GEOSPATIAL ASSESSMENTS FOR CWIS PLANNING

Assessments of Hard to Reach (HTR) Settlements

Data Requirements

Stepwise Process Flow Details

Now, you should have three categories of buildings: those within 100 feet of roads, those between 100 feet and 200 feet, and those more than 200 feet away (inaccessible buildings). The results will be stored in separate layers based on your specified output file names and locations.

Figure 7 Illustrations of town desludging schemes based on hard-to-reach area findings, Sherpur (Bangladesh)

Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

The output here provides a clear understanding of the settlements accessible by large and small volume trucks. It pinpoints areas requiring additional infrastructure such as pipes and electric pumps and identifies inaccessible areas where manual or electric small carts are necessary for mechanical desludging.

As for its application, such framework can be instrumental in designing a desludging scheme for any towns. It aims to ensure a 100% safe collection mechanism for all users, effectively integrating data, analysis, and visualization to assist in efficient decisionmaking and strategy formulation for sludge emptying and collections.

Assessments of Waterlogging/Flood Prone Settlements

Data Requirements

  1. Elevation data
  2. Waterbodies/ Rivers
  3. Past Flood data with location
  4. High Flood Line for rivers

Stepwise Process Flow Details

Figure 8 Illustrations of identifying of water logging prone settlements, Sherpur (Bangladesh)


Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

Areas with waterlogging risks present operational challenges for the smooth functioning of toilet units. These challenges include toilet back-flow and non-functional soak pits. Understanding such risk areas may aid in understanding such risk hot spots on at city scale and integrating them with building bye-laws could also assist in the development of an appropriate monitoring framework.

Assessment of Drainage Network with Orders and Density

Data Requirements

1.     Elevation data

2.     Waterbodies/ Rivers

Stepwise Process Flow Details

Step-by-step instructions in paragraph form for identifying natural drainage network and catchment areas from DEM using QGIS Hydrology tools:

With these steps, you will be able to identify the natural drainage network and catchment areas from the DEM data using QGIS.

Figure 9 Illustrations of watershed regions at Dhanbad (India)

Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

A drainage network map helps delineate the different watersheds within a region, which play a significant role in both sewer and non-sewer zoning for any large town. Furthermore, watershed zones have significant applications in grey water management using an interceptor and diversion (I&D) framework. They can serve as functional linkages with the sewer system or may also operate as independent modules. Further this also has applications in identifying water logged prone area within the city. 

Assessment for Identifying Settlements Close to Waterbodies

Data Requirements

Stepwise Process Flow Details

Stepwise Process Flow Details

Figure 10 Illustrations for identifying settlements close to water bodies, Sherpur

Source – CWIS spatial analysis , Innpact Solutions and GWSC

Output Application

Areas in proximity to water tend to have a heightened risk of untreated wastewater encroaching into nearby water bodies, which can have significant public health and environmental ramifications. Identifying such settlements can guide the selection of safe containment provisions in both existing and upcoming units. These units can also be integrated with building by-laws and ensure safe containment provisions in all future constructions. 

Assessments for Identifying Economic Vulnerability Assessment

Data Requirements

  1. Building footprint with Typology
  2. Slum boundary

Stepwise Process Flow Details

Figure 11 Illustrations for identifying economic vulnerable settlements, Sherpur (Bangladesh)

Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

Settlements identified as economically vulnerable are given priority when designing and implementing sanitation interventions across the sanitation value chain. These settlements can also be overlaid with other environmental and climate risk outputs to identify those with a higher degree of vulnerability.

Assessment for Settlement Identification for Bulk Volume of Wastewater Generation

Data Requirements

1. Building with type of use and number of floors

Stepwise Process Flow Details

Figure 12 Illustrations of identifying settlements of bulk wastewater volume generator, Sherpur (Bangladesh)

Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

Buildings that produce significant wastewater should be prioritized for on-site treatment, particularly if they're near water-sensitive areas, given the considerable environmental and health risks. Recognizing these bulk generators can guide us in two ways. For government buildings, we can suggest interventions and financial aid to establish on-site wastewater systems. For private buildings, regulation and monitoring can gradually improve conditions. Including these generators in building bye-laws ensures future buildings consider wastewater management, promoting both immediate and long-term improvement

Assessment for Containment Improvement Scheme at Town Scale

Data Requirements

  1. Output map of settlement near to water bodies,
  2. Output map of settlement with waterlogged and flood prone risk
  3. Output map of hard-to-reach settlement area
  4. Output map of bulk wastewater generator building

Stepwise Process Flow Details

Figure 13 Illustrations of developing containment improvement scheme, Sherpur (Bangladesh)

Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

Location-based information can assist in tracking the evolution of improved containment systems over time. Such data also offers crucial insights for shaping city sanitation regulations, thereby facilitating an understanding of overall containment improvement objectives and designing service-level benchmarks for ongoing monitoring. Moreover, this information can be integrated with building bye-laws to ensure the selection of contextually appropriate containment systems in all future construction projects.

Assessments for Public Toilet Gap and Required Upgrades

Data Requirements

  1. Major commercial and institutional land uses
  2. Network Dataset using the road network layer
  3. Location of public toilets with number of seats

Stepwise Process Flow Details

Figure 14 Illustrations of public toilet assessment of Sherpur, Bangladesh

Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

Implementing and adapting these recommendations would contribute to an adequate distribution and coverage of public toilet services throughout the city. A primary focus is on achieving a balanced gender distribution of water closets (WCs). Common observations across various cities have revealed a significant shortage of women's facilities in public toilet premises. Therefore, alongside general upgrades, there is a proposal to establish dedicated 'She Toilets' in high footfall areas to meet this demand.

Assessment of Pan City Level Settlements Proximity to Existing and Proposed FSTP

Data Requirements

  1. Location of existing and proposed FSTPs
  2. Network dataset using the road network layer

Stepwise Process Flow Details

Figure 15 Illustrations of assessment of settlements proximity of proposed and existing FSTP, Sherpur (Bangladesh)

Source – CWIS spatial analysis, Innpact Solutions and GWSC

Output Application

This type of analysis aids in assessing the locational suitability of both existing and proposed Faecal Sludge Treatment Plant (FSTP) sites. Based on the results, areas outside of smooth travel distances might consider the possibility of implementing transfer stations or additional treatment facilities, contingent on the volume of sludge generated from their respective settlement areas. This spatial understanding provides a comprehensive approach for faecal sludge management planning and implementation across the city.