scholarly journals USULAN PEMANFAATAN TEKNOLOGI MODIFIKASI CUACA DENGAN GROUND-BASED GENERATOR UNTUK MENAMBAH DEBIT ALIRAN SUNGAI MAMASA, SULAWESI

2013 ◽  
Vol 14 (2) ◽  
pp. 75 ◽  
Author(s):  
Tri Handoko Seto ◽  
Erwin Mulyana
Keyword(s):  
Water Vapor ◽  
River Flow ◽  
Middle Part ◽  
Electricity Production ◽  
Dominant Factor ◽  
Cloud Seeding ◽  
Weather Modification ◽  
West Side ◽  
Eastern Side ◽  
Steep Slopes

IntisariTelah didesain sebuah usulan pemanfaatan teknologi modifikasi cuaca (TMC) dengan ground-based generator (GBG) untuk menambah debit aliran sungai Mamasa di Sulawesi guna meningkatkan produksi listrik dari Pembangkit Listrik Tenaga Air (PLTA) Bakaru. GBG adalah metode alternatif operasi penyemaian awan dari darat menggunakan menara. Penelitian tentang GBG telah selesai dilakukan di kawasan Puncak Bogor yang merupakan bagian dari sistem orografik Gunung Gede-Pangrango. Daerah Aliran Sungai (DAS) Mamasa memiliki kemiringan lereng antara 25%-40%. Topografi dengan kelerengan curam berada di bagian tengah, sebagian kecil di bagian hulu serta di bagian hilir DAS. Faktor orografi sangat dominan dalam pembentukan awan di DAS Mamasa. Uap air yang masuk ke DAS dipaksa naik oleh pebukitan di batas DAS sehingga terjadi pembentukan awan. Bagian tengah DAS sisi sebelah barat (Sikuku dan Sumarorong) memiliki curah hujan paling banyak sedangkan bagian tengah sisi sebelah timur (Rippung, Tabone, Tatoa dan Salembongan) memiliki curah hujan paling rendah. Hasil kajian topografi merekomendasikan wilayah Sikuku, Makuang dan Sumarorong sebagai lokasi menara GBG. Sementara itu,  Polewali direkomendasikan untuk lokasi radar. Karena DAS Mamasa adalah daerah yang rawan longsor maka pembangunan menara GBG disarankan dilakukan pada bulan bulan tidak banyak hujan yaitu pada bulan Juni sampai dengan Agustus.AbstractA proposed use of weather modification technology (TMC) with ground-based generator (GBG) to increase Mamasa river flow in Sulawesi to increase electricity production from Bakaru hydropower was designed. GBG is an alternative method of cloud seeding operations from the ground using towers. Research on GBG has been completed in the area of Puncak, Bogor, which is part of the orographic system Gunung Gede-Pangrango. Mamasa Watershed has a slope of between 25% -40%. Topography with steep slopes are in the middle, a small portion in the upstream and in the downstream of watershed. Orography is very dominant factor in the formation of clouds in the Mamasa watershed. Water vapor that enters the watershed is forced up by the hills in the watershed resulting in the formation of clouds. The middle part of west side (Sikuku and Sumarorong) have the most rainfall, while the central part of the eastern side (Rippung, Tabone, Tatoa and Salembongan) has the lowest rainfall. Results of the assessment of topography recommend the area of Sikuku, Makuang and Sumarorong as GBG tower locations. Meanwhile, Polewali recommended for radar location. Because Mamasa watershed is an area that is prone to landslides, the construction of the GBG tower suggested carried out during June to August.   

Influenza di esposizione ed altitudine sulla distribuzione della vegetazione seriale nelle Alpi Orobie (Lombardia, Italia). Elevation and exposition influence on vegetation serial distribution in Orobie Alps (Lombardia, Italy)

2010 ◽  
Vol 35 ◽  
pp. 77-95 ◽  
Author(s):  
Elena Castoldi ◽  
José A. Molina
Keyword(s):  
Cluster Analysis ◽  
Drainage Basin ◽  
Vegetation Types ◽  
West Side ◽  
Eastern Side ◽  
Sono Stati ◽  
Spatially Distributed ◽  
Altitudinal Belts ◽  
Lake Drainage ◽  
Steep Slopes

Italiano.  Il presente lavoro si occupa di indagare gli effetti che l’esposizione e l’altitudine esercitano sulle formazioni erbacee ed arbustive della Val Varrone, valle prealpina orientale del bacino imbrifero del lago di Como. Tramite cluster analysis sono stati caratterizzati 6 aggruppamenti vegetali attribuibili a 6 associazioni fitosociologiche. Gli aggruppamenti sono stati poi caratterizzati dal punto di vista ecologico, d’accordo con i parametri di Landolt. Dall’analisi dell’assolazione, tramite la formula di Bartorelli, le comunità vegetali vengono distribuite spazialmente nel territorio. L’associazione Centaureo –Arrhenatheretum è diffusa a basse quote principalmente su versanti con esposizione meridionale. L’associazione Festucetum variae, invece, è stata rilevata ad altitudini piú elevate, sempre con esposizione sud. In corrispondenza della fascia intermedia, l’associazione Homogyno alpinae-Nardetum presenta la maggior ampiezza altitudinale, le associazioni Rumicetum alpinii e Alnetum viridis prediligono fasce altitudinali meno ampie, mentre l’associazione Vaccinio-Rhododendretum ferrugineum cresce su pendii ripidi. La vegetazione seriale delle Alpi Orobie (lato orientale del lago di Como) risulta essere simile a quella dell’Alto Lario Occidentale (lato occidentale).English. The aim of this work is to seek the influence of certain geographical factors such as elevation and exposition on herbaceous and shrub vegetation in Val Varrone, a pre-alpine eastern valley of Como Lake drainage basin. Through cluster analysis were identified 6 vegetation groups, referable to 6 phytosociological associations. They were ecologically characterized according to Landolt parameters. Insolation analysis based on Bartorelli formulae revealed that vegetation types are spatially distributed in the area. The CentaureoArrhenatheretum association occurs at the lower altitudes, mainly on slopes with southern exposure. The Festucetum variae association, however, was found at higher altitudes, always facing south. At the mid-range, the Homogyno alpinae-Nardetum association presents the widest altitude, both the Rumicetum alpinii and Alnetum viridis associations prefer altitudinal belts less extensive, and finally the Vaccinio-Rhododendretum ferrugineum association grows on steep slopes. The vegetation of serial Orobie Alps (the eastern side of Como Lake) appears to be similar to the Alto Lario (west side).

Kajian Debit Sungai di DAS Wae Ruhu, Kota Ambon

2018 ◽  
Vol 1 (1) ◽  
pp. 18-23
Author(s):  
Matheus Souisa ◽  
Paulus R. Atihuta ◽  
Josephus R. Kelibulin
Keyword(s):  
River Discharge ◽  
River Flow ◽  
Secondary Data ◽  
Data Retrieval ◽  
Sediment Discharge ◽  
Flood Prevention ◽  
Retrieval Processes ◽  
Water Catchment ◽  
Steep Slopes ◽  
Station Point

Ambon City is a region consisting of hilly areas and steep slopes with diverse river characteristics. Research has been carried out in the Wae Ruhu watershed in Ambon City which starts from upstream (water catchment) to downstream. This study aims to determine the magnitude of river discharge and sediment discharge in the Wae Ruhu watershed. This research was conducted in several stages including, secondary data collection, research location survey, preparation of research tools and materials as well as field data retrieval processes which included tracking coordinates at each station point and entire watershed, calculation of river flow velocity, river geometry measurements, and sampling sediment. The results showed that the average river discharge in the Wae watershed in the year 2018 was 1.24 m3 / s, and the average sediment discharge was 6.27 kg / s. From the results of this study and the field observations proposed for flood prevention and the rate of sediment movement are the construction of cliffs with sheet pile and gabions.

scholarly journals Evaluation of the Wyoming Weather Modification Pilot Project (WWMPP) Using Two Approaches: Traditional Statistics and Ensemble Modeling

2018 ◽  
Vol 57 (11) ◽  
pp. 2639-2660 ◽  
Author(s):  
Roy M. Rasmussen ◽  
Sarah A. Tessendorf ◽  
Lulin Xue ◽  
Courtney Weeks ◽  
Kyoko Ikeda ◽  
...  
Keyword(s):  
Null Hypothesis ◽  
Initial Conditions ◽  
Pilot Project ◽  
Physical Experiment ◽  
Annual Precipitation ◽  
Ensemble Modeling ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Mountain Ranges ◽  
The Impact

AbstractThe Wyoming Weather Modification Pilot Project randomized cloud seeding experiment was a crossover statistical experiment conducted over two mountain ranges in eastern Wyoming and lasted for 6 years (2008–13). The goal of the experiment was to determine if cloud seeding of orographic barriers could increase snowfall and snowpack. The experimental design included triply redundant snow gauges deployed in a target–control configuration, covariate snow gauges to account for precipitation variability, and ground-based seeding with silver iodide (AgI). The outcomes of this experiment are evaluated with the statistical–physical experiment design and with ensemble modeling. The root regression ratio (RRR) applied to 118 experimental units provided insufficient statistical evidence (p value of 0.28) to reject the null hypothesis that there was no effect from ground-based cloud seeding. Ensemble modeling estimates of the impact of ground-based seeding provide an alternate evaluation of the 6-yr experiment. The results of the model ensemble approach with and without seeding estimated a mean enhancement of precipitation of 5%, with an inner-quartile range of 3%–7%. Estimating the impact on annual precipitation over these mountain ranges requires results from another study that indicated that approximately 30% of the annual precipitation results from clouds identified as seedable within the seeding experiment. Thus the seeding impact is on the order of 1.5% of the annual precipitation, compared to 1% for the statistical–physical experiment, which was not sufficient to reject the null hypothesis. These results provide an estimate of the impact of ground-based cloud seeding in the Sierra Madre and Medicine Bow Mountains in Wyoming that accounts for uncertainties in both initial conditions and model physics.

scholarly journals Charged Particle (Negative Ion)-Based Cloud Seeding and Rain Enhancement Trial Design and Implementation

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1644
Author(s):  
Wei Zheng ◽  
Fengming Xue ◽  
Ming Zhang ◽  
Qiqi Wu ◽  
Zhou Yang ◽  
...  
Keyword(s):  
Large Scale ◽  
Evaluation Method ◽  
Water Shortage ◽  
Northwest China ◽  
Negative Ion ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Solid Carbon Dioxide ◽  
Design And Implementation ◽  
Hygroscopic Salts

China has been suffering from water shortage for a long time. Weather modification and rainfall enhancement via cloud seeding has been proved to be effective to alleviate the problem. Current cloud seeding methods mostly rely on solid carbon dioxide and chemicals such as silver iodide and hygroscopic salts, which may have negative impacts on the environment and are expensive to operate. Lab experiments have proved the efficiency of ion-based cloud seeding compared with traditional methods. Moreover, it is also more environmentally friendly and more economical to operate at a large scale. Thus, it is necessary to carry out a field experiment to further investigate the characteristics and feasibility of the method. This paper provides the design and implementation of the ion-based cloud seeding and rain enhancement trial currently running in Northwest China. It introduces the basic principle of the trial and the devices developed for it, as well as the installation of the bases and the evaluation method design for the trial.

A Critical Assessment of Hygroscopic Seeding of Convective Clouds for Rainfall Enhancement

2003 ◽  
Vol 84 (9) ◽  
pp. 1219-1230 ◽  
Author(s):  
Bernard A. Silverman
Keyword(s):  
Scientific Evidence ◽  
Critical Examination ◽  
Policy Statement ◽  
Proof Of Concept ◽  
Randomized Experiments ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Convective Clouds ◽  
Physical Evidence ◽  
Hygroscopic Particles

During the past decade, statistically positive results have been reported for four major, randomized hygroscopic seeding experiments, each in a different part of the world. Experiments on cold convective clouds using hygroscopic flares were carried out in South Africa and Mexico. Experiments on warm convective clouds using hygroscopic particles were carried out in Thailand and India. The scientific evidence for enhancing rainfall from convective clouds by hygroscopic seeding from these four randomized experiments is examined and critically assessed. The assessment uses, as a measure of proof of concept, the criteria for success of any cloud seeding activity that were recommended in the Scientific Background for the 1998 AMS Policy Statement on Planned and Inadvertent Weather Modifications, criteria that required both statistical and physical evidence. Based on a critical examination of the results of these four major, randomized hygroscopic seeding experiments, it has been concluded that they have not yet provided either the statistical or physical evidence required to establish that the effectiveness of hygroscopic seeding of convective clouds to increase precipitation is scientifically proven. The impressive statistical results from these experiments must be viewed with caution because, according to the proof-of-concept criteria, credibility of the results depends on the physical plausibility of the seeding conceptual model that forms the basis for anticipating seeding-induced increases in rainfall. The credibility of the hygroscopic seeding for microphysical effects hypothesis has been seriously undermined because it cannot explain the magnitude and timing of the statistically significant increases in precipitation that were observed. Theories suggesting that the microphysical effects of seeding-enhanced downdraft circulations to produce longer-lived clouds have been advanced; however, in the absence of any supporting physical or model evidence, they must be considered to be in the realm of speculation. These results do not alter this author's basic position; cloud seeding is advocated in situations where it is scientifically and operationally appropriate, and it is strongly recommended that an independent evaluation accompany each research or operational project in order that the science of weather modification benefit from the experience.

Bottom-driven upwelling generated by eastern intensification in closed and semi-closed basins with a sloping bottom

1999 ◽  
Vol 50 (7) ◽  
pp. 613 ◽  
Author(s):  
M. Herzfeld ◽  
M. Tomczak
Keyword(s):  
Numerical Model ◽  
Cold Water ◽  
Ekman Transport ◽  
Dominant Factor ◽  
Bottom Slope ◽  
Boundary Current ◽  
Bottom Stress ◽  
Eastern Side ◽  
Great Australian Bight ◽  
Sloping Bottom

Cold water is observed in the eastern Great Australian Bight, and the presence of this water is inconsistent with that expected from surface Ekman-induced upwelling resulting from the imposed windfield. A numerical model is employed to investigate this situation under idealized conditions, from which the bottom slope has been identified as the most dominant factor contributing towards the presence of the cold water. A boundary current generated on the eastern side of the idealized bight is attributed to eastern intensification of a predominantly Stommel type, induced by the topographical gradient. It is proposed that the cold water observed at the eastern boundary is the result of upwelling driven by a bottom Ekman-transport convergence in this region, which is in turn the result of a large bottom stress curl maintained by the eastern intensification.

A Transformational Approach to Winter Orographic Weather Modification Research: The SNOWIE Project

2019 ◽  
Vol 100 (1) ◽  
pp. 71-92 ◽  
Author(s):  
Sarah A. Tessendorf ◽  
Jeffrey R. French ◽  
Katja Friedrich ◽  
Bart Geerts ◽  
Robert M. Rauber ◽  
...  
Keyword(s):  
Silver Iodide ◽  
Supercooled Liquid ◽  
Cloud Seeding ◽  
Remotely Sensed Data ◽  
Weather Modification ◽  
Before And After ◽  
Orographic Clouds ◽  
Seeding Material ◽  
Airborne Sensors

AbstractThe Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment (SNOWIE) project aims to study the impacts of cloud seeding on winter orographic clouds. The field campaign took place in Idaho between 7 January and 17 March 2017 and employed a comprehensive suite of instrumentation, including ground-based radars and airborne sensors, to collect in situ and remotely sensed data in and around clouds containing supercooled liquid water before and after seeding with silver iodide aerosol particles. The seeding material was released primarily by an aircraft. It was hypothesized that the dispersal of the seeding material from aircraft would produce zigzag lines of silver iodide as it dispersed downwind. In several cases, unambiguous zigzag lines of reflectivity were detected by radar, and in situ measurements within these lines have been examined to determine the microphysical response of the cloud to seeding. The measurements from SNOWIE aim to address long-standing questions about the efficacy of cloud seeding, starting with documenting the physical chain of events following seeding. The data will also be used to evaluate and improve computer modeling parameterizations, including a new cloud-seeding parameterization designed to further evaluate and quantify the impacts of cloud seeding.

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