Penentuan Batas DAS Tojo Berbasis GIS Menggunakan Perangkat HEC HMS 4.4 dan QGIS 3.16

Watershed delineation is the process of determining an area that contributes to the flow of rainfall (precipitation) into runoff to the outlet. The watershed delineation analysis in this study used the HEC-HMS version 4.4 and QGIS 3.16 . HEC HMS version 4.4 has GIS tools that have been directly integrated to facilitate the watershed delineation process. The study area in this research is the Tojo watershed which is located in Central Sulawesi Province. The digital elevation model (DEM) data source used is DEMNAS BIG with a spatial resolution is 8,1 meters. The results of watershed delineation using HEC-HMS 4.4 software are the same as the results of watershed delineation using QGIS 3.16 software. There is a slight difference in the watershed boundary in some parts when zoomed in. The watershed area produced by each GIS Softwares are HEC-HMS 212,583 km2, QGIS 212,5404 km2. The HEC-HMS 4.4 software gives quite good results on the boundary analysis of the Tojo watershed, so the HEC-HMS 4.4 software can also be used in other researches in the field of water resources.

Invasion of the European River Lamprey Lampetra fluviatilis in the Upper Volga

The European river lamprey came to the Upper Volga from the Baltic Sea most probably via a system of shipways developed in the 18th and 19th centuries. The Vyshnii Volochek, Tikhvin, and Mariinskaya water systems are possible invasion pathways for this species. Dispersal and colonization of the Caspian Basin was likely a combination of upstream and downstream migrations. Analysis of museum and our own samples showed that lamprey possibly migrated upstream (for spawning) along rivers of the Baltic Basin until they reached the watershed boundary from which they could disperse downstream (in the juvenile period) into rivers of the Caspian Basin. Dispersal in the Volga River could occur in accordance with the migration cycle of this opportunistic lamprey species and lead to the present distribution. Key features (dentition and number of trunk myomeres) showed that lamprey from the studied area are similar to lampreys from the Baltic basin, although specimens in each population have their own peculiarities in morphology (size and coloration). Genetic data (Cyt-b) support the idea of a relatively recent invasion of lamprey into the Upper Volga. The haplotype, found in three rivers, is one of the most widespread in Europe and is found along the supposed route of invasion.

A Geospatial Morphometric Analysis of Kulbera and Daurighara River Basins in Western Part of Purulia District of West Bengal, India

Morphometric analysis is used to understand the hydrological process and assessment of hydrological characteristics of surface water basin. In the present paper, an attempt has been made to study the detail morphometric characteristics of Kulbera and Daurighara river basin, which are tributaries of Subarnarekha River in Purulia district, West Bengal. For detailed study, SRTM data has been used for preparing digital elevation model (DEM), and Geographic Information System (GIS) has been used for the analysis of linear, areal, and relief aspects of the basins. Watershed boundary, flow accumulation, flow length, stream ordering have been prepared by using ILWIS 3.0. Different thematic maps i.e. elevation, geology, drainage density, slope and longitudinal profiles of river channels have been prepared by using QGIS 3.0 and MapInfo 10.0 GIS software. More than 58 morphometric parameters of all aspects of the basins have been computed. On the basis of morphometric analysis it has been argued that the erosional development has progressed well beyond maturity and that the drainage development is controlled by lithology. Besides,it can be concluded that this study will also be very useful for rain water harvesting planning and watershed management.

DINAMIKA PERUBAHAN PETA BATAS DAS MALUKA PROVINSI KALIMANTAN SELATAN

A study on the dynamics of the Change Dynamics of the Maluka Watershed Boundary Map in South Kalimantan Province, which aims to analyze the Maluka Watershed Boundary is a large-scale approach, analyzing the dynamics of changes in some watershed characteristics (morphological and morphometric aspects) and conducting a policy direction towards the Compilation of the Maluka Watershed Boundary Watershed. The results of the Maluka watershed boundary scale of 1:50.000 there are changes and improvements in watershed boundaries in the downstream watershed due to river drainage, dredging, river displacement caused by human activities, new watersheds formed and SRTM level 30 x 30 m resolution, line repair and correction coastal and river networks and optical remote sensing. Morphometric and morphologic characteristics of Watersheds Significant changes in watershed area and administration area (reduced by 4.678 Ha or 5,3%). Other properties did not change significantly (Hydrologic DAS: 2 sub-watersheds, namely the Bati-Bati sub-watershed and Banyuhirang sub-watersheds), (Watershed shape: elongated (Rc <0,5)), (Slope class: flat 90,24%, steep and rather steep 2,14%), (Altitude/Elevation) Watershed: 2 masl to 50 masl 81,71%, above 300 masl 4,37%), (Watershed orientation: heading east to west in a straight direction, middle watershed symmetrical ballooning), (flow density, index value: 1,09 medium category) and (DAS flow pattern: Dendritic). Policy recommendations are suggested to synchronize the implementation of UU No. 23 Tahun 2014 and UU No. 37 Tahun 2014 in terms of carrying out the mandate of PP. 37 Tahun 2012, namely the implementation of the management of watershed management in the context of conservation of land, water in the ecosystem/watershed unit by giving the mandate to assist the task of sub-affairs management of watershed management from the provincial government to the district / city government.

Debris-flow volume quantile prediction from catchment morphometry

&lt;p&gt;Estimation of the volumes of potential future debris flows is key for hazard assessment and mitigation. Worldwide, however, there are few catchments for which detailed volume-frequency information is available. We (1) reconstruct volume-frequency curves for 10 debris-flow catchments in Saline Valley, California, USA, from a large number of well-preserved, unmodified surficial flow deposits, and (2) assess the correlations between lobe-volume quantiles and a set of morphometric catchment characteristics. We find statistically-significant correlations between lobe-volume quantiles, including median and maximum, and catchment relief, length (planimetric distance from the fan apex to the most distant point along the watershed boundary), perimeter, and Melton ratio (relief divided by the square root of catchment area). These findings show that it may be possible to roughly estimate debris-flow lobe-volume quantiles from basic catchment characteristics that can be obtained from globally-available elevation data. This may assist with design-volume estimation in debris-flow catchments where past flow volumes are otherwise unknown.&lt;/p&gt;

Irrigation Water Potential and Land Suitability Assessment in Kurfa Chele-Girawa Watershed, Wabe Shebelle River Basin, Ethiopia

Assessing available water and land for irrigation are important for planning their use. In the watershed, stream flows from some of the rivers are not known and potential irrigable areas have not been identified. By delineating watershed boundary, irrigation suitability factors such as soil type, slope, land cover/use, and distance from the water supply were classified based on the FAO guideline for land evaluation in to S1, S2, S3 and N suitability classes independently. The irrigation potential suitability analysis of soil, slope, land cover/use and Euclidean distance indicates that 55.1 %, 95.6 %, 88.6% and 93.7% respectively are in the range of highly to marginally suitable. By weighted overlay analysis, total surface irrigation suitability potential of the study area is 54.6%, from this, the potential irrigable land obtained by multi_ criteria analysis has 45.9%. The total available flow above abstraction site is 335.7m3/s or 2.9-million-meter cube (MMC) annually.

Calculation Of Sedimentation Rate at Sempor Reservoirs in 2018 Using Modified Universal Soil Loss Equation Method (MUSLE)

Sempor Reservoir located in the Telomoyo River Basin in the Serayu River region is categorized as one of the priority watersheds based on the 2015-2019 Strategic Plan of the Ministry of Environment and Forestry. Priority watershed is a watershed that gets more attention in controlling water pollution, one of which is sedimentation. Watershed observation and management activities are needed for the reservoir to operate optimally. One of the observations and management activities of the Sempor Watershed is the calculation of sedimentation rate. In this research the sedimentation rate was calculated using the MUSLE method that included runoff parameter, erodibility, slope, land cover and conservation factor. The Sempor watershed boundary is obtained through delineation of DEM. The calculation is done by utilizing a Geographic Information System (GIS) through analysis of soil type maps, length and slope maps, land cover and conservation maps with the boundaries of the Sempor Reservoir. Based on this result, the Sempor Reservoir has a sedimentation rate of 166,173,500 tons/year and a sedimentation thickness rate of 3,7259 mm/year. According to the provisions of the Ministry of Forestry in 2009, the rate of sedimentation thickness in the Sempor Reservoir is included in the medium class. The river as one of the potential means of sediment transport contributes to the rate of sediment thickness of 3.7256 mm /year, while for areas outside the river coverage it only 0.003 mm/year. The river has a major influence on sedimentation in the Sempor Reservoir.

Debris-flow volume quantile prediction from catchment morphometry

Estimation of the volumes of potential future debris flows is a key factor in hazard assessment and mitigation. Worldwide, however, there are few catchments for which detailed volume-frequency information is available. We (1) reconstructed volume-frequency curves for 10 debris-flow catchments in Saline Valley, California (USA), from a large number of well-preserved, unmodified surficial flow deposits, and (2) assessed the correlations between lobe-volume quantiles and a set of morphometric catchment characteristics. We found statistically significant correlations between lobe-volume quantiles, including median and maximum, and catchment relief, length (planimetric distance from the fan apex to the most distant point along the watershed boundary), perimeter, and Melton ratio (relief divided by the square root of catchment area). These findings show that it may be possible to roughly estimate debris-flow lobe-volume quantiles from basic catchment characteristics that can be obtained from globally available elevation data. This may assist in design-volume estimation for debris-flow catchments where past flow volumes are otherwise unknown.

MODELLING OF DOMESTIC WATER DEMAND USING SPATIAL DATA POPULATION FOR CISADANE UPSTREAM WATERSHED

<p><em>In Indonesia, water resources management planning has done based on river area. But the problem is the calculation still based on population data with administrative boundary. This is caused by the lack of population data with watershed or river area boundary. Geographical Information System (GIS) is a tools to analyze, visualize and interpret data with spatial and geographic data. For this research, GIS is used to generate population data with watershed and river area boundary,then the result will used for domestic water demand calculation for Cisadane upstream watershed. For all district in Cisadane Upstream Watershed, the largest district in entire watershed are Cibungbulang, Leuwiliang and Nanggung. But the most dense population are Ciomas, Ciampea and Cibungbulang. The calculation using watershed boundary resulting significant difference from district boundary. With spatial data population using watershed boundary, domestic water demand calculation result can be more accurate than using all district population data. </em></p>