For monitoring burst events in a kind of reactive wireless sensor networks (WSNs), a novel scheme of dynamic clustering routing algorithm (DCRA) based on support degree is proposed. The new approach lets sensors decide whether become a clusterhead (CH) according to the support degree coming from neighbors. Unlike traditional distributed clustering algorithms, DCRA combines energy, load balancing and topology information together by defining an objective function based on support degree. Furthermore, the clusterhead aggregates data and transmits the result to base station (sink node) along multiple paths. The new algorithm is completely distributed and location-unaware. Simulation results show that DCRA has great potential in efficiently distributing energy consumption and extending the network lifetime.