillage (COT) was significantly higher than CT and NT by 6.7 % and 7.1 %, respectively, confirming the reliability and universality of the field experiment results. Overall, NC rotation is recommended as the best tillage system for sustainable crop production under semi-arid conditions, while RNT can be used in areas with abundant rainfall and prone to flooding. Our research findings offer evidence-based insights into management strategies that can enhance agricultural ecosystem resilience and production stability under extreme climate conditions.

Optimalisasi Lahan Kering Untuk Budidaya Bibit Tanaman Kenaf Sebagai Bahan Baku Industri Menuju Kebangkitan Ekonomi Kreatif Desa Suradadi Kabupaten Tegal

Agriculture in the Suradadi area, Tegal Regency, is still traditional and a tradition passed down from generations to generations. The agricultural pattern of farming is due to the experience and teachings of his parents. For agricultural production, only food crops, secondary crops and fruit are used. They grow crops when the rainy season arrives with high rainwater discharge. The problem that occurs in Suradadi village is less than optimal management of agricultural land which has an impact on the low economic life of Suradadi village farmers. And the aim of this PKM activity is to cultivate kenaf plants in Suradadi village to revive the economic life of farmers in Suradadi village, Tegal Regency. The partner of this PKM is the Gema Ripah farmer group, Suradadi village, Tegal Regency. The problems faced are the frequent harvest failures experienced by PKM Partners, the results obtained are not commensurate with the costs incurred by farmers, and the risk of losses is greater. So that the rice fields can be optimized by planting plants that can withstand heat or rain, and can be planted in various types of soil. Optimizing dry land can be carried out for cultivating kenaf seeds as a farming business in the Suradadi village farmer group, Tegal Regency. The results achieved during the assistance and training in kenaf cultivation, up to the age of 14 days, the kenaf plants grew very well, while keeping the soil moist to avoid evaporation and the plants wilting and dying.

A Model and Its Performance of Evapotranspirative Irrigation Tested to Grow Water Lettuces

Efficient use of irrigation water is crucial to face the uncertain trend of a declining water resource. Ensuring a supply of water that matches crop evapotranspiration (ETc) while optimizing soil moisture is challenging. This study aimed to come up with a model of an irrigation system that can supply water immediately to meet ETc without using electricity. To test the proposed water balance model a trial was established in water lettuces. The system consisted of 15 pots connected in serial using water pipes and hoses through the bottoms of the pots. The first pot was used as a water level controller and the last pot used as a drain water collector. Irrigation water would flow immediately to the pots that had water levels lower than the setting level. Testing carried out on rainy days resulted in considerably higher rainwater (99.8%) being utilized compared to the irrigation water (0.2%). For water lettuces, the yield was 258.9 g/m2, water use efficiency reached 95% while the economical and physical water productivity were 2.17 g/L and 2.28 g/L, respectively. The water level in the pots could be maintained within the expected range while the soil moisture maintained an unsaturated condition. Further tests however are still needed, which currently is underway.

Wire Extensometer Based on Optical Encoder for Translational Landslide Measurement

A landslide is a natural disaster mostly accompanied by heavy rains, earthquakes, or volcanic eruptions. Due to its significant incurred losses, several studies have been conducted to develop a landslide monitoring system. In this report, we built and implemented optical-based wire-extensometers to measure and monitor a translational landslide in a prone area. This extensometer was built of an optical rotary encoder (whose shaft bonded to a spiral spring and sling rope) interfaced to a low-cost microcontroller as a principal component and subsequently linked to a GSM-based wireless network. The working principle of the employed sensor described in this paperwork is to count optical pulse signal and convert it into a length unit. This sensor can provide much better signal stability and show high resolution for a wide-range measurement than voltage- or current-based sensors. The specification of the engaged optical encoder provides 2000 pulses per rotation, leading to a length resolution of 0.011 ± 0.0083 mm with a speed limit of about 36 mm/s. Furthermore, the wire extensometer was examined in a remote place near a double-track train road to assess its performance in an actual field. A solar cell system was applied as its main power supply. An example of transmitted data shows a land shift from 12 mm to 150 mm, which is mainly triggered by high rainwater infiltration. This result demonstrates that the developed extensometer is deserved to be promoted for landslide monitoring in the geological research-work area.

Study of ecodrainage system for hydrometeorological disaster mitigation

Hydrometeorological disasters such as floods and landslides are triggered by high rainwater. The disasters often cause loss of property, loss of fertile soil layers, and loss of life. Ecodrainages such as biopore holes, silt pits, and infiltration wells are soil and water conservation technique that can be useful for reducing surface runoff and increasing infiltration so that they can be used for hydrometeorological disaster mitigation. The study was carried out in the Keduang Sub-Watershed, Wonogiri District. The purpose of the study was to calculate the volume of rainwater during the year 2017 and the volume of rainwater that could be stored. Based on the Minister of Public Works Regulation of the Republic of Indonesia No.14 / PRT / M / 2010, each person needs an average of 60 liters/day of clean water. Monthly rainwater data were obtained from the Department of Agriculture and Food Crops Wonogiri district; the population data were obtained from the Central Bureau of Statistics (BPS), and administrative and sub-watershed maps were analyzed from the Indonesia Topographic Map (RBI) scale of 1: 25,000. Total rainwater during the year 2017 was 1,027,523,049.78 m3, while the population in the year 2017 was 492,725 people. Based on the calculation, the need for clean water was 10,790,677,500 liters (10,790,677.5 m3). The average runoff coefficient in the study area was 38.57%. Therefore during 2017, there was a rainwater surplus of 631,117,906,037.99 liters (631,117,906.04 m3) in The Keduang Sub Watershed.

Use of major ions to evaluate groundwater chemistry and identify hydrochemical processes in a shallow coastal aquifer in southeast Brazil

Coastal aquifers of southeastern Brazil have a fundamental role in economic and social terms, as it is a densely populated region with intense economic activity. The present research was carried out in the coastal region of the State of Rio de Janeiro and enclosed the Brazilian Nuclear Power Plants (NPP) site. The study aimed to assess the hydrochemistry of the shallow aquifer at the NPP's site and surroundings. The hydrochemical study was carried out based on data from 12 water samples, collected in October 2018, in which parameters were measured in situ (such as electrical conductivity, total dissolved solids, temperature, and pH) and in the laboratory (such as alkalinity; Ca2+, Mg2+, Na+, K+; Cl−, SO42−, and silicon). Using Piper and Chadha diagrams, the research identified four water types: Group 1 (Ca2+–Na+–HCO3−), Group 2 (Ca2+–HCO3−), Group 3 [Ca2+ (Na+ rich)–HCO3−], and Group 4 (Na+–Cl−). From the hillsides towards the beach line, the research results suggest a hydrochemical evolution of local groundwater from Group 1 (high rainwater influence), passing through Group 3 (intermediate between Group 1 and 2) and Group 2 (rock influence), to Group 4 (seawater like). The waters of groups 1 to 3 showed potential for base cation exchange (softening or freshening process), while, in Group 4, the potential is for reverse cation exchange (hardening or salinizing process). In a general hydrogeology context, the methods and applied techniques proved to be particularly efficient in identifying potential hydrochemical processes. Noteworthy is the freshening cation exchange identified in the shallow aquifer at NPP’s site. Therefore, theoretically, in case of an accidental release of radionuclides from the NPP to the aqueous phase, the local clay lenses can capture the divalent cation Ra2+ in a natural contamination attenuation process.

A lucerne-digit grass pasture offers herbage production and rainwater productivity equal to a digit grass pasture fertilized with applied nitrogen

In recent years, livestock producers have widely sown tropical perennial grasses, such as digit grass (Digitaria eriantha), in the frost-prone summer dominant rainfall zone of eastern Australia. Tropical grasses require substantial nitrogen inputs to maintain water productivity and forage quality. Perennial legumes offer a potential nitrogen source for these perennial grasses when sown in a mixed sward. Lucerne (Medicago sativa) is the perennial legume most widely sown in grazing systems in south-eastern Australia. In this study, conducted over the period 2014–2018, we compared the soil water dynamics and rainwater productivity of pure stands of digit grass (fertilized with applied nitrogen), lucerne, desmanthus (Desmanthus virgatus) and leucaena (Leucaena leucocephala) and binary mixtures of digit grass (not fertilized with applied nitrogen) with each legume. We found that often growing season actual evapotranspiration (ETa) was similar among the treatments (P > 0.05), but rainwater productivity (kg DM/ha.mm) and proportion (%) of legume herbage mass were not (P < 0.05). Our results showed that the lucerne-digit grass mix was equally productive and efficient as fertilized digit grass (P > 0.05), particularly in the latter three seasons. However, lucerne dominated the herbage mass (c. > 67% legume). Leucaena production was delayed by frost and severely impacted by competition with digit grass, and generally underperformed both lucerne and desmanthus. This observation did always not hold when alfalfa mosaic virus (AMV) impacted desmanthus in specific seasons. Our experiment has shown that a mixed sward of lucerne-digit grass is highly productive and offered high rainwater productivity. Both desmanthus and leucaena, in mixes with digit grass, provided useful contributions of legume herbage mass, in specific seasons and under specific conditions, but both underperformed overall compared with lucerne.

A new solution of high-efficiency rainwater irrigation mode for water management in apple plantation: Design and application

Due to the lack of stable irrigation water sources and low rainwater utilization efficiency, soil water deficit has become the main factor restricting the sustainable development of the apple industry in the Loess Plateau. The scientific and efficient use of rainwater for irrigation may provide a new solution to alleviate the regional soil water deficit. Rainwater is the only water source for the growth of apple trees, and whether it can be used as a stable and sustainable irrigation water source should be quantitatively considered. At present, there is still a lack of quantitative data to support whether rainwater can meet the irrigation needs of apple orchards. In this research, rainwater harvesting technology is combined with a solar intelligent irrigation system equipped with soil moisture sensors to form a high-efficiency rainwater irrigation (HRI) mode suitable for dryland apple orchards. Through practical application, this study found that HRI mode can effectively improve the soil drought of 0–200 cm and keep the soil water content in a relatively stable range during the apple growth period. Compared with only using rainwater harvesting technology and combined with traditional irrigation methods (SDI), HRI mode can increase apple yield by 56.2% and 22.0%, WUE by 40.4% and 12.6%, respectively. With the increase of apple yield, HRI mode has good economic feasibility, and its economic recovery period is 2 years. On the regional scale, this study selected irrigation guarantee rate and solar energy resources as evaluation indicators to further divide the areas suitable for rainwater irrigation in apple-cultivating region on the Loess Plateau. The area where the irrigation guarantee rate of rainwater was greater than 75% is 1.22 × 107 m2, accounting for 47.6% of the total area. This means that apple production in the Loess Plateau can increase by approximately 549.8 tons/year, save 1.5 × 104 m3 of irrigation water resources, and increase WUE by about 33.4%. Under the two different future climate scenarios (RCP 2.6 and RCP 8.5), the area accounted for 49.7% and 57.2% respectively, which was higher than the current situation. The areas with high rainwater irrigation guarantee rates are mostly concentrated in the central and southern parts of the apple-cultivating region. To maintain the sustainable development of the orchard ecological environment, areas with insufficient rainwater should assist other water management measures. In conclusion, high-efficiency rainwater irrigation can effectively alleviate the water contradiction in apple-cultivating region. In future agricultural water management, more attention should be paid to precision rainwater irrigation to ensure the coordinated development of agricultural economy and ecological environment.

Assessment of Rainwater Harvesting Potential from Roof Catchments through Clustering Analysis

Rainwater harvesting from rooftop catchments represents a climate change adaptation measure that is especially significant in areas affected by water scarcity. This article develops a Geographic Information Systems-based methodology to evaluate the spatial distribution of rainwater catchment potential to identify the most favorable urban areas for the installation of these infrastructures. Since performance and water saving potential of rainwater harvesting systems greatly depends on population density and roof size, this assessment was performed for each residential plot on a per capita basis, based on cadastral data and a method of demographic disaggregation. Furthermore, to evaluate spatial variation of runoff coefficient per building, a supervised classification was carried out to consider the influence of roof types on the rainwater catchment potential. After calculating rainwater catchment potential per capita for each residential plot, the spatial clustering of high (hot spots) and low values (cold spots) was assessed through the Getis-Ord General G statistic. Results indicate a spatial pattern of high rainwater catchment potential values in low-density urban areas, where rainwater catchment systems are expected to offer a better performance and a shorter amortization period. These results may be useful for the enactment of local legislation that regulates the obligation to install these infrastructures or offers subsidies for their implementation.

Effect of organic and inorganic nutrients on pearl millet (Pennisetum glaucum)- gobhi sarson (Brassica napus var. napus) cropping sequence

A pronounced residual effect of organic and inorganic nutrients, applied in pearl millet crop was observed on yields of pearl millet [Pennisetum glaucum (L.) R Br]-gobhi sarson (Brassica napus L. var napus) cropping system. The experiment was conducted (by way of inorganic and organic sources combinations) with 8 treatments of FYM, vermicompost, inorganic N and control. The highest growth, yield and yield parameters of pearl millet crop were recorded with 100% recommended fertilizer dose-RFD and the grain yield (2899 kg/ha) was about 85.2% higher over the control and was followed by statistically similar treatment 75% N inorganic + 25% VC with the grain yield value of 2703 kg/ha. In case of gobhi sarson, the highest grain yield (855 kg/ha) was observed owing to residual effect of 100% N through vermicompost (VC) applied in preceding pearl millet crop, which was about 82.3% higher over the control. The treatments where 50% N was substituted by FYM and VC in pearl millet crop had the statistically similar grain yield values of gobhi sarson. The highest rain water use efficiency (RWUE) and heat-use efficiency (HUE) was recorded in treatment 100% RFD in pearl millet crop and 100% N through VC in gobhi sarson.

Multi-proxy approach on the hydrocarbon generation perspective of Barjora Basin, India

Abstract Barjora Basin in India is a small basin characterized by a high organic richness of early mature nature. The present study aims to find the source of organic matter (OM) and hydrocarbon generation potential of Barjora Basin. Systematically collected coal and shale samples from R-II seam of the basin were used for proximate and ultimate analyses, Rock Eval pyrolysis along with total organic carbon (TOC) content, organo-micropetrographic framework, thermal maturity, carbon isotopic signature, biomarker composition, functional group studies and estimation of relative aliphaticity and aromaticity through Fourier Transform infrared spectroscopy (FTIR). The novelty of the present work lies in the application of multiple proxies such as stable isotope ratio of organic carbon (δ13C), biomarker signatures, thermal maturity parameters, organo-micropetrography and estimation and quantification of functional groups for palaeoenvironmental reconstruction and to assess the hydrocarbon productivity of the basin. A dominant terrestrial OM input in Barjora Basin is indicated by the TOC to total nitrogen ratio (C/N), δ13C and biomarker compositions. High gelification index (GI), tissue preservation index (TPI), and carbon preference index (CPI) values indicate that coals are deposited in wet swamp forest regime under high rainwater conditions and shales are formed in upper delta plain regime under high groundwater activity. In addition, large liptinite content, TPI and GI designate short transportation of the OM before burial leading to organic richness of the Barjora Basin. Moreover, high liptinite content, type II-III admixed kerogen input, S2/S3 ratio, TPI and index for hydrocarbon generation (IHG) signify higher potential of the basin for hydrocarbon generation.

Evidence of precedent wind role on controlling PM1 wet scavenging of aerosols during monsoon rain events

The role of precedent winds over fine mode (0.05–1 μm) aerosols during 2016 rainfall event is studied in this manuscript. Here, we show that concomitant wind actions influence over scavenging process during south-west monsoon rainfall over Mahabaleshwar at High Altitude Cloud Physics Laboratory (HACPL-17.56°N, 73.4°E, site altitude-1373m). During monsoon, PM1/PM10 mass ratios revealed dominance of PM1 for June, July, August, September and October as ∼80%, 90%, 98%, 97%, and 95% respectively. Fine mode aerosols and rains associated with lower precedent wind speeds ∼2 m/s were found to enhance the scavenging from ∼60 to 90% based (before minus after rainfall event) on Aerosol Chemical Speciation Monitor (ACSM) mass (SO42−, NO3−) concentrations. Similarly, before rain CCN number concentration and wind speed exhibited, −0.34 correlation coefficient (at 0.99% significance level) suggesting a viable decrease in CCN concentration due to increased wind speed. It was also observed that ventilation coefficients maxima values ∼12500 m2/s to be negatively correlated with before rain minima Cloud Condensation Nuclei (CCN) concentrations falling down to ∼1000 cm−3. Moreover, three major sources such as vehicular, thunder lightning frequency and long range transport were found to control the monthly volume weighted average concentrations of rainwater. The mass (SO42−, NO3−) concentration for the monthly volume weighted averages with relatively high rainwater concentrations of NO3− (9.02 ± 4.71μg/m3) and SO42−(11.61 ± 6.71μg/m3) for the month of June, with minimum of NO3−(4.11 ± 1.16 μg/m3) and SO42−(9.91 ± 7.07μg/m3) were seen in month of July and September respectively. However, October (16.45 ± 5.17μg/m3, 8.08 ± 3.46μg/m3) displayed an increase in both SO42− and NO3− rainwater concentration due to long range and increased local sources scavenging processes. Our results indicate that aerosol loading are mostly wind speed and direction driven by anthropogenic and natural origin, and have a notable impact on removal processes.

Degradation of the urban ecosystem function due to soil sealing: involvement in the heat island phenomenon and hydrologic cycle in the Tokyo metropolitan area

ABSTRACT We reviewed the role of the soil function of urban green space in mitigating the heat island phenomenon and urban flood damage, which are important issues in the modern urban environment. Urban sprawl has progressed remarkably in the southern part of the Kanto District of Japan, especially since the 1960s. The grassland/bare land area ratio in the center of Tokyo was more than 70% in the 1930s but less than 40% in 1990. On the other hand, the paving area ratio was ~2% in the 1930s but more than 10 times that amount in 1990. Thus, cities, such as Tokyo, in the southern part of the Kanto District have been significantly sealed soil throughout time, and the heat island phenomenon has intensified. Urban green space helps to mitigate the heat island phenomenon based on the water retention and heat dissipation function of plants and unsealed soil. A cool island effect was reported during summer days in urban green spaces in Tokyo. The mitigation of the heat island effect seems to be large, even when conditions, such as the park area, land use, afforestation area ratio, and soil type, differ. Soil sealing and compaction affect urban flooding by hindering the penetration of rainwater and increasing surface runoff. According to a survey in the hilly basin (1 km2) of the western part of Tokyo, the proportion of farm- and forestland decreased due to development. The urban area increased from ~10% in the 1970s to ~60% in the 1980s. As a result, the flood arrival time shortened. Green spaces have a high rainwater permeability. The forest soil structure and presence of O horizons further increase the permeability. By promoting permeability to the underground, it is possible to reduce and delay the water runoff on the land surface. To develop urban green space as green infrastructure, it is necessary to accumulate more information on the current situation and agenda for the future of urban green space.

Improvement of Rainwater Infiltration Property and Its Effect on the Corresponding Storage Capacity of Soil in Urban Green Space

Urban green space whose soil permeability is the main factor affecting hydrological cycle plays a very important role in promoting rainwater infiltration, replenishing groundwater and reducing peak flow. In order to enhance the storage and infiltration ability of soil, different types and contents of conditioner are added to study the laws of the changes in permeability of various soils. The results showed that straw and sawdust can effectively increase the permeability coefficient of soil. According to the comparison under the same conditions, the improvement effects of straw is slightly better than sawdust, but no order of magnitude difference. The sandy soil reformed by 3.6% Straw or 4.2% Sawdust and the loam reformed by 29.5% Straw or 30.2% Sawdust can meet infiltration requires of rainwater whose rainstorm recurrence period is 10 years. The clay is not suitable for urban green space soils with higher rainwater storage and infiltration requirements. The reformed green space can effectively reduce the runoff peak flow and delay the generated time of the runoff. The higher the content of the modifier, the more obvious the advantage of promoting the hydrological cycle and reducing the runoff.

Evolution of Mesoscale Convective System Organizational Structure and Convective Line Propagation

AbstractThis study examines organizational changes and periods of rapid forward propagation in an MCS on 6 July 2015 in South Dakota. The MCS case was the focus of a Plains Elevated Convection at Night (PECAN) IOP. Data from the Sioux Falls WSR-88D and a high-resolution WRF simulation are analyzed to examine two periods of rapid forward propagation (or surges) and organizational changes. During the first surge (surge A), the northern portion of the convective line propagates eastward faster than the southern portion, and the northern portion of the leading line transitions from a single convective core to a multicellular structure as it merges with convection initiation. Radar reflectivity factor Z and graupel concentrations decrease above the melting layer, while at lower altitudes Z increases. The MCS cold pool also intensifies and deepens beneath an expanded region of high rainwater content and subsaturated air. Throughout surge A, a mesoscale circulation with strong rear-to-front near-surface flow and front-to-rear midlevel flow is also evident. By the end of surge A, the leading edge of the MCS cold pool is beneath developing convection initiation ahead of the original convective line while the original convective updraft weakened and moved rearward. This MCS evolution is similar to discrete propagation events discussed in past studies, except with new convection developing along an intersecting convective band. During surge B, the MCS transitions from a multicellular structure to a single, intense updraft. Smaller microphysical and thermodynamic changes are observed within the MCS during surge B compared to surge A, and the mesoscale circulation continues to develop.

The influence of diesel-truck exhaust particles on the kinetics of the atmospheric oxidation of dissolved sulfur dioxide by oxygen.

The automobile exhausts are one of the major sources of particulate matter in urban areas and these particles are known to influence the atmospheric chemistry in a variety of ways. Because of this, the oxidation of dissolved sulfur dioxide by oxygen was studied in aqueous suspensions of particulates, obtained by scraping the particles deposited inside a diesel truck exhaust pipe (DEP). A variation in pH showed the rate to increase with increase in pH from 5.22 to about ∼6.3 and to decrease thereafter becoming very slow at pH = 8.2. In acetate-buffered medium, the reaction rate was higher than the rate in unbuffered medium at the same pH. Further, the rate was found to be higher in suspension than in the leachate under otherwise identical conditions. And, the reaction rate in the blank reaction was the slowest. This appears to be due to catalysis by leached metal ions in leachate and due to catalysis by leached metal ions and particulate surface both in suspensions. The kinetics of dissolved SO2 oxidation in acetate-buffered medium as well as in unbuffered medium at pH = 5.22 were defined by rate law: k obs = k 0 + k cat [DEP], where k obs and k 0 are observed rate constants in the presence and the absence of DEP and k cat is the rate constant for DEP-catalyzed pathway. At pH = 8.2, the reaction rate was strongly inhibited by DEP in buffered and unbuffered media. Results suggest that the DEP would have an inhibiting effect in those areas where rainwater pH is 7 or more. These results at high pH are of particular significance to the Indian subcontinent, because of high rainwater pH. Conversely, it indicates the DEP to retard the oxidation of dissolved SO2 and control rainwater acidification.

Effects of integrated nutrient management on growth and yield of maize (Zea mays L.) - Gobhi sarson (Brassica napus L.) cropping system in sub-tropical region under foothills of north-west Himalayas

A pronounced residual effect of organic and inorganic fertilizers, applied in maize crop was observed on yields of maize-gobhi sarson cropping system. The experiment was conducted with 10 treatments of N, P, K, FYM, crop residue and zinc sulphate nutrients. The highest growth, yield and yield components of maize crop were recorded with 100% recommended fertilizer dose-RFD + ZnSO4 20 kg/ha and the grain yield (2409 kg/ha) was about 101% higher over the control. In case of gobhi sarson, the highest seed yield (1081 kg/ha) was observed as a pronounced residual effect of 10 t/ha FYM in preceding maize crop; which was about 81% higher over the control. The treatments where 50% N was substituted by FYM and crop residue in maize crop had the best reflection in enhancing the seed yield of gobhi sarson to the tune of 74 and 70% over the control and 16 and 13% over farmer’s practice. The highest rain water use efficiency (RWUE) and heatuse efficiency (HUE) was recorded in treatment 100% RFD + ZnSO4 20 kg/ha in maize crop and 10 t/ha FYM in gobhi sarson. DOI: http://dx.doi.org/10.3329/bjb.v43i2.21666 Bangladesh J. Bot. 43(2): 147-155, 2014 (September)