Drainage Distance Research Articles

Optimizing Cervical Target Volume in Patients with Nasopharyngeal Cancer Based On Nodal Drainage Distance.

To determine the potential nodal drainage distances of nasopharyngeal carcinoma (NPC) by investigating spatial distribution of metastatic lymph nodes (LN). Patients with NPC harboring at least two ipsilateral metastatic LNs were enrolled. LN spreading distances were analyzed in nonrestricted direction, cranial-to-caudal direction, and between the two most caudal LNs. Euclidean distance (ED) and vertical distance (VD) between any two LNs were computed. The nearest-neighbor ED and VD covering 95% of LNs or patients (p95-ED and p95-VD) were considered drainage distances, and were further validated by independent internal and external cohorts with recurrent LNs. In all, 5,836 metastatic LNs in 948 patients were contoured. Corresponding to the three scenarios, per-LN level, the p95-EDs were 2.83, 3.28, and 3.55 cm, and p95-VDs were 2.17, 2.32, and 2.63 cm, respectively. Per-patient level, the p95-EDs were 3.25, 3.95, and 3.81 cm, and p95-VDs were 2.67, 2.81, and 2.73 cm, respectively. In internal validation, over 95% of recurred LNs occurred within ED of 2.91 cm and VD of 0.82 cm to the neighbor LN, and the corresponding distances in external validation were 2.77 and 0.67 cm, respectively. In NPC, the maximum LN drainage distance was 3.95 cm without considering the direction. Specifically, in cranial-to-caudal direction, the sufficient vertical drainage distance was 2.81 cm, indicating that a 3-cm extension from the most inferior node may be rational as caudal border of the prophylactic clinical target volume (CTV). These findings promote in-depth understanding of nodal spreading patterns, uncovering paramount evidence for individualized CTV.

Case study of optimizing Low Impact Development Strategy in School: Allocation by the Drainage Distance

Under the concept of urban stormwater management, integrated efficiency of runoff and pollutant control via low impact development facilities came into focus, whereas a few specific descriptions are provided to quantify the strategy of these facilities, including the selection patterns of the locations and sizes and the connection of LID facilities and the drainage system, which is of important for the evolvement of LID strategy. Based on the weighted multi-object goal, the optimizing LID strategy reduces of runoff, pollutant, peak flow, and flooding time under required precipitation conditions, respectively. This paper concluded LID strategy under local requirements and tougher conditions in the aspect of the size and drainage distance of each facility, a new quantified index of locations of specific types of facilities. Then interpret the adjustment pattern based on the feature of rainfalls by correlation analysis. Correlation results show that the drainage distance of green roofs and the storage tank correlated to stormwater management indicators while the retention facilities did not, and the correlation respectively weakened and stronger when storm intensity increased, helping designers to establish better LID planning for schools.

ANALISIS KONDISI SANITASI LINGKUNGAN TERKAIT PENCEMARAN TOTAL COLIFORM TERHADAP AIR TANAH DI KELURAHAN TEBET BARAT

The majority of RW 07 residents use groundwater daily. While flood and still water often happens and the inadequately of wastewater management are one of many problems RW 07 residents faced. The purpose of this research are to be able to identify sanitation condition in residential area and identify the bacteriological quality of groundwater in West Tebet Urban Village, and analyze the relationship between those variable. Total coliform test of groundwater procured from the local well using Most Probable Number (MPN) method. This research showed that the amount of total Coliform ranging from 3/ 100 ml to >240.000/ 100 ml and as much as 83% of groundwater in local wells have surpassed the amount Total Coliform standard which Indonesian Health Ministry regulated in No. 416/ Menkes/ IX/ 1990. Other than that, the result showed that there is no relation between septic tank and drainage distance also well depth to the amount of Total Coliform.

Lake-TopoCat: a global lake drainage topology and catchment database

Abstract. Lakes and reservoirs are ubiquitous across global landscapes, functioning as the largest repository of liquid surface freshwater, hotspots of carbon cycling, and sentinels of climate change. Although typically considered lentic (hydrologically stationary) environments, lakes are an integral part of global drainage networks. Through perennial and intermittent hydrological connections, lakes often interact with each other, and these connections actively affect water mass, quality, and energy balances in both lacustrine and fluvial systems. Deciphering how global lakes are hydrologically interconnected (or the so-called “lake drainage topology”) is not only important for lake change attribution but also increasingly critical for discharge, sediment, and carbon modeling. Despite the proliferation of river hydrography data, lakes remain poorly represented in routing models, partially because there has been no global-scale hydrography dataset tailored to lake drainage basins and networks. Here, we introduce the global Lake drainage Topology and Catchment database (Lake-TopoCat), which reveals detailed lake hydrography information with careful consideration of possible multifurcation. Lake-TopoCat contains the outlet(s) and catchment(s) of each lake; the interconnecting reaches among lakes; and a wide suite of attributes depicting lake drainage topology such as upstream and downstream relationship, drainage distance between lakes, and a priori drainage type and connectivity with river networks. Using the HydroLAKES v1.0 (Messager et al., 2016) global lake mask, Lake-TopoCat identifies ∼ 1.46 million outlets for ∼ 1.43 million lakes larger than 10 ha and delineates 77.5×106 km2 of lake catchments covering 57 % of the Earth's landmass except Antarctica. The global lakes are interconnected by ∼ 3 million reaches, derived from MERIT Hydro v1.0.1 (Yamazaki et al., 2019), stretching a total distance of ∼10×106 km, of which ∼ 80 % are shorter than 10 km. With such unprecedented lake hydrography details, Lake-TopoCat contributes towards a globally coupled lake–river routing model. It may also facilitate a variety of limnological applications such as attributing water quality from lake scale to basin scale, tracing inter-lake fish migration due to changing climate, monitoring fluvial–lacustrine connectivity, and improving estimates of terrestrial carbon fluxes. Lake-TopoCat is freely accessible at https://doi.org/10.5281/zenodo.7916729 (Sikder et al., 2023).

Multicriteria analysis for flood risk map development: a hierarchical method applied to Brazilian cities.

Floods have caused socio-economic and environmental damage globally and, thus, require research. Several factors influence flooding events, such as extreme rainfall, physical characteristics, and local anthropogenic factors; therefore, such factors are essential for mapping flood risk areas and enabling measures that mitigate the damage they cause. This study aimed to map and analyze regions susceptible to flood risk in three different study areas belonging to the same Atlantic Forest biome, in which flood disasters are recurrent. Due to the presence of numerous factors, a multicriteria analysis using the Analytical Hierarchical Process was conducted. First, a geospatial database was composed of layers of elevation, slope, drainage distance, soil drainage, soil hydrological group, precipitation, relief, and land use and cover. Flood risk maps for the study area were then generated, and patterns in the study areas were verified, with the greatest influence being exerted by intense precipitation on consecutive days, elevation at the edges of the channel with low altimetric variation and a flat combination, densely built areas close to the banks of the main river, and an expressive water mass in the main watercourse. The results demonstrate that these characteristics together can indicate the occurrence of flooding events.

Morphodynamics and sediment connectivity index in an unmanaged, debris-flow prone catchment: a through time perspective

Torrential processes are among the main actors responsible for sediment production and mobility in mountain catchments. For this reason, the understanding of preferential pathways for sediment routing has become a priority in hazard assessment and mitigation. In this context, the sediment Connectivity Index (IC) enables to analyse the existing linkage between sediment sources and the selected target (channel network or catchment outlet). The IC is a grid-based index that allows fast computation of sediment connectivity based on landscape information derived from a single Digital Terrain Model (DTM). The index computation is based on the log-ratio between an upslope and a downslope component, including information about drainage area, slope, terrain roughness, and distance to the analysis target (e.g. outlet). The output is a map that highlights the degree of structural connectivity of sediment pathways over analysed catchments. Until now, these maps are however rarely used to help defining debris-flow hazard maps, notably due to a lack of guidelines to interpret the IC spatial distribution. This paper proposes an exploitation procedure along profiles to extract more information from the analysis of mapped IC values. The methodology relies on the analysis of the IC and its component variables along the main channel profile, integrated with information about sediment budgeting derived from Difference of DEMs (DoD). The study of connectivity was applied in the unmanaged sub-catchment (without torrent control works) of the Rio Soial (Autonomous Province of Trento – NE Italy) to understanding the geomorphic evolution of the area after five debris flows (in ten years) and the related changes of sediment connectivity. Using a recent DTM as validation, we demonstrated how an IC analysis over the older DTM can help predicting geomorphic changes and associated hazards. The results show an IC aptitude to capture geomorphic trajectories, anticipate debris flow deposits in a specific channel location, and depict preferential routing pathways..

Factors Affecting the Maximum Leachate Head in the Landfill Drainage Layer under Clogging Conditions

Clogging of the landfill drainage layer leads to a high leachate head developing over the bottom liner, which increases the risk of leachate leakage. Estimation of the maximum leachate head in the landfill drainage layer is of great significance to the pollution control of bottom liners. In this study, a simplified model considering the development of clogging is established through assuming the spatial and temporal distributions of clogging in a drainage layer of landfill. The calculation results are compared with a previous study to verify the proposed model. Through parameter analysis, it is discovered that the larger the initial hydraulic conductivity, the less the influence of clogging on the leachate head at the beginning, but it will increase over time. Meanwhile, a longer drainage distance, a larger inflow rate, or a higher ion concentration will lead to a greater influence of clogging on the leachate head. The completion time of clogging is more sensitive to the variation of inflow rate and ion concentration. In order to effectively control the maximum leachate head, it is suggested that the drainage material with large hydraulic conductivity such as pebbles or gravel should be used, the drainage slope should be greater than 4%, the drainage distance should be controlled at 20 m, and calcium products should be removed from leachate through adsorption, precipitation, or waste reuse.

Molecular and morphological evidence revalidates Acrobrycontarijae (Characiformes, Characidae) and shows hidden diversity.

We conducted a revision of the Neotropical genus Acrobrycon. A previous study synonymized the species, A.ipanquianus, distributed from the western portion of the Amazon River to the north-western region of the La Plata River Basin, and A.tarijae, with type locality in the Lipeo River in Bolivia. We revisited this result by collecting new morphometric, meristic, and genetic data (COI mitochondrial gene) for 24 individuals distributed along La Plata River Basin in Argentina, and discussed our results in the context of multiple biogeographic processes of isolation in that basin. Our results revealed a more complex history of diversification and geographic distribution across Acrobrycon species than previously suspected, probably associated with multiple biogeographic processes of isolation in La Plata River Basin. We present new evidence that led us to reconsider the validity of A.tarijae, which is distinguishable from A.ipanquianus by the number of vertebrae (37–39 vs. 41–42) and pleural ribs (12–13 vs. 14). These results were also supported by our molecular analyses that revealed a genetic divergence >4% between A.ipanquianus and A.tarijae. We also identified two main genetic clusters within A.tarijae: the first cluster consisted of specimens from the Bermejo, Pilcomayo, Itiyuro and Juramento river basins (northern Argentina); and the second cluster included specimens from the southernmost basins, such as the Salí River in Tucumán, Cuarto River in the province of Cordoba and the Quinto River in the province of San Luis. Our results suggest that the genetic structure observed in A.tarijae is the result of the type of drainage (endorheic vs. exorheic) and geographical distance.

Insights on formation damage associated with hydraulic fracturing using image analysis and machine learning

AbstractHydraulic fracturing is a well‐recognized technique used to produce as much as possible from unconventional resources. Yet, the communication between the main fracture and the fracture process zone (FPZ) around the primary fracture is still a mystery. Some research was conducted on actual samples to statistically examine the behaviour of these parameters along and parallel to the main fracture and the degree of damage/enhancement induced in the FPZ. Therefore, to understand the formation damage near the hydraulic fracture and its relation to the induced fractures, I am introducing a comprehensive analysis to shed light on some of the observations that I drew through the investigation throughout the previous years. Image analysis was performed on tight core samples under the triaxial compression test in addition to other sources of data and image analysis using data mining and machine learning. The number, length, and aspect ratios of the microcracks were measured. The drainage distance from the main fracture and the development of the microcracks were analyzed. A periodic cycle distribution was apparent around the main fracture and was related to the orientation of the microcracks and the surface roughness of the main hydraulic fracture. These results will help differentiate between the natural and induced microcracks. Additionally, a clear understanding of the relation between the primary fracture and the microcracks, the direction of the microcracks relative to the primary fracture, and the effectiveness of hydraulic fractures in the real world is presented. This work helps find the relation between the natural fractures and the induced fractures in a more realistic way, which helps in the design of the hydraulic fracture implementation and production increase.

Multivariate Analysis and Machine Learning Approach for Mapping the Variability and Vulnerability of Urban Flooding: The Case of Tangier City, Morocco

Urban flooding is a complex natural hazard, driven by the interaction between several parameters related to urban development in a context of climate change, which makes it highly variable in space and time and challenging to predict. In this study, we apply a multivariate analysis method (PCA) and four machine learning algorithms to investigate and map the variability and vulnerability of urban floods in the city of Tangier, northern Morocco. Thirteen parameters that could potentially affect urban flooding were selected and divided into two categories: geo-environmental parameters and socio-economic parameters. PCA processing allowed identifying and classifying six principal components (PCs), totaling 73% of the initial information. The scores of the parameters on the PCs and the spatial distribution of the PCs allow to highlight the interconnection between the topographic properties and urban characteristics (population density and building density) as the main source of variability of flooding, followed by the relationship between the drainage (drainage density and distance to channels) and urban properties. All four machine learning algorithms show excellent performance in predicting urban flood vulnerability (ROC curve > 0.9). The Classifications and Regression Tree and Support Vector Machine models show the best prediction performance (ACC = 91.6%). Urban flood vulnerability maps highlight, on the one hand, low lands with a high drainage density and recent buildings, and on the other, higher, steep-sloping areas with old buildings and a high population density, as areas of high to very-high vulnerability.

Finite Element Analysis of Vertical and Horizontal Drainage Structures under Vacuum Combined Surcharge Preloading

Combined vacuum and surcharge preloading has gradually been widely used because of its advantages of low cost, green environmental protection, and good treatment effect. The conventional prefabricated vertical drain presents obvious defects in vacuum preloading treatment, such as obvious silting, serious bending of the drainage board, large attenuation of vacuum degree of drainage board along the depth, long construction period, and so on, which affect the final reinforcement effect. In this paper, the MIDAS finite element simulation of combined vacuum and surcharge preloading of prefabricated vertical drains (PVDs) and prefabricated horizontal drains (PHDs) is established through the comparative experiment of the engineering field. The comparative experimental study is carried out from the aspects of the vertical settlement, horizontal displacement, and pore water pressure. The results show that under combined vacuum and surcharge preloading, the consolidation effect of soft soil with PHDs is better than that with PVDs. When PHDs are used, the vertical settlement increases by 7.2% compared with PVDs; the horizontal displacement is larger; and the pore water pressure dissipates faster. This is because when the PHDs are adopted, the consolidation direction of the soil is consistent with the direction of the vacuum suction, which is mainly caused by vertical settlement. With the consolidation, the spacing between PHDs is gradually shortened, and the drainage distance is reduced, which can effectively reduce the consolidation time and improve the reinforcement effect of the soil. In addition, the PHDs can move downward uniformly with the soil during the consolidation process and have almost no bending deformation, which makes the vacuum transfer more uniform and effective.

Distribution of carbon stocks in drainage areas on peatlands of Sungai Tohor Village, Meranti Islands District, Indonesia

Abstract. Silviana SH, Saharjo BH, Sutikno S. 2021. Distribution of carbon stocks in drainage areas on peatlands of Sungai Tohor Village, Meranti Islands District, Indonesia. Biodiversitas 22: 5106-5114. Peatland ecosystems provide a variety of environmental services and biodiversity with their ability to store and absorb carbon. The increase of land clearing followed by the construction of drainage or canal has resulted in the degradation of peatlands and is prone to fire incidences. Canal construction, whether we realize it or not, has a negative ecological impact on the in situ (local) environment, namely land degradation and subsidence, as well as a wider (global) impact in the form of loss of carbon stocks, increased GHG emissions that can trigger global warming. This study aims to identify the distribution of carbon in the area where drainage is made where the distribution of carbon stock in starting at a distance of 10 m, 50 m, 100 m, 250 m, and 350 m from the canal. The study was conducted on the community plantations including unburned areas (rubber plantations and secondary forests) and burned areas. The influence of land use and drainage development on carbon stock distribution is rarely known. The results showed a decrease in C-Stock with a decrease in drainage distance. The quantity of carbon stock in secondary forests ranged from 13.275 ton ha-1 - 24.839 ton ha-1, Burnt Area-1 ranged from 6.995 ton ha-1 - 11.59 ton ha-1, and Burnt Area 2 ranged from 4.677 ton ha-1 - 12.580 ton ha-1. In contrast, rubber plantations had higher C-stock in the initial observation distance, around 9.064 ton ha-1 - 11.805 ton ha-1, which may be due to intensive land use near the canal.

Evaluating urban flood risk using hybrid method of TOPSIS and machine learning

With the growth of cities, urban flooding has increasingly become an issue for regional and national governments. The destructive effects of floods are magnified in cities. Accurate models of urban flood susceptibility are required to mitigate this hazard mitigation and build resilience in cities. In this paper, we evaluate flood riskin Jiroft city, Iran, using a combination of machine learning and decision-making methods. Flood hazard maps were created using three state-of-the-art machine learning methods (support vector machine, random forest, and boosted regression tree). The metadata supporting our analysis comprises 218 flood inundation points and a variety of derived factors: slope aspect, elevation, slope angle, rainfall, distance to streets, distance to rivers, land use/land cover, distance to urban drainages, urban drainage density, and curve number. We then employed the TOPSIS decision-making tool for urban flood vulnerability analysis, which is based on socio-economic factors such as building density, population density, building history, and socio-economic conditions. Finally, we derived an urban flood risk map for Jiroft based on flood hazard and vulnerability maps. Of the three models tested, the random forest model yielded the most accurate map. The results indicate that urban drainage density and distance to urban drainages are the most important factors in urban flood hazard modeling. As might be expected, areas with a high or very high population density are most vulnerable to flooding. These results show that flood risk mapping provide insights for priority planning in flood risk management, especially in areas with limited hydrological data.

Landslide Hazard Zonation along the MH SH-73 at Kelghar Ghat, Satara, Maharashtra

Road transportation is the most common victim of landslide in the world. The present study investigates the landslide hazard zonation along the MH SH-73 at Kelghar ghat between Medha and Mahabaleshwar hill station of Maharashtra. Remote Sensing and GIS were used for the landslide hazard zonation of this section. The ghat section was buffered 100 m on both side to define the extent of study area based on the field investigation. The study incorporated predefined important landslide causative factors, viz. slope, rainfall, relief, lithology, soil depth, soil erosion, soil texture, land use / land cover, drainage distance, drainage density, lineament distance, lineament density, aspect, temperature, landslide inventory and in this approach fifteen thematic layers were prepared in GIS platform. The weight and score were assigned to each thematic layer based on heuristic approach on their relative importance in causing landslide. Multi-criteria model in ArcGIS 10.5 software were used for the mapping landslide hazard zones and it were classified into six zones: very high (1.3 %), high (1.7 %), moderate (3.4 %), low (7.6 %) very low (8.4 %) and no risk zone (77.7 %). The final result of this research can help for proper mitigation and adaptation measures for engineers, planners and administrators for this ghat section. Keywords: GIS, Landslide Hazard Zonation, Remote Sensing, Susceptibility, Sahyadri, Kelghar.

GIS-Based Irrigation Potential Assessment for Surface Irrigation: The Case of Birbir River Watershed, Oromia, Ethiopia

The assessment process of surface irrigation has to integrate information about the suitability of the land; water resource availability and water requirements of irrigate able areas in time and place. Birbir River is one of well-known river found in western Ethiopia. The Birbir River is a tributary of the Baro-Akobo river basin, which creates Baro River when it joins with Gebba River. Ethiopia has immense potential in expanding irrigation using available water resources. But due to lack of information related to cultivable and irrigation suitability of the land, its agricultural system does not yet fully productive. Geographic Information System can be an effective tool in identifying irrigable land and mapping of suitable land for irrigation. Therefore, the objective of the present study was to assess the surface irrigation potential of the Birbir river watershed using ArcGIS 10.3. Different methods of data processing and analysis have been employed in this study. The main suitability factors used to identify the potential irrigable land for surface irrigation were slope, soil texture, soil depth, soil type, soil drainage characteristics, land use, land cover and distance to water source. The consistency of rainfall and stream flow data were checked by double mass curve and the areal mean of rainfall and temperature data were determined by using Theissen polygon method whereas the irrigation water demands of the selected two crops (maize and potato) were calculated separately using FAO cropwat model. By weighting values of the seven factors using Analytic Hierarchy Process and overlaying by weighted overlay in ArcGIS 10.3, the irrigation suitability map was developed and potential irrigable land for surface irrigation was found to be 17%, 63% and 20% for highly suitable (S1), moderately suitable (S2), and marginally suitable (S3) respectively. Irrigation potential of the Birbir river watershed was obtained by comparing monthly gross irrigation requirements of the identified land suitable for surface irrigation and the available 80% mean monthly dependable flows in the river catchments. The potential irrigable land that can be irrigated without provision of storage structures was found to be around 68,000 ha from the total of 106,223 ha suitable land for surface irrigation.

Numerical modeling the injection of Super-Critical CO2 in non-dewatered coal bed methane formation

Dewatering the formation is the conventional methodology used when extracting methane (CH4) from the coal bed formation. A novel approach of not initially dewatering is to be studied. The approach has many advantages regarding the quantity of water produced, ground subsidence, and many more. Proving the latter best over the former requires several steps to be followed. The injection of Super-Critical CO2 (sCO2) is numerically modeled, in a naturally fractured coal bed methane (CBM) reservoir. Part-by- the part influence of each factor on the gas produced and the cleat properties are understood. Eventually, the sorption strain, effective stresses, reservoir compaction, varying overburden, and reservoir temperature, for the purpose, were coupled. The impact of non-isothermal conditions of the reservoir in the non-dewatered formation behavior is significant enough to reframe the conclusions. sCO2 enhances the recovery to 100% from 54% (with no injection) and is an essential application in CH4 production. The injection pressure is selected to sequester it to nearly 100%, assuming no breakthrough. The drainage distance dynamically varies with time as the production of gas proceeds. Flow phases are analysed, from the start, including the transitional effects till either the reserves are 100% recovered or pay zone length reaches. Earlier works relied on the conventional means, and the injected fluid was not the sCO2 to analyse the gas produced. The CO2 injected into the formation exists in supercritical form, which was, so far, ignored in the earlier models.The present study establishes that non-dewatered is a better alternative for the dewatered formation. The production time differs by 30 days. The additional production cost incurred is compensated by reduced water treatment costs. An economic analysis of the operations is required to support the work.

Numerical simulation of seepage in the landfill leachate layers

In order to control the environmental pollution caused by landfill leachate, the numerical simulation of landfill leachate seepage was carry out, which considered the influence of anisotropy of permeability coefficient, the permeability coefficient, matrix suction, infiltration amount of leachate, slope of drainage layer, drainage distance and initial water head on the maximum saturation depth. The results showed that when the horizontal permeability coefficient is fixed and the vertical permeability coefficient is reduced, the maximum saturation depth of leachate increased sharply. The maximum saturation depth linearly increased with the infiltration of leachate, whereas sharply decreased with the increasing of drainage slope. The maximum saturation depth is less affected by small drainage distance, whereas more affected by the large drainage distance. The initial head has a great effect on the maximum saturation depth, and whether the drainage pipe can discharge the leachate or not has an important influence on the maximum saturation depth.

An Investigation of Time‐Dependent Deformation Characteristics of Soft Dredger Fill

The creep characteristics of soft clays have been studied for decades. However, the lateral deformation of soils is not allowed during the commonly used one‐dimensional consolidation tests, which cannot describe the real deformation features of soils in practice. On the other hand, the influence of drainage distance on the mechanical properties of soil is still controversial, classified as hypothesis A and hypothesis B. For a better understanding of deformation characteristics of soft clay, especially which in long‐terms, a series of conventional oedometer tests as well as novel geometric confined consolidation tests was conducted on soft dredger fill. The results show that the secondary consolidation coefficient of the soil sample Cα would increase firstly, followed by a small decrease with the increase of consolidation pressure generally. Cα would decrease with the consolidation time and also be reduced by preloading. The strain at the completion of primary consolidation would increase with the drainage distance, but the Cα would be affected little. Both compression index Cc and Cα of soft clay would reduce after preconsolidation, in which two parameters show an approximate linear relationship. The creep coefficient of soft clay under the geometric confinement is larger than that under the oedometer test Cαε. However, the trends of the relationship between the creep coefficient and loading are consistent regardless of the confinement conditions.

Analysis of determining deliverability test and transient pressure in the PW-02 Well of Alpha Fields by using Ecrin software

Quantitative analysis of reservoir properties in a well is determined by transient pressure analysis. Transient pressure according to its type consists of Pressure Build up and Pressure Draw Down. this analysis provides an overview of the characteristics of a reservoir. This analysis includes the process of determining drainage area, shape, heterogeneity, porosity, average pressure, skin, permeability, and distance from a reservoir to boundary or flow discontinuities. This test is to determine the ability of gas production in the PW-02 Well, carried out by using the Modified Isochronal test method. This test aims to determine the productivity of a potential (Absolute Open flow). Transient pressure test on PW-02 Well using the Pressure Build up Test (Type Curve Pressure Derivative) method, it is found that the well model is Vertical well and the reservoir model is Two porosity PSS. While the boundary model obtained is Rectangle. Then, the data obtained in the form of positive skin is 1.46, the permeability is 62.5 mD and the reservoir pressure is 2529.32 psia. Based on the analysis obtained Absolute Open Flow Potential (AOFP) is 117406 mscf/D. While the deliverability test value obtained is 117413 mscf/D with n value of 0.825.

Geohazard Assessment in the Kota Kinabalu area, Sabah, Malaysia

This study focused on the Flood Susceptibility Analysis (FSA) and Landslide Susceptibility Analysis (LSA)of the Kota Kinabalu area, Sabah by using Multi Criteria Evaluation Model (MCE) for FSA and Deterministic Model for LSA. The study area had been affected by flood and landslide throughout the years. The aims of this study are to determine the flood susceptibility level and landslide susceptibility level of the study area and to identify the contributing factors that leads to the geohazards. Thus, a few mitigation measures can be recommended. The contributing factors that leads to the geohazards had been identified through desk studies and fieldwork. The data were obtained and digitized using ArcGIS software and the thematic maps were produced. The factors that contributing to the geohazards such as slope gradient, elevation, topographic curvature, flow accumulation and drainage distance were retrieved from the topographic database, whereas the land use, rainfall, soil types and soil properties were obtained from various agencies. Several areas are considered as susceptible, such as areas of Taman Kingfisher, Kg. Bantayan, Menggatal area, and Kg. Tebobon. To avoid or minimize the flood disasters, the Flood Susceptibility Level Map and the Landslide Susceptibility Map can be used in future development planning and a few structural controls can be implemented such as the land use planning of the area and hazard zoning. This study can be used as a resource for consulting, planning agencies and local governments in managing risk, land-use zoning and remediation efforts to mitigate risks.