Heavy Rainfall Distributions Over Java Sea in Wet Season

Abstract In this study, meridional migration characteristic of diurnal heavy rainfall (DHR) over Java and surrounding waters and its relation to Madden Julian Oscillation (MJO) during extreme events was investigated. The rainfall data was the Climate Prediction Centre Morphing (CMORPH) V1.0 in the December-January-February (DJF) wet season of the 1998-2019 period. The thresholds of extreme events were based on the 95% percentile of daily rainfall area average of mountainous area (MA), northern plain area (NPA), northern waters (NW), southern plain area (SPA), and southern waters (SW) that were based on Global Land One-kilometer Base Elevation (GLOBE) Digital Elevation Model. We analyzed meridional migration of DHR through composite and the Hovmoller diagram. To get the MJO signal, we used the Wheeler-Kiladis wavenumber-frequency domain to filter outgoing longwave radiation (OLR). The results showed that DHR was stationary over the mountains, migrated to the Java Sea (The Indian Ocean), and was stationary over the Java Sea (Indian Ocean) in conjuction with migration from Java to the waters when extreme events occur over MA, NPA (SPA), and NW (SW), respectively. Based on a comparison of MJO-OLR during extreme events period of MA, NPA, SPA, NW, and SW, it seems that MJO had a stronger impact on the DHR of NW and SW than the others, but it must be examined based on significant test in the further study.

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Characteristics of Groundwater Response to Precipitation for Landslide Prevention at Kiyomizu-Dera

Journal of Disaster Research ◽

10.20965/jdr.2017.p0993 ◽

2017 ◽

Vol 12 (5) ◽

pp. 993-1001

Author(s):

Toru Danjo ◽

Tomohiro Ishizawa ◽

Masamitsu Fujimoto ◽

Naoki Sakai ◽

Ryoichi Fukagawa ◽

...

Keyword(s):

Groundwater Level ◽

Heavy Rainfall ◽

Slope Failure ◽

Field Measurements ◽

Scale Model ◽

Slope Failures ◽

Wet Season ◽

Soil Failure ◽

Groundwater Response ◽

Typhoon Season

Every year in Japan, slope failures often occur due to heavy rainfall during the wet season and typhoon season. The main reasons for soil failure are thought to be the increase of soil weight from infiltrated precipitation, the decrease in shear strength, and effects of the increase groundwater elevation. It is therefore important to consider to characteristics of groundwater behavior to improve slope disaster prevention. Kiyomizu-dera experienced major slope failures in 1972, 1999, and 2013, and a large slope failure occurred nearby in 2015. The two most recent events occurred since observation of precipitation and groundwater conditions began at the site in 2004. In this research, we determine the relationship between rainfall and groundwater level using both a full-scale model experiment and field measurements. Results indicate strong connection between rainfall intensity and the velocity of increase in groundwater level, indicating that it is possible to predict changes in the groundwater level due to heavy rainfall.

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Some Notes and Remarks on the Bionomics of Glossina morsitans

Bulletin of Entomological Research ◽

10.1017/s0007485300044527 ◽

1920 ◽

Vol 11 (2) ◽

pp. 113-132 ◽

Cited By ~ 6

Author(s):

Rupert W. Jack

Keyword(s):

Heavy Rainfall ◽

First Grade ◽

Dry Season ◽

Maximum Distance ◽

Appreciable Effect ◽

Wet Season ◽

Glossina Morsitans ◽

Capacity For Increase

In the foregoing pages the following tentative views have been put forward in the hope that they may receive either confirmation or criticism from other investigators : (1). The latter part of the dry season is probably, in general, the most favourable portion of the year to the fly. (2). The later the onset of the rains the greater the capacity for increase. (3). Seasons of unusually heavy rainfall are inimical, at least in certain areas. (4).A series of years of lew rainfall is favourable. (5).Regions where the fly commonly attains the greatest concentration of numbers are the regions where it is most liable to be reduced or to die out,namely, parts of the infested areas where first-grade foci predominate. (6).In Southern Khodesia the passage of grass fires has, as a rule, no appreciable effect on the numbers of the fly. (7).Mopani belts are probably of considerable value to the fly in providing limited areas attractive to game in the wet season, where the grass remains short; they possibly also afford a convenient refuge from grass fires in the dry season. (8).The fly does not migrate under the stimulus of hunger or in company with game. (9).The fly as a whole does not follow game about infested areas. (10).The maximum distance at which a hungry fly readily detects its hosts is a short one, possibly less than 100 yards. (11).The maximum following distance of the females remains to be determined ; the writer is not yet convinced that the females seek animals and humanbeings only for the purpose of feeding, though this appears probable.

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Extended-Range Forecasts of Areal-Averaged Rainfall over Saudi Arabia

Weather and Forecasting ◽

10.1175/waf-d-15-0011.1 ◽

2015 ◽

Vol 30 (4) ◽

pp. 1090-1105 ◽

Cited By ~ 8

Author(s):

Michael K. Tippett ◽

Mansour Almazroui ◽

In-Sik Kang

Keyword(s):

Saudi Arabia ◽

Heavy Rainfall ◽

Mean Value ◽

Forecast Skill ◽

Global Ocean ◽

Heavy Rainfall Event ◽

Wet Season ◽

Rainfall Occurrence ◽

Extended Range ◽

Clear Relation

Abstract The climate of Saudi Arabia is arid–semiarid with infrequent but sometimes intense rainfall, which can cause flooding. Interannual and intraseasonal precipitation variability in the region is related to ENSO and MJO tropical convection. The predictability of these tropical signals gives some expectation of skillful extended-range rainfall forecasts in the region. Here, the extent to which this predictability is realizable in the Climate Forecast System (CFS), version 2, a state-of-the-art coupled global ocean–atmosphere model, is assessed. While there are deficiencies in the forecast climatology likely related to orography and resolution, as well as lead-dependent biases, CFS represents the climatology of the region reasonably well. Forecasts of the areal average of rainfall over Saudi Arabia show that the CFS captures some features of a spring 2013 heavy rainfall event up to 10 days in advance and a transition from dry to wet conditions up to 20 days in advance. Analysis of a 12-yr (1999–2010) reforecast dataset shows that the CFS can skillfully predict the rainfall amount, the number of days exceeding a threshold, and the probability of heavy rainfall occurrence for forecast windows ranging from 1 to 30 days. While the probability forecasts show good discrimination, they are overconfident. Logistic regression based on the ensemble mean value improves forecast skill and reliability. Forecast probabilities have a clear relation with the MJO phase in the wet season, providing a physical basis for the observed forecast skill.

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Assessment of spatial uncertainty of heavy local rainfall using a dense gauge network

10.5194/hess-2018-517 ◽

2018 ◽

Cited By ~ 1

Author(s):

Sungmin O ◽

Ulrich Foelsche

Keyword(s):

Heavy Rainfall ◽

Extreme Rainfall ◽

Rain Gauge ◽

Spatial Uncertainty ◽

Wet Season ◽

Rainfall Events ◽

Rain Gauges ◽

Areal Rainfall ◽

The Impact ◽

Heavy Rainfall Events

Abstract. Hydrology and remote-sensing communities have made use of dense rain-gauge networks for studying rainfall uncertainty and variability. However, in most regions, these dense networks are only available at sub-pixel scales and over short periods of time. Just a few studies have applied a similar approach, employing dense gauge networks, to local-scale areas, which limits the verification of their results in other regions. Using 10-year rainfall measurements from a network of 150 rain gauges, we assess spatial uncertainty in observed heavy rainfall events. The network is located in southeastern Austria over an area of 20 km × 15 km with no significant orography. First, the spatial variability of rainfall in the region was characterised using a correlogram at daily and sub-daily scales. Differences in the spatial structure of rainfall events between wet and dry seasons are apparent and we selected heavy rainfall events, the upper 10 % of wettest days during the wet season, for further analyses because of their high potential for causing hazard risk. Secondly, we investigated uncertainty in estimating mean areal rainfall arising from a limited gauge density. The number of gauges required to obtain areal rainfall with > 20 % accuracy tends to increase roughly following a power law as time scale decreases. Lastly, the impact of spatial aggregation on extreme rainfall was examined using gridded rainfall data with horizontal grid spacings from 0.1° to 0.01°. The spatial scale dependence was clearly observed at high intensity thresholds and high temporal resolutions. Quantitative uncertainty information from this study can guide both data users and producers to estimate uncertainty in their own observational datasets, consequently leading to the rational use of the data in relevant applications. Our findings are generalisable to other plain regions in mid-latitudes, however the degree of uncertainty could be affected by regional variations, like rainfall type or topography.

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Solar Energy for Sludge Drying in Alexandria Metropolitan Area: Case Study in Egypt

Water Science & Technology ◽

10.2166/wst.1990.0114 ◽

1990 ◽

Vol 22 (12) ◽

pp. 193-204 ◽

Cited By ~ 3

Author(s):

A. A. Hossam ◽

S. G. Saad ◽

H. H. Mitwally ◽

L. M. Saad ◽

L. Noufal

Keyword(s):

Heavy Rainfall ◽

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Climatic Conditions ◽

Wet Season ◽

Drying Time ◽

Treatment Processes ◽

Sludge Drying

An experimental study was conducted to assess the drainability of sludge generated by different treatment processes, and to assess a pilot solar heated sand drying bed in comparison with the regular beds located in the pilot plant at Alexandria Eastern Sewage Treatment Plant. It was found that the climatic conditions were generally favourable for dewatering sludge on sand drying beds except when there was heavy rainfall during the wet season which prolonged the drying time. The solar air heated drying beds saved about 35% of the bed area as compared with conventional sand drying beds, and the drying time was cut from 18 days to 8 days. It was also found that the solar air heated beds were less expensive than the conventional open sand beds.

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Fluvial organic carbon losses from a Bornean blackwater river

Biogeosciences ◽

10.5194/bg-8-901-2011 ◽

2011 ◽

Vol 8 (4) ◽

pp. 901-909 ◽

Cited By ~ 61

Author(s):

S. Moore ◽

V. Gauci ◽

C. D. Evans ◽

S. E. Page

Keyword(s):

Organic Carbon ◽

Unit Area ◽

Wet Season ◽

Blackwater River ◽

Covered Area ◽

Doc Concentration ◽

Annual Total ◽

Java Sea ◽

Blackwater Rivers ◽

Carbon Losses

Abstract. Concentrations of dissolved organic carbon (DOC) and particulate organic carbon (POC) were analysed from the source to the mouth of the River Sebangau in Central Kalimantan, Indonesia during the dry and wet seasons in 2008/2009 and an annual total organic carbon (TOC) flux estimated. DOC concentrations were higher and POC concentrations lower in the wet season compared to the dry season. As seen in other tropical blackwater rivers, DOC concentration is consistently around 10 times greater than POC concentration. We estimate the annual TOC flux discharged to the Java Sea to be 0.46 Tg year−1 comprising of 93% (0.43 Tg) DOC and 7% (0.03 Tg) POC. This equates to a fluvial TOC loss flux per unit area over the entire Sebangau catchment of 88 g C m−2 yr−1. When extrapolating the River Sebangau DOC loss flux (83 g C m−2 yr−1) to the peat covered area of Indonesia (206 950 km2), we estimate a DOC loss of 17.2 Tg C yr−1 or ~10% of current estimates of the global annual riverine DOC discharge into the ocean.

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SEASONAL VARIATIONS OF CERTAIN MAJOR ZOOPLANKTON GROUPS AROUND PANGGANG ISLAND, NORTH-WEST OFF JAKARTA

Marine Research in Indonesia ◽

10.14203/mri.v21i0.390 ◽

2018 ◽

Vol 21 ◽

pp. 61-80 ◽

Cited By ~ 2

Author(s):

O. H. Arinardi

Keyword(s):

Seasonal Variations ◽

Heavy Rainfall ◽

Annual Variation ◽

North West ◽

Annual Variations ◽

Java Sea

Seasonal and annual variations of the composition of zooplankton in the water around Panggang Island were studied from May 1971 to April 1973. Temperature and salinity of the water and the abundance of zooplankton were assumed to be affected by the monsoon. It was usually found that the abundance of zooplankton in this area coincided with or occurred after the heavy rainfall. The occurrence of many zooplankton groups in each season did not greatly change, but the intensity of total number were vary in certain groups. The pattern of the annual variation of the zooplankton number was nearly regular in the two years of investigations. The major groups of zooplankton observed during this investigations were also discussed. In general the zooplankton of the water of Panggang Island were typically neritic. Some bigger species of copepods were even less than in the Java Sea.

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