Willingness to pay for the ecological restoration of an inland freshwater shallow lake: case of Lake Malombe, Malawi

Economic evaluation of groundwater resource in the Effutu Municipality: An application of the Gisser-Sanchez effect

This study presents an economic valuation of the groundwater resource in the Effutu Municipality. It tests the validity of the Gisser-Sanchez's position that the benefits derived from implementing a groundwater management intervention are insignificantly small compared to when no intervention is made. Hundred groundwater-user households were sampled by quota, convenience, and simple random sampling techniques. Assuming a quantitative approach, a contingent valuation-based willingness to pay questionnaire was used for data collection. Respondents were asked to value groundwater under two regimes based on quality: (1) unmanaged quality and (2) hypothetically-managed quality regimes. Using the Lancaster demand theory, the values assigned under either regime were assumed as the benefits users would derive from using groundwater. The statistical difference between the benefits of the two regimes was established by the Wilcoxon Signed Rank Test. The findings revealed that groundwater users are willing to pay 20 Pesewas (GH₵ 0.2) and 30 Pesewas (GH₵ 0.3), respectively, for a 10 L bucket of groundwater from the unmanaged quality regime and groundwater from the hypothetically-managed quality regime. The study established a statistically significant difference between the economic values of groundwater under either regime, indicating that the Gisser-Sanchez effect does not hold for groundwater used for drinking and domestic purposes in the Effutu Municipality. It has been expressed that improving groundwater quality will significantly increase the economic value of the resource. It has therefore been recommended that efforts should be made to treat groundwater to assume the quality of the Ghana Water Company's pipe-borne water after drilling projects in the Municipality.

Monitoring trophic status using in situ data and Sentinel-2 MSI algorithm: lesson from Lake Malombe, Malawi

With excessive nutrient enrichment exacerbated by anthropogenic drivers, many standing water bodies are changing from oligotrophic to mesotrophic, eutrophic, and finally hypertrophic-negatively affecting ecosystem functioning, biodiversity, and human populations. Efforts have been devoted to developing novel algorithms for estimating chlorophyll-a (chl-a), cyno-blooms, and floating vegetation. However, to this date, little research has focused on freshwater lakes in the data-scarce Sub-Saharan African countries such as Malawi. We, therefore, estimated the trophic status of Lake Malombe in Malawi-a lake likely to be affected by eutrophication and algal bloom-emerging threats to freshwater ecosystem functioning globally-especially with the onset of climatic and anthropogenic drivers. We integrated in situ data with high-resolution Sentinel-2 Multispectral Imagery Analysis (MSI). We independently assessed the remote sensing technique using in situ data and tested the model at multiple stages. The scatter plot showed that most points were in the 95% confidence interval. The validation results between the measured in situ chl-a concentrations and the Sentinel-2 MSI-based chl-a retrieval had a root mean square error (RMSE) of 2.88 µg/L. The chl-a concentrations retrieved from MSI images were consistent with in situ data, indicating that the normalized difference chlorophyll index (NDCI) algorithm estimated chl-a concentrations in Lake Malombe with acceptable accuracy. Dissolved oxygen (DO), sulfate (SO₄^2-), nitrite [Formula: see text], soluble reactive phosphorous [Formula: see text]), total dissolved solids (TDS), and chl-a, except for temperatures from the hot-dry-season, cold-dry-windy-season, and rainy-season, were significantly different (P < 0.05). The Sentinel-2 MSI imagery analysis also depicted similar results, with high chl-a concentration reported in March (rainy season) and October (hot-dry season) and the lowest from May to August (cold-dry-windy season). On the contrary, the ANOVA results for water quality parameters from all five points had P > 0.05. The correlation matrix showed coefficients of (0.798 < r < 0.930, n = 30, P < 0.005), suggesting that Lake Malombe is homogenous. Our results demonstrate that integrating remote sensing based on MSI imagery and in situ data to estimate chl-a can provide an effective tool for monitoring eutrophication in small, medium, and large standing waterbodies-crucial information required to respond to global ecological and climatic dynamics.

Participatory management of weed infestation in Lake Tana - setting a better future in the front mirror

Lake Tana is one of the biosphere reserves in Ethiopia registered by the United Nations Educational, Scientific, and Cultural Organization (UNESCO). Water hyacinth is expanding in the lake owing to increased nutrient load from the watershed. As efforts from the government alone could not bring the anticipated change, local peoples’ engagement and contribution are believed to sustainably and effectively manage the watershed and prevent the weed’s spreading. This study, therefore, aims to estimate households’ contribution (willingness to pay–WTP–and willingness to contribute labor–WTCL–) to prevent and control water hyacinth and hence improve lake ecosystem services through a hypothetical watershed management in Lake Tana. This study applied quantitative and qualitative methods. It was conducted among 560 randomly selected households of the Libo-kemkem district using a contingent valuation method from March to April/2021. Eleven key informant interviews were also conducted. Bivariable and multivariable interval regression models were used to identify the determinants of households’ potential contribution. Thematic analysis was used to analyze the qualitative data. As the weed is believed negatively impact the ecosystem services provided by the lake, 72% of the respondents showed willingness to contribute to the proposed management program. About 32 and 39% of the respondents were willing to pay in cash and to contribute labor, respectively, to prevent weed infestation. On the other hand, 28% of them were neither willing to contribute in cash nor in labor to the hypothetical market. The findings showed respondents’ mean annual WTP and WTCL were 632.8 Ethiopian birr and 30.1 man-days per household, respectively. The place of residence, educational status, farm plot area, household income, family size, and conference participation significantly influenced WTP and/or WTCL. In this hypothetical improvement scenario, an estimated annual WTP and WTCL of nearly 12 million Ethiopian birr and 700 man-days per year, respectively, are reported considering the total households in the study area. Therefore, collaborative efforts by different stakeholders are the next steps to realize the hypothetical contributions.

Does agro-ecological efficiency contribute to poverty alleviation? An empirical study based on panel data regression

Worldwide degradation of the ecological environment could be the cause of poverty. The poverty-stricken areas may face the dilemma of a "vicious circle of poverty." The complex ecological conditions have intertwined with poverty alleviation, which makes the demand for ecological poverty alleviation particularly prominent in these areas. However, the research on the relationship between agro-ecological efficiency and poverty are limited. It is far from clear what is the impact of the agro-ecological efficiency on poverty. To explore the impact of agro-ecological efficiency on poverty reduction, we adopt the panel data model based on cross-correlation and regression coefficient, using the data from 25 counties/districts in the Three Gorges Reservoir Region (TGRR) from 2006 to 2017. The results show that (1) there is significant heterogeneity in agro-ecological efficiency in the TGRR, and the agro-ecological efficiency in the middle area is significantly lower than that of the head and tail areas of the TGRR; (2) the improvement of regional agro-ecological efficiency could accelerate the alleviation of poverty; and (3) the widening of urban-rural income disparity is not conducive to poverty alleviation and eradication. This study would provide basis for further policy recommendations aimed at improving agro-ecological efficiency and alleviating poverty.