Read the passage below carefully:
In the Hadejia-Nguru wetlands of northern Nigeria, pastoralists and farmers have long adapted to the seasonal inundation of the Komadugu-Yobe river basin. During the wet season, overflow creates vast floodplains that replenish shallow aquifers and sustain wild fish stocks. As the waters recede in the dry months, farmers cultivate residual moisture plots known as 'fadama', producing high-value vegetables without artificial irrigation. Concurrently, nomadic Fulani herders rely on these lush seasonal pastures when surrounding upland grazing lands dry up. However, the construction of upstream dams and large-scale irrigation projects over recent decades has regulated the river’s natural flood regime. While upstream wheat schemes aimed to boost national grain production, downstream wetland inundation decreased by over forty percent. Consequently, the natural recharge of underground aquifers has faltered, fish yields have declined, and competition for remaining damp pasture has intensified between sedentary cultivators and migratory herders, triggering recurrent local conflicts.
Based on the passage, which of the following can be logically inferred regarding the upstream development projects?
- AUpstream wheat planners deliberately engineered river diversions to diminish downstream livestock grazing capacity.
- The national agricultural gains pursued upstream created severe economic and ecological trade-offs for downstream communities.Cevap
- CThe upstream dams completely eliminated the seasonal flooding cycle of the Komadugu-Yobe river basin.
- DDownstream vegetable growers were compelled to abandon 'fadama' farming in order to adopt wheat cultivation.