scholarly journals Legacies of stream channel modification revealed using General Land Office surveys, with implications for water temperature and aquatic life

Elem Sci Anth ◽  
2017 ◽  
Vol 5 (0) ◽  
pp. 3 ◽  
Author(s):  
Seth M. White ◽  
Casey Justice ◽  
Denise A. Kelsey ◽  
Dale A. McCullough ◽  
Tyanna Smith
Keyword(s):  
Water Temperature ◽  
Stream Channel ◽  
Aquatic Life ◽  
General Land Office ◽  
General Land Office Surveys

scholarly journals The Relationship Between Grazing, Erosion and Adult Aquatic Insects in Streams in Mongolia

2010 ◽  
Vol 8 (1) ◽  
pp. 27-39
Author(s):  
Barbara Hayford ◽  
◽  
Jon Gelhaus ◽  
Keyword(s):  
Water Quality ◽  
Regression Analysis ◽  
Water Temperature ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Aquatic Insect ◽  
Stream Channel ◽  
Temperature Conductivity ◽  
Level Data ◽  
Family Level

Overgrazing along stream channels in Mongolia may impact streams by increasing stream channel erosion and in-stream sediments, water temperature, pH, and conductivity. Grazing and erosion impacts may impair stream insects. The Mongolian Aquatic Insect Survey sampled 250 streams during summer seasons in 2003-2006 and 2008. On-site identifi cations of aquatic insect families mostly based on collections of adults were recorded for each site, leading us to ask whether the family-level data were useful in biological assessment related to impacts and impairment from grazing and erosion. A double dendrogram based on hierarchical cluster analysis was used to fi nd patterns in sites and aquatic insect communities. Sites did not group by sampling period, but some sites did group by stream size and elevation. However, elevation was not a signifi cant predictor of variation in aquatic insect metrics. Analysis of variance was used to determine whether insect metrics and water quality variables varied signifi cantly between categories of erosion in the stream channel. Plecoptera and Diptera richness decreased with increased erosion and Percent Diptera Richness was the only aquatic insect metric to vary signifi cantly between categories of erosion along the stream channel. Water temperature, conductivity, and pH also signifi cantly increased with increased erosion. Multiple regression analysis was used to determine whether aquatic insect metrics could be predicted by variation in landscape, water quality and stream reach variables. Trichoptera, Ephemeroptera, and Coleoptera richness increased with increased erosion, conductivity, and pH, but not signifi cantly. Percent Diptera Richness formed the only signifi cant model in the multiple regression analysis, with conductivity the only signifi cant predictor of variation in Percent Diptera Richness. Family-level data generated in the fi eld indicated that sampling for Trichoptera and Ephemeroptera diversity would be maximized by sampling streams undergoing intermediate levels of disturbance from grazing and erosion, that sampling for the Diptera and Plecoptera diversity would be maximized by sampling streams with less erosion and grazing, and that Diptera richness was impaired by erosion related to grazing in Mongolian streams.

Application of the Neural Networks in Prediction of the Thermal Flow on the Jiu River

2020 ◽  
Author(s):  
Victorita Radulescu
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Water Temperature ◽  
Power Plants ◽  
Human Life ◽  
Chemical Properties ◽  
Gradient Algorithm ◽  
Thermo Electric ◽  
Aquatic Life ◽  
Contact Points

Abstract Water temperature is an important parameter that influences the life near watercourses. The physical and chemical properties as the density and viscosity, gas solubility in water and in particular of the oxygen, the kinematics of the micro-biological and chemical phenomena affects not only the aquatic life but also the human life and animals living near the watercourse. In the Jiu river is discharged the water coming from the cooling towers of three thermo-electric power plants placed upstream. According to the recent researches realized by the EU Environmental Commission in Romania until 2050 the average temperature could rise by about 2°C. This paper presents the ability of a “neural networks” model to predict the water temperature in the lower part of the Jiu River. A database realized in over nine years in the measuring station Izbiceni, from the Olt County is used, concerning the water temperature (Tw) and the air temperature (Ta). The developed neural network is structured on five input variables and 9 hidden layers, 7 as sub-input and 2 as output. The stochastic time series is based on the separation of values for water Tw and air Ta in seasonal and daily fluctuations components. The schematic structure of the implemented neural network is presented, for obtaining the short-term and the seasonal components of the temperatures. The contact points are adjusted by the method of reprogramming after a gradient algorithm, in order to minimize the quadratic error between the output results and the relevant observed values. The performance of the neural network is based on estimation the thermal changes of the operation mode. For testing the numerical model, the calculations were performed using only the data recorded in nine years, in order to estimate a forecast for the next two years. The results are very close to the experimental recorded data and the obtained errors are less than 0.5°C. At the end of the paper are presented some results, conclusions and references.

Vegetational Reconstruction and Climatic Episodes

1976 ◽  
Vol 41 (2) ◽  
pp. 206-208 ◽  
Author(s):  
W. Raymond Wood
Keyword(s):  
United States ◽  
Little Ice Age ◽  
Ice Age ◽  
General Land Office ◽  
Climatic Regime ◽  
Vegetation Models ◽  
General Land Office Surveys ◽  
Biotic Change

AbstractData from United States General Land Office Surveys are commonly used to create vegetation models for the American Pioneer period. These models are then used as baselines for understanding past biotic change. It should be realized that many of these surveys were made near the end of a climatic episode (the Neo-Boreal or "Little Ice Age") when world temperatures were much lower than at the present time. These baselines therefore do not represent vegetational responses to a climatic regime like that of the present, and the vegetation models must be interpreted accordingly.

scholarly journals Kajian Dispersi Panas Dampak Rencana Pembangunan PLTU Sampit-Kotawaringin Timur Propinsi Kalimantan Tengah

2018 ◽  
Vol 16 (1) ◽  
pp. 86 ◽  
Author(s):  
Mardi Wibowo ◽  
Wahyu Hendriyono
Keyword(s):  
Waste Water ◽  
Power Plant ◽  
Water Temperature ◽  
River Flow ◽  
Cooling System ◽  
High Tide ◽  
Cooling Water ◽  
Aquatic Life ◽  
The Impact ◽  
Mike 21

ABSTRAKSaat ini untuk memenuhi kebutuhan energi listrik pemerintah mencanangkan program pembangunan pembangkit listrik 10.000 MW. Salah satu implementasinya dengan membangun Pembangkit Listrik Tenaga Uap (PLTU) berbahan bakar batubara seperti PLTU Sampit di Kabupaten Kotawaringin Timur, Propinsi Kalimantan Tengah. Permasalahan utama kegiatan PLTU adalah suhu air buangan yang jauh lebih tinggi dari suhu perairan di sekitarnya. Kenaikan suhu iniselain akan mengurangi efisiensi system pendinginan juga dapat membahayakan kehidupan aquatik. Untuk meminimalkan dampak perlu dilakukan pemodelan adveksi/dispersi panas sebelum dilakukan pembangunan PLTU. Dengan pemodelan ini akan diketahui sebaran panas buangan PLTU sehingga sejak awal dapat dilakukan upaya-upaya untuk mengurangi dampak negatif yang muncul. Selain itu model ini dapat dipakai sebagai bahan pertimbangan dalam penentuan lokasi intake dan outfall sistem air pendingin. Studi ini dilakukan dalam beberapa skenario dengan menggunakan perangkat lunak MIKE-21. Berdasarkan hasil pemodelan diketahui bahwapola arus di perairan sekitar PLTU Sampit lebih dipengaruhi pasang surut dan debit sungai dari hulu. Pada musim timur, suhu air pada lokasi intake cukup terpengaruh oleh suhu air bahang pada outfall khususnya ketika air laut pasang. Perubahan temperaturair pada intake berkisar antara 30,1 – 32 oC. Kenaikan tertinggi terjadi ketika air menuju pasang naik maksimum. Pada musim angin barat, suhu air pada lokasi intake hanya sedikit terpengaruh oleh suhu air bahang pada outfall, perubahan temperatur air pada intake hanya berkisar antara 29,99 – 30,1 oC. Kenaikan tertinggi terjadi ketika air menuju pasang naik maksimum. Resirkulasi air pendingin dengan intensitas cukup besar (+ 2oC) diprediksi terjadi saat air pasang. Hal ini dapat menjadi lebih parah bila debit sungai dari hulu berkurang yaitu ketika musim kemarau.Kata kunci: dispersi panas, PLTU, air bahang, intake, outfallABSTRACTNow to comply the electricity needs, government announced the construction of 10,000 MW power plant. One of its implementation by building Steam Power Plant (PLTU) with coal-fired power such as Sampit in the District of Eastern Kotawaringin, Province of Center of Kalimantan. The main problem of power plant activities is the waste water temperatures much higher than the temperature of the surrounding waters. The rise of temperature will not only reduce the efficiency of the cooling system but also be harmful to aquatic life. To minimize the impact needs to be done advection/dispersion modeling of heat water prior to the construction of the power plant. With this modeling will be known distribution of heat waste from power plant in 2-dimensional, so that can be done since the beginning of efforts to reduce the negative impacts that arise. In addition, this model can be used as a consideration in the determination of the location of the intake and outfall system cooling water. This study was conducted in several scenarios using software MIKE-21. Based on modeling results is known that the current pattern in the waters around the Sampit power plant is more affected by tidal and river flow from upstream. In east monsoon, the water temperature at the intake is quite affected by the heat water temperature at the outfall especially when high tides. Water temperatur changes in intake ranged from 30.1 to 32 oC. The highest increase occurred when the water toward the maximum high tide. In the west monsoon, the water temperature at intake only slightly affected by the heat water temperature on the outfall. Eater temperatur changes on the intake only ranged from 29.99 to 30.1°C. The highest increase occurred when the water toward the maximum high tide. Recirculation cooling water with considerable intensity (+ 2°C) could occur during high tide. It can be more severe if the river flow from upstream is reduced like as at the dry season.Keywords: thermal dispersion, steam powerplant, heat waste water, intake, outfallCitation: Wibowo, M., Hendriyono, W., Nugroho, S., Al Hakim, B., Velly Asvaliantina. V.  (2017). Kajian Dispersi Panas Dampak Rencana Pembangunan PLTU Sampit-Kotawaringin Timur Propinsi Kalimantan Tengah. Jurnal Ilmu Lingkungan, 16(1), 86-97, doi:10.14710/jil.16.1.86-97

scholarly journals MAINTAINING NATURAL WATER TEMPERATURE REGIME FOR PROTECTING AQUATIC LIFE

2003 ◽  
Vol 31 ◽  
pp. 159-168
Author(s):  
Guangwei HUANG ◽  
Takashi IZUMIYA
Keyword(s):  
Water Temperature ◽  
Temperature Regime ◽  
Natural Water ◽  
Aquatic Life

Additional Cautions on the Use of the Glo Survey Records in Vegetational Reconstructions in the Midwest

1978 ◽  
Vol 43 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Frances B. King
Keyword(s):  
United States ◽  
The United States ◽  
Climatic Conditions ◽  
Forest Vegetation ◽  
Climatic Effects ◽  
European Settlement ◽  
General Land Office ◽  
General Land Office Surveys

Data from the United States General Land Office Surveys are frequently used to reconstruct the vegetation existing at the time of European settlement as a basis for biotic models. The vegetation recorded in those surveys had been influenced not only by climatic conditions considerably colder and more moist than the present, but by frequent, widespread burning as well. The effect of such burning on the distribution and composition of forest vegetation was as great as the climatic effects and must be taken into account when building prehistoric vegetational models in the Midwest.

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