High Times and Dry Times In a Salt Marsh: Budgeting For Supplemental Freshwater Needs at the Big Boggy National Wildlife Refuge, USA

Salt marshes can be vulnerable to reduced freshwater input. Reduced freshwater inflows, particularly during a hot or dry summer season, can be catastrophic for vegetation productivity, organic accretion and inorganic sedimentation, and the ability of a marsh to maintain a sustainable elevation facing relative sea level rise (RSLR). Unfortunately, it is challenging for scientists to obtain inflow records for ungauged watersheds and link them with historical trends of salt marsh loss. We sought to address this challenge in Big Boggy National Wildlife Refuge (NWR), a small watershed in East Matagorda Bay, Texas. Our objective was to link the quantity of freshwater inflow with salt marsh sustainability and recommend management actions for the NWR. We first explored land cover trends and found that this watershed lost more than one-third of its low marsh since 1953. We then measured the streamflow into and out of the watershed, created a water budget, and modeled historical and future inflows from 1953 to 2100. Freshwater inflows have been increasing on average since 1953, but a combination of RSLR, sediment starvation, and punctuated seasonal droughts are likely responsible for the loss of salt marsh. We also estimated supplemental water needs during potential droughts out to 2100. We conclude that managers cannot fundamentally alter the accretion versus RSLR balance in this basin except by modifying freshwater input. Thus, during droughts, they should focus on providing these inputs and avoiding vegetation loss. Our work points to both water purchases and land management options that can achieve this goal.

Real time implementation of agricultural contingency plans to cope with weather aberrations in Indian agriculture

Weather aberrations impact agriculture and allied sectors in one or other parts of the India round the year. Seasonal droughts and extreme weather events in 21st century have caused alarming losses not only in agricultural production but also horticulture, livestock, poultry and fisheries. ICAR-CRIDA, SAUs and DAC, MoA, GoI, prepared more than 580 district level agriculture plans within formation on contingency measures for sustaining higher agriculture production and to cope with extreme events. Real-time contingency planning (RTCP) is being conceptualized and implemented at micro level in farmers’ fields in this country. RTCP implementation during delayed onset of monsoon, seasonal droughts and floods resulted in better crop performance, higher agricultural production, better incomes and overall stability in house-hold livelihoods. In this paper, the real-contingency measures to cope with extreme events for management of horticultural crops, livestock, poultry and fisheries are proposed. Further, the preparedness for RTCP implementation with policy initiatives is also suggested.

Relationship between Drought and Precipitation Heterogeneity: An Analysis across Rain-Fed Agricultural Regions in Eastern Gansu, China

Based on daily meteorological data from 55 meteorological stations in eastern Gansu from 1960 to 2017, the characteristics of the drought process and precipitation heterogeneity were analyzed, and the relationship between drought and precipitation heterogeneity was evaluated. Results showed that there were 1–3 drought processes in the study area every year. Drought processes in the eastern and north-central regions were more frequent than those in other regions. Droughts were mainly manifested as intra-seasonal droughts, especially across the spring and summer. PCD (Precipitation Concentration Degree, the concentration degree of the precipitation at a certain time) ranged from 0.2 to 0.7 in the area. PCD increased in spring and autumn but decreased in summer and winter for most regions from 1960 to 2017. PCP (Precipitation Concentration Period, the shortest time which the precipitation was concentrated in) was from late April to early May in spring, mid-to-late July in summer, mid-September in autumn, and late January in winter. In the last 58 years, PCP has remained consistent in most regions, varying by approximately 10 days. In addition to insignificant changes in winter, the days with light and moderate rain presented a declining trend, especially in summer and autumn. The larger the PCD, the fewer the days with light and moderate rain, and the stronger the drought intensity. However, in the east-central region, the larger the PCD in autumn, the weaker was the drought intensity. This difference is related to the PCP and the evapotranspiration. Additionally, the later the PCP, the stronger was the drought intensity, particularly in summer and autumn. When PCD was ≥0.5 in spring and ≥0.4 in summer, the PCP was after May and August in spring and summer, respectively. Droughts appeared in 28–56% of periods when seasonal precipitation was above normal. When PCD was ≥0.5 in autumn and PCP was in early and middle September, droughts appeared in 7% of periods when precipitation was above normal. Our results show that although less precipitation is the leading influencing factor of drought in the dry rain-fed agricultural areas, the influence of precipitation heterogeneity should be also considered for the prediction and diagnosis of seasonal drought.

Integrated Evaluation of Changing Water Resources in an Active Ecotourism Area: The Case of Puerto Princesa City, Palawan, Philippines

Rapid urbanization, tourism, and climate change (CC) threaten water resource management in developing countries. Conventional water-planning tools cannot account for the changing effects of water disparity, climate risks, and environmental flow (EF) requirements. This paper proposes an alternative approach that applies stylized water-demand forecasting and predicting water availability from the perspectives of CC, changing society, and EF, thereby providing managers with future scenarios of surface water sufficiency/deficiency in an active ecotourism area, namely, Puerto Princesa City, Philippines. We considered (1) scenarios of seasonal droughts to prepare for climate risks in the future and (2) scenarios of water availability that do not depend on groundwater supply, in which the projected water deficiency is frequent both annually and seasonally. The results of this case study showed that an additional water supply from the Montible Watershed to the city was projected to secure sufficient amounts of water to achieve surface-water sufficiency, which is consistent with the goals of both the municipality and the water company to reduce the dependency on groundwater. Moreover, significant infrastructure investment costs must be anticipated in Scenario 3. Our approach proves efficient in modeling water demand in regions with active tourism and hydrology and therefore has the potential for further analyses and application.

Performance of Three Sorghum Cultivars under Excessive Rainfall and Waterlogged Conditions in the Sudano-Sahelian Zone of West Africa: A Case Study at the Climate-Smart Village of Cinzana in Mali

Recent climate analyses show trends for increasing precipitation variability with increasing precipitation sums in Mali. The increasing occurrence of temporary intra-seasonal droughts and waterlogging longer than a week demands climate-smart solutions. Research has focused on water deficits since the 1980s. However, besides droughts, waterlogging can restrict productivity of sensitive cash and staple crops as cotton and corn. The year 2019 offered the historically unique opportunity to monitor waterlogging effects with 1088 mm precipitation in the rural commune Cinzanawith an isohyet of 681 mm. Impacts of two extreme downpours on three sorghum cultivars were monitored in a farmers-field experiment with three replications. All sorghum cultivars performed well in 2019 with significantly higher grain and above ground biomass yields than in the reference year 2007, with well distributed rainfall in Cinzana. “Jakumbè” (CSM63E) produced significantly higher grain yields than the hybrid cultivar “PR3009B” bred for high harvest index. The local cultivar “Gnofing” selected by local farmers produced significantly higher above ground biomass. All cultivars tolerated without severe stress symptoms 20 days waterlogging and 72 h inundation. Further waterlogging resilience research of other crops and other sorghum cultivars is needed to strengthen food security in Mali with expected increasing precipitation variation in the future.