| Literature DB >> 35028459 |
Rodgers Makwinja1,2, Seyoum Mengistou1, Emmanuel Kaunda3, Tena Alamirew4.
Abstract
Lake Malombe is ranked among the most vulnerable inland freshwater shallow lakes in Malawi. The lake has lost over US$79.83 million ecosystem service values from 1999 to 2019 due to rapid population growth, increased poverty, landscape transformation, and over exploitation-hampering the effort to achieve United Nations (UN) Sustainable Development Goals (SDGs), in particular, life underwater (SDG 14), life on land (SDG 15), climate action (SDG 13), and no poverty (SDG 1) and Aichi Biodiversity Targets. In line with the 2021-2030 United Nations' Declaration on massive upscaling of the ecosystems restoration effort, this study applied the contingent valuation method (CVM) and binary logistic regression model to determine the public's willingness to pay (WTP) for ecosystem restoration and the influencing factors. The aim was to integrate science into policy framework to achieve a sustainable flow of ecosystem services (ESs). Qualitative data were collected by employing focus group discussion, key informant interviews, and field observation. Quantitative data were collected using structured questionnaires covering 420 households. The results revealed that 56% of the respondents were willing to pay an average of US$28.42/household/year. These respondents believed that the initiative would improve lake ESs, fish biodiversity, income level, water quality and mitigate climate change impact. Age, gender, literacy, income, social trust, institutional trust, access to extension services, period stay in the area, household distance from the lake, lake ecological dynamics impact, having the hope of reviving the lake health ecological status, perception of having lake ecological restoration program, participation in lake restoration program, access to food from the lake, involved in fishing and Lake Malombe primary livelihood sources significantly (p < 0.05) influenced WTP. This study provides a reference point to policymakers to undertake cost-benefit analysis and develop a practical policy response framework to reverse the situation and achieve United Nations Sustainable Development Goals and Aichi Biodiversity Targets.Entities:
Keywords: Binary logistic regression model; Contingent valuation method (CVM); Ecosystem services; Willingness to pay
Year: 2021 PMID: 35028459 PMCID: PMC8741457 DOI: 10.1016/j.heliyon.2021.e08676
Source DB: PubMed Journal: Heliyon ISSN: 2405-8440
Figure 1Map of Lake Malombe catchment (Makwinja et al., 2021b).
Demographic and socio-economic characteristics of the respondents.
| Explanatory Variables | Information | Value | Percent | Mean ± STD Error | Min-Max |
|---|---|---|---|---|---|
| AGH | <20 | 420 | - | 39 ± | 17–86 |
| 20–24 | 4.62 | 1.1 | - | - | |
| 25–29 | 58.8 | 14 | - | ||
| 30–34 | 64.26 | 15.3 | - | - | |
| 35–39 | 118.86 | 28.3 | - | - | |
| 40–44 | 79.38 | 18.9 | - | - | |
| 45–49 | 42 | 10 | - | - | |
| 50–54 | 26.88 | 6.4 | - | - | |
| 55–59 | 25.2 | 6 | - | - | |
| LU | crop production | 162.96 | 38.8 | - | - |
| settlements | 246.54 | 58.7 | - | - | |
| fallow | 1.68 | 0.4 | - | - | |
| rent | 2.94 | 0.7 | - | - | |
| livestock production | 7.56 | 1.8 | - | - | |
| MS | Married | 311 | 74.1 | - | - |
| Single | 109 | 25.9 | - | - | |
| HLSC | More than 10 yrs | 374 | 89 | - | - |
| Less than 10 years | 46 | 11 | - | - | |
| GHH | Male | 290 | 69.1 | - | - |
| Female | 130 | 30.9 | - | - | |
| HFS | 1 person | 6 | 1.1 | - | - |
| 2-3 persons | 85 | 15.9 | - | - | |
| 4-5 persons | 162 | 30.4 | - | - | |
| 6 above | 280 | 52.5 | - | - | |
| HLE | No Education | 136 | 25.9 | - | - |
| Primary | 327 | 62.2 | - | - | |
| Secondary | 59 | 11.2 | - | - | |
| Tertiary | 4 | 0.8 | - | - | |
| HLS | 1 acre | 86.4 | 87.5 | - | - |
| 1 ha | 11.8 | 11.8 | - | - | |
| 3 acres | 0.4 | 0.4 | - | - | |
| 4 acre | 0.4 | 0.3 | - | - | |
| ADLI | 420 | 1.77 ± | 0–17.6 | ||
| HC | Farmer | 8 | 2 | - | - |
| Fishermen | 55 | 13 | - | - | |
| Farmer and Fishermen | 143 | 34 | - | - | |
| Business owner | 3 | 0.6 | - | - | |
| formally employed | 0 | 0.1 | - | - | |
| Traders | 1 | 0.3 | - | - | |
| Crew members | 185 | 44 | - | - | |
| firewood/charcoal seller | 25 | 6 | - | - |
Note: AGH means age of the household, MS means Marital status, HLI means the household level of income, HS means household size, GHH means gender of household, HFS means household family size, HLE means the household level of education, HLS means household land size, ADLI means an average daily level of income, HC means household occupation, LU means land use.
Figure 2The current status of Lake Malombe and its catchment.
Figure 3The rate of carbon sequestration(a), rate of water quality(b), rate of scenic view(c), rate of ecosystem provisioning services(d), rate of culture and aesthetic services (e), rate of flood control(f).
The best fitted logistic regression models of indicators for Lake Malombe Lake ecosystem degradation.
| Indicator variables | Hypothesis | B | S. E | Wald | Sig. level |
|---|---|---|---|---|---|
| Prolonged dry spell | + | 0.67 | 0.08 | 0.60 | 0.03∗∗ |
| droughts | + | 0.53 | 0.01 | 0.96 | 0.02∗ |
| Floods | + | 0.82 | 0.09 | 0.38 | 0.03∗ |
| Heavy rain | + | 0.01 | 0.06 | 0.06 | 0.54ns |
| Erratic rain | + | 0.25 | 0.02 | 0..23 | 0.32ns |
| Late-onset rain | + | 0.29 | 0.07 | 0.07 | 0.14ns |
| Early-onset rains | + | 2.66 | 0.02 | 0.98 | 0.10ns |
| Water scarcity | + | 1.25 | 0.02 | 0.26 | 0.02∗ |
| Disease outbreak | + | 0.34 | 0.01 | 0.05 | 0.03∗ |
| Soil productivity | - | -0.55 | 0.02 | 3.54 | 0.04∗ |
| Agricultural yields | - | -0.63 | 0.04 | 0.97 | 0.03∗ |
| Crop damage | + | 0.18 | 0.00 | 0.47 | 0.12ns |
| Mangroves population | - | -0.25 | 0.03 | 0.39 | 0.03∗ |
| Reeds population | - | -0.80 | 0.07 | 0.17 | 0.02∗ |
| Rivers' flow | - | -0.49 | 0.02 | 0.22 | 0.01∗ |
| Invasion of alien spp | + | 0.22 | 0.03 | 0.14 | 0.02∗ |
| Water levels | - | -1.35 | 0.01 | 0.97 | 0.01∗ |
| Biodiversity status | - | -0.49 | 0.00 | 0.44 | 0.02∗ |
| Water clarity | + | -0.22 | 0.01 | 0.23 | 0.04∗ |
Note: response variable is lake Malombe ecosystem degradation and is a dummy variable (where 0 = positive suggesting that as indicator increases, the lake ecosystem degradation also increases, 1 = negative suggesting that as indicator decreases, the lake ecosystem degradation increase). Hosmer and Lemeshow test, Chi-square = 5.44 (df = 8), P = 0.71. -2 log likelihood = 59.1%. Note: Nagelkerke R Square = 0.73, Cox & Snell R Square = 0.54, Sig = 0.695. ns indicates not significant while ∗∗ and ∗ indicate significance at 0.01 and 0.05 probability level of Confidence, negative hypothesis (-) means decrease, positive hypothesis (+) means increase assuming that these indicators were not static.
Figure 4Lake Malombe ecosystem opportunities (a) and threats (b).
Analysis of WTP amount (US$/year).
| Parameter | Number of positive responses | Percent | Mean | Median | Mode | Min-Max |
|---|---|---|---|---|---|---|
| WTP/year | 235 | 56 | 28.42 | 4.62 | 0.88 | 0.88–321.18 |
Figure 5The analysis of WTP bid amount (US$/yr).
The best fitted logistic regression model of factors influencing household’ WTP.
| Parameters | Description of Variable | B | S. E | Wald | Sig |
|---|---|---|---|---|---|
| AGH | Dummy variable where 45 years below = 0 and 46 above = 1 | 2.90 | 3.15 | 0.84 | 0.02∗ |
| GH | Dummy variable where male = and female = 1 | 5.29 | 2.72 | 3.77 | 0.04∗ |
| HS | Dummy variable where 4 below = 0 and 5 above = 1 | 1.24 | 3.17 | 3.86 | 0.05ns |
| LL | Dummy variables where literate = 0 and illiterate = 1 | 3.46 | 3.28 | 0.02 | 0.01∗ |
| LI | Dummy variable where US$2/day above = 0 and less than US$2/day = 1 | 2.80 | 2.87 | 0.95 | 0.03∗ |
| LO | Dummy variable where own land = 0 and doesn't own the land = 1 | -1.17 | 3.45 | 0.12 | 0.74ns |
| MS | Dummy variable where married = 0 and single = 1 | -1.26 | 2.81 | 0.20 | 0.65ns |
| ST | Dummy variable where yes = 0 and no = 1 | 3.47 | 3.79 | 0.02 | 0.02∗ |
| SP | Dummy variable where yes = 0 and no = 1 | 4.24 | 3.34 | 1.61 | 0.20ns |
| IT | Dummy variable where yes = 0 and no = 1 | 5.60 | 3.81 | 2.16 | 0.04∗ |
| AES | Dummy variable where yes = 0 and no = 1 | 3.41 | 2.10 | 0.04 | 0.01∗ |
| ASN | Dummy variable where yes = 0 and no = 1 | 0.28 | 0.15 | 3.61 | 0.06ns |
| ALMED | Dummy variable where yes = 0 and no = 1 | 2.45 | 2.42 | 0.36 | 0.04∗ |
| PSA | Dummy variable where less than 10 yes = 0 and more than 10 years = 1 | 3.01 | 3.28 | 0.85 | 0.02∗ |
| DHL | Dummy variable where less than 5km = 0 and more than 10km = 1 | 2.30 | 4.67 | 0.24 | 0.02∗ |
| HALED | Dummy variable where yes = 0 and no = 1 | 4.70 | 1.90 | 6.13 | 0.01∗ |
| HRLHES | Dummy variable where yes = 0 and no = 1 | 3.03 | 1.72 | 5.11 | 0.02∗ |
| PHLEP | Dummy variable where yes = 0 and no = 1 | 3.89 | 2.12 | 8.32 | 0.01∗∗ |
| PLRP | Dummy variable where yes = 0 and no = 1 | 6.10 | 21031.48 | 0.00 | 0.02∗ |
| AFL | Dummy variable where yes = 0 and no = 1 | 0.92 | 1.57 | 2.97 | 0.04∗ |
| IF | Dummy variable where yes = 0 and no = 1 | 2.71 | 1.58 | 2.75 | 0.01∗∗ |
| LMLS | Dummy variable where yes = 0 and no = 1 | 2.62 | 21031.48 | 0.00 | 0.02∗ |
Hosmer and Lemeshow test, Chi-square = 8.22 (df = 8), P = 0.69 -2 log likelihood = 66.8%, Note: Nagelkerke R Square = 0.84, Cox & Snell R Square = 0.39. ns indicates not significant while ∗∗ and ∗ indicate significance at 0.01 and 0.05 probability level of Confidence. Note: AGH means age of the household, GH means gender of the household, HS means household size, LL means literacy level, LI means level of income, MS means marital status, IIF means involved in fishing, LO means land ownership, ST means social trust, SP means social position, IT means institutional trust, AES means access to extension services, ASN means access to social network, aware of Lake Malombe ecosystem degradation (ALMED), period stay in this area (PSA), a distance of the household from the lake (DHL), household affected by the lake ecological dynamics (HALED), having the hope of reviving the lake health ecological status (HRLHES), perception of having lake ecological restoration program, (PHLEP), participation in lake restoration program (PLRP), access to food from the lake (AFL), involved in fishing (IF) and Lake Malombe main livelihood sources (LMLS).
The WTP values for freshwater ecosystems across the global.
| Freshwater ecosystems | Country | WTP (US/household/yr | Reference |
|---|---|---|---|
| Lake Malombe | Malawi | 28.42 | - |
| Heine River basin | China | 19.96 | |
| Lake Chiuta | Malawi | 10.92 | |
| Naivasha watershed | Kenya | 88.35–218.48 | |
| Ghodaghodi Lake | Nepal | 5.4 | |
| Guadiana estuary | Portugal and France | 55.6 | |
| Bhod wetland | India | 5.43 | |
| Shadegon wetland | Iran | 1.74 | |
| Central Rift Valley wetlands | Ethiopia | 7.5 | |
| Linthipe River | Malawi | 3.51 | |
| McKenzie River | USA | 7.5 | |
| Chia lagoon | Malawi | 128.78 | |
| Natural urban lake | Philippines | 4.17 | |
| Platte River | USA | 252 | |
| Yaqui River delta | Mexico | 61.2 | |
| Wei River | China | 17.96 |
The percentage of positive and negative WTP responses and the reasons.
| Factors | Categories | Freq | percent |
|---|---|---|---|
| WTP | yes | 235 | 56 |
| No | 185 | 44 | |
| Reasons for WTP | Improve ESs | 17 | 4 |
| improved income | 118 | 28 | |
| Mitigate climate change impact | 25 | 6 | |
| Improved fish biodiversity | 168 | 40 | |
| Improve water quality | 8 | 2 | |
| Reasons for not WTP | Cannot afford | 42 | 10 |
| Has no trust | 189 | 45 | |
| It is a government responsibility | 63 | 15 | |
| Does not get affected by ESs change | 8 | 2 | |
| We pay through tax | 34 | 8 | |
| Not interested | 84 | 20 |