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"Nowadays, severe flooding frequently occurs in various parts of Thailand resulted from changesin climatic condition and land use patterns. The flooding has caused great damages to propertiesand lives and affects country economy. Experience from the most severe flooding in the northernand central regions of Thailand in the year 2011 reveals that reliable flood warning system is stilllagging. For flood warning purpose, it is necessary to have an accurate flood routing system. Thisstudy is aimed at developing mathematical models for flood routing so as to provide data for floodwarning. Two different models are developed, i.e., kinematic overland flow model and kinematicstream flow model. The finite element method with Galerkin’s weighted residual technique is usedin model development. The second order Runge-Kutta method is applied to solve the set ofdifferential equations obtained from finite element formulation. The developed models are appliedto simulate flows in the Wang river basin in the northern region of Thailand during July 1 -October 31, 2011 when severe flooding occurred in this region. Model calibration is made byadjusting some parameters in the models and comparing the obtained results with measured datarecorded by RID at 5 stream flow gauge stations along the Wang river. For correlation analysis.three statistical indices are determined, these include coefficient of determination, R2, Nash-Sutcliffe model efficiency coefficient, NSE, and coefficient of variation of the root mean squareerror, CV(RMSE). It is found that the model results at the upstream portion of the riversatisfactorily agree with the observed data, with the values of R2 greater than 0.55 and CV(RMSE)less than 0.57. For the downstream portion of the river, there are remarkable differences betweenthe model results and the observed data. The values of R2 are less than 0.35, CV(RMSE) greaterthan 0.76, and the NSE values are less than 0.16. This might be due to some errors in the inputdata, including rainfall pattern, topography, land use, river cross-sectional area, and water seepagealong the river. More detailed field investigation and model calibration are still needed."

"In 2011, massive flooding and inundation in the Chao Phraya River basin, in Thailand, causedserious damage to various activities for a prolonged period of time. Although snapshot images ofthe inundated area are available, detailed information including temporal changes of the inundatedareas and the relationship with meteorological and hydrological conditions are not welldocumented, particularly for the middle and upper sections of the basin. Therefore, we conductedan analysis using two types of satellite data, HJ-1A and Envisat, to better understand behavior ofthe large-scale inundation occurred in 2011, focusing on the middle section of the Chao PhrayaRiver basin. In the analysis, water surface in selected domains was extracted using the NDWI valuecalculated from HJ-1A data. The threshold value of the Envisat ASAR image was then adjusted sothat the inundated area estimated from Envisat gives the closest possible match with that estimatedfrom HJ-1A. Finally, the inundated area was estimated for the whole study domain based on thesame threshold value from the Envisat data. Results indicated that the inundated area began toextend along the Yom and Nan rivers in early August and continued to spread down to the NakhonSawan city area until October. A significant increase in inundated areas occurred between Sep. 2and Sep. l3, during which higher rainfall intensity was observed. Even after the water level inrivers receded below the bank-full elevation, large areas were left inundated along rivers,particularly over lowlying marsh and paddy fields. In addition, several areas located far fromrivers were also inundated, which was likely a consequence of water ponding in paddy fields."

"Alih fungsi lahan memiliki kaitan yang erat dengan pertumbuhan penduduk dan ekonomi. Perubahan ini memiliki dampak positif dan tidak sedikit dampak negatifnya. Salah satu hal yang disebabkan oleh adanya alih fungsi lahan adalah meningkatnya lahan kedap air dan berkurangnya baseflow. Perubahan fungsi lahan ini berujung kepada meningkatnya aliran permukaan dan bencana banjir. Melihat hal ini, dibutuhkan studi lebih lanjut mengenai hubungan perubahan fungsi lahan dan banjir yang terjadi pada suatu kawasan. Penelitian ini berfokus pada DAS Martapura yang merupakan bagian DAS Barito, salah satu DAS terbesar di Indonesia. Penelitian ini menggunakan pendekatan spasial terhadap hasil tangkapan Citra Landsat pada tahun 1990, 2000, 2010, dan 2020. Menggunakan fitur maximum likelihood classification, penelitian ini mendeteksi tutupan lahan pada setiap data Citra Landsat yang digunakan. Penelitian ini juga menggunakan bantuan HEC-HMS dalam menghasilkan hidrograf banjir untuk setiap sub-DAS, reach, dan junction. Data ini yang bervariasi menurut tutupan lahan setiap tahunnya dan menjadi input ke dalam HEC-RAS. Penelitian ini menggunakan fitur analisis hidrolika HEC-RAS 2D untuk menghasilkan peta genangan. Berdasarkan simulasi yang telah dilakukan, perubahan tutupan lahan menjadi kedap air semakin meningkat. Hal ini juga meningkatkan limpasan permukaan dan puncak debit banjir yang terlihat pada hasil hidrograf. Menurut analisis genangan banjir yang terjadi, didapatkan peningkatan luas genangan banjir seiring bertambahnya tahun Sebagai upaya pengendalian banjir di lokasi ini, diperlukan perencanaan tata ruang dan penataan kawasan dengan lebih baik. Hal ini perlu dilakukan untuk mengendalikan laju perubahan tutupan lahan dan mengendalikan dampak bencana banjir.

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Land conversion has a very close relation with population and economic growth. This change has had both positive and negative impacts. One of the things caused by land use change is the increase in impermeable land and reduced baseflow. This land use change leads to an increase in surface runoff and flooding. In regards to this problem, further studies are needed to determine the relation between land use change and flooding that occur in an area. This study focuses on the Martapura Watershed which is a part of the Barito Watershed, one of the largest watershed in Indonesia. This study uses a spatial approach to Landsat Image capture in 1990, 2000, 2010 and 2020. Using the maximum likelihood classification feature, this study detects land cover in each Landsat Image data used. This study also uses HEC-HMS assistance in generating flood hydrographs for each sub-watershed, reach, and junction. This data, which varies by land cover each year, is the input to the HEC-RAS. This study uses the HEC-RAS 2D hydraulics analysis feature to generate inundation maps. Based on the simulations that have been carried out, land cover changes to a more impermeable cover are increasing. This also increase surface runoff and peak flood discharge as seen in the hydrograph results. According to the analysis of the flood inundation that occurred, it was found that there was an increase in the area of ​​​​the flood inundation in every year modelled. As an effort to control flooding in this location, better spatial planning and regional arrangement are needed. This needs to be done in order to control the rate of land cover change and the impact of floods."

"This book is designed to provide concepts, methodologies, and approaches for river basin studies with respect to water resources and environment. The book is not limited to the Yamuna River basin, but will help in the study of various other river basins for integrated water resources management. The book covers the essential components of integrated water resources management, including analysis of climatic variables, climate change detection, analysis of natural resources, geology, geomorphology, socio-economics, water budgeting, flood estimation, river pollution, etc. Furthermore, the book addresses recent issues pertaining to water quality, water quality indices, environmental flows, water resources management through cropping pattern change, etc. along with methodologies and application to the Yamuna River system. However, the main objective of this book is to address important issues of water resources management of river basins. "

"Investigations underlying this study were carried out within the framework of the Nuffic Serayu Valley Project. To survey the disturbances of the natural balance due to environmental changes, many soil profiles have been studied; some inconsiderably detail. One of these will be discussed thoroughly. The results enabled a reconstruction of the Quaternary landscape development of the Serayu Valley to be made. The Quaternary history of Serayu River basin is characterized by a succession of stable and unstable phases in landscape development, each leaving its specific effects in soil Alternation of the landscape forming processes as well as changes in climate and vegetation types can be deduced from the soil profile investigated. During the last two centuries erosive processes prevailed as deforestation increased enormously, induced by the growing demand for arable land. Consequently, the erosion rate has multiplied and soils developed under previous environments have been largely eroded. This accelerated soil erosion has already resulted in a decrease of the available agricultural land and the rural population is forced to bring marginal areas into use."

"Soil loss and its transport processes were coupled with an existing distributed hydrological modelto assess the effects of land use change on stream flow and suspended sediment load in the ChaoPhraya River basin, Thailand. The simulation period spanned from 2001 to 2010. The resultsindicate that the Nash-Sutcliffe efficiency of upper sub-basins fluctuated in the range 0.51- 0.72,indicating the applicability of the model for longterm simulation at the monthly scale. Land usechange during 200l-2010 caused a 1.6% increase in suspended sediment load based on the presenttrend. The changes were particularly pronounced in the Wang River basin, where the delivery ratiowas highest. Moreover, the urbanization and conversion of farm land from paddy fields exertednegative effects on sediment runoff in Chao Phraya River basin. The proposed model has theability to quantitatively evaluate the heterogeneity of sediment runoff in the basin, demonstratingthe benefits and trade-offs of each land use change class. The results of this study can support basinand local land development policy to control sediment losses during development."

"Tujuan utama penelitian ini adalah membangun model peningkatan resiliensi sistem sosio-hidrologis melalui tata kelola air polisentrik yang mengintegrasikan resiliensi komunitas untuk menjamin keberlanjutan fungsi ekosistem sungai di Wilayah Sungai Citarum. Metode yang digunakan adalah formula matematis untuk menghitung vulnerability index dengan menggunakan data sekunder dari berbagai institusi pengelola Wilayah Sungai Citarum, yang selanjutnya disebut sebagai WS Citarum. Hasil perhitungan vulnerability index digunakan sebagai dasar penetapan status resiliensi sistem sosio-hidrologis WS Citarum. Selain itu digunakan pula permodelan statistik Structural Equation Modelling (SEM) dengan menggunakan perangkat lunak LISREL versi 8.7 untuk menetapkan resiliensi komunitas. Resiliensi komunitas dianalisis berdasarkan data primer hasil pengukuran modal sosial masyarakat (social capital) dan nilai, keyakinan, norma serta perilaku peduli lingkungan (values, beliefs, norms and pro-environmental behavior), individu anggota masyarakat di WS Citarum. Model konseptual upaya peningkatan resiliensi sistem sosio-hidrologis dibangun menggunakan permodelan system dynamics dengan perangkat lunak VensimPLE versi 9.3.0. Hasil penelitian menunjukkan bahwa vulnerability index (VI) di Wilayah Sungai Citarum adalah sebesar 1,80 pada Zona Citarum Hulu yang menunjukkan bahwa sistem sosio-hidrologis pada zona ini berada pada status rentan sedang (moderate vulnerability). Sedangkan pada Zona Citarum Tengah, nilai VI adalah 2,52 dan pada Zona Citarum Hilir adalah 2,06, yang menunjukkan bahwa sistem sosio-hidrologis pada kedua zona tersebut berada pada status sangat rentan (significant vulnerability). Kesimpulan penelitian ini adalah bahwa untuk mengatasi kerentanan sistem sosio-hidrologis di WS Citarum diperlukan implementasi model peningkatan resiliensi sistem sosio-hidrologis melalui intervensi tata kelola air polisentrik. Tata kelola air polisentrik yang didukung oleh aksi kolektif masyarakat dengan kekuatan modal sosial dan perilaku peduli lingkungan, sebagai wujud resiliensi komunitas, diharapkan dapat mencapai keberlanjutan fungsi ekosistem sungai di Wilayah Sungai Citarum.

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The main objective of this research was to develop a model representing the resilience of the socio-hydrological system through polycentric water governance that integrates community resilience to ensure the sustainability of river ecosystem services in the Citarum River Basin. The method used in this study is a mathematical formula to calculate the vulnerability index using secondary data from various institutions managing the Citarum River Basin (CRB). The results of the vulnerability index calculations were used as the basis for determining the resilience of the CRB socio-hydrological system. Furthermore, statistical modeling of structural equation Modelling (SEM) using LISREL software version 8.7 is also used to assess community resilience. Community resilience was analyzed based on primary data from the results of measuring community social capital and the values, beliefs, norms, and pro-environmental behavior of individual community members in the Citarum River Basin. A conceptual model representing the resilience of the socio-hydrological system was built using system dynamics modeling with the VensimPLE software version 9.3.0. The results show that the vulnerability index (VI) in the Citarum River Basin is 1.80 in the upstream zone, indicating that the socio-hydrological system in this zone is moderately vulnerable. In the middle zone, the value of VI is 2.52 and in the downstream zone, it is 2.06, which indicates that the socio-hydrological system in the two zones is significantly vulnerable. This study concludes that to overcome the vulnerability of the socio-hydrological system in the Citarum River Basin, it is necessary to implement a model to increase the resilience of the socio-hydrological system through polycentric water governance interventions. Polycentric water governance supported by collective community action with the strength of social capital and pro-environmental behavior as a form of community resilience will achieve the sustainability of river ecosystem services in the Citarum River Basin.

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"ABSTRACTCitarum Harum is a program to restore the Citarum River. The problem of waste and sewage and the existence of the strategic Citarum River by splitting West Java Province are very supportive of economic growth, especially labour-intensive industries that can absorb a lot of labour into serious problems. Citarum, which is known as one of the dirtiest rivers in the world, urges the government to immediately issue regulations to start the restoration of the Citarum River Basin (DAS Citarum). Citarum watershed pollution and damage mitigation measures in an integrated strategic pace for control and law enforcement that integrate authority between government agencies and stakeholders related to Citarum watershed recovery based on Presidential Regulation No. 15 of 2018 concerning Acceleration of Pollution and Damage Control in the Citarum River Basin. Various steps and methods were taken to restore the Citarum watershed, as well as communication and coordination of the central government with various related parties such as the Environmental Service Office (DLH) of the West Java Provincial Government and Kodam III Siliwangi to be enhanced to immediately realize Harum Citarum."

"ABSTRAKThe retention basin is a tub or pond that can accommodate or absorb water while it is contained in it. retention basin is the most effective and efficient system in handling floods that occur in an area. an environmentally flood control effort needs to be done such as retention basin. this study aims to plan the dimensions of retention basins from the central region of the Deli river. planning the volumje of retention basins made around Deli river is calculated using maximum daily rainfall data of Deli river area. maximum rainfall data can be obtained from Climatology Meteorology and Geophysies Agency (BMKG) Medan City or Dinas PSDA Medan. The maximum daily rainfall is calculated first then the volume, the retention basin construction can accommodate the excessive water discharge of the Deli River. from the results of 25 years rainfall period data processing with Nakayashu method obtained Qplan of 229 m3/s is used to design drainage channel plan. The obtained the capacity of retention basin at the center of 6462288 m3. Then the retention basin dimension planned with area of 2154096 m2 and depth of 3 m. "