**5. Discussion**

Lakes are essential to achieving the SDGs because they offer solutions to a variety of global problems. The majority of the SDGs are linked to surface water, but this study concentrated on goal 6, target 6a, and indicator 6.6.1. Target 6a emphasizes the involvement of the local community in improving the availability of water and sewage management. Indicator 6.6.1 highlights the extent to which the water-related ecosystem can change over time. In the study, we see that Agulu Lake has been shrinking during the 1985–2000–2015 study years and is anticipated to shrink further by 2030. If we are set to achieve UN SDG 6 by 2030, then there is a need to manage, maintain, and rehabilitate deteriorating lakes and other open water bodies.

### **6. Conclusions and Recommendations**

This study demonstrated the ability to capture spatial-temporal data using GIS and remote sensing every 15 years, from 1985 to 2000 and from 2015 to 2030. Remote sensing technology is widely used for monitoring and mapping water bodies as a result of its availability and wide coverage. The Sustainable Development Goals (SDGs) of the United Nations emphasize the need to manage the marine environment. Altogether, there are 17 SDGs in total, but goals 6a and 6.6.1 are crucial to this study. The study's findings show that Agulu Lake has been shrinking and is anticipated to shrink further by 2030. This shrinkage in the study area (Agulu Lake) may be a result of the numerous anthropogenic activities taking place in the study area's periphery. To accomplish SDG 6 by 2030, it is recommended that sustainable practices be mandated. Due to this, the following suggestions are offered based on the study's findings: An interim master plan should be created to prevent shrinkage, and the local authority should publish a stop notice to all types of development within and around the study area. In conclusion, open surface water should be monitored frequently with remote sensing technology.

**Author Contributions:** Conceptualization, M.A.E. and C.A.O.; methodology, M.A.E.; software, M.A.E.; validation, M.A.E., C.A.O. and N.Y.N.; formal analysis, M.A.E. and N.Y.N.; investigation, C.A.O.; writing original draft preparation, M.A.E.; writing-review and editing supervision, M.A.E., C.A.O. and N.Y.N.; project administration, M.A.E., funding acquisition, C.A.O. and N.Y.N. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study had received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare that no conflict of interest exists.
