Possible mechanisms related to internal dynamics for anomalously high rainfall during August 2020 of Indian Summer Monsoon

In the present study, an investigation is made to understand the physical mechanism behind the anomalous high rainfall during August 2020 over the Indian subcontinent using both observation and GFS T1534 weather forecast model. According to India Meteorological Department (IMD), the country receives 27% excess rainfall in the month of August 2020. The excess rainfall is mainly contributed by the 5 well marked low pressure systems which formed over Bay of Bengal and moved west-northwestwards across central India up to Western Madhya Pradesh and Rajasthan. The analysis reveals that the observed anomalous rainfall is distributed over central India region extending from coastal Orissa to central part of Chhattisgarh, Madhya Pradesh and western coast of Gujarat region. It is also found that the August-2020 heavy rainfall is mainly contributed by the synoptic (2-10 days) component of the total rainfall whereas the contribution of the large-scale intraseasonal oscillation (ISO) component (10-90 days) is quite less. Although the present operational Global Forecast System (GFS) T1534 (GFS T1534) is able to predict the anomalous high rainfall with day-1 lead time, it underestimates the magnitude of the synoptic variance. Further, the large-scale dynamical and thermodynamical parameters show anomalous behaviour in terms of strong low level (850 hPa) jet, vertical velocity and associated moisture convergence in the lower level. The GFS T1534 is able to forecast the above large-scale features reasonably well even with day-5 lead time. From energetics analysis, it is found that the mean kinetic energy (MKE) is stronger for August 2020 as compared to climatological value and the strong MKE efficiently transfers the energy to the synoptic scale, and hence the synoptic eddy kinetic energy is higher. Along with that, the ISO scale kinetic energy for August 2020 is less compared to the August climatological value. GFS T1534 model has some fidelity in capturing the energy conversion processes, but it has some difficulty in capturing the magnitude with increased lead time.

Past rainfall and trace element variations in a tropical speleothem from India

An actively growing stalagmite (cave deposit) was collected in 1996 from the Dandak cave in Madhya Pradesh. Trace elements Mg, Sr and Ba were measured in order to asses their palaeoclimatic significance. More than 100% variations in the concentrations of trace elements have been observed during the growth period. The chemical and physical properties of the trace elements along with the data of stable isotope ratios of exygen and carbon from our earlier work has been discussed in this paper. Ratio of Ba to Sr concentrations has remained constant suggesting that the soil layers and bedrock dissolution have contributed the same proporation of trace elements to the cave seepage water. Slowly varying components in the Mg, Sr and Ba concentrations and profiles show high degrees of correlations. It is found that changes in the trace elements are mainly driven by the varying intensity of past rainfall. Trace element variations of speleothems in tropical regions can be used as indicators of the past rainfall intensities. Different climatic intervals are characterised based on trace elements and stable isotoes. Period 3700 to 3350 yr BP was found to be arid. High rainfall was observed between 3350 to 3200 yr BP. After a hiatus period of 2000 yr due to non-climate dependent proceses, again a high rainfall phase between 1200 to 400 yr BP was observed with a peak level at ~200 yr BP and a short arid phase at ~90 yr BP was also observed.

Existence of Vivipary in Mango (Mangifera indica cv. ‘Amrapali’) – A Report

Aim: The Amrapalii cultivar of mango is known for its dwarf stature, high productivity and ability to capture the market late when mango from other regions of the country gets over. Vivipary is of unusual occurrence in mango. The aim of the study is to report the occurrence of vivipary in mango especially in cultivar Amrapali under the sub-Himalayan subtropics of India. Materials and Methods: Incidental occurrence of vivipary in mango has been reported from the Hamirpur district of Himachal Pradesh during the growing season of the year 2021. Upon observance of abnormal protuberances from the fruit surface, the harvesting was commenced at the weekly intervals and the per cent proportion of viviparous fruits was ascertained by cutting the fruits longitudinally and confirming the viviparous germination of the seeds. Weather data of the fruit development state were analysed for the accumulation of heat units and rainfall distribution. Efforts have been made for ascertaining the reason behind the viviparous seed development. Results and Discussion: The proportion of viviparous seeds increased with the progression of time and by the mid of September, more than 12% of seeds were found viviparous. The weather data show that there was an early accumulation of heat units. Also, the rainfall during the period of fruit development was high particularly at the time when fruits were advancing toward maturity. It has been observed that the seed maturity has preceded the fruit pulp maturity and ripening may be due to the early accumulation of heat units and high rainfall. This coincidence might have resulted in precocious germination of seed inside the fruit, leading to vivipary. Conclusion: The development of vivipary in Amrapali mango has been found to be associated with the early accumulation of heat units and high rainfall. Under the current changing climatic scenario, a need has been projected for strategic research for curtailing vivipary incidences and saving economic losses to the growers of late mango varieties in the sub-Himalayan subtropics.

CHANGE OF MAXIMUM RAIN PATTERN BASED ON RAINFALL DATA OF BANJARBARU CLIMATOLOGY STATION CAUSED BY CLIMATE CHANGE

According to the World Meteorological Organization that 2014 was the hottest year in which the hot weather alternated with high rainfall and floods which destroyed the people's economy. Banjarbaru, as one of the central cities of the government of South Kalimantan Province, has a topographic condition that is at an altitude of 0-500 m above sea level, causing rainfall, which is enough frequent. Banjarbaru itself is one of the cities affected by climate change in 2014. Disasters that occurred in the form of flooding at several points of residents and also crippled traffic at that time. Thus, it is important to know the pattern of maximum rainfall changes that occur. By knowing the pattern of maximum rainfall changes, the impact of the high rainfall that can occur will be minimized and can even be anticipated as early as possible. Data processing is performed with maximum daily rainfall data of 30 years and divided into a database before and after climate change that is 25 years old data and 5 years of new data. Each database calculates the planned rainfall for the return period of 2-1000 years with the distribution obtained from the analyzed database. Next, analyze the deviation of the two data. The purpose of analyzing the deviation of old data and new data is to determine changes in the planned rainfall from both data. Deviation analysis uses the Peak-Weight Root Mean Square Error function. The conclusion of the analysis is that based on the Statistical Parameters test, the Chi-Square test, and the Smirnov-Kolmogorov test on the old database using the Gumbel distribution and the new data using the Pearson Log Type III distribution for the calculation of the planned rain. Based on the analysis of the rain plan to get new data 5 years has the results of the rain plan is greater than the old data of 25 years and the analysis of the deviation to get the results of the new data 5 years has a greater value of deviation each time when revisiting the old data of 25 years. So it can be suggested that rainfall data with the same characteristics, can use 5 years of new data for the analysis of water building planning.

Flood Vulnerability Study of Pangkalpinang City, Bangka Belitung Archipelago Province

Pangkalpinang city is one part of Bangka Belitung Archipelago Province which has an area of 118.41 km2 with seven districts and consist of forty-two villages. Based on its location on the eastern part of bangka island make pangkalpinang closer to the coast and watersheds so that it can be said it have a relatively low average land elevation (topography) with a height of 20-50 meters above the sea with a slope of 0-25 %. The research was carried out quantitatively and qualitatively with the parameters of determining the administrative boundaries of each district, the selection of applicable rules regarding the applicable land use zoning or spatial planning (RT/RW), topography, surrounding watersheds, and population density of settlements in Pangkalpinang City. These parameters are then carried out using overlay, scoring and layout techniques to see the distribution of the flood vulnerability level pattern. The results showed that flood vulnerability (very vulnerable) with low topography (0-10 meters above sea level) was in the northwest area of Bukit Intan District and Taman Sari District. Flood vulnerability (vulnerable to less vulnerable) with moderate topographic values (10-19 meters above sea level) is in Gerunggang and Gabek Districts, while vulnerability is not vulnerable with high average topographic values (above 20 meters above sea level). in the northern part in the Districts of Gerunggang, Gabek, and Pangkalbalam. In the northwest part of Pangkalpinang City, if there is an increase in tides or high rainfall intensity, the area will be inundated (flooded).

The community adaptation strategy in dealing with landslide disaster in Banaran Village Ponorogo Regency

A landslide disaster occurred in Tangkil, Banaran Village, Ponorogo Regency on April 1st, 2017 which caused many casualties. The objectives of this research were to determine the factors that caused the landslide and to determine the community adaptation strategy in dealing with landslide. This research applied descriptive qualitative method with its data collection included observation, interview, and documentation. The research results showed, 1) the factors causing landslide were steep slopes, fertile rocks and soils, land conversion, high rainfall, and human activities, 2) the community adaptation strategy involved adaptation and adjustment in dealing with landslide. The impacts of landslide have been felt by the community thus, they could change their behavior towards their environment and make adjustments to the new environment.

Analysis of the role of plant canopy on hydrological systems

High rainfall intensity causing high erosion rates in Indonesia. Land cover conditions greatly determine water degradation in the hydrological cycle. The shape and type of plants canopy have significant effect on soil structure and water absorption. This study aimed to examine the role of plant canopy on the value of rainwater canopy escape as a supporter of hydrological cycle. Tree species were determined based on the level of dominance at study site using transect method. The dominant trees are Sea Sengon Tree (Paraserianthes falcataria), Teak Tree (Tectona grandis), Suren Tree (Toona sinensis) and Durian Tree (Durio zibethinus). The results showed that high rainfall intensity with a long rain period affected the amount of canopy escape. Durian Tree has highest canopy density with value of 0.301, and Sengon Laut is the lowest with value of 0.240. The value of passing the canopy of the Suren Tree is lower than the other tree species. The shape of canopy of Suren tree, which is round and oval, also affects the lower pass value of canopy compared to other tree species. The higher the value of canopy density can reduce the value of canopy escape to support the hydrological cycle.

Rainfall driven and wild-bird mediated avian influenza virus outbreaks in Australian poultry

Globally, outbreaks of Avian Influenza Virus (AIV) in poultry continue to burden economies and endanger human, livestock and wildlife health. Wild waterbirds are often identified as possible sources for poultry infection. Therefore, it is important to understand the ecological and environmental factors that directly influence infection dynamics in wild birds, as these factors may thereby indirectly affect outbreaks in poultry. In Australia, where large parts of the country experience erratic rainfall patterns, intense rainfalls lead to wild waterfowl breeding events at temporary wetlands and increased proportions of immunologically naïve juvenile birds. It is hypothesized that after breeding, when the temporary wetlands dry, increasing densities of immunologically naïve waterbirds returning to permanent water bodies might strongly contribute to AIV prevalence in wild waterfowl in Australia. Since rainfall has been implicated as an important environmental driver in AIV dynamics in wild waterbirds in southeast Australia and wild waterbirds are identified globally to have a role in virus spillover into poultry, we hypothesise that rainfall events have an indirect effect on AIV outbreaks in poultry in southeast Australia. In this study we investigated this hypothesis by examining the correlation between the timing of AIV outbreaks in poultry in and near the Murray-Darling basin in relation to temporal patterns in regional rainfall since 1970. Our findings support our hypothesis and suggest that the risk of AIV outbreaks in poultry increases after a period of high rainfall, with peak AIV risk two years after the onset of the high-rainfall period. This is presumably triggered by increased rates of waterbird breeding and consequent higher proportions of immunologically naïve juvenile waterbirds entering the population directly after major rainfall events, which subsequently aggregate near permanent water bodies when the landscape dries out.

Kajian Lokasi Rawan Bencana Banjir Pada Daerah Aliran Sungai (DAS) Walanae Kecamatan Dua Boccoe Kabupaten Bone

Bencana Banjir yang sering melanda Kabupaten Bone khususnya Kecamatan Dua Boccoe bukan hal baru. Dalam 20 tahun terakhir, Kecamatan ini sudah identik dengan kawasan banjir yang di sebabkan oleh curah hujan yang tinggi sehingga DAS Walanae meluap. Penelitian yang dilakukan bersifat deskriptif kualitatif atau penelitian terapan. Penelitian kualitatif merupakan penelitian non matematis dengan proses menghasilkan data-data dari hasil temuan berupa Observasi Lapangan. Analisis yang digunakan dalam penelitian yaitu analisis deskriptif kualitatif dengan menggunakan pendekatan Overlay (Superimpose). Dari hasil analisis data diketahui yang sangat berpotensi banjir ada 8 kelurahan/desa, yang meliputi Kelurahan Unyi, Desa Uloe, Desa Pekkasalo, Desa Kampoti, Desa Tocina, Desa Tawaroe, Desa Solo, dan Desa Matajang. Dengan seluas 131 km2, dan tinggi genangan eksisting ± 100-200 cm den periode genangan 10 jam menyebabkan Kecamatan Dua Boccoe sangat berpotensi terkena banjir. Floods is one of disaster that often hit Bone Regency, especially Dua Boccoe Subdistrict. In the last 20 years, flood that happened in this sub-district caused by high rainfall so that the Walanae watershed overflows. The research conducted is descriptive qualitative or applied research. Qualitative research is a non-mathematical research with the process of generating data from the findings in the form of field observations. The analysis used in this research is qualitative descriptive analysis using the Overlay (Superimpose) approach. From the results of data analysis, it is known that there are 8 sub-districts/villages with high potential for flooding, which include Unyi Village, Uloe Village, Pekkasalo Village, Kampoti Village, Tocina Village, Tawaroe Village, Solo Village, and Matajang Village. With an area of 131 km2, and an existing inundation height of ± 100-200 cm with an inundation period of 10 hours, Dua Boccoe District is very potentially affected by flooding