Sittidaj Pongkijvorasin

Optimal management of a Hawaiian Coastal aquifer with nearshore marine ecological interactions

We optimize groundwater management in the presence of marine consequences of submarine groundwater discharge (SGD). Concern for marine biota increases the optimal steady-state head level of the aquifer. The model is discussed in general terms for any coastal groundwater resource where SGD has a positive impact on valuable near-shore resources. Our application focuses of the Kona Coast of Hawai’i, where SGD is being actively studied and where both near-shore ecology and groundwater resources are serious sociopolitical issues. To incorporate the consequences of water extraction on nearshore resources, we impose a safe minimum standard for the quantity of SGD. Efficient pumping rates fluctuate according to various growth requirements on the keystone marine algae and different assumptions regarding recharge rates. Desalination is required under average recharge conditions and a strict minimum standard, and under low recharge conditions regardless of minimum standards of growth.

Win–Win Solutions for Reforestation and Maize Farming: A Case Study of Nan, Thailand

The dramatic increase in highland maize farming and the rapid deforestation over the past few years in Nan, a province in northern Thailand, have highlighted an undesirable trade-off between poverty reduction and environmental degradation. Using survey data from the area, this chapter compares and discusses the trade-off problem between maize farmers’ incomes and excessive deforestation. It proposes a simple analytical tool to examine how farmers exchange their private benefits from the forest for gains from maize farming and to show how the current government policy of crop subsidy aggravates the deforestation problem. Two possible win–win solutions are presented, whereby farmers’ incomes increase along with forest area: green subsidy and irrigation development. Numerical exercises of green subsidy estimation and possible reforestation reclaimed from subsidy and irrigation development are compared. Given a correct understanding of the situation and a well-designed policy, a win–win solution toward economic development and environmental restoration is viable.The dramatic increase in highland maize farming and the rapid deforestation over the past few years in Nan, a province in northern Thailand, have highlighted an undesirable trade-off between poverty reduction and environmental degradation. Using survey data from the area, this chapter compares and discusses the trade-off problem between maize farmers’ incomes and excessive deforestation. It proposes a simple analytical tool to examine how farmers exchange their private benefits from the forest for gains from maize farming and to show how the current government policy of crop subsidy aggravates the deforestation problem. Two possible win–win solutions are presented, whereby farmers’ incomes increase along with forest area: green subsidy and irrigation development. Numerical exercises of green subsidy estimation and possible reforestation reclaimed from subsidy and irrigation development are compared. Given a correct understanding of the situation and a well-designed policy, a win–win solution toward economic development and environmental restoration is viable.

Incentivizing interdependent resource management: watersheds, groundwater, and coastal ecology

Managing water resources independently may result in substantial economic losses when those resources are interdependent with each other and with other environmental resources. We first develop general principles for using resources with spillovers, including corrective taxes (subsidies) for incentivizing private resource users. We then analyze specific cases of managing water resources, in particular the interaction of groundwater with upstream or downstream resource systems.