Watershed Delineation Research Articles

USUAL Watershed Tools: A new geospatial toolkit for hydro-geomorphic delineation

Watershed and hydro-geomorphic delineation is a critical first step in most environmental and natural resource assessments, analyses, and research. While existing geospatial tools have provided exceptional advances, less attention has been put toward developing fully automated tools for subdividing landscapes into their constituent hydro-geomorphic units or discretizing river corridor features. Here, we present a new, open-source ArcGIS toolbox, called the Utah State University AppLied (USUAL) Watershed Tools. The USUAL Tools are a set of streamlined, easy-to-use ArcGIS toolboxes that automate the delineation of watersheds, sub-catchments, river-adjacent interfluves, and discretized river networks with the topological structure and feature attributes necessary for one-dimensional source-to-sink transport modeling through large watersheds. This novel geospatial toolset replaces the need for extensive delineation workflows, providing the Earth science, environmental science, and natural resources communities with the ability to rapidly and easily automate necessary but often time-intensive tasks in a format familiar to ArcGIS users.

Spatial dynamic model of land use land cover change on hydrological response characteristics in the Upper Ciliwung Sub-Watershed

Ciliwung Watershed is one whose state is critical. This condition causes the expansion of residential areas upstream of Ciliwung. Land use and land cover change affect a region’s hydrological characteristics. As a hydrological model, the SWAT (Soil and Water Assessment Tools) can predict the hydrological watershed characteristics affected by land use. This study aims to assess the land use change influence on hydrological characteristics and variations in inflow and outflow to develop the ideal recommendations for land use in the Ciliwung sub-watershed using system dynamics. The main river channel is constructed based on the watershed delineation process results, the watershed boundary consisting of 27 sub-watersheds. Due to average monthly discharge, the impact of land use change on hydrological characteristics in 2011, 2016, and 2020 were 65.01, 63.59, and 64.31 m3/second, respectively. The hydrological characteristics of all HRUs generated revealed that the Q max was 13,09 m3/s, and the Q min was 0.18 m3/s. In upstream Ciliwung, based on an inflows and outflows analysis, there were variations in 2011-2016 and 2016-2020. Based on the calibrated simulation results, the coefficient of determination (R2) was 0.8, and NSE was 0.78. The resulting R2 and NSE values indicate excellent model performance in the validation results. The ideal scenario is the intervention scenario on land use and population demography since it can reduce runoff. Runoff is the water that flows over the surface because the soil has reached its maximum infiltration capacity.

Cascade Reservoirs: An Exploration of Spatial Runoff Storage Sites for Water Harvesting and Mitigation of Climate Change Impacts, Using an Integrated Approach of GIS and Hydrological Modeling

Torrents play an essential role in water resources through rainfall in arid to semi-arid mountainous regions, serving large populations worldwide, and are also crucial in maintaining the downstream environment. The natural flows (floods, ephemeral flows) in arid hill regions result in potential hydrological fluctuations caused by climate change. However, the feasibility of eventual storage in remote hilly catchments would force a more sudden change. The current study was conducted in the lower part of the Khirthar National Range in the Sindh province of Pakistan, with the aim to explore spatial runoff storage sites for sustainable development to mitigate the impacts of climate change in arid areas. In total, 83 years of precipitation data were used to estimate water availability, along with satellite imagery for LULC pre- and post-monsoon conditions, delineation of watersheds, and identification of potential runoff storage locations and return periods, using Remote Sensing (RS)/Geographical Information System (GIS) 10.5.1, HEC-HMS 3.1, and Origin Pro 9.0 for statistical approaches. The model delineated two potential watersheds: Goth Sumar, covering an area of 61.0456 km2, wherein ten cascading reservoirs were identified, and Goth Baro, covering an area of 14,236 km2, wherein two cascading reservoirs were identified. Different storage capacities were determined for the cascade-type reservoirs. The maximum live volumetric potential storage of the reservoirs varies from 0.25 to 1.32 million cubic meters (MCM) in the villages of Baro and Sumar. The return periods have been estimated at 5, 10, 20, 25, 50, and 75 years, corresponding to 12.35, 16.47, 21.43, 21.72, 25.21, and 40.53 MCM for Goth Sumar, while Goth Baro’s storage capacity has been estimated at 2.88, 3.84, 5.00, 5.06, 5.88, and 9.45 MCM, respectively. All results obtained were authenticated using accuracy assessment, validation, and sensitivity analysis. The proposed potential storage sites were recommended for a planning period of five years. The live storage capacity of the identified cascade reservoirs can be improved by raising the marginal banks and developing the spillways to control inlet and outlet flow in order to maintain internal pressure on the reservoir banks. The stored water can be used for climate-friendly agricultural activities to increase crop production and productivity. The proposed study area has extensive experience with flood irrigation systems and rainwater harvesting to sustain agriculture due to rainfall being the only water resource (WR) in the region. However, the study area has enormous potential for surface runoff WRs, especially during the rainy season (monsoon); the current 2022 monsoon is showing flooding. The modeling approaches of Remote Sensing, GIS, and HEC-HMS play an important role in delineating watershed areas, developing hydrographs, and simulating water availability for different return periods by minimizing cost and time.

Assessment of the geomorphic indices in relation to tectonics along selected sectors of Borpani River Basin, Assam using Cartosat DEM data

• A total of eleven geomorphic indices were studied in detail for the assessment of tectonic activity along Borpani River. • Results indicates satellite imageries based Geomorphic indices can witnesses tectonic influences. • Overall tectonic activity indicates classes - active, moderately active and less active zones in the study region. • On average, 23.86%, 29.54%, and 46.58% of the geomorphic indices falls in active, moderately active and low active classes. We studied geomorphic indices related to tectonics along the Borpani River using Cartosat 10 m spatial resolution Digital Elevation Model (DEM) data. A total of 11 geomorphic indices such as transverse topographic symmetry factor (Tt), drainage basin asymmetry (AF), valley floor width to valley height ratio (Vf), bifurcation ratio (Rb), hypsometric integral (HI), basin elongation ratio (Re), basin shape index (Bs), circularity ratio (Rc), drainage density (Dd), relief ratio (Rh), hypsometric curves (HC) were studied to access the tectonics along the river in selected locations. Five locations along the river were selected for detailed analysis (sub-basin I, II a, II b, III, and IV). Horton's (1945) scheme was adopted for watershed delineation, while stream ordering was performed using Strahler's (1964) method. The results infer that the sub-basins along the Borpani River are tectonically active. In the case of sub-basin I, 3 geomorphic indices out of 11 falls in the category of highly active, and 2, 1, 2, and 4 indices out of 11 falls in the category of highly active in the case of sub-basins II a, II b, III, and IV. Similarly, 4, 1, 3, 6, 1 and 4, 8, 7, 3, 6 indices fall under moderately active and low active classes in sub-basins I, II a, II b, III, and IV. On average, 23.86 %, 29.54%, and 46.58% of the geomorphic indices fall in the active, moderately active, and low active classes.

Development of Novel QAPEX Analysis System Using Open-Source GIS

The Agricultural Policy/Environmental eXtender (APEX) model has been used for farm/small watershed management, and the ArcAPEX interface was developed using the ArcGIS extension. However, the interface requires a paid license and limits dynamic applications that reflect various agricultural farming practices. In this study, a novel APEX model interface using Quantum GIS, the QAPEX analysis system, was developed by incorporating open-source-based GIS software for the simulation of water quality impacts of various best management practices reflecting local farming activities. The watershed delineation process running on the QAPEX interface is more flexible than that on the ArcAPEX interface, which renders simulations on hydrology and water quality with considerable precision. The newly developed system can be used to visually interpret simulation results (e.g., flow and load duration curve functions). Therefore, the open-source-based model can be used to derive data for sustainable agricultural policies, with a focus on the field-level application of management practices.

Experimental and Numerical Simulations of Sediment in Fusre River Basin, Nepal

This study presents about the analysis of sediment generation of the ungauged basin Fusre basin by modeling and also with the help of rainfall simulator. Many rivers in Nepal are either ungauged or poorly gauged due to extreme complex terrains, monsoon climate and lack of technical and financial supports. The Soil and Water Assessment Tool (SWAT) was applied for watershed delineation of the Fusre basin and the basin delineated into seven sub-basin that generate the river network, which also provides the information like stream link, stream order, stream length, slope etc. The calibration was performed using data from 2003 to 2010 and validation for the period from 2011 to 2015 at a daily time step. The model performance was evaluated based on computed statistical parameters. For the calibration period of the discharge and sediment flow, the performance of the model was very good, with a coefficient of determination R2= 0.9528, Nash-Sutcliffe Efficiency NSE = 0.942, RMSE = 0.24, and Percent Bias= 14.78, Similarly, the continuous model performance for the validation period was good, with R2 = 0.8655, NSE = 0.925, RMSE = 0.275 and Percent Bias = 18.03. Also a series of laboratory experiments was also carried out by changing the land use, soil parameter, and rainfall intensity by varying depth of soil sample and slope for comparative study with model but just for performance of apparatus. The performance of rainfall simulator was good. From the experimental method the calculation value of coefficient of determination R2 is equal to 0.67, NSE value is equal to 0.865 and PBIAS was equal to 30. The performance of both experimental and simulated data was satisfactory.

Morphometric Analysis of Saz-Çayırova Drainage Basin using Geographic Information Systems and Different Digital Elevation Models

Drainage basin/watershed analysis based on morphometric parameters has an essential role in watershed management and planning. Reliable delineation of watersheds and drainage networks is critical for hydrological and geomorphological studies. Since access to high-resolution digital elevation models (DEMs) and digital surface models (DSMs) is costly, many researchers need to evaluate low-resolution open-source products. Several data sources produced from different surveying techniques are used in the morphometric analysis. In this study, five different datasets such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) GDEM, Shuttle Radar Topography Mission (SRTM) DEM, Advanced Land Observing Satellite (ALOS) DSM, National Aeronautics and Space Administration (NASA) DEM, and a DEM from topographic maps (TOPO DEM), were investigated based on morphometric parameters. The tests was carried out in the Saz-Çayırova Basin, which is one of the critical urbanization and industrialization regions of Kocaeli, Turkey. In this study, the TOPO DEM, whose horizontal resolution is 30 m, was produced from 1:25K scaled digitized topographical maps. It was used for comparative analysis, as in all DEMs sources. The morphometric parameters' result of the TOPO DEM was used as the reference data for comparing the results of the other DEMs sources. In addition, the mean absolute percentage error (MAPE) was used to compute the accuracy between the freely available DEMs and the TOPO DEM for each morphometric parameter. The outcomes of this study reveal that the most consistent results with the TOPO DEM are provided by SRTM DEM, following the NASA DEM.

Application of the Compound Factor for Runoff Potential in Sub-watersheds Prioritisation Based on Quantitative Morphometric Analysis

Abstract Accurate watershed delineation and drainage system extraction are critical tasks for the hydrological and geomorphological model. Watershed morphology evaluation is very important for flood control and recovery planning. It is beneficial for understanding the basin’s hydrology. In this study, the Rel river basin was selected, located in Gujarat, India. This study deals with the runoff potential in the semi-gauged Rel river basin depending on the detailed morphometric study. The Survey of India (SOI) topographic sheet (1:50000) and geographical information system (GIS) tools have been used for the detailed study in the evaluation of morphometric parameters. For accuracy in flat terrain, a topographic sheet has been used instead of DEM. Manually digitise the drainage from the SOI topographic sheet to precisely divide the watershed boundary; after that, the Rel basin has been divided into five sub-watersheds (SWs), namely, SW1 SW2, SW3, SW4 and SW5. Twenty-eight morphometric parameters have been calculated for each sub-watershed (SW). For runoff potential, twenty-one effective morphometric parameters have been selected based on previous studies.A compound factor (CF) model has been used for the SWs prioritisation. Twenty-one effective morphometric parameters have been considered in the CF model. The model results indicated that SW2 has a very-high runoff potential, and SW3 has a very-low runoff potential. The methodology developed and the results presented here will be critical in developing a comprehensive sub-watershed management plan. The work’s results can better understand the topography, nature of the basin, and the delineation of a suitable soil conservation site and mitigate flash floods in the flat region.

Effects of Watershed Delineation on the Prediction of Water Quality Parameters in Gaa Akanbi Area, Ilorin

Watershed delineation is a required step when conducting any spatially distributed hydrological modelling. The prediction of water quality parameters in a basin entails delineation of watershed into different number of sub-basins. Thus, this research evaluated effects of watershed delineation on the prediction of water quality parameters in Gaa Akanbi area of Ilorin, Kwara state, Nigeria. The objectives are to model and predict water quality parameters in the watershed; delineate the selected watershed in various numbers of sub-basins and study the effects of watershed delineation in the prediction of water quality parameters of the basin. For proper implementation of this study, Geographical Information System (GIS) software, physically based watershed model – Soil and Water Assessment Tool (SWAT) and other data processing software were used. Since the model is physically based, the surface properties (i.e. Digital Elevation Model (DEM), stream network, digital soil map, digital land use and land cover map, climatic and hydrological data) served as input in the model. The model was daily for a period of 30 years (i.e. January 1991 to December, 2020). The results showed that the watershed was successfully delineated to 3,7,11,21,32,53 sub-basins. Also, it was noted that the predicted values of water quality parameters (Nitrate, organic phosphorus and sediment concentration) are directly proportional to increase in the number of sub-basins delineated in the watershed.

Rapid Watershed Delineation Using an Automatic Outlet Relocation Algorithm

AbstractDelineating the boundaries of numerous watersheds is essential for hydrological analysis in the big data era. Various techniques, such as ArcGIS, have been developed to delineate watershed boundaries. However, existing techniques suffer from two laborious manual processes: (a) Determine flow accumulation thresholds through trial and error to derive digital stream networks; (b) Manually relocate watershed outlets to the correct stream networks. Here, we proposed an automatic outlet relocation (AOR) algorithm for rapid watershed delineation without manual processing. The AOR algorithm relocates outlets to correct stream networks by analyzing flow accumulation gradients along the flow directions. An experiment using the AOR algorithm in 1,398 watersheds across the contiguous United States showed that 94.1% of the watersheds were correctly delineated, compared to 81.3% accuracy of the ArcGIS relocation algorithm (Snap Pour Point). In addition, the AOR algorithm took 58 min to delineate the 1,398 watersheds on a 90 m‐resolution flow direction, while the ArcGIS algorithm required 586 min to perform the same task. Thus, the AOR algorithm offers an opportunity to automatically delineate a large number of watersheds for hydrological simulations in the big data era. Software with a graphical user interface for the AOR algorithm is freely available on GitHub (https://github.com/xiejx5/watershed_delineation).

The Application of Watershed Delineation Technique and Water Harvesting Analysis to Select and Design Small Dams: A Case Study in Qara-Hanjeer Subbasin, Kirkuk-NE Iraq

The rainwater harvesting technique is one of the solutions to overcome the effect of water shortage crises in arid and semi-arid regions. In this study, the feasibility of using small dams in water harvesting has been examined at Qara- Hanjeer sub-basin that lies east of Kirkuk, N-Iraq with a surface area of 503.88 Km2. Watershed boundary for entire basin has been delineated comparatively by mask method, using hydrology toolset in ArcGIS (10) software. Direct surface runoff is calculated using Soil Conservation Service Curve Number method based on data from Kirkuk meteorological station for the period (1995-2020), information obtained from land use map, and soil type, the basin is divided into six zones with different CN values, Moreover, for average annual rainfall (334.33 mm/year), water surplus was 190.2 mm and surface runoff was 25.77 mm representing 7.708 % of the total rainfall. The runoff depth was 167.03 mm/year and the total annual harvested runoff is 12.99x106 m3 Several temporary and semi-permanent check dams could be built across the valleys, with height (< 3m.). These dams are of low cost, reduce the loss of runoff water, improve agriculture, tourism and add impetus to the ecosystem programs in Qara-Hanjeer city.

River pollution monitoring over an industrial catchment in urban ecosystem: Challenges and proposed geospatial framework

Urban river pollution is considered a ‘necessary evil’ consequence of disproportionate developmental expansion in metropolises. Unprecedented expansion and anthropic activities amongst other reasons lead to choking of urban rivers with municipal and industrial sewage. Urban rivers are dying while awaiting rescue, despite the hard efforts by civic authorities, largely due to lack of coordination amongst river authorities and stakeholders, underlying conflicts spanning across all levels, balkanisation, pluralization, scarcity of reliable technical data, and financial constraints. Challenges faced by stakeholders in river pollution management as revealed in informational interviews are foregrounded. In an attempt to reduce some of the overwhelm faced by officials on ground, a geospatial framework is proposed which if functionally implemented can transparentize river water quality (WQ) monitoring, and facilitate pollution control. The pollution situation in a persistently polluted urban river near Mumbai city, India was explored and assessed in the middle of a restoration battle waged by environmental activists. Following secondary river water quality data acquisition, primary sample collection campaign and WQ testing, multivariate statistical data analysis was performed under data- and resource-constraint situation. Spatiotemporal monitoring and visualization of river water quality data holds great promise for effectively controlling anthropic river pollution. A subsequent geospatial analysis of the study area was performed using digital elevation model (DEM) based watershed delineation, land use land cover (LULC) classification, mapping of WQ monitoring locations, mapping of industrial clusters, integration of spatial data, and identifying polluter industries. This steered us to formulate and propose the geospatial framework and supplementary recommendations on how better to save this dying river. The framework displays near real-time information on river water quality at different impaired river stretches in urban industrial ecosystem. Applicable universally for monitoring any river in urban industrial catchment, it can be used as a reference by stakeholders and research aspirants.

Advances in hexagon mesh-based flow direction modeling

Watershed delineation and flow direction representation are the foundations of streamflow routing in spatially distributed hydrologic modeling. A recent study showed that hexagon-based watershed discretization has several advantages compared to the traditional Cartesian (latitude–longitude) discretization, such as uniform connectivity and compatibility with other Earth system model components based on unstructured mesh systems (e.g., oceanic models). Despite these advantages, hexagon-based discretization has not been widely adopted by the current generation of hydrologic models. One major reason is that there is no existing model that can delineate hexagon-based watersheds while maintaining accurate representations of flow direction across various spatial resolutions. In this study, we explored approaches such as spatial resampling and hybrid breaching-filling stream burning techniques to improve watershed delineation and flow direction representation using a newly developed hexagonal mesh watershed delineation model (HexWatershed). We applied these improvements to the Columbia River basin and performed 16 simulations with different configurations. The results show that (1) spatial resampling modulates flow direction around headwaters and provides an opportunity to extract subgrid information; and (2) stream burning corrects the flow directions in mountainous areas with complex terrain features.

Morphometric Analysis of Baner, Neogal and Awa River Basins, Himachal Pradesh, India

Abstract The present study aims at evaluating the morphometric parameters of Baner, Neogal and Awa river basins in Himachal Pradesh, India for making important assessments about the morphometric characteristics and geo-hydrological conditions of these watersheds. Georeferenced Survey of India toposheets, Cartosat-DEM are the datasets used in ArcGIS software for the delineation of watersheds and calculating important morphometric parameters along with the preparation of relief, slope, aspect and drainage basin asymmetry maps. The results show that the Neogal and Awa rivers are of 6th order whereas Baner river is of 7th order. The basins are of elongated shape and the drainage is mainly of sub-dendritic to dendritic type. In the northern regions of these river basins, the slopes are very steep and the relief is very high that results in rapid runoff and increases the intensity of erosion. High drainage density (>2.8) and fine drainage texture (>9) indicate moderately permeable subsurface material that causes groundwater deficit. These watersheds have developed asymmetrical drainage and their high ruggedness values (>12) refers to the rejuvenated stage of their geomorphic development. The study concludes that erosion-prone areas with rapid runoff are present in the area and adequate measures will assist in the sustainable management of land and water resources.

Basinmaker 3.0: A GIS Toolbox for Distributed Watershed Delineation of Complex Lake-River Routing Networks

Basinmaker 3.0: A GIS Toolbox for Distributed Watershed Delineation of Complex Lake-River Routing Networks

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.

The impact of (DEM) Accuracy on the Watersheds areas as a function of spatial data

Digital Elevation Model (DEM) is main input for watershed modelling. Recently, (DEM) is available online for free in different accuracies, and spatial resolutions as a product of several remote sensing satellites. Hence, it is necessary to find out which one is the best for watershed modeling in the study area. In this study, the different accuracies 30m spatial resolution DEMs of (Copernicus, SRTM, and ASTER) can be examined by using Remote sensing (RS) and Geographic Information systems (GIS) techniques to delineate and calculate the topographic characteristics for five different size and topography watersheds (Swaidy, Garlond, Khuwayr Hirah, Naqab, and Kalak) located on both sides of the Mosul reservoir in the northeastern part of Iraq. The analysis results can be led to find that the Copernicus (GLO-30) 30 m resolution DEM is the optimum and most accurate DEM in the selected study area at the vertical accuracy (1.3521 m) and with 95% confidence level is (2.6502 m) represented by the minimum Root Mean Square Error (RMSE) of the elevations differences between check points (MOWR elevations and LIDAR DEM 1 m resolution) and the used DEMs. The watershed delineation and calculated topographic characteristics (watersheds boundary, elevations, area, perimeter and slope areas) are affected by DEM accuracy. Where the considerable accuracy of the differences is with the (Copernicus-SRTM) DEMS at the minimum RMSE of watersheds characteristics.

Land cover based simulation of urban stormwater runoff and pollutant loading

Urban stormwater models such as PCSWMM are important tools for evaluating urban stormwater quantity and quality. However, due to the lack of consideration of land covers, traditional catchment delineation methods have defects in model precision, parameter transferability and assessment of contribution from individual land cover types. This paper used PCSWMM model as a foundation, built a new land-cover based (LCB) model and made a systematic comparison with the traditional watershed delineation tool (WDT) model to study the impacts of land cover on the simulation of stormwater runoff and pollutant loading. The models were applied to two urban catchments in Calgary, Canada. The results revealed that the LCB model performed better than the WDT model in hydrological simulation, and land cover consideration can considerably improve model accuracy. The two models showed comparable performances in simulation of total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) loading. The LCB model parameters could be regionalized based on land cover types. The hydrologic-hydraulic parameters can be satisfactorily transferred from neighboring gauged catchments to similar ungauged catchments. The transferring of water quality parameters did not perform as satisfactory. The LCB model could quantitively evaluate the contribution to runoff and pollutant loads of different land covers. Roads and roofs were found to be the major contributors to urban runoff and pollutants in the two urban catchments. Green space became important only during large storms events and its contribution could be ignored during dryer years.

LAND USE POLICY AREA (LUPA) CONCEPT MODEL

Abstract. The paper presents a Land Use Policy Area (LUPA) Concept Model adding the three basic elements: (i) ecosystem-based land use regarded as the intersection of the ecosystem and land use elements, (ii) subwatershed-based land use as the intersection of the subwatershed and land use elements, and (iii) integrated environmental management is the intersection of the subwatershed and ecosystem elements regarded as the Integrated Ecosystem Development Planning Unit (IE-DPU). The basic (spatial) elements are mathematically expressed as the paired sets of the three main variables, namely: ecosystem (dependent), watershed (dependent) and land use (independent) variables. The challenging work in this study was the development of a geospatial information model for use in policy areas LUPA applying these variables. There are four steps applied to answer the research objective, these are: ecological zone assessment, ridge-to-reef watershed delineation, land and water use heads-up mapping, ecosystem-based land use overlay analysis, watershed-based land use overlay analysis, integrated environmental management overlay analysis, and LUPA overlay analysis. The concept model analysis steers the geospatial information modeling for LUPA which carried the intersections of the paired variables: ecosystem-based land use, subwatershed-based land use and integrated environmental management as variating inputs to process by extracting the science-based information (overlay output) which practically highlighted the LUPA classification: (i) Protection with 49.1% or 3858.2 Ha of mangrove forest reserve and water use, (ii) Production areas with 46.5% or 3631.7 Ha mostly agricultural and aquacultural areas, (iii) Settlement with 2.7% or 209.2 Ha of urban and urban uses, and (iv) Infrastructure with 1.5% or 116.7 Ha of development. The authors concluded that land use policy areas will relatively change as land use changes which is also seen reliant on the impacts of climate change.

​The Significance Impact Assessment of Morphological Parameters on Watershed: A Review

Watershed morphological analysis is momentous for controlling floods risk, forethought and management of the watershed area, as well as it is foremost useful to perceive catchment hydrology. Remote sensing and geographic information system are used in recent times as a tool for watershed delineation and its planning. Many types of input parameters generally use for watershed delineation such as Toposheet, ALOS, SRTM DEM, ASTER DEM and CARTOSAT DEM. Based on analysis SRTM DEM gives meticulous and clear results compared to other DEM files. Morphometric based prioritization of watershed was given in many research papers but an appropriate result of priority range was not given and this type of study confusing to evaluate the rank of priority based on its erosional behaviour. In many papers results of morphometric parameters were not indicate how to retaliate these results of morphometric parameters to a watershed. This paper deals with the implication of different values of morphometric parameters with adequate contextual information. This review paper can give useful information for the morphometric analysis of watersheds.